This article was downloaded by: [USC University of Southern California] On: 13 March 2015, At: 09:05 Publisher: Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Journal of Sports Sciences Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/rjsp20
Acute effects of whole-body vibration on running gait in marathon runners a
b
c
d
Johnny Padulo , Davide Filingeri , Karim Chamari , Gian Mario Migliaccio , Giuseppe e
f
g
h
i
Calcagno , Gerardo Bosco , Giuseppe Annino , Jozsef Tihanyi & Fabio Pizzolato a
Tunisian Research Laboratory “Sports Performance Optimization”, National Center of Medicine and Science in Sport, Tunis, Tunisia b
Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough LE11 3TU, UK c
Research and Education Centre, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
Click for updates
d
CONI – Italian Regional Olympic Committee, Sardinia, Cagliari, Italy
e
Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy
f
Department of Medicine, University of Padova, Padova, Italy
g
Faculty of Medicine and Surgery, University of “Tor Vergata”, Rome 00133, Italy
h
Biomechanics, Semmelweis University, Budapest 1123, Hungary
i
Department of Neurological and Movement Sciences, University of Verona, Verona, Italy Published online: 28 Feb 2014.
To cite this article: Johnny Padulo, Davide Filingeri, Karim Chamari, Gian Mario Migliaccio, Giuseppe Calcagno, Gerardo Bosco, Giuseppe Annino, Jozsef Tihanyi & Fabio Pizzolato (2014) Acute effects of whole-body vibration on running gait in marathon runners, Journal of Sports Sciences, 32:12, 1120-1126, DOI: 10.1080/02640414.2014.889840 To link to this article: http://dx.doi.org/10.1080/02640414.2014.889840
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Journal of Sports Sciences, 2014 Vol. 32, No. 12, 1120–1126, http://dx.doi.org/10.1080/02640414.2014.889840
Acute effects of whole-body vibration on running gait in marathon runners
JOHNNY PADULO1, DAVIDE FILINGERI2, KARIM CHAMARI3, GIAN MARIO MIGLIACCIO4, GIUSEPPE CALCAGNO5, GERARDO BOSCO6, GIUSEPPE ANNINO7, JOZSEF TIHANYI8 & FABIO PIZZOLATO9 Tunisian Research Laboratory “Sports Performance Optimization”, National Center of Medicine and Science in Sport, Tunis, Tunisia, 2Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough LE11 3TU, UK, 3Research and Education Centre, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar, 4CONI – Italian Regional Olympic Committee, Sardinia, Cagliari, Italy, 5Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy, 6Department of Medicine, University of Padova, Padova, Italy, 7Faculty of Medicine and Surgery, University of “Tor Vergata”, Rome 00133, Italy, 8Biomechanics, Semmelweis University, Budapest 1123, Hungary and 9Department of Neurological and Movement Sciences, University of Verona, Verona, Italy
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
1
(Accepted 27 January 2014)
Abstract The aim of this study was to investigate the effects of a single bout of whole-body vibration (WBV) on running gait. The running kinematic of sixteen male marathon runners was assessed on a treadmill at iso-efficiency speed after 10 min of WBV and SHAM (i.e. no WBV) conditions. A high-speed camera (210 Hz) was used for the video analysis and heart rate (HR) was also monitored. The following parameters were investigated: step length (SL), flight time (FT), step frequency (SF), contact time (CT), HR and the internal work (WINT). Full-within one-way analysis of variance (ANOVA) of the randomised crossover design indicated that when compared to SHAM conditions, WBV decreased the SL and the FT by ~4% (P < 0.0001) and ~7.2% (P < 0.001), respectively, and increased the SF ~4% (P < 0.0001) while the CT was not changed. This effect occurred during the first minute of running: the SL decreased ~3.5% (P < 0.001) and SF increased ~3.3% (P < 0.001). During the second minute the SL decreased ~1.2% (P = 0.017) and the SF increased ~1.1% (P = 0.02). From the third minute onwards, there was a return to the pre-vibration condition. The WINT was increased by ~4% (P < 0.0001) during the WBV condition. Ten minutes of WBV produced a significant alteration of the running kinematics during the first minutes post exposure. These results provide insights on the effects of WBV on the central components controlling muscle function. Keywords: kinematic analysis, iso-efficiency speed, internal work, heart rate, motor control
The interest in whole-body vibration (WBV) training and its acute and long-term effects on the human body has grown rapidly in the last two decades, as shown by the numerous applications of this novel training method to exercise performance and rehabilitation (Luo, McNamara, & Moran, 2005; Rittweger, 2010; Rittweger, Beller, & Felsenberg, 2000). The reason of such interest lays on the fact that exposure to low-frequency vibration has been shown to elicit a greater muscle activity as a result of a reflex contraction known as tonic vibration reflex (Cochrane, 2011). This neurophysiological response has been speculated to occur as low-frequency vibration might activate the muscle Ia
endings which, in turn, stimulate the alpha motoneurons thus producing involuntary muscle contractions (Delecluse, Roelants, & Verschueren, 2003). This neuromuscular response translates in an increased motor units recruitment during sub-maximal voluntary contractions (Krol, Piecha, Slomka, & Sobota, 2010; Rittweger, 2010). The possibility to elicit a greater muscle activity (Rittweger, 2010) followed by an increase in tissue oxygenation (Coza, Nigg, & Dunn, 2011) and muscle blood flow (Herrero et al., 2011) has therefore driven the interest on WBV as a potential alternative to more traditional training methods (Delecluse et al., 2003). This has been particularly true in the
Correspondence: Johnny Padulo, Tunisian Research Laboratory “Sports Performance Optimization”, National Center of Medicine and Science in Sport, Tunis, Tunisia. E-mail: [email protected] © 2014 Taylor & Francis
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
Footstep analysis after vibrations treatment context of sprint and power-based sports, in which acute and chronic WBV protocols showed benefits on performance (Di Giminiani, Tihanyi, Safar, & Scrimaglio, 2009).These benefits on sprint performance and repeated sprint ability (Padulo et al., 2014) could be due to the fact that training protocols endorsing the use of vibration have been shown to induce a greater fast twitch muscle fibres’ recruitment (Filingeri, Jemni, Bianco, Zeinstra, & Jimenez, 2012). However, although the use of vibration as a training modality has been shown to be effective in enhancing different physiological parameters such as strength, power, flexibility, bone mineral density (Maikala & Bhambhani, 2008; Rittweger et al., 2002; Sands, McNeal, Stone, & Kimmel, 2008; Sands, McNeal, Stone, Russell, & Jemni, 2006; Suhr et al., 2007), to our knowledge, no investigations are currently available on the effects of WBV on the kinematics parameter in running gait. Investigating the effects of WBV on these parameters could be of interest in the light of potential applications within the context of endurance running (e.g. marathon), in which this training modality has been scarcely investigated. Acute exposures to vibration have been shown to influence the activity of the proprioceptive sensory system (which is based on the excitation of Ia afferent signals situated at the neuromuscular spindle) (Iodice, Bellomo, Gialluca, Fano, & Saggini, 2011) and to result in activating larger motoneurons, leading to the recruitment of previously inactive muscle fibres. As the sensorimotor feedback from the proprioceptive system plays a critical role in the kinematic of running (Dugan & Bhat, 2005) and in the ankle stability (Munn, Sullivan, & Schneiders, 2010; Sefton et al., 2009), it is therefore reasonable to hypothesise that an acute exposure to vibration could potentially affect the biomechanics and kinematics of running gait, particularly in the first few minutes following exposure. Increasing the knowledge on how WBV could potentially affect the biomechanics and kinematics of running gait could have important implication in the context of using this exercise modality for warmup (pre-competition) as well as for training purposes (Padulo, Annino, Migliaccio, et al., 2013). Therefore, the aim of this study was to investigate whether and to what extent an acute exposure to WBV would alter the running gait. In this study, the kinematics of the footstep was investigated in marathon runners before and after a session of 10 min WBV at 45 Hz. To our knowledge, this represents the first exploratory study to provide experimental data on the effects of vibration treatment on the running gait.
1121
Methods Participants Sixteen male marathon runners (age 41.06 ± 3.71 years; body mass 67.44 ± 3.55 kg; body height 172 ± 3.42 cm; BMI 22.84 ± 1.35 kg/m2, training background of 8 ± 0.12 years and who had covered 131 ± 2.78 km per week last year with personal best marathon race ~2 h 50 min participated in this study). The participants were healthy without any muscular, neurological and tendinous injuries and did not report any consumption of drugs. After being informed of the procedures, methods, benefits and possible risks involved in the study, each participant reviewed and signed an informed consent form prior to participation in the study, in accordance with the ethical standards. All experimental procedures were approved by the University Human Research Ethics Committee, which followed the ethical principles laid out in the 2008 revision of the Declaration of Helsinki. Experimental setting Testing was carried out in a Human Performance Laboratory (Regional Olympic Committee of Sardinia). All the participants were in good health at the time of the study. Research reported a high correlation (r = 0.93) between over-ground and treadmill running for biomechanical analysis (Riley et al., 2008). In order to more accurately control the slope and the velocity (Padulo, Annino, D'Ottavio, et al., 2013), tests were performed on a motorised treadmill (Run Race Technogym® Run 500, Gambettola, Italy). All participants wore marathonrunning shoes (Category A3) and performed a standardised 10-min warm-up, which consisted of running at 9 km · h−1 at 0% of slope, to familiarise themselves with the treadmill (Padulo, Annino, Migliaccio, et al., 2013). The speed of the test (mean ± SD) was set at 1 km h−1 less than the best mean speed performed by each participant on 10,000 m (14.81 ± 1.11 km · h−1) in the last 3 months. This allowed them to run at iso-efficiency speed (Padulo, Annino, Smith, et al., 2012). The randomised crossover with a repeated measure design was applied to this study to verify the effects of WBV compared to a SHAM (i.e. no WBV) condition. The experiment consisted of 5 min of running, followed by 2 min of passive recovery. Then, in a randomised order, the participants underwent to the experimental conditions that were: the WBV or the SHAM condition. Then, after 2 min of passive recovery, the participants had to run for 5 min to evaluate the treatment effects. Finally, the experimental conditions were repeated in inverted
1122
J. Padulo et al.
order: the participants that started with the WBV performed the SHAM condition and vice versa. For each participant, we had the following evaluations: before, after WBV and after SHAM conditions.
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
WBV treatment The vibration platform used for the study was: Power Plate pro5™ (Power Plate International LTD, The Netherlands). The vibration frequency was set at 45 Hz, with a peak-to-peak displacement of 2.2 mm (Martinez-Pardo, Romero-Arenas, Alcaraz, 2013) and an acceleration of 7.7 g (1 g = 9.81 m · s−2). The vibrating platform used shows a high reliability for the accelerations delivered between unloaded and loaded condition (Pel et al., 2009). For the WBV, ten bouts of 60-s vertical sinusoidal vibrations at 45 Hz (according to the manufactures instructions) with a 1:1 work-to-relief ratio were used. During WBV the participants stood on the plate with the knees flexed at ~90° and the heels raised ~10 cm (Di Giminiani et al., 2009; Di Giminiani, Masedu, Tihanyi, Scrimaglio, & Valenti, 2013; Padulo et al., 2014; Ritzmann, Gollhofer, & Kramer, 2013). The SHAM condition was performed using the same participant position and for the same time of the experimental protocol but, without preceding vibrations. Motion analysis Two-dimensional video data were collected while the participants’ running on the treadmill using a single high-speed (Balsalobre-Fernandez, TejeroGonzalez, Campo-Vecino, & Bavaresco, 2014) digital camera (Casio Exilim FH20, Japan) sampled at 210 Hz and collected in accordance with a previous study protocol (Padulo, Annino, Migliaccio, D‘Ottavio, & Tihanyi, 2012). The camera was positioned on a 1.5 m high tripod, 6 m from the participant and was located perpendicular to the plane of motion at the participant’s sagittal plane (Belli, Rey, Bonnefoy, & Lacour, 1992). The film sequences were analysed off-line using Kinovea™ 0.8.15 motion analysis software. Kinematic markers were taped on both feet (heel and third metatarsus) of each participant in accordance with other study (Padulo, Degortes, et al., 2013). The following kinematic variables were studied: (i) contact time (CT) (ms), (ii) flight time (FT) (ms), (iii) step length (SL) (m), (iv) step frequency (SF) (Hz); for each velocity 120 steps were sampled for frequency calculation (Padulo, Annino, Smith, et al., 2012; Padulo, Annino, et al., 2013). Since the velocity of the treadmill was known, both SL and SF could be calculated (Padulo,
Annino, et al., 2013). The CT and FT were calculated by counting the frames in contact and flight on the 2D data. The CT and FT were calculated for both the left and right foot. The CT was defined and calculated as the time between initial contact with the ground and the last frame of contact before toeoff. The FT was defined and calculated as the time between toe-off and subsequent initial contact of the contralateral foot. Initial contact and toe-off were visually detected. In accordance with the previous studies (Padulo, Annino, Migliaccio, et al., 2012; Padulo, Annino, Smith, et al., 2012; Padulo, Degortes, et al., 2013; Padulo, Powell et al., 2013) SF was calculated as: SF = [1000/(CT+ FT)]; alternatively SL was calculated with the following equation: SL = (speed km · h−1/3.6/SF). Data analysis The internal work (WINT) was also calculated with the formula (Equation (1)) proposed by Nardello, Ardigo, and Minetti (2011) WINT ¼ SF v ð1 þ ðDF ð1 DFÞ1 Þ2 Þ q (1) where SF is the SF (Hz), v is the velocity (m · s−1), DF is the duty factor, that is, deflection of the duration of stride period when each foot is on the ground (%) and q value of 0.08 referring to the inertial properties of the oscillating limbs. The HR was recorded throughout the experiment and an average computed during the full 5 min for each condition (Sport Tester PE 3000; Polar Electro, Kempele, Finland). The HR was expressed in percentage of maximum theoretical HR (HRmax) by Equation (2) (Miller, Wallace, & Eggert, 1993). HR max ¼ 217 ð0:85 ageÞ
(2)
Statistical analyses The results are expressed as mean ± SD. The variables investigated were: CT, FT, SL, SF, WINT, HR and the Percentage of HR with respect to the maximal theoretical HR (HR%). The effect size (ES) was calculated for all variables between pre and posttesting. The thresholds for small, moderate and large effects were 0.20, 0.50 and 0.80, respectively. Statistical analysis was performed using SPSS 16.0 software. The level set for significance was P < 0.05. Assumption of normality was verified using the Shapiro–Wilk Test, after that, on the absolute variables of CT, FT, HR and HR% a full-within oneway analysis of variance (ANOVA) with repeated measures was used to compare responses in each
Footstep analysis after vibrations treatment
1123
3.18
variable across the three tests (before, SHAM condition and after WBV). Bonferroni post hoc analysis was used to identify where changes occurred. Moreover, on SL and SF a two-way ANOVA was carried out with repeated measures adding Assessment Time as a second factor, with five levels (1 < 5 min), to investigate the changes over time. For this analysis, we were not interested in the main factor Assessment Time but in the interaction Test × Assessment Time. When a global difference over time was determined, Bonferroni post hoc analysis was used to identify where changes occurred.
Step Frequency (Hz)
3.16 3.14 3.12
*
3.10
#
3.08 3.06 3.04 0
1
2
3
4
5
6
1.36
Results
1.35
Neither subjective adverse reactions nor exhaustive fatigue were reported after the vibration bout, while most of the participants reported that they felt that the WBVs had an effect on the lower limbs. The results are reported in Table I. The contact time of the feet on the ground did not change significantly even though decreased F(2,30) = 2.792, P = 0.077 (ES = 15.7%, small effect) while the FT decreased significantly F(2,30) = 21.629, P < 0.0001 with a large effect (ES = 59%). The WINT increases after vibrations F(2,30) = 64.662, P < 0.0001 (ES = 81.2%, large effect), as well as the HR increased over the three tests F (2,30) = 15.818, P < 0.0001 (ES = 51.3%, moderate effect). We obtained the same result by calculating the percentage of the HRmax of each participant F (2,30) = 15.623, P < 0.0001 (ES = 51%, moderate effect). The main effect of Test was found significant for the SL F(2,30) = 9.183, P < 0.001 (ES = 38%, moderate effect) (Table I) and the interaction Test × Assessment Time F(8,120) = 47.322, P < 0.0001 (ES = 75.9%, moderate effect). Pairwise comparisons (Figure 1) showed that the vibrations reduced the effect in the first minute (Δ% = – 3.456% between WBV and PRE, and Δ% =
1.34 Step Length (m)
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
Time (Minutes)
# 1.33
*
1.32
PRE SHAM WBV
1.31 1.30 1.29
0
1
2
3
4
5
6
Time (Minutes)
Figure 1. Step frequency and the step length over time of the three tests (PRE, SHAM and WBV). “*” Significant difference between WBV and the other two tests PRE and SHAM. “#” Significant difference between WBV and SHAM (Bonferroni post hoc analysis was used to identify where changes occurred, P < 0.05).
–3.379% between WBV and SHAM condition), and also in the second minute (Δ% = –1.053% between WBV and SHAM condition). While the trend analysis of the SF showed a significant difference among the three tests F(2,30) = 9.76, P < 0.001 (ES = 39.4%, moderate effect)
Table I. Effects among tests. Δ%
Mean (SD) Variables
PRE
SHAM
WBV
Step length (m) 1.351 (0.102) 1.352 (0.098) 1.299 (0.103) Step frequency (Hz) 3.047 (0.121) 3.046 (0.126) 3.17 (0.137) Contact time (ms) 194 (14) 195 (14) 191 (16) Flight time (ms) 134 (16) 134 (16) 125 (17) Internal work (J · (kg · m)−1) 2.043 (0.191) 2.042 (0.199) 2.124 (0.196) Heart rate (%max) 66 (4.05) 66.6 (4.09) 67.4 (4.13)
SHAM/PRE (%) WBV/PRE (%) WBV/SHAM (%)
P2
–4.003* 3.88* –1.57 –7.2* 3.965* 2.077*
0.834 0.813 0.157 0.590 0.812 0.484
0.074 –0.033 0.513 0 –0.049 0.901*
–4.08* 3.912* –2.094 –7.2* 4.016* 1.187*
Notes: Mean and standard deviation (SD) with perceptual difference (Δ%) among conditions and effect size P2 of the listed running variables and heart rate. The data are: before treatment (PRE), after whole-body vibration (WBV) and after SHAM condition (SHAM). * Indicates the significant difference between conditions (P < 0.05).
1124
J. Padulo et al.
(Table I). Pair-wise comparisons showed an increment of the SF after vibrations and a significant interaction of Test × Assessment Time F(8,120) = 53.701, P < 0.0001 (ES = 78.2%, moderate effect). Pair-wise comparisons (Figure 1) showed that the vibrations had an effect in the first minute (Δ% = 3.258% before and after WBV, and Δ% = 3.227% between WBV and SHAM condition) and in the second minute in (Δ% = 1.259% between WBV and SHAM condition).
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
Discussion The results of this study indicate that 10 min of WBV (with 1:1 min work to relief ratio) at 45 Hz produces a significant alteration of the running kinematics. Interestingly, this alteration appears to be similar to what has been observed to occur during endurance races like the marathon (Hausswirth, Bigard, & Guezennec, 1997; Kyrolainen et al., 2000). A decrease in the SL of ~4% has been indeed observed in moderate to top level athletes during a marathon race performed at a nearly constant velocity within a time of 2.5 h (Hausswirth et al., 1997; Kyrolainen et al., 2000). As a result of fatigue, during endurance races, athletes reduced the stride time while maintaining a constant speed (Hasegawa, Yamauchi, & Kraemer, 2007; Meardon, Hamill, & Derrick, 2011). Although induced by different factors, an endurance race such as the marathon and a single bout of vibration result in a similar alteration of the running kinematics. This could be related to the effects of WBV on the central components controlling muscle function, compared to the mechanism related to onset of fatigue during the marathon. Muscle fatigue during endurance running has been suggested to depend both on central (decrease of neuromuscular response (Kyrolainen et al., 2000)) and peripheral (depletion of muscle glycogen (Callow, Morton, & Guppy, 1986)) changes. During the marathon, a decrease in the signal amplitude has been shown by the electromyography analysis of the contractile activity of the soleus, gastrocnemius, and vastus lateralis, which are the main muscle groups involved in plantar flexion (Avela, Kyrolainen, Komi, & Rama, 1999). A similar response could occur during WBV exposure, as this has been shown to influence the electromyography activity of the lower limbs muscles, among which the vastus lateralis, soleus and gastrocnemius (Torvinen et al., 2002). This could have eventually resulted in altering the running gait of the marathon athletes tested in this study. WBV could, therefore, result in a neuro-physiological alteration of muscular activity which is similar to the central mechanisms responsible of the onset of
fatigue during the marathon race (Bosco et al., 1999; Cardinale & Bosco, 2003). The effects produced by both WBV and the marathon race are transient: with regards to the WBV exposure, we observed that the running kinematic pattern had returned to the pretest values after ~4 min. This rapid remission of the effects of WBV could be related to its temporary effects on central motor commands. An alteration of the inter-muscular coordination patterns causing a decrease of muscular strength (Romaiguere, Vedel, Azulay, & Pagni, 1991) could be produced by WBV exposure, as the vibratory stimulus might be capable of generating kinesthetic illusion at a spinal level (Naito et al., 2000), through the inhibition of the antagonist muscle (via Ia inhibitory neurons). In this study, the duration of these effects have been shown to be attenuated after 3 min, when the physiological and neuromuscular conditions were probably restored (Roll, Martin, Gauthier, & Mussa, 1980). It cannot be excluded that WBV could lead to an alteration of the neuro-muscular properties of the type II fibres, as 10 min of intermittent vibrations might be not able to induce fatigue in this type of fibres. In support of this consideration, previous studies have suggested that the acute effects of WBV might prevail on the recruitment of type II fibres (Kofotolis, Vrabas, Vamvakoudis, Papanikolaou, & Mandroukas, 2005). WBV seems also to have an influence on the internal workload, as shown in this study by an increase of ~4% in WINT. Although a certain variability of the running kinematics is physiological (Hausswirth et al., 1997), it might be possible to find the best trade-off between the length and frequency of the steps in order to reduce the stress to the tissues (Kyrolainen et al., 2000). This fact is of interest in terms of performance analysis, as these changes, if unmonitored, can become a limiting factor of performance. Indeed, if the SF increases excessively, the internal workload and the energy expenditure to maintain a constant speed will also increase (Hausswirth et al., 1997). Eventually, this would result in a greater effort required for the same workload. In conclusion, this study has proposed an experimental approach to determine the alteration which occurs to the running kinematics of marathon runners as a result of WBV exposure. This was investigated not only in terms of the impact of WBV on cyclic neuromuscular patterns, but also on the internal workload and HR. It results that, despite the potential benefits of vibration training, it seems essential that the implications of this type of treatment are acquired prior to its use in athletic situations. Indeed, within the context of endurance running, this treatment could generate an increase (although transient) in neuromuscular fatigue which
Footstep analysis after vibrations treatment could affect the running gait and thus performance. Future research should be done with the aim of understanding the physiological effects of different WBV protocols on muscle performance. Acknowledgements
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
This research was supported by the CONI “Italian Regional Olympic Committee, Sardinia, Italy” project A2. The authors thank Prof. Marco Cardinale and Prof. Paola Zamparo of British Olympic Medical Institute, London (UK), and the University of Verona, respectively, for their help and valuable suggestions that allowed to clarify the study. References Avela, J., Kyrolainen, H., Komi, P. V., & Rama, D. (1999). Reduced reflex sensitivity persists several days after long-lasting stretch-shortening cycle exercise. Journal of Applied Physiology, 86, 1292–1300. Balsalobre-Fernandez, C., Tejero-Gonzalez, C. M., CampoVecino, J. D., & Bavaresco, N. (2014). The concurrent validity and reliability of a low-cost, high-speed camera-based method for measuring the flight time of vertical jumps. The Journal of Strength & Conditioning Research, 28, 528–533. Belli, A., Rey, S., Bonnefoy, R., & Lacour, J. R. (1992). A simple device for kinematic measurements of human movement. Ergonomics, 35, 177–186. Bosco, B., Colli, C., Introini, I., Cardinale, C., Tsarpela, T., Madella, M., … Viru, A. (1999). Adaptive responses of human skeletal muscle to vibration exposure. Clinical Physiology, 19, 183–187. Callow, M., Morton, A., & Guppy, M. (1986). Marathon fatigue: The role of plasma fatty acids, muscle glycogen and blood glucose. European Journal of Applied Physiology and Occupational Physiology, 55, 654–661. Cardinale, M., & Bosco, C. (2003). The use of vibration as an exercise intervention. Exercise and Sport Sciences Reviews, 31, 3–7. Cochrane, D. J. (2011). The potential neural mechanisms of acute indirect vibration. Journal of Sports Science and Medicine, 10, 19–30. Coza, A., Nigg, B. M., & Dunn, J. F. (2011). Effects of vibrations on gastrocnemius medialis tissue oxygenation. Medicine and Science in Sports and Exercise, 43, 509–515. Delecluse, C., Roelants, M., & Verschueren, S. (2003). Strength increase after whole-body vibration compared with resistance training. Medicine and Science in Sports and Exercise, 35, 1033– 1041. Di Giminiani, R., Masedu, F., Tihanyi, J., Scrimaglio, R., & Valenti, M. (2013). The interaction between body position and vibration frequency on acute response to whole body vibration. Journal of Electromyography and Kinesiology, 23, 245–251. Di Giminiani, R., Tihanyi, J., Safar, S., & Scrimaglio, R. (2009). The effects of vibration on explosive and reactive strength when applying individualized vibration frequencies. Journal of Sports Sciences, 27, 169–177. Dugan, S. A., & Bhat, K. P. (2005). Biomechanics and analysis of running gait. Physical Medicine and Rehabilitation Clinics of North America, 16, 603–621. Filingeri, D., Jemni, M., Bianco, A., Zeinstra, E., & Jimenez, A. (2012). The effects of vibration during maximal graded cycling exercise: A pilot study. Journal of Sports Science and Medicine, 11, 423–429. Hasegawa, H., Yamauchi, T., & Kraemer, W. J. (2007). Foot strike patterns of runners at the 15-km point during an elite-
1125
level half marathon. The Journal of Strength and Conditioning Research, 21, 888–893. Hausswirth, C., Bigard, A. X., & Guezennec, C. Y. (1997). Relationships between running mechanics and energy cost of running at the end of a triathlon and a marathon. International Journal of Sports Medicine, 18, 330–339. Herrero, A. J., Menéndez, H., Gil, L., Martín, J., Martín, T., García-López, D., … Marín P.J. (2011). Effects of wholebody vibration on blood flow and neuromuscular activity in spinal cord injury. Spinal Cord, 49, 554–559. Iodice, P., Bellomo, R. G., Gialluca, G., Fanò, G., & Saggini, R. (2011). Acute and cumulative effects of focused high-frequency vibrations on the endocrine system and muscle strength. European Journal of Applied Physiology, 111, 897–904. Kofotolis, N., Vrabas, I. S., Vamvakoudis, E., Papanikolaou, A., & Mandroukas, K. (2005). Proprioceptive neuromuscular facilitation training induced alterations in muscle fibre type and cross sectional area. British Journal of Sports Medicine, 39, e11. Krol, P., Piecha, M., Slomka, K., & Sobota, G. (2010). The effect of whole-body vibration frequency and amplitude on the myoelectric activity of vastus medialis and vastus lateralis. Journal of Sports Science and Medicine, 10, 169–174. Kyröläinen, H., Pullinen, T., Candau, R., Avela, J., Huttunen, P., & Komi, P. V. (2000). Effects of marathon running on running economy and kinematics. European Journal of Applied Physiology, 82, 297–304. Luo, J., McNamara, B., & Moran, K. (2005). The use of vibration training to enhance muscle strength and power. Sports Medicine, 35, 23–41. Maikala, R. V., & Bhambhani, Y. N. (2008). Cardiovascular responses in healthy young women during exposure to wholebody vibration. International Journal of Industrial Ergonomics, 38, 775–782. Martínez-Pardo, E., Romero-Arenas, S., & Alcaraz, P. E. (2013). Effects of different amplitudes (high vs. low) of whole-body vibration training in active adults. The Journal of Strength and Conditioning Research, 27, 1798–1806. Meardon, S. A., Hamill, J., & Derrick, T. R. (2011). Running injury and stride time variability over a prolonged run. Gait and Posture, 33, 36–40. Miller, W. C., Wallace, J. P., & Eggert, K. E. (1993). Predicting max HR and the HR-&OV0312;2 relationship for exercise prescription in obesity. Medicine and Science in Sports and Exercise, 25, 1077–1081. Munn, J., Sullivan, S. J., & Schneiders, A. G. (2010). Evidence of sensorimotor deficits in functional ankle instability: A systematic review with meta-analysis. Journal of Science and Medicine in Sport, 13, 2–12. Naito, E., Kinomura, S., Geyer, S., Kawashima, R., Roland, P. E., & Zilles, K. (2000). Fast reaction to different sensory modalities activates common fields in the motor areas, but the anterior cingulate cortex is involved in the speed of reaction. Journal of Neurophysiology, 83, 1701–1709. Nardello, F., Ardigò, L. P., & Minetti, A. E. (2011). Measured and predicted mechanical internal work in human locomotion. Human Movement Science, 30, 90–104. Padulo, J., Annino, G., DʼOttavio, S., Vernillo, G., Smith, L., Migliaccio, G. M., & Tihanyi J. (2013). Footstep analysis at different slopes and speeds in Elite Racewalking. The Journal of Strength and Conditioning Research, 27, 125–129. Padulo, J., Annino, G., Migliaccio, G. M., DʼOttavio, S., & Tihanyi, J. (2012). Kinematics of running at different slopes and speeds. The Journal of Strength and Conditioning Research, 26, 1331–1339. Padulo, J., Annino, G., Smith, L., Migliaccio, G. M., Camino, R., Tihanyi, J., & D’Ottavio S. (2012). Uphill running at ISOefficiency speed. International Journal of Sports Medicine, 33, 819–823.
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
1126
J. Padulo et al.
Padulo, J., Degortes, N., Migliaccio, G. M., Attene, G., Smith, L., Salernitano, G., … D’Ottavio S. (2013). Footstep Manipulation during Uphill Running. International Journal of Sports Medicine, 34, 244–247. Padulo, J., Di Giminiani, R., Ibba, G., Zarrouk, N., Moalla, W., Attene, G., … Chamari, K. (2014). The acute effect of whole body vibration on repeated shuttle-running in young soccer players. International Journal of Sports Medicine, 35, 49–54. Padulo, J., Powell, D., Milia, R., & Ardigò, L. P. (2013). A paradigm of uphill running. Plos One, 8, e69006. Pel, J. J., Bagheri, J., van Dam, L. M., van den Berg-Emons, H. J., Horemans, H. L., Stam, H. J., … van der Steen, J. (2009). Platform accelerations of three different whole-body vibration devices and the transmission of vertical vibrations to the lower limbs. Medical Engineering and Physics, 31, 937–944. Riley, P. O., Dicharry, J., Franz, J., Croce, U. D., Wilder, R. P., & Kerrigan, D. C. (2008). A kinematics and kinetic comparison of overground and treadmill running. Medicine and Science in Sports and Exercise, 40, 1093–1100. Rittweger, J. (2010). Vibration as an exercise modality: How it may work, and what its potential might be. European Journal of Applied Physiology, 108, 877–904. Rittweger, J., Ehrig, J., Just, K., Mutschelknauss, M., Kirsch, K. A., & Felsenberg, D. (2002). Oxygen uptake in whole-body vibration exercise: Influence of vibration frequency, amplitude, and external load. International Journal of Sports Medicine, 23, 428–432. Rittweger, R., Beller, B., & Felsenberg, F. (2000). Acute physiological effects of exhaustive whole-body vibration exercise in man. Clinical Physiology, 20, 134–142. Ritzmann, R., Gollhofer, A., & Kramer, A. (2013). The influence of vibration type, frequency, body position and additional load
on the neuromuscular activity during whole body vibration. European Journal of Applied Physiology, 113, 1–11. Roll, J. P., Martin, B., Gauthier, G. M., & Mussa, I. F. (1980). Effects of whole-body vibration on spinal reflexes in man. Aviation, Space, and Environmental Medicine, 51, 1227–1233. Romaiguere, P., Vedel, J. P., Azulay, J. P., & Pagni, S. (1991). Differential activation of motor units in the wrist extensor muscles during the tonic vibration reflex in man. The Journal of Physiology, 444, 645–667. Sands, W. A., McNeal, J. R., Stone, M. H., Kimmel, W. L. Gregory Haff G., & Jemni M. (2008). The effect of vibration on active and passive range of motion in elite female synchronized swimmers. European Journal of Sport Science, 8, 217–223. Sands, W. A., McNeal, J. R., Stone, M. H., Russell, E. M., & Jemni, M. (2006). Flexibility enhancement with vibration: Acute and long-term. Medicine and Science in Sports and Exercise, 38, 720–725. Sefton, J. M., Hicks-Little, C. A., Hubbard, T. J., Clemens, M. G., Yengo, C. M., Koceja, D. M., … Cordova M.L. (2009). Sensorimotor function as a predictor of chronic ankle instability. Clinical Biomechanics, 24, 451–458. Suhr, F., Brixius, K., de, M. M., Bolck, B., Kleinoder, H., Achtzehn, S., … Mester J. (2007). Effects of short-term vibration and hypoxia during high-intensity cycling exercise on circulating levels of angiogenic regulators in humans. Journal of Applied Physiology, 103, 474–483. Torvinen, S., Sievänen, H., Järvinen, T. A., Pasanen, M., Kontulainen, S., & Kannus, P. (2002). Effect of 4-min vertical whole body vibration on muscle performance and body balance: A randomized cross-over study. International Journal of Sports Medicine, 23, 374–379.
Journal of Sports Sciences Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/rjsp20
Acute effects of whole-body vibration on running gait in marathon runners a
b
c
d
Johnny Padulo , Davide Filingeri , Karim Chamari , Gian Mario Migliaccio , Giuseppe e
f
g
h
i
Calcagno , Gerardo Bosco , Giuseppe Annino , Jozsef Tihanyi & Fabio Pizzolato a
Tunisian Research Laboratory “Sports Performance Optimization”, National Center of Medicine and Science in Sport, Tunis, Tunisia b
Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough LE11 3TU, UK c
Research and Education Centre, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
Click for updates
d
CONI – Italian Regional Olympic Committee, Sardinia, Cagliari, Italy
e
Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy
f
Department of Medicine, University of Padova, Padova, Italy
g
Faculty of Medicine and Surgery, University of “Tor Vergata”, Rome 00133, Italy
h
Biomechanics, Semmelweis University, Budapest 1123, Hungary
i
Department of Neurological and Movement Sciences, University of Verona, Verona, Italy Published online: 28 Feb 2014.
To cite this article: Johnny Padulo, Davide Filingeri, Karim Chamari, Gian Mario Migliaccio, Giuseppe Calcagno, Gerardo Bosco, Giuseppe Annino, Jozsef Tihanyi & Fabio Pizzolato (2014) Acute effects of whole-body vibration on running gait in marathon runners, Journal of Sports Sciences, 32:12, 1120-1126, DOI: 10.1080/02640414.2014.889840 To link to this article: http://dx.doi.org/10.1080/02640414.2014.889840
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Journal of Sports Sciences, 2014 Vol. 32, No. 12, 1120–1126, http://dx.doi.org/10.1080/02640414.2014.889840
Acute effects of whole-body vibration on running gait in marathon runners
JOHNNY PADULO1, DAVIDE FILINGERI2, KARIM CHAMARI3, GIAN MARIO MIGLIACCIO4, GIUSEPPE CALCAGNO5, GERARDO BOSCO6, GIUSEPPE ANNINO7, JOZSEF TIHANYI8 & FABIO PIZZOLATO9 Tunisian Research Laboratory “Sports Performance Optimization”, National Center of Medicine and Science in Sport, Tunis, Tunisia, 2Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough LE11 3TU, UK, 3Research and Education Centre, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar, 4CONI – Italian Regional Olympic Committee, Sardinia, Cagliari, Italy, 5Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy, 6Department of Medicine, University of Padova, Padova, Italy, 7Faculty of Medicine and Surgery, University of “Tor Vergata”, Rome 00133, Italy, 8Biomechanics, Semmelweis University, Budapest 1123, Hungary and 9Department of Neurological and Movement Sciences, University of Verona, Verona, Italy
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
1
(Accepted 27 January 2014)
Abstract The aim of this study was to investigate the effects of a single bout of whole-body vibration (WBV) on running gait. The running kinematic of sixteen male marathon runners was assessed on a treadmill at iso-efficiency speed after 10 min of WBV and SHAM (i.e. no WBV) conditions. A high-speed camera (210 Hz) was used for the video analysis and heart rate (HR) was also monitored. The following parameters were investigated: step length (SL), flight time (FT), step frequency (SF), contact time (CT), HR and the internal work (WINT). Full-within one-way analysis of variance (ANOVA) of the randomised crossover design indicated that when compared to SHAM conditions, WBV decreased the SL and the FT by ~4% (P < 0.0001) and ~7.2% (P < 0.001), respectively, and increased the SF ~4% (P < 0.0001) while the CT was not changed. This effect occurred during the first minute of running: the SL decreased ~3.5% (P < 0.001) and SF increased ~3.3% (P < 0.001). During the second minute the SL decreased ~1.2% (P = 0.017) and the SF increased ~1.1% (P = 0.02). From the third minute onwards, there was a return to the pre-vibration condition. The WINT was increased by ~4% (P < 0.0001) during the WBV condition. Ten minutes of WBV produced a significant alteration of the running kinematics during the first minutes post exposure. These results provide insights on the effects of WBV on the central components controlling muscle function. Keywords: kinematic analysis, iso-efficiency speed, internal work, heart rate, motor control
The interest in whole-body vibration (WBV) training and its acute and long-term effects on the human body has grown rapidly in the last two decades, as shown by the numerous applications of this novel training method to exercise performance and rehabilitation (Luo, McNamara, & Moran, 2005; Rittweger, 2010; Rittweger, Beller, & Felsenberg, 2000). The reason of such interest lays on the fact that exposure to low-frequency vibration has been shown to elicit a greater muscle activity as a result of a reflex contraction known as tonic vibration reflex (Cochrane, 2011). This neurophysiological response has been speculated to occur as low-frequency vibration might activate the muscle Ia
endings which, in turn, stimulate the alpha motoneurons thus producing involuntary muscle contractions (Delecluse, Roelants, & Verschueren, 2003). This neuromuscular response translates in an increased motor units recruitment during sub-maximal voluntary contractions (Krol, Piecha, Slomka, & Sobota, 2010; Rittweger, 2010). The possibility to elicit a greater muscle activity (Rittweger, 2010) followed by an increase in tissue oxygenation (Coza, Nigg, & Dunn, 2011) and muscle blood flow (Herrero et al., 2011) has therefore driven the interest on WBV as a potential alternative to more traditional training methods (Delecluse et al., 2003). This has been particularly true in the
Correspondence: Johnny Padulo, Tunisian Research Laboratory “Sports Performance Optimization”, National Center of Medicine and Science in Sport, Tunis, Tunisia. E-mail: [email protected] © 2014 Taylor & Francis
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
Footstep analysis after vibrations treatment context of sprint and power-based sports, in which acute and chronic WBV protocols showed benefits on performance (Di Giminiani, Tihanyi, Safar, & Scrimaglio, 2009).These benefits on sprint performance and repeated sprint ability (Padulo et al., 2014) could be due to the fact that training protocols endorsing the use of vibration have been shown to induce a greater fast twitch muscle fibres’ recruitment (Filingeri, Jemni, Bianco, Zeinstra, & Jimenez, 2012). However, although the use of vibration as a training modality has been shown to be effective in enhancing different physiological parameters such as strength, power, flexibility, bone mineral density (Maikala & Bhambhani, 2008; Rittweger et al., 2002; Sands, McNeal, Stone, & Kimmel, 2008; Sands, McNeal, Stone, Russell, & Jemni, 2006; Suhr et al., 2007), to our knowledge, no investigations are currently available on the effects of WBV on the kinematics parameter in running gait. Investigating the effects of WBV on these parameters could be of interest in the light of potential applications within the context of endurance running (e.g. marathon), in which this training modality has been scarcely investigated. Acute exposures to vibration have been shown to influence the activity of the proprioceptive sensory system (which is based on the excitation of Ia afferent signals situated at the neuromuscular spindle) (Iodice, Bellomo, Gialluca, Fano, & Saggini, 2011) and to result in activating larger motoneurons, leading to the recruitment of previously inactive muscle fibres. As the sensorimotor feedback from the proprioceptive system plays a critical role in the kinematic of running (Dugan & Bhat, 2005) and in the ankle stability (Munn, Sullivan, & Schneiders, 2010; Sefton et al., 2009), it is therefore reasonable to hypothesise that an acute exposure to vibration could potentially affect the biomechanics and kinematics of running gait, particularly in the first few minutes following exposure. Increasing the knowledge on how WBV could potentially affect the biomechanics and kinematics of running gait could have important implication in the context of using this exercise modality for warmup (pre-competition) as well as for training purposes (Padulo, Annino, Migliaccio, et al., 2013). Therefore, the aim of this study was to investigate whether and to what extent an acute exposure to WBV would alter the running gait. In this study, the kinematics of the footstep was investigated in marathon runners before and after a session of 10 min WBV at 45 Hz. To our knowledge, this represents the first exploratory study to provide experimental data on the effects of vibration treatment on the running gait.
1121
Methods Participants Sixteen male marathon runners (age 41.06 ± 3.71 years; body mass 67.44 ± 3.55 kg; body height 172 ± 3.42 cm; BMI 22.84 ± 1.35 kg/m2, training background of 8 ± 0.12 years and who had covered 131 ± 2.78 km per week last year with personal best marathon race ~2 h 50 min participated in this study). The participants were healthy without any muscular, neurological and tendinous injuries and did not report any consumption of drugs. After being informed of the procedures, methods, benefits and possible risks involved in the study, each participant reviewed and signed an informed consent form prior to participation in the study, in accordance with the ethical standards. All experimental procedures were approved by the University Human Research Ethics Committee, which followed the ethical principles laid out in the 2008 revision of the Declaration of Helsinki. Experimental setting Testing was carried out in a Human Performance Laboratory (Regional Olympic Committee of Sardinia). All the participants were in good health at the time of the study. Research reported a high correlation (r = 0.93) between over-ground and treadmill running for biomechanical analysis (Riley et al., 2008). In order to more accurately control the slope and the velocity (Padulo, Annino, D'Ottavio, et al., 2013), tests were performed on a motorised treadmill (Run Race Technogym® Run 500, Gambettola, Italy). All participants wore marathonrunning shoes (Category A3) and performed a standardised 10-min warm-up, which consisted of running at 9 km · h−1 at 0% of slope, to familiarise themselves with the treadmill (Padulo, Annino, Migliaccio, et al., 2013). The speed of the test (mean ± SD) was set at 1 km h−1 less than the best mean speed performed by each participant on 10,000 m (14.81 ± 1.11 km · h−1) in the last 3 months. This allowed them to run at iso-efficiency speed (Padulo, Annino, Smith, et al., 2012). The randomised crossover with a repeated measure design was applied to this study to verify the effects of WBV compared to a SHAM (i.e. no WBV) condition. The experiment consisted of 5 min of running, followed by 2 min of passive recovery. Then, in a randomised order, the participants underwent to the experimental conditions that were: the WBV or the SHAM condition. Then, after 2 min of passive recovery, the participants had to run for 5 min to evaluate the treatment effects. Finally, the experimental conditions were repeated in inverted
1122
J. Padulo et al.
order: the participants that started with the WBV performed the SHAM condition and vice versa. For each participant, we had the following evaluations: before, after WBV and after SHAM conditions.
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
WBV treatment The vibration platform used for the study was: Power Plate pro5™ (Power Plate International LTD, The Netherlands). The vibration frequency was set at 45 Hz, with a peak-to-peak displacement of 2.2 mm (Martinez-Pardo, Romero-Arenas, Alcaraz, 2013) and an acceleration of 7.7 g (1 g = 9.81 m · s−2). The vibrating platform used shows a high reliability for the accelerations delivered between unloaded and loaded condition (Pel et al., 2009). For the WBV, ten bouts of 60-s vertical sinusoidal vibrations at 45 Hz (according to the manufactures instructions) with a 1:1 work-to-relief ratio were used. During WBV the participants stood on the plate with the knees flexed at ~90° and the heels raised ~10 cm (Di Giminiani et al., 2009; Di Giminiani, Masedu, Tihanyi, Scrimaglio, & Valenti, 2013; Padulo et al., 2014; Ritzmann, Gollhofer, & Kramer, 2013). The SHAM condition was performed using the same participant position and for the same time of the experimental protocol but, without preceding vibrations. Motion analysis Two-dimensional video data were collected while the participants’ running on the treadmill using a single high-speed (Balsalobre-Fernandez, TejeroGonzalez, Campo-Vecino, & Bavaresco, 2014) digital camera (Casio Exilim FH20, Japan) sampled at 210 Hz and collected in accordance with a previous study protocol (Padulo, Annino, Migliaccio, D‘Ottavio, & Tihanyi, 2012). The camera was positioned on a 1.5 m high tripod, 6 m from the participant and was located perpendicular to the plane of motion at the participant’s sagittal plane (Belli, Rey, Bonnefoy, & Lacour, 1992). The film sequences were analysed off-line using Kinovea™ 0.8.15 motion analysis software. Kinematic markers were taped on both feet (heel and third metatarsus) of each participant in accordance with other study (Padulo, Degortes, et al., 2013). The following kinematic variables were studied: (i) contact time (CT) (ms), (ii) flight time (FT) (ms), (iii) step length (SL) (m), (iv) step frequency (SF) (Hz); for each velocity 120 steps were sampled for frequency calculation (Padulo, Annino, Smith, et al., 2012; Padulo, Annino, et al., 2013). Since the velocity of the treadmill was known, both SL and SF could be calculated (Padulo,
Annino, et al., 2013). The CT and FT were calculated by counting the frames in contact and flight on the 2D data. The CT and FT were calculated for both the left and right foot. The CT was defined and calculated as the time between initial contact with the ground and the last frame of contact before toeoff. The FT was defined and calculated as the time between toe-off and subsequent initial contact of the contralateral foot. Initial contact and toe-off were visually detected. In accordance with the previous studies (Padulo, Annino, Migliaccio, et al., 2012; Padulo, Annino, Smith, et al., 2012; Padulo, Degortes, et al., 2013; Padulo, Powell et al., 2013) SF was calculated as: SF = [1000/(CT+ FT)]; alternatively SL was calculated with the following equation: SL = (speed km · h−1/3.6/SF). Data analysis The internal work (WINT) was also calculated with the formula (Equation (1)) proposed by Nardello, Ardigo, and Minetti (2011) WINT ¼ SF v ð1 þ ðDF ð1 DFÞ1 Þ2 Þ q (1) where SF is the SF (Hz), v is the velocity (m · s−1), DF is the duty factor, that is, deflection of the duration of stride period when each foot is on the ground (%) and q value of 0.08 referring to the inertial properties of the oscillating limbs. The HR was recorded throughout the experiment and an average computed during the full 5 min for each condition (Sport Tester PE 3000; Polar Electro, Kempele, Finland). The HR was expressed in percentage of maximum theoretical HR (HRmax) by Equation (2) (Miller, Wallace, & Eggert, 1993). HR max ¼ 217 ð0:85 ageÞ
(2)
Statistical analyses The results are expressed as mean ± SD. The variables investigated were: CT, FT, SL, SF, WINT, HR and the Percentage of HR with respect to the maximal theoretical HR (HR%). The effect size (ES) was calculated for all variables between pre and posttesting. The thresholds for small, moderate and large effects were 0.20, 0.50 and 0.80, respectively. Statistical analysis was performed using SPSS 16.0 software. The level set for significance was P < 0.05. Assumption of normality was verified using the Shapiro–Wilk Test, after that, on the absolute variables of CT, FT, HR and HR% a full-within oneway analysis of variance (ANOVA) with repeated measures was used to compare responses in each
Footstep analysis after vibrations treatment
1123
3.18
variable across the three tests (before, SHAM condition and after WBV). Bonferroni post hoc analysis was used to identify where changes occurred. Moreover, on SL and SF a two-way ANOVA was carried out with repeated measures adding Assessment Time as a second factor, with five levels (1 < 5 min), to investigate the changes over time. For this analysis, we were not interested in the main factor Assessment Time but in the interaction Test × Assessment Time. When a global difference over time was determined, Bonferroni post hoc analysis was used to identify where changes occurred.
Step Frequency (Hz)
3.16 3.14 3.12
*
3.10
#
3.08 3.06 3.04 0
1
2
3
4
5
6
1.36
Results
1.35
Neither subjective adverse reactions nor exhaustive fatigue were reported after the vibration bout, while most of the participants reported that they felt that the WBVs had an effect on the lower limbs. The results are reported in Table I. The contact time of the feet on the ground did not change significantly even though decreased F(2,30) = 2.792, P = 0.077 (ES = 15.7%, small effect) while the FT decreased significantly F(2,30) = 21.629, P < 0.0001 with a large effect (ES = 59%). The WINT increases after vibrations F(2,30) = 64.662, P < 0.0001 (ES = 81.2%, large effect), as well as the HR increased over the three tests F (2,30) = 15.818, P < 0.0001 (ES = 51.3%, moderate effect). We obtained the same result by calculating the percentage of the HRmax of each participant F (2,30) = 15.623, P < 0.0001 (ES = 51%, moderate effect). The main effect of Test was found significant for the SL F(2,30) = 9.183, P < 0.001 (ES = 38%, moderate effect) (Table I) and the interaction Test × Assessment Time F(8,120) = 47.322, P < 0.0001 (ES = 75.9%, moderate effect). Pairwise comparisons (Figure 1) showed that the vibrations reduced the effect in the first minute (Δ% = – 3.456% between WBV and PRE, and Δ% =
1.34 Step Length (m)
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
Time (Minutes)
# 1.33
*
1.32
PRE SHAM WBV
1.31 1.30 1.29
0
1
2
3
4
5
6
Time (Minutes)
Figure 1. Step frequency and the step length over time of the three tests (PRE, SHAM and WBV). “*” Significant difference between WBV and the other two tests PRE and SHAM. “#” Significant difference between WBV and SHAM (Bonferroni post hoc analysis was used to identify where changes occurred, P < 0.05).
–3.379% between WBV and SHAM condition), and also in the second minute (Δ% = –1.053% between WBV and SHAM condition). While the trend analysis of the SF showed a significant difference among the three tests F(2,30) = 9.76, P < 0.001 (ES = 39.4%, moderate effect)
Table I. Effects among tests. Δ%
Mean (SD) Variables
PRE
SHAM
WBV
Step length (m) 1.351 (0.102) 1.352 (0.098) 1.299 (0.103) Step frequency (Hz) 3.047 (0.121) 3.046 (0.126) 3.17 (0.137) Contact time (ms) 194 (14) 195 (14) 191 (16) Flight time (ms) 134 (16) 134 (16) 125 (17) Internal work (J · (kg · m)−1) 2.043 (0.191) 2.042 (0.199) 2.124 (0.196) Heart rate (%max) 66 (4.05) 66.6 (4.09) 67.4 (4.13)
SHAM/PRE (%) WBV/PRE (%) WBV/SHAM (%)
P2
–4.003* 3.88* –1.57 –7.2* 3.965* 2.077*
0.834 0.813 0.157 0.590 0.812 0.484
0.074 –0.033 0.513 0 –0.049 0.901*
–4.08* 3.912* –2.094 –7.2* 4.016* 1.187*
Notes: Mean and standard deviation (SD) with perceptual difference (Δ%) among conditions and effect size P2 of the listed running variables and heart rate. The data are: before treatment (PRE), after whole-body vibration (WBV) and after SHAM condition (SHAM). * Indicates the significant difference between conditions (P < 0.05).
1124
J. Padulo et al.
(Table I). Pair-wise comparisons showed an increment of the SF after vibrations and a significant interaction of Test × Assessment Time F(8,120) = 53.701, P < 0.0001 (ES = 78.2%, moderate effect). Pair-wise comparisons (Figure 1) showed that the vibrations had an effect in the first minute (Δ% = 3.258% before and after WBV, and Δ% = 3.227% between WBV and SHAM condition) and in the second minute in (Δ% = 1.259% between WBV and SHAM condition).
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
Discussion The results of this study indicate that 10 min of WBV (with 1:1 min work to relief ratio) at 45 Hz produces a significant alteration of the running kinematics. Interestingly, this alteration appears to be similar to what has been observed to occur during endurance races like the marathon (Hausswirth, Bigard, & Guezennec, 1997; Kyrolainen et al., 2000). A decrease in the SL of ~4% has been indeed observed in moderate to top level athletes during a marathon race performed at a nearly constant velocity within a time of 2.5 h (Hausswirth et al., 1997; Kyrolainen et al., 2000). As a result of fatigue, during endurance races, athletes reduced the stride time while maintaining a constant speed (Hasegawa, Yamauchi, & Kraemer, 2007; Meardon, Hamill, & Derrick, 2011). Although induced by different factors, an endurance race such as the marathon and a single bout of vibration result in a similar alteration of the running kinematics. This could be related to the effects of WBV on the central components controlling muscle function, compared to the mechanism related to onset of fatigue during the marathon. Muscle fatigue during endurance running has been suggested to depend both on central (decrease of neuromuscular response (Kyrolainen et al., 2000)) and peripheral (depletion of muscle glycogen (Callow, Morton, & Guppy, 1986)) changes. During the marathon, a decrease in the signal amplitude has been shown by the electromyography analysis of the contractile activity of the soleus, gastrocnemius, and vastus lateralis, which are the main muscle groups involved in plantar flexion (Avela, Kyrolainen, Komi, & Rama, 1999). A similar response could occur during WBV exposure, as this has been shown to influence the electromyography activity of the lower limbs muscles, among which the vastus lateralis, soleus and gastrocnemius (Torvinen et al., 2002). This could have eventually resulted in altering the running gait of the marathon athletes tested in this study. WBV could, therefore, result in a neuro-physiological alteration of muscular activity which is similar to the central mechanisms responsible of the onset of
fatigue during the marathon race (Bosco et al., 1999; Cardinale & Bosco, 2003). The effects produced by both WBV and the marathon race are transient: with regards to the WBV exposure, we observed that the running kinematic pattern had returned to the pretest values after ~4 min. This rapid remission of the effects of WBV could be related to its temporary effects on central motor commands. An alteration of the inter-muscular coordination patterns causing a decrease of muscular strength (Romaiguere, Vedel, Azulay, & Pagni, 1991) could be produced by WBV exposure, as the vibratory stimulus might be capable of generating kinesthetic illusion at a spinal level (Naito et al., 2000), through the inhibition of the antagonist muscle (via Ia inhibitory neurons). In this study, the duration of these effects have been shown to be attenuated after 3 min, when the physiological and neuromuscular conditions were probably restored (Roll, Martin, Gauthier, & Mussa, 1980). It cannot be excluded that WBV could lead to an alteration of the neuro-muscular properties of the type II fibres, as 10 min of intermittent vibrations might be not able to induce fatigue in this type of fibres. In support of this consideration, previous studies have suggested that the acute effects of WBV might prevail on the recruitment of type II fibres (Kofotolis, Vrabas, Vamvakoudis, Papanikolaou, & Mandroukas, 2005). WBV seems also to have an influence on the internal workload, as shown in this study by an increase of ~4% in WINT. Although a certain variability of the running kinematics is physiological (Hausswirth et al., 1997), it might be possible to find the best trade-off between the length and frequency of the steps in order to reduce the stress to the tissues (Kyrolainen et al., 2000). This fact is of interest in terms of performance analysis, as these changes, if unmonitored, can become a limiting factor of performance. Indeed, if the SF increases excessively, the internal workload and the energy expenditure to maintain a constant speed will also increase (Hausswirth et al., 1997). Eventually, this would result in a greater effort required for the same workload. In conclusion, this study has proposed an experimental approach to determine the alteration which occurs to the running kinematics of marathon runners as a result of WBV exposure. This was investigated not only in terms of the impact of WBV on cyclic neuromuscular patterns, but also on the internal workload and HR. It results that, despite the potential benefits of vibration training, it seems essential that the implications of this type of treatment are acquired prior to its use in athletic situations. Indeed, within the context of endurance running, this treatment could generate an increase (although transient) in neuromuscular fatigue which
Footstep analysis after vibrations treatment could affect the running gait and thus performance. Future research should be done with the aim of understanding the physiological effects of different WBV protocols on muscle performance. Acknowledgements
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
This research was supported by the CONI “Italian Regional Olympic Committee, Sardinia, Italy” project A2. The authors thank Prof. Marco Cardinale and Prof. Paola Zamparo of British Olympic Medical Institute, London (UK), and the University of Verona, respectively, for their help and valuable suggestions that allowed to clarify the study. References Avela, J., Kyrolainen, H., Komi, P. V., & Rama, D. (1999). Reduced reflex sensitivity persists several days after long-lasting stretch-shortening cycle exercise. Journal of Applied Physiology, 86, 1292–1300. Balsalobre-Fernandez, C., Tejero-Gonzalez, C. M., CampoVecino, J. D., & Bavaresco, N. (2014). The concurrent validity and reliability of a low-cost, high-speed camera-based method for measuring the flight time of vertical jumps. The Journal of Strength & Conditioning Research, 28, 528–533. Belli, A., Rey, S., Bonnefoy, R., & Lacour, J. R. (1992). A simple device for kinematic measurements of human movement. Ergonomics, 35, 177–186. Bosco, B., Colli, C., Introini, I., Cardinale, C., Tsarpela, T., Madella, M., … Viru, A. (1999). Adaptive responses of human skeletal muscle to vibration exposure. Clinical Physiology, 19, 183–187. Callow, M., Morton, A., & Guppy, M. (1986). Marathon fatigue: The role of plasma fatty acids, muscle glycogen and blood glucose. European Journal of Applied Physiology and Occupational Physiology, 55, 654–661. Cardinale, M., & Bosco, C. (2003). The use of vibration as an exercise intervention. Exercise and Sport Sciences Reviews, 31, 3–7. Cochrane, D. J. (2011). The potential neural mechanisms of acute indirect vibration. Journal of Sports Science and Medicine, 10, 19–30. Coza, A., Nigg, B. M., & Dunn, J. F. (2011). Effects of vibrations on gastrocnemius medialis tissue oxygenation. Medicine and Science in Sports and Exercise, 43, 509–515. Delecluse, C., Roelants, M., & Verschueren, S. (2003). Strength increase after whole-body vibration compared with resistance training. Medicine and Science in Sports and Exercise, 35, 1033– 1041. Di Giminiani, R., Masedu, F., Tihanyi, J., Scrimaglio, R., & Valenti, M. (2013). The interaction between body position and vibration frequency on acute response to whole body vibration. Journal of Electromyography and Kinesiology, 23, 245–251. Di Giminiani, R., Tihanyi, J., Safar, S., & Scrimaglio, R. (2009). The effects of vibration on explosive and reactive strength when applying individualized vibration frequencies. Journal of Sports Sciences, 27, 169–177. Dugan, S. A., & Bhat, K. P. (2005). Biomechanics and analysis of running gait. Physical Medicine and Rehabilitation Clinics of North America, 16, 603–621. Filingeri, D., Jemni, M., Bianco, A., Zeinstra, E., & Jimenez, A. (2012). The effects of vibration during maximal graded cycling exercise: A pilot study. Journal of Sports Science and Medicine, 11, 423–429. Hasegawa, H., Yamauchi, T., & Kraemer, W. J. (2007). Foot strike patterns of runners at the 15-km point during an elite-
1125
level half marathon. The Journal of Strength and Conditioning Research, 21, 888–893. Hausswirth, C., Bigard, A. X., & Guezennec, C. Y. (1997). Relationships between running mechanics and energy cost of running at the end of a triathlon and a marathon. International Journal of Sports Medicine, 18, 330–339. Herrero, A. J., Menéndez, H., Gil, L., Martín, J., Martín, T., García-López, D., … Marín P.J. (2011). Effects of wholebody vibration on blood flow and neuromuscular activity in spinal cord injury. Spinal Cord, 49, 554–559. Iodice, P., Bellomo, R. G., Gialluca, G., Fanò, G., & Saggini, R. (2011). Acute and cumulative effects of focused high-frequency vibrations on the endocrine system and muscle strength. European Journal of Applied Physiology, 111, 897–904. Kofotolis, N., Vrabas, I. S., Vamvakoudis, E., Papanikolaou, A., & Mandroukas, K. (2005). Proprioceptive neuromuscular facilitation training induced alterations in muscle fibre type and cross sectional area. British Journal of Sports Medicine, 39, e11. Krol, P., Piecha, M., Slomka, K., & Sobota, G. (2010). The effect of whole-body vibration frequency and amplitude on the myoelectric activity of vastus medialis and vastus lateralis. Journal of Sports Science and Medicine, 10, 169–174. Kyröläinen, H., Pullinen, T., Candau, R., Avela, J., Huttunen, P., & Komi, P. V. (2000). Effects of marathon running on running economy and kinematics. European Journal of Applied Physiology, 82, 297–304. Luo, J., McNamara, B., & Moran, K. (2005). The use of vibration training to enhance muscle strength and power. Sports Medicine, 35, 23–41. Maikala, R. V., & Bhambhani, Y. N. (2008). Cardiovascular responses in healthy young women during exposure to wholebody vibration. International Journal of Industrial Ergonomics, 38, 775–782. Martínez-Pardo, E., Romero-Arenas, S., & Alcaraz, P. E. (2013). Effects of different amplitudes (high vs. low) of whole-body vibration training in active adults. The Journal of Strength and Conditioning Research, 27, 1798–1806. Meardon, S. A., Hamill, J., & Derrick, T. R. (2011). Running injury and stride time variability over a prolonged run. Gait and Posture, 33, 36–40. Miller, W. C., Wallace, J. P., & Eggert, K. E. (1993). Predicting max HR and the HR-&OV0312;2 relationship for exercise prescription in obesity. Medicine and Science in Sports and Exercise, 25, 1077–1081. Munn, J., Sullivan, S. J., & Schneiders, A. G. (2010). Evidence of sensorimotor deficits in functional ankle instability: A systematic review with meta-analysis. Journal of Science and Medicine in Sport, 13, 2–12. Naito, E., Kinomura, S., Geyer, S., Kawashima, R., Roland, P. E., & Zilles, K. (2000). Fast reaction to different sensory modalities activates common fields in the motor areas, but the anterior cingulate cortex is involved in the speed of reaction. Journal of Neurophysiology, 83, 1701–1709. Nardello, F., Ardigò, L. P., & Minetti, A. E. (2011). Measured and predicted mechanical internal work in human locomotion. Human Movement Science, 30, 90–104. Padulo, J., Annino, G., DʼOttavio, S., Vernillo, G., Smith, L., Migliaccio, G. M., & Tihanyi J. (2013). Footstep analysis at different slopes and speeds in Elite Racewalking. The Journal of Strength and Conditioning Research, 27, 125–129. Padulo, J., Annino, G., Migliaccio, G. M., DʼOttavio, S., & Tihanyi, J. (2012). Kinematics of running at different slopes and speeds. The Journal of Strength and Conditioning Research, 26, 1331–1339. Padulo, J., Annino, G., Smith, L., Migliaccio, G. M., Camino, R., Tihanyi, J., & D’Ottavio S. (2012). Uphill running at ISOefficiency speed. International Journal of Sports Medicine, 33, 819–823.
Downloaded by [USC University of Southern California] at 09:05 13 March 2015
1126
J. Padulo et al.
Padulo, J., Degortes, N., Migliaccio, G. M., Attene, G., Smith, L., Salernitano, G., … D’Ottavio S. (2013). Footstep Manipulation during Uphill Running. International Journal of Sports Medicine, 34, 244–247. Padulo, J., Di Giminiani, R., Ibba, G., Zarrouk, N., Moalla, W., Attene, G., … Chamari, K. (2014). The acute effect of whole body vibration on repeated shuttle-running in young soccer players. International Journal of Sports Medicine, 35, 49–54. Padulo, J., Powell, D., Milia, R., & Ardigò, L. P. (2013). A paradigm of uphill running. Plos One, 8, e69006. Pel, J. J., Bagheri, J., van Dam, L. M., van den Berg-Emons, H. J., Horemans, H. L., Stam, H. J., … van der Steen, J. (2009). Platform accelerations of three different whole-body vibration devices and the transmission of vertical vibrations to the lower limbs. Medical Engineering and Physics, 31, 937–944. Riley, P. O., Dicharry, J., Franz, J., Croce, U. D., Wilder, R. P., & Kerrigan, D. C. (2008). A kinematics and kinetic comparison of overground and treadmill running. Medicine and Science in Sports and Exercise, 40, 1093–1100. Rittweger, J. (2010). Vibration as an exercise modality: How it may work, and what its potential might be. European Journal of Applied Physiology, 108, 877–904. Rittweger, J., Ehrig, J., Just, K., Mutschelknauss, M., Kirsch, K. A., & Felsenberg, D. (2002). Oxygen uptake in whole-body vibration exercise: Influence of vibration frequency, amplitude, and external load. International Journal of Sports Medicine, 23, 428–432. Rittweger, R., Beller, B., & Felsenberg, F. (2000). Acute physiological effects of exhaustive whole-body vibration exercise in man. Clinical Physiology, 20, 134–142. Ritzmann, R., Gollhofer, A., & Kramer, A. (2013). The influence of vibration type, frequency, body position and additional load
on the neuromuscular activity during whole body vibration. European Journal of Applied Physiology, 113, 1–11. Roll, J. P., Martin, B., Gauthier, G. M., & Mussa, I. F. (1980). Effects of whole-body vibration on spinal reflexes in man. Aviation, Space, and Environmental Medicine, 51, 1227–1233. Romaiguere, P., Vedel, J. P., Azulay, J. P., & Pagni, S. (1991). Differential activation of motor units in the wrist extensor muscles during the tonic vibration reflex in man. The Journal of Physiology, 444, 645–667. Sands, W. A., McNeal, J. R., Stone, M. H., Kimmel, W. L. Gregory Haff G., & Jemni M. (2008). The effect of vibration on active and passive range of motion in elite female synchronized swimmers. European Journal of Sport Science, 8, 217–223. Sands, W. A., McNeal, J. R., Stone, M. H., Russell, E. M., & Jemni, M. (2006). Flexibility enhancement with vibration: Acute and long-term. Medicine and Science in Sports and Exercise, 38, 720–725. Sefton, J. M., Hicks-Little, C. A., Hubbard, T. J., Clemens, M. G., Yengo, C. M., Koceja, D. M., … Cordova M.L. (2009). Sensorimotor function as a predictor of chronic ankle instability. Clinical Biomechanics, 24, 451–458. Suhr, F., Brixius, K., de, M. M., Bolck, B., Kleinoder, H., Achtzehn, S., … Mester J. (2007). Effects of short-term vibration and hypoxia during high-intensity cycling exercise on circulating levels of angiogenic regulators in humans. Journal of Applied Physiology, 103, 474–483. Torvinen, S., Sievänen, H., Järvinen, T. A., Pasanen, M., Kontulainen, S., & Kannus, P. (2002). Effect of 4-min vertical whole body vibration on muscle performance and body balance: A randomized cross-over study. International Journal of Sports Medicine, 23, 374–379.
