http://informahealthcare.com/idt ISSN 1748-3107 print/ISSN 1748-3115 online Disabil Rehabil Assist Technol, Early Online: 1–4 ! 2015 Informa UK Ltd. DOI: 10.3109/17483107.2015.1027300
RESEARCH PAPER
Role of ankle foot orthoses in functional stability of individuals with stroke Disabil Rehabil Assist Technol Downloaded from informahealthcare.com by Nyu Medical Center on 04/12/15 For personal use only.
N. Rao1 and A. S. Aruin1,2 1
Marianjoy Rehabilitation Hospital, Wheaton, IL, USA and 2Department of Physical Therapy, University of Illinois at Chicago, Chicago, IL, USA
Abstract
Keywords
Purpose: Ankle foot orthoses (AFOs) are frequently prescribed to improve ambulation in individuals with stroke. However, the role of AFOs in balance control is not completely understood. The aim of the study was to evaluate the contribution of the AFOs in functional stability of individuals with stroke. Methods: Twenty three individuals with unilateral hemiparesis due to stroke were assessed using the Functional Reach Test. The subjects performed reaches forward, left and right while standing with or without an AFO. Results: When provided with AFO, individuals with stroke improved the maximal reaching distance in all the directions (p50.05). Conclusions: The study found that individuals with unilateral stroke clearly demonstrated improvements in functional stability when they were provided with AFOs. This outcome could be used in the optimization of balance rehabilitation of individuals with stroke.
Ankle foot orthosis, functional stability, stroke History Received 17 October 2014 Revised 24 December 2014 Accepted 5 March 2015 Published online 31 March 2015
ä Implications for Rehabilitation
Functional stability is impaired in individuals with stroke. Functional Reach Test (FRT) was used to assess the role of ankle foot orthoses (AFOs) in balance control. Individuals with stroke improved their functional stability while they were provided with AFOs. Functional Reach Test could assist clinicians in the evaluation of postural stability associated with the use of AFOs.
Introduction Stroke is the leading cause of serious, long-term disability among adults. Annually, about 16 million first-ever strokes occur in the world, causing a total of 5.7 million deaths [1]. In the United States, approximately 800 000 people sustain a stroke each year, and nearly 400 000 survive with some level of neurological impairment and disability [2]. The estimated annual burden from stroke-related disability in 2007 was $40.9 billion [3]. Humans constantly use upper extremities during performance of activities involving bending or reaching up or to the side (e.g. reaching for a high cabinet or bending over to pick up an object from the floor). Thus, it is reported that community-dwelling adults use arms 8–9 h during a typical day [4]. Performance of activities involving reaching is associated with shifting the center of mass (COM) within the base of support. To maintain functional stability in such a case, the central nervous system (CNS) uses an automatic movement strategy by either realigning the COM within the base of support (BOS) or by using a step strategy
Address for correspondence: Alexander S. Aruin, Ph.D., Department of Physical Therapy (MC 898), University of Illinois at Chicago, 1919 W. Taylor St., Chicago, IL 60612, USA. Tel: +1-312-3550904. Fax: +1-312-9964583. E-mail: [email protected]
to establish a new BOS. If the ability to maintain functional stability is compromised as it is in case of a stroke accident [5], appropriate movement strategy is not executed and the individual may stumble or fall in an attempt to regain balance. Impairments of gait and balance are among major problems for many individuals who have sustained a stroke because their inability to ambulate greatly restricts activities of daily life (ADL) [6]. Ankle-foot orthoses (AFOs) are often used to restore a more normal and safe walking pattern in people with stroke, because AFOs provide lateral stability to the ankle in stance phase, facilitate toe clearance in swing phase and promote heel strike [7,8]. However, the ability to maintain functional stability could also be affected by the use of ankle foot orthoses (AFOs) because by design, AFOs limit the motion of the ankle joint in one or more planes. It was reported in the literature that AFOs that help with the management of various pathological conditions might not be efficient in relation to balance control [9]. For example, it was shown that AFOs impede the performance of clinical tests of balance in healthy individuals [10]. On the other hand, AFO use was associated with improvement of stability seen as the increase in the Berg Balance scores (BBS) of patients using AFO [11,12]. Moreover, it was shown that AFO was associated with decreased body sway while standing with eyes open [13]. Nevertheless, the literature is generally inconclusive about the
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effects of AFOs in functional stability of individuals with stroke. Thus the aim of the study was to evaluate AFO-related changes in the functional stability in individuals with unilateral impairment due to stroke. The investigation of this question is important in physical rehabilitation of individuals with stroke. Specifically, better understanding of the role of AFOs in functional stability can provide information to be incorporated into therapeutic programs designed to improve functional abilities in this population.
Methods
Disabil Rehabil Assist Technol Downloaded from informahealthcare.com by Nyu Medical Center on 04/12/15 For personal use only.
Study participants Twenty three individuals with stroke were recruited from inpatient and outpatient services of Marianjoy Rehabilitation Hospital. The participants were 11 men and 12 women, mean age was 60.90 ± 16.90 years, mean weight was 85.29 ± 19.71 kg and mean height was 173.4 ± 10.52 cm. 12 patients had left hemisphere infarct with right hemiparesis and 11 patients had right hemisphere infarct with left hemiparesis. The time since stroke accident was 7.8 ± 12.7 months. Inclusion criteria were: diagnosis of hemiparesis secondary to cerebrovascular accident with the duration of symptoms less than 10 months, ability to walk for 10 m with or without assistive devices, and ability to follow simple instructions. Exclusion criteria were: stroke with more than one hemisphere involvement, a marked increase in muscle tone (Modified Ashworth Scale score more than 2) and a history of significant orthopedic problems that would interfere with performing the test. All the subjects were users of an AFO: 12 patients utilized rigid plastic AFOs, 7 were the users of semi-rigid plastic AFOs and 4 used flexible plastic AFO. Plastic AFOs were custom modified and fabricated from 3/16’’ polypropylene and included a proximal calf strap and distal ankle wrap around strap. The three types of AFOs are shown in Figure 1. The Institutional Review Board at Marianjoy Rehabilitation Hospital approved the study. Written consent was obtained from each subject prior to participation. Procedure Clinical assessments of balance were performed using the Functional Reach Test [14]. The Functional Reach test measures
Figure 1. Rigid (A), semi-rigid (B) and flexible (C) plastic AFOs used by the individuals with stroke.
Disabil Rehabil Assist Technol, Early Online: 1–4
the maximum distance reached in a forward direction [14] and can identify individuals at higher risk for a fall [15]. It was shown that the Reach test has a high-predictive validity, test–retest reliability and interobserver reliability for younger and older adults [14,16,17]. The test was performed with and without AFOs. A yardstick was affixed to the wall to measure the reach distance. Three experimental conditions were implemented: forward reach, reach to the left and to the right. The subjects were told to lift an outstretched arm to shoulder height, pause for an initial reading, then reach as far forward (FR) as possible without losing balance or taking a step [16]. Specific instructions given to subjects were ‘‘without moving your feet or taking a step, reach as far (direction given) as you can, and try to keep your hand along the yardstick’’ [18]. For the left (LR) or right (RR) reaches, the subject was asked to use the respective arm. The start and end positions of the index finger of the outstretched hand were recorded, and the difference represented the total reach for that direction [16]. In case, the individual cannot outstretch the affected upper extremity, the start and end point of the shoulder were recorded. Feet were maintained flat on the floor; if the feet were moved, the trial was discarded. Three trials were recorded in each condition, and before the recording each subject was given a practice trial. The reach distance was measured in centimeters. Data processing and analysis All the data were subjected to Shapiro–Wilk test for normality. Split-Plot ANOVA was performed with factors AFO (two levels: No AFO, AFO) and direction (reach forward reach, reach to the left and to the right) to analyze the effect of AFOs on reach distance. Pairwise comparisons were used for further analyses of significant effects. For all tests, statistical significance was set at p50.05. Statistical analysis was performed in SPSS 17 for Windows 7 (SPSS Inc., Chicago, IL).
Results The outcome of the Functional Reach Test is shown in Figure 2. The effects of AFO and reaching direction were statistically significant (F1,22 ¼ 46.88, p ¼ 0.0001, F2,22 ¼ 13.28, p ¼ 0.0001, respectively). The mean reach distance in the forward direction without AFOs was 17.99 ± 5.25 cm, and when the subjects were provided with AFOs it increased to 25.77 ± 6.09 cm. This difference was statistically significant (F1,22 ¼ 21.51, p50.0001). Reaching distance in either left or right direction was smaller compared to the forward reach distance. Thus, in the left reach the maximum distance without AFOs was 14.84 ± 6.01 cm, and when the subjects were provided with AFOs, it increased to 20.91 ± 5.70 cm. This difference was statistically significant (F1,22 ¼ 12.35, p ¼ 0.001). When the subjects were reaching to the right, the maximum distance without AFOs was 12.75 ± 5.00 cm, and when the subjects were provided with AFOs it increased to 18.92 ± 6.19 cm. This difference was statistically significant (F1,22 ¼ 13.84, p ¼ 0.0005). Table 1 shows the effect of side of hemiparesis on the reach distance for two subgroups (left hemiparesis, N ¼ 11; right hemiparesis, N ¼ 12). While the AFO use was associated with the increase of the reach distance by all the subjects in all the directions, the location of the AFO affected maximal reach to the left and right differently. Thus, individuals with left hemiparesis reached 20.30 ± 5.43 cm to the right while wearing AFO, whilst individuals with right hemiparesis reached only 17.10 ± 6.48 cm while performing the task in the left direction. The difference between the subgroups was statistically significant (p ¼ 0.01). At the same time, individuals with left hemiparesis wearing AFO
Functional stability of individuals with stroke
DOI: 10.3109/17483107.2015.1027300
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Disabil Rehabil Assist Technol Downloaded from informahealthcare.com by Nyu Medical Center on 04/12/15 For personal use only.
Figure 2. Changes in the reaching distance with no AFO and when AFOs were used. Statistical significance (p50.05) is shown with *. Reaching distance is in cm.
Table 1. Effect of side of hemiparesis on reaching distance. Group
AFO
Forward reach
No AFO AFO
15.04 ± 3.65 25.08 ± 5.65
13.71 ± 4.33 13.18 ± 6.68 20.30 ± 5.43* 17.88 ± 4.63*
Right hemiparesis No AFO AFO
20.16 ± 5.25 25.63 ± 6.53
11.79 ± 5.48 15.89 ± 5.08 17.10 ± 6.48* 23.06 ± 5.45*
Left hemiparesis
Right reach
Left reach
*Statistically significant difference between the subgroups.
were able to reach only 17.88 ± 4.63 cm to the left, while individuals with right hemiparesis reached 23.06 ± 5.45 cm to the left (Table 1). The difference between the subgroups was statistically significant (p ¼ 0.01).
Discussion This study examined the effect of AFOs on functional stability of individuals with stroke measured with the Functional Reach Test. When provided with an AFO, the individuals with unilateral hemiparesis due to stroke improved the maximal reaching distance in all the directions. Reaching forward Reaching test is a valuable tool used clinically to assess functional stability of standing or seated individuals with stroke. Thus, it was reported in the literature that reaching distance of seated individuals with stroke was 31.7 ± 7.8 cm, while reaching distance of age and gender matched healthy subjects was 41.6 ± 7.5 cm [19]. The forward reach distance measured for a group of individuals with acute stroke was 25.6 ± 7.4 cm [20]. The forward reach distance of individuals with stroke participated in the current study and performed the test in standing was 17.99 ± 5.25 cm. The differences in the forward reach distance between the current and former study could be explained by two factors affecting the body stability during the tests. First, the base of support in sitting is much larger than in standing, and second, the vertical position of the center of mass is much higher in standing. Both the factors make the task of reaching in standing more challenging than in sitting. The literature on the effect of AFOs in the outcome of the forward reach in individuals with stroke is limited. Thus, in a study involving two groups of individuals with chronic stroke (experimental group was provided with a dynamic ankle-foot orthosis and control group was wearing tennis shoes), no difference was found between the groups for the forward
Functional Reach test [21]. Moreover, long-term use of AFOs was not beneficial to the study participants who showed similar to the control group reach distances (after three months of wearing AFOs) [21]. In another study investigating the effect of two types of physical therapy intervention (high intensity and low intensity), no between-group difference was found for the Functional Reach test [20]. Using AFOs improved the forward reaching distance as compared to the reaching forward with no AFOs. Thus, the study participants were able to reach 43.2% further provided with AFOs (from 17.99 ± 5.25 to 25.77 ± 6.09 cm). A possible explanation for the increased reach distance when utilizing AFOs could be that AFOs stabilize the ankle joint thus creating a condition allowing a user to learn further. Reaching to the side With no AFOs, the study participants showed smaller reaching distances when reaching to the side as compared to the reaching forward. Thus, they were able to reach 21.2% lesser distance to the left and 41.1% to the right, respectively, as compared to the reaching distance forward in No AFO conditions. Moreover, while in healthy individuals, the reaching distance to the right and left is similar [18], this was not the case in individuals with stroke. Thus, with No AFO, the individuals with stroke demonstrated the reach distance to the right 16.4% smaller than reaching distance to the left side. When AFOs were used, the reach distance increased. Thus, it was increased 40.9% while reaching to the left and 48.4% while reaching to the right. Moreover, the side of hemiparesis affected the ability of the subjects to improve their performance of the test: the reaching distance to the healthy side was larger than to the hemiparetic side (Table 1). Two issues could contribute to such a difference. First, weak muscles on one side of the body prevented the subjects from reaching substantial distances to the hemiparetic side. Second, since upper extremities on the side of hemiparesis were affected in most of the subjects, their inability to reach using the affected upper extremity could possibly contributed to smaller reaching distances to one side. The present study found that individuals with stroke clearly demonstrated improvements in functional stability while they were provided with AFOs. The findings of this study underscore an important role that the Functional Reach Test may play in assessment of balance of individuals with stroke and demonstrate that the test could assist clinicians in the appropriate management of postural instability associated with the use of AFOs. Moreover, the outcome of the current study taken together with the result of the studies on the positive role of an AFO in improvement of ambulation provides a support to the general beneficial role of AFOs to individuals with stroke.
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Declaration of interest
11. Dogan A, Mengulluoglu M, Ozgirgin N. Evaluation of the effect of ankle-foot orthosis use on balance and mobility in hemiparetic stroke patients. Disabil Rehabil 2011;33:1433–9. 12. Wang RY, Yen L, Lee CC, et al. Effects of an ankle-foot orthosis on balance performance in patients with hemiparesis of different durations. Clin Rehabil 2005;19:37–44. 13. Pohl M, Mehrholz J. Immediate effects of an individually designed functional ankle-foot orthosis on stance and gait in hemiparetic patients. Clin Rehabil 2006;20:324–30. 14. Duncan PW, Weiner DK, Chandler J, Studenski S. Functional reach: a new clinical measure of balance. J Gerontol 1990;45:M192–7. 15. Jenkins ME, Johnson AM, Holmes JD, et al. Predictive validity of the UPDRS postural stability score and the Functional Reach Test, when compared with ecologically valid reaching tasks. Parkinsonism Relat Disord 2010;16:409–11. 16. Duncan PW, Studenski S, Chandler J, Prescott B. Functional reach: predictive validity in a sample of elderly male veterans. J Gerontol 1992;47:M93–8. 17. Hageman PA, Leibowitz JM, Blanke D. Age and gender effects on postural control measures. Arch Phys Med Rehabil 1995;76: 961–5. 18. Newton RA. Validity of the multi-directional reach test: a practical measure for limits of stability in older adults. J Gerontol A Biol Sci Med Sci 2001;56:M248–52. 19. Katz-Leurer M, Fisher I, Neeb M, et al. Reliability and validity of the modified functional reach test at the sub-acute stage post-stroke. Disabil Rehabil 2009;31:243–8. 20. Outermans JC, van Peppen RP, Wittink H, et al. Effects of a highintensity task-oriented training on gait performance early after stroke: a pilot study. Clin Rehabil 2010;24:979–87. 21. Erel S, Uygur F, Engin Simsek I, Yakut Y. The effects of dynamic ankle-foot orthoses in chronic stroke patients at threemonth follow-up: a randomized controlled trial. Clin Rehabil 2011;25:515–23.
The authors report no conflict of interest.
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References 1. Strong K, Mathers C, Bonita R. Preventing stroke: saving lives around the world. Lancet Neurol 2007;6:182–7. 2. Kelly-Hayes M, Robertson JT, Broderick JP, et al. The American Heart Association Stroke Outcome Classification. Stroke 1998;29: 1274–80. 3. Roger VL, Go AS, Lloyd-Jones DM, et al. Heart disease and stroke statistics – 2011 update: a report from the American Heart Association. Circulation 2011;123:e18–209. 4. Bailey RR, Lang CE. Upper-limb activity in adults: referent values using accelerometry. J Rehabil Res Dev 2013;50:1213–22. 5. Corriveau H, Hebert R, Raiche M, et al. Evaluation of postural stability in the elderly with stroke. Arch Phys Med Rehabil 2004;85: 1095–101. 6. Geurts AC, de Haart M, van Nes IJ, et al. A review of standing balance recovery from stroke. Gait Posture 2005;22:267–81. 7. Rao N, Chaudhuri G, Hasso D, et al. Gait assessment during the initial fitting of an ankle foot orthosis in individuals with stroke. Disabil Rehabil Assist Technol 2008;3:201–7. 8. Simons CD, van Asseldonk EH, van der Kooij H, et al. Ankle-foot orthoses in stroke: effects on functional balance, weight-bearing asymmetry and the contribution of each lower limb to balance control. Clin Biomech (Bristol, Avon) 2009;24:769–75. 9. Ramstrand N, Ramstrand S. The effect of ankle-foot orthoses on balance – a systematic review. Official Findings of the State-of-theScience Conference. J Prosthet Orthot 2010;10:4–23. 10. Panwalkar N, Aruin AS. Role of ankle foot orthoses in the outcome of clinical tests of balance. Disabil Rehabil Assist Technol 2013;8: 314–20.
RESEARCH PAPER
Role of ankle foot orthoses in functional stability of individuals with stroke Disabil Rehabil Assist Technol Downloaded from informahealthcare.com by Nyu Medical Center on 04/12/15 For personal use only.
N. Rao1 and A. S. Aruin1,2 1
Marianjoy Rehabilitation Hospital, Wheaton, IL, USA and 2Department of Physical Therapy, University of Illinois at Chicago, Chicago, IL, USA
Abstract
Keywords
Purpose: Ankle foot orthoses (AFOs) are frequently prescribed to improve ambulation in individuals with stroke. However, the role of AFOs in balance control is not completely understood. The aim of the study was to evaluate the contribution of the AFOs in functional stability of individuals with stroke. Methods: Twenty three individuals with unilateral hemiparesis due to stroke were assessed using the Functional Reach Test. The subjects performed reaches forward, left and right while standing with or without an AFO. Results: When provided with AFO, individuals with stroke improved the maximal reaching distance in all the directions (p50.05). Conclusions: The study found that individuals with unilateral stroke clearly demonstrated improvements in functional stability when they were provided with AFOs. This outcome could be used in the optimization of balance rehabilitation of individuals with stroke.
Ankle foot orthosis, functional stability, stroke History Received 17 October 2014 Revised 24 December 2014 Accepted 5 March 2015 Published online 31 March 2015
ä Implications for Rehabilitation
Functional stability is impaired in individuals with stroke. Functional Reach Test (FRT) was used to assess the role of ankle foot orthoses (AFOs) in balance control. Individuals with stroke improved their functional stability while they were provided with AFOs. Functional Reach Test could assist clinicians in the evaluation of postural stability associated with the use of AFOs.
Introduction Stroke is the leading cause of serious, long-term disability among adults. Annually, about 16 million first-ever strokes occur in the world, causing a total of 5.7 million deaths [1]. In the United States, approximately 800 000 people sustain a stroke each year, and nearly 400 000 survive with some level of neurological impairment and disability [2]. The estimated annual burden from stroke-related disability in 2007 was $40.9 billion [3]. Humans constantly use upper extremities during performance of activities involving bending or reaching up or to the side (e.g. reaching for a high cabinet or bending over to pick up an object from the floor). Thus, it is reported that community-dwelling adults use arms 8–9 h during a typical day [4]. Performance of activities involving reaching is associated with shifting the center of mass (COM) within the base of support. To maintain functional stability in such a case, the central nervous system (CNS) uses an automatic movement strategy by either realigning the COM within the base of support (BOS) or by using a step strategy
Address for correspondence: Alexander S. Aruin, Ph.D., Department of Physical Therapy (MC 898), University of Illinois at Chicago, 1919 W. Taylor St., Chicago, IL 60612, USA. Tel: +1-312-3550904. Fax: +1-312-9964583. E-mail: [email protected]
to establish a new BOS. If the ability to maintain functional stability is compromised as it is in case of a stroke accident [5], appropriate movement strategy is not executed and the individual may stumble or fall in an attempt to regain balance. Impairments of gait and balance are among major problems for many individuals who have sustained a stroke because their inability to ambulate greatly restricts activities of daily life (ADL) [6]. Ankle-foot orthoses (AFOs) are often used to restore a more normal and safe walking pattern in people with stroke, because AFOs provide lateral stability to the ankle in stance phase, facilitate toe clearance in swing phase and promote heel strike [7,8]. However, the ability to maintain functional stability could also be affected by the use of ankle foot orthoses (AFOs) because by design, AFOs limit the motion of the ankle joint in one or more planes. It was reported in the literature that AFOs that help with the management of various pathological conditions might not be efficient in relation to balance control [9]. For example, it was shown that AFOs impede the performance of clinical tests of balance in healthy individuals [10]. On the other hand, AFO use was associated with improvement of stability seen as the increase in the Berg Balance scores (BBS) of patients using AFO [11,12]. Moreover, it was shown that AFO was associated with decreased body sway while standing with eyes open [13]. Nevertheless, the literature is generally inconclusive about the
2
N. Rao & A. S. Aruin
effects of AFOs in functional stability of individuals with stroke. Thus the aim of the study was to evaluate AFO-related changes in the functional stability in individuals with unilateral impairment due to stroke. The investigation of this question is important in physical rehabilitation of individuals with stroke. Specifically, better understanding of the role of AFOs in functional stability can provide information to be incorporated into therapeutic programs designed to improve functional abilities in this population.
Methods
Disabil Rehabil Assist Technol Downloaded from informahealthcare.com by Nyu Medical Center on 04/12/15 For personal use only.
Study participants Twenty three individuals with stroke were recruited from inpatient and outpatient services of Marianjoy Rehabilitation Hospital. The participants were 11 men and 12 women, mean age was 60.90 ± 16.90 years, mean weight was 85.29 ± 19.71 kg and mean height was 173.4 ± 10.52 cm. 12 patients had left hemisphere infarct with right hemiparesis and 11 patients had right hemisphere infarct with left hemiparesis. The time since stroke accident was 7.8 ± 12.7 months. Inclusion criteria were: diagnosis of hemiparesis secondary to cerebrovascular accident with the duration of symptoms less than 10 months, ability to walk for 10 m with or without assistive devices, and ability to follow simple instructions. Exclusion criteria were: stroke with more than one hemisphere involvement, a marked increase in muscle tone (Modified Ashworth Scale score more than 2) and a history of significant orthopedic problems that would interfere with performing the test. All the subjects were users of an AFO: 12 patients utilized rigid plastic AFOs, 7 were the users of semi-rigid plastic AFOs and 4 used flexible plastic AFO. Plastic AFOs were custom modified and fabricated from 3/16’’ polypropylene and included a proximal calf strap and distal ankle wrap around strap. The three types of AFOs are shown in Figure 1. The Institutional Review Board at Marianjoy Rehabilitation Hospital approved the study. Written consent was obtained from each subject prior to participation. Procedure Clinical assessments of balance were performed using the Functional Reach Test [14]. The Functional Reach test measures
Figure 1. Rigid (A), semi-rigid (B) and flexible (C) plastic AFOs used by the individuals with stroke.
Disabil Rehabil Assist Technol, Early Online: 1–4
the maximum distance reached in a forward direction [14] and can identify individuals at higher risk for a fall [15]. It was shown that the Reach test has a high-predictive validity, test–retest reliability and interobserver reliability for younger and older adults [14,16,17]. The test was performed with and without AFOs. A yardstick was affixed to the wall to measure the reach distance. Three experimental conditions were implemented: forward reach, reach to the left and to the right. The subjects were told to lift an outstretched arm to shoulder height, pause for an initial reading, then reach as far forward (FR) as possible without losing balance or taking a step [16]. Specific instructions given to subjects were ‘‘without moving your feet or taking a step, reach as far (direction given) as you can, and try to keep your hand along the yardstick’’ [18]. For the left (LR) or right (RR) reaches, the subject was asked to use the respective arm. The start and end positions of the index finger of the outstretched hand were recorded, and the difference represented the total reach for that direction [16]. In case, the individual cannot outstretch the affected upper extremity, the start and end point of the shoulder were recorded. Feet were maintained flat on the floor; if the feet were moved, the trial was discarded. Three trials were recorded in each condition, and before the recording each subject was given a practice trial. The reach distance was measured in centimeters. Data processing and analysis All the data were subjected to Shapiro–Wilk test for normality. Split-Plot ANOVA was performed with factors AFO (two levels: No AFO, AFO) and direction (reach forward reach, reach to the left and to the right) to analyze the effect of AFOs on reach distance. Pairwise comparisons were used for further analyses of significant effects. For all tests, statistical significance was set at p50.05. Statistical analysis was performed in SPSS 17 for Windows 7 (SPSS Inc., Chicago, IL).
Results The outcome of the Functional Reach Test is shown in Figure 2. The effects of AFO and reaching direction were statistically significant (F1,22 ¼ 46.88, p ¼ 0.0001, F2,22 ¼ 13.28, p ¼ 0.0001, respectively). The mean reach distance in the forward direction without AFOs was 17.99 ± 5.25 cm, and when the subjects were provided with AFOs it increased to 25.77 ± 6.09 cm. This difference was statistically significant (F1,22 ¼ 21.51, p50.0001). Reaching distance in either left or right direction was smaller compared to the forward reach distance. Thus, in the left reach the maximum distance without AFOs was 14.84 ± 6.01 cm, and when the subjects were provided with AFOs, it increased to 20.91 ± 5.70 cm. This difference was statistically significant (F1,22 ¼ 12.35, p ¼ 0.001). When the subjects were reaching to the right, the maximum distance without AFOs was 12.75 ± 5.00 cm, and when the subjects were provided with AFOs it increased to 18.92 ± 6.19 cm. This difference was statistically significant (F1,22 ¼ 13.84, p ¼ 0.0005). Table 1 shows the effect of side of hemiparesis on the reach distance for two subgroups (left hemiparesis, N ¼ 11; right hemiparesis, N ¼ 12). While the AFO use was associated with the increase of the reach distance by all the subjects in all the directions, the location of the AFO affected maximal reach to the left and right differently. Thus, individuals with left hemiparesis reached 20.30 ± 5.43 cm to the right while wearing AFO, whilst individuals with right hemiparesis reached only 17.10 ± 6.48 cm while performing the task in the left direction. The difference between the subgroups was statistically significant (p ¼ 0.01). At the same time, individuals with left hemiparesis wearing AFO
Functional stability of individuals with stroke
DOI: 10.3109/17483107.2015.1027300
3
Disabil Rehabil Assist Technol Downloaded from informahealthcare.com by Nyu Medical Center on 04/12/15 For personal use only.
Figure 2. Changes in the reaching distance with no AFO and when AFOs were used. Statistical significance (p50.05) is shown with *. Reaching distance is in cm.
Table 1. Effect of side of hemiparesis on reaching distance. Group
AFO
Forward reach
No AFO AFO
15.04 ± 3.65 25.08 ± 5.65
13.71 ± 4.33 13.18 ± 6.68 20.30 ± 5.43* 17.88 ± 4.63*
Right hemiparesis No AFO AFO
20.16 ± 5.25 25.63 ± 6.53
11.79 ± 5.48 15.89 ± 5.08 17.10 ± 6.48* 23.06 ± 5.45*
Left hemiparesis
Right reach
Left reach
*Statistically significant difference between the subgroups.
were able to reach only 17.88 ± 4.63 cm to the left, while individuals with right hemiparesis reached 23.06 ± 5.45 cm to the left (Table 1). The difference between the subgroups was statistically significant (p ¼ 0.01).
Discussion This study examined the effect of AFOs on functional stability of individuals with stroke measured with the Functional Reach Test. When provided with an AFO, the individuals with unilateral hemiparesis due to stroke improved the maximal reaching distance in all the directions. Reaching forward Reaching test is a valuable tool used clinically to assess functional stability of standing or seated individuals with stroke. Thus, it was reported in the literature that reaching distance of seated individuals with stroke was 31.7 ± 7.8 cm, while reaching distance of age and gender matched healthy subjects was 41.6 ± 7.5 cm [19]. The forward reach distance measured for a group of individuals with acute stroke was 25.6 ± 7.4 cm [20]. The forward reach distance of individuals with stroke participated in the current study and performed the test in standing was 17.99 ± 5.25 cm. The differences in the forward reach distance between the current and former study could be explained by two factors affecting the body stability during the tests. First, the base of support in sitting is much larger than in standing, and second, the vertical position of the center of mass is much higher in standing. Both the factors make the task of reaching in standing more challenging than in sitting. The literature on the effect of AFOs in the outcome of the forward reach in individuals with stroke is limited. Thus, in a study involving two groups of individuals with chronic stroke (experimental group was provided with a dynamic ankle-foot orthosis and control group was wearing tennis shoes), no difference was found between the groups for the forward
Functional Reach test [21]. Moreover, long-term use of AFOs was not beneficial to the study participants who showed similar to the control group reach distances (after three months of wearing AFOs) [21]. In another study investigating the effect of two types of physical therapy intervention (high intensity and low intensity), no between-group difference was found for the Functional Reach test [20]. Using AFOs improved the forward reaching distance as compared to the reaching forward with no AFOs. Thus, the study participants were able to reach 43.2% further provided with AFOs (from 17.99 ± 5.25 to 25.77 ± 6.09 cm). A possible explanation for the increased reach distance when utilizing AFOs could be that AFOs stabilize the ankle joint thus creating a condition allowing a user to learn further. Reaching to the side With no AFOs, the study participants showed smaller reaching distances when reaching to the side as compared to the reaching forward. Thus, they were able to reach 21.2% lesser distance to the left and 41.1% to the right, respectively, as compared to the reaching distance forward in No AFO conditions. Moreover, while in healthy individuals, the reaching distance to the right and left is similar [18], this was not the case in individuals with stroke. Thus, with No AFO, the individuals with stroke demonstrated the reach distance to the right 16.4% smaller than reaching distance to the left side. When AFOs were used, the reach distance increased. Thus, it was increased 40.9% while reaching to the left and 48.4% while reaching to the right. Moreover, the side of hemiparesis affected the ability of the subjects to improve their performance of the test: the reaching distance to the healthy side was larger than to the hemiparetic side (Table 1). Two issues could contribute to such a difference. First, weak muscles on one side of the body prevented the subjects from reaching substantial distances to the hemiparetic side. Second, since upper extremities on the side of hemiparesis were affected in most of the subjects, their inability to reach using the affected upper extremity could possibly contributed to smaller reaching distances to one side. The present study found that individuals with stroke clearly demonstrated improvements in functional stability while they were provided with AFOs. The findings of this study underscore an important role that the Functional Reach Test may play in assessment of balance of individuals with stroke and demonstrate that the test could assist clinicians in the appropriate management of postural instability associated with the use of AFOs. Moreover, the outcome of the current study taken together with the result of the studies on the positive role of an AFO in improvement of ambulation provides a support to the general beneficial role of AFOs to individuals with stroke.
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N. Rao & A. S. Aruin
Disabil Rehabil Assist Technol, Early Online: 1–4
Declaration of interest
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The authors report no conflict of interest.
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