AGG-3031; No. of Pages 6 Archives of Gerontology and Geriatrics xxx (2014) xxx–xxx
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Effect of light and vigorous physical activity on balance and gait of older adults Massimiliano Pau a,*, Bruno Leban a, Giorgia Collu b, Gian Mario Migliaccio b a b
Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Cagliari, Italy CONI Italian National Olympic Committee, Sardinia, Italy
A R T I C L E I N F O
A B S T R A C T
Article history: Received 27 March 2014 Received in revised form 3 July 2014 Accepted 6 July 2014 Available online xxx
This study aims to quantitatively assess the effects of vigorous and light physical activity (VPA, LPA) on static balance, gait and sit-to-stand (STS) tasks in a cohort of healthy older adults. To this end, 34 individuals of age >65 years were divided into two groups (n = 17 each) who underwent 36 sessions (3 12 weeks) of PA characterized by different levels of intensity, assessed through continuous heart rate monitoring during the training session. Their balance and mobility were objectively evaluated on the basis of postural sway and time of STS measurements performed using a force platform. The main spatiotemporal parameters of gait (i.e. speed, stride and gait cycle duration, stance, swing and double support phase duration) were also acquired using a wearable inertial measurement unit. The results show that most gait parameters and STS time signiﬁcantly improve in the VPA group but not in the LPA one. For the latter group a reduction only of swing phase duration was detected. PA also induced a generalized reduction of postural sway in both groups in the case of absence of visual input. These ﬁndings suggest that PA programs characterized by superior levels of intensity might be more suitable in generally improving static and dynamic daily motor tasks, while in terms of static balance acceptable results can be achieved even when only light activity is performed. ß 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Physical activity Gait Balance Postural sway Elderly
1. Introduction Falls represent one of the most critical issues among older adults, as approximately 35–40% of individuals over 65 years of age annually experience such negative events (Lundebjerg et al., 2001; Todd & Skelton, 2004). Although there are a number of different causes that alone or in combination may originate a fall, it is to be observed that gait and balance deﬁcits are included among the most common risk factors (Kannus, Sieva¨ne, Palvanen, Ja¨rvinen, & Parkkari, 2005; Lee & Paffenbarger, 2000). Thus, it clearly appears that the ability to correctly maintain an upright posture (both statically and dynamically) and to have gait patterns minimally impaired even in presence of external disturbances must be the primary goal of any fall prevention program.
* Corresponding author at: Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Piazza d’Armi 09123 Cagliari, Italy. Tel.: +39 070 6753264; fax: +39 070 6755717. E-mail address: [email protected]
This can be achieved through suitable physical activity (PA) programs, such as forms of gait and balance training, resistance/ strength training, Tai-Chi etc., have proven to be effective in reducing the risk of falls and fractures (Gillespie et al., 2012). However, it is noteworthy that there is a lack of standardization in terms of type and intensity of exercises and as regards assessment of outcome measures and related techniques. In particular, while the use of scales or other subjective/non-instrumental evaluations is widespread, fewer data are available from dedicated laboratory equipment able to provide quantitative measures of movement and posture. In recent years, a number of authors have evaluated the effect of PA on balance abilities using force platforms. Such devices provide information on center of pressure (COP) trajectory during static stance in uni- or bipedal stance, thus characterizing individual postural sway, which is the constant slight corrective deviation from the vertical when standing upright (Sheldon, 1963). Using parameters derived from the COP time-series, such as Sway Area (SA) and Path, COP displacements and velocities in anteroposterior (AP) and medio-lateral (ML) directions, a number of studies (ACSM, 2013; Hue, Seynnes, Ledrole, Colson, & Bernard,
http://dx.doi.org/10.1016/j.archger.2014.07.008 0167-4943/ß 2014 Elsevier Ireland Ltd. All rights reserved.
Please cite this article in press as: Pau, M., et al., Effect of light and vigorous physical activity on balance and gait of older adults. Arch. Gerontol. Geriatr. (2014), http://dx.doi.org/10.1016/j.archger.2014.07.008
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2004; Nejc et al., 2012; Newell, Shead, & Sloane, 2012; Perrin, Gauchard, Perrot, & Jeandel, 1999) have detected a beneﬁcial effect of PA (i.e. increase in stability) in the form of postural sway reduction. At the same time, the validity of COP measures as indicators of the risk of future falls has also been recognized (Pajala et al., 2008; Piirtola & Era, 2006). As regards gait patterns, the studies that employed quantitative techniques (such as opto-electronic systems and computerized walkways or treadmills) reported improvements associated with PA mainly in terms of changes in spatiotemporal parameters. In particular, stretching exercises, treadmill, Pilates, strength and balance training have been found effective in increasing step length, gait speed and swing phase duration and in reducing gait cycle duration, stance phase duration and double support time (Cristopoliski, Barela, Leite, Fowler, & Rodacki, 2009; Halvarsson et al., 2013; Newell et al., 2012; Oh-Park, Holtzer, Mahoney, Wang, & Verghese, 2011; Persch, Ugrinowitsch, Pereira, & Rodacki, 2009). Nevertheless, despite such general consensus on the beneﬁt of PA on balance and gait in the elderly, some aspects still remain partly unexplored. For instance, there are no studies that have systematically investigated the effect of different exercise intensities. Such information might be useful when PA protocols have to be designed and prescribed according to individuals’ needs and health status, to foresee their cost/beneﬁts ratio. Therefore, this study aims to verify the effect of two different PA protocols of light and vigorous intensity on static and dynamic postural control (expressed in terms of postural sway measured during static upright posture and time to complete a sit-to-stand task, STS) and gait performances, objectively assessed using a pressure platform and an inertial sensor, in a cohort of 34 healthy older adults who underwent a 12-week PA program. We hypothesized that the different intensity of PA would modulate the beneﬁts derived from exercise in terms of balance and mobility. 2. Methods 2.1. Participants In March 2013, the Sardinian Regional Committee of the Italian National Olympic Committee (CONI) launched the project ‘‘A Chent’Annos in Salude’’ (a typical Sardinian wish, that can be translated as ‘‘May you live to a hundred in good health’’) aimed to quantitatively and objectively assess, from multiple points of view (i.e. physiological, biomechanical and psychological), the effect of PA on older adults. A 90-day call for participation was issued by means of public announcements in a regional newspaper, direct information from family physicians and ﬂyers distributed in pharmacies. Approximately 180 individuals expressed their willingness to participate in the study and they were screened by inclusionexclusion criteria established by the medical staff of the project. In particular, the basic inclusion criteria was age 65 and not to be engaged in regular PA programs, while individuals characterized by the presence of cardiovascular dysfunctions (coronary heart disease, uncontrolled hypertension, severe cardiac arrhythmias, valvular heart disease) osteoarticular pathologies not compatible with physical exercise (severe osteoporosis, acute connective tissue diseases, recent fractures etc.), neurological diseases or outcomes of debilitating neurological disorders (stroke, dementia, neurodegenerative diseases, etc.), presence of neoplasms or disabling outcomes of cancer, moderate to severe anemia (Hb 35) were excluded. After a detailed medical examination and an interview (to establish the motivation level) 34 participants were selected and randomly assigned to either the Vigorous Physical Activity (VPA) or
Light Physical Activity (LPA) group in a 1:1 fashion, using blocked randomization (Schulz & Grimes, 2002). Their main anthropometric features are reported in Table 1. 2.2. Design of the study and PA protocol The study was a 12-week randomized controlled trial that started in April (T0) and ended in July 2013 (T1), structured in three physical training sessions per week (36 sessions in all) of 1-h duration. The participants were instructed not to modify their usual daily activities and dietary habits and not to engage in any supplemental physical routine program for the entire duration of the program. They were also informed that a maximum of three days of absence, even not consecutive, was allowed before excluding them from the study. According to the American College of Sports Medicine (ACSM) guidelines  the training intensity for the VPA group was set to reach a value of the percentage of Heart Rate Reserve (%HRR deﬁned according to Karvonen, Kentala, & Mustal, 1957) in the 60–84% range. To this end, the HR signal was monitored during the activity by means of a Polar1 T31 CodedTM transmitter (Polar, Kempele, Finland) and also remotely transmitted using a Hosand1 Group Telemetry system (Hosand Technologies, Verbania, Italy) to ﬁtness professionals for continuous analysis during the session. The individual HRR for each participant (i.e. the difference between the maximal and the resting state heart rate) was calculated on the basis of the maximal heart rate value (HRmax) derived from the equation proposed by Gellish et al. (2007).
HRmax ¼ 206:9 ð0:67 AgeÞ while the resting state heart rate (HRrest) was established as the mean value of three measurements performed immediately after awakening. The typical training session was articulated as follows: 1. warm-up (approximately 10 min at %HRR up to 60%) included walking, joint movements within the full range of motion, static and dynamic balance drills and stretching exercises; 2. active phase (45 min with %HRR in the range 60–84%). This phase was designed to integrate aerobic and anaerobic exercises, performed also using elevated platforms (steps) and resistance bands, with a gradually increasing level of difﬁculty and intensity. Care was taken to design drills similar to the most common activities of daily life such as ascending and descending stairs, avoiding and overcoming obstacles, reaching and grasping objects, etc.; 3. cool-down (5 min at %HRR