THE EFFECT OF FOOT POSITION ON THE PERFORMANCE OF THE SIT-TO-STAND MOVEMENT IN STROKE SUBJECTS

Abstract

INTRODUCTION: Muscular weaknesses contralateral to the injury side are the most common problems of stroke survivors. These individuals have difficulty in performing functional activities, such as the sit-to-stand (STS) movement without assistance. During the period of recovery from a stroke, loading on the affected leg (AL) tends to be spontaneously avoided, leading to difficulties to accomplish the STS movement and, consequently, compromising individual?s independence. Distinct strategies can be used to favor weight loading on the AL during STS movement. For instance, backward positioning of the AL is a strategy commonly employed in clinical practice. However, its effect in improving performance with chronic hemiparetic subjects is still lacking. Therefore, the aim of the present study was to investigate the effect of different positions of lower limbs during the STS movement with chronic stroke subjects, by randomly investigating four strategies: (A) spontaneous; (B) symmetrical; (C) asymmetrical-1-affected foot behind; and (D) asymmetrical-2-non-affected foot behind. METHODS: Twelve chronic hemiparetic subjects participated in this study. Participants were aged between 60 and 80 years, with time since onset of stroke between one and 14 years. For STS movement, the following outcome measures were investigated for the four strategies: differential latency (DIFLAT) and electromyographic (EMG) activity of the tibialis anterior, soleus, quadriceps and hamstring muscles of the AL, as well as movement time (MT) and time of seat-off. Repeated measures ANOVA followed by planned contrasts were employed to investigate the effect of strategies B, C, D in relation to the A strategy. RESULTS AND DISCUSSION: The results indicated that when compared with the A strategy, soleus showed a greater DIFLAT in the D strategy, while the hamstrings had lower EMG in B strategy. The MT was greater in strategies C and D. Time of seat-off did not differ significantly for the investigated strategies. CONCLUSIONS: The D strategy appeared to be less favorable to the accomplishment of STS movement, since it increased movement time. The C strategy did not appear advantageous, whereas the B strategy showed little need of stabilization of the affected knee and MT was similar to A strategy. The spontaneous (A) and the symmetrical (B) strategies appeared to be more favorable in improving the performance of the STS movement with chronic hemiparetic subjects with lower functional impairments.