%0 Journal Article
%T Weight-Bearing and Effort Distributions at the Lower Limbs during the Five-Repetition Sit-to-Stand Test in Hemiparetic and Healthy Individuals
%A Anab¨¨le Bri¨¨re
%A Sylvie Nadeau
%A S¨Śl¨Śna Lauzi¨¨re
%A Denis Gravel
%J ISRN Rehabilitation
%D 2012
%R 10.5402/2012/295038
%X 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
%U http://www.hindawi.com/journals/isrn.rehabilitation/2012/295038/