Background. The weight-bearing (WB) and effort distributions during the five-repetition sit-to-stand test (5R-STS) were assessed in healthy and hemiparetic subjects and were compared to the distributions obtained for a single STS task (1-STS). Methods. Eighteen hemiparetic subjects and 12 controls were included. The WB distribution and time were computed using the vertical ground reaction forces. The knee muscles' effort distribution was quantified with the electromyographic (EMG) data of the STS transfers expressed relatively to the EMG values of maximal strength assessments. Results. In both groups, the time, WB, and effort distributions did not differ between repetitions of the 5R-STS test. The WB and effort distributions of the first repetition were more asymmetrical than those for the 1-STS for the hemiparetic subjects only. Conclusions. Since no changes were found between repetitions, the 5R-STS test might not be demanding enough. The hemiparetic subjects adopt different WB and effort distribution strategies according to the number of STSs to complete. 1. Introduction Initially introduced as a measure of lower limb strength [1, 2], the five-repetition sit-to-stand (5R-STS) test is also used to assess balance [3], fall risk [4], and the effect of interventions to improve balance, muscle strength, or mobility in various populations [5, 6]. In subjects with chronic stroke, the 5R-STS test has also been used to evaluate functional performance [7]. Following a stroke, STS and stand-to-sit transfers are performed with an asymmetrical weight-bearing (WB) distribution with more weight usually taken by the nonparetic limb [8, 9]. The knee extensor joint moments are also asymmetrical with greater moments produced by the nonparetic side [10]. Interestingly, except for measuring the time to complete the 5R-STS test, no study to date has tested the effect of repeating consecutive STS transfers on WB and on the muscular demand at the knee in healthy and physically impaired participants such as poststroke survivors. This would help to clarify how WB and effort distributions are managed in more demanding situations involving repeated lower limb muscular efforts. The idea being that knowing the number of repetitions to be completed might change the motor strategy in order to consider the additional effort needed to complete the task. The objectives of this study were to (1) assess the association between time to execute the 5R-STS test and WB distribution and the effort distribution at the knees; (2) determine whether time, WB distribution, and effort distribution
References
[1]
M. Csuka and D. J. McCarty, “Simple method for measurement of lower extremity muscle strength,” American Journal of Medicine, vol. 78, no. 1, pp. 77–81, 1985.
[2]
R. W. Bohannon, “Alternatives for measuring knee extension strength of the elderly at home,” Clinical Rehabilitation, vol. 12, no. 5, pp. 434–440, 1998.
[3]
S. L. Whitney, D. M. Wrisley, G. F. Marchetti, M. A. Gee, M. S. Redfern, and J. M. Furman, “Clinical measurement of sit-to-stand performance in people with balance disorders: validity of data for the Five-Times-Sit-to-Stand test,” Physical Therapy, vol. 85, no. 10, pp. 1034–1045, 2005.
[4]
B. Belgen, M. Beninato, P. E. Sullivan, and K. Narielwalla, “The association of balance capacity and falls self-efficacy with history of falling in community-dwelling people with chronic stroke,” Archives of Physical Medicine and Rehabilitation, vol. 87, no. 4, pp. 554–561, 2006.
[5]
J. M. Chandler, P. W. Duncan, G. Kochersberger, and S. A. Studenski, “Is lower extremity strength gain associated with improvement in physical performance and disability in frail, community-dwelling elders?” Archives of Physical Medicine and Rehabilitation, vol. 79, no. 1, pp. 24–30, 1998.
[6]
C. Monger, J. H. Carr, and V. Fowler, “Evaluation of a home-based: exercise and training programme to improve sit-to-stand in patients with chronic stroke,” Clinical Rehabilitation, vol. 16, no. 4, pp. 361–367, 2002.
[7]
A. Weiss, T. Suzuki, J. Bean, and R. A. Fielding, “High intensity strength training improves strength and functional performance after stroke,” American Journal of Physical Medicine and Rehabilitation, vol. 79, no. 4, pp. 369–376, 2000.
[8]
A. Brière, S. Lauziere, D. Gravel, and S. Nadeau, “Perception of weight-bearing distribution during sit-to-stand tasks in hemiparetic and healthy individuals,” Stroke, vol. 41, no. 8, pp. 1704–1708, 2010.
[9]
G. Roy, S. Nadeau, D. Gravel, F. Malouin, B. J. McFadyen, and F. Piotte, “The effect of foot position and chair height on the asymmetry of vertical forces during sit-to-stand and stand-to-sit tasks in individuals with hemiparesis,” Clinical Biomechanics, vol. 21, no. 6, pp. 585–593, 2006.
[10]
G. Roy, S. Nadeau, D. Gravel, F. Piotte, F. Malouin, and B. J. McFadyen, “Side difference in the hip and knee joint moments during sit-to-stand and stand-to-sit tasks in individuals with hemiparesis,” Clinical Biomechanics, vol. 22, no. 7, pp. 795–804, 2007.
[11]
C. Gowland, P. Stratford, M. Ward et al., “Measuring physical impairment and disability with the Chedoke-McMaster stroke assessment,” Stroke, vol. 24, no. 1, pp. 58–63, 1993.
[12]
E. C. Huskisson, “Visual analogue scale,” in Pain Measurements and Assessment, R. Melzack, Ed., pp. 33–37, Raven, New York, NY, USA, 1983.
[13]
A. Thibault, R. Forget, and J. Lambert, “Evaluation of cutaneous and proprioceptive sensation in children: a reliability study,” Developmental Medicine and Child Neurology, vol. 36, no. 9, pp. 796–812, 1994.
[14]
M. F. Levin and C. W. Y. Hui-Chan, “Relief of hemiparetic spasticity by TENS is associated with improvement in reflex and voluntary motor functions,” Electroencephalography and Clinical Neurophysiology, vol. 85, no. 2, pp. 131–142, 1992.
[15]
K. Berg, S. Wood-Dauphinee, and J. I. Williams, “The balance scale: reliability assessment with elderly residents and patients with an acute stroke,” Scandinavian Journal of Rehabilitation Medicine, vol. 27, no. 1, pp. 27–36, 1995.
[16]
N. M. Salbach, N. E. Mayo, J. Higgins, S. Ahmed, L. E. Finch, and C. L. Richards, “Responsiveness and predictability of gait speed and other disability measures in acute stroke,” Archives of Physical Medicine and Rehabilitation, vol. 82, no. 9, pp. 1204–1212, 2001.
[17]
M. F. Folstein, S. E. Folstein, and P. R. McHugh, “‘Mini mental state’. A practical method for grading the cognitive state of patients for the clinician,” Journal of Psychiatric Research, vol. 12, no. 3, pp. 189–198, 1975.
[18]
L. J. Hébert, D. Gravel, and B. Arsenault, “Comparisons of mechanical and electromyographical muscular utilisation ratios,” Scandinavian Journal of Rehabilitation Medicine, vol. 27, no. 2, pp. 83–88, 1995.
[19]
T. Kotake, N. Dohi, T. Kajiwara, N. Sumi, Y. Koyama, and T. Miura, “An analysis of sit-to-stand movements,” Archives of Physical Medicine and Rehabilitation, vol. 74, no. 10, pp. 1095–1099, 1993.
[20]
R. Merletti and H. J. Hermens, “Detection and conditionning of the surface EMG signal,” in Electromyography. Physiology, Engineering, and Noninvasive Applications, R. Merletti and P. Parker, Eds., pp. 107–131, John Wiley & Sons, Hoboken, NJ, USA, 2004.
[21]
P. R. Cavanagh and P. V. Komi, “Electromechanical delay in human skeletal muscle under concentric and eccentric contractions,” European Journal of Applied Physiology and Occupational Physiology, vol. 42, no. 3, pp. 159–163, 1979.
[22]
S. R. Lord, S. M. Murray, K. Chapman, B. Munro, and A. Tiedemann, “Sit-to-stand performance depends on sensation, speed, balance, and psychological status in addition to strength in older people,” Journals of Gerontology A, vol. 57, no. 8, pp. M539–M543, 2002.
[23]
E. K. McCarthy, M. A. Horvat, P. A. Holtsberg, and J. M. Wisenbaker, “Repeated chair stands as a measure of lower limb strength in sexagenarian women,” Journals of Gerontology A, vol. 59, no. 11, pp. 1207–1212, 2004.
[24]
C. G. Canning, L. Ada, and N. O'Dwyer, “Slowness to develop force contributes to weakness after stroke,” Archives of Physical Medicine and Rehabilitation, vol. 80, no. 1, pp. 66–70, 1999.
[25]
J. J. Eng, K. S. Chu, A. S. Dawson, C. M. Kim, and K. E. Hepburn, “Functional walk tests in individuals with stroke: relation to perceived exertion and myocardial exertion,” Stroke, vol. 33, no. 3, pp. 756–761, 2002.
[26]
C. M. Dean, C. L. Richards, and F. Malouin, “Walking speed over 10？metres overestimates locomotor capacity after stroke,” Clinical Rehabilitation, vol. 15, no. 4, pp. 415–421, 2001.
[27]
C. Duclos, S. Nadeau, and J. Lecours, “Lateral trunk displacement and stability during sit-to-stand transfer in relation to foot placement in patients with hemiparesis,” Neurorehabilitation and Neural Repair, vol. 22, no. 6, pp. 715–722, 2008.
