O efeito do posicionamento dos membros inferiores durante o movimento de sentado para de pé em hemiparéticos crônicos

Abstract

Muscular weaknesses contralateral to the injury side are the most common problems of individuals who had suffered a stroke. These individuals have difficulty in performing functional activities, such as sit-to-stand (STS) from a chair without assistance. During the period of recovery from a stroke, the loading on the affected leg (AL) tends to be spontaneously avoided, leading to difficulties to accomplish the STS movement and, consequently, compromising the individuals independence. Distinct strategies can be used to favor the weight loading on the AL during the STS movement. For instance, the 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 the lower limbs during the STS movement with chronic stroke subjects, by investigating four strategies: (A) spontaneous; (B) symmetrical; (C) asymmetrical-1; and (D) asymmetrical-2. Twelve chronic hemiparetic subjects participate, aged between 60 and 80 years and the time since onset of stroke between one and 14 years participated. The sample characteristics included assessment of the ankle range of motion, natural gait speed, muscle tone and bilateral isocinetic performance of flexor/extensors of the hip, knee and ankle. For the STS movement, the following outcome measures were investigated for the four strategies: the differential latency (DIFLAT) and the electromyographic activity (EMG) of the tibialis anterior, soleus, quadriceps and hamstring muscles of the AL, as well as the movement time, the time of seat-off, the symmetry, and the rise index. Repeated measures ANOVA followed by planned contrasts were employed to investigate the effect of the B, C, D strategies in relation to the A strategy. The results indicated that when compared with the A strategy, the soleus showed greater DIFLAT in the D strategy, the hamstrings had lower EMG in B strategy, the TM was greater in C and D strategies and the rise index was lower in the D strategy. Conclusions: The D strategy appeared to be less favorable to the accomplishment of the movement, since it increased the movement time and decreased the rise index. The C strategy appeared not to be advantageous, whereas the B strategy showed little need of stabilization of the affected knee and the movement time was similar to the A. 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.