Bilateral deficit in leg flexion and extension and elbow flexion movements

Abstract

Endurance exercises (EE) may be performed unilaterally and bilaterally. The objective was to compare the maximum load (ML) in leg flexion and extension and elbow flexion alone and between the sum of these two results with that developed simultaneously by both legs and arms, respectively. Sixty individuals were submitted to leg flexion and extension/and elbow flexion exercises at 1 RM. The results for left and right leg flexion and extension and left and right elbow flexion at ML were of 31.6 (± 7.9), 32.0 (± 8.0), 20.2 (± 9.2), 20.2 (± 9.8), 29.3 (± 13.9) and 29.8 (± 14.1) kg, respectively and seemed to be similar (p > 0.05) and strongly associated (r = 0.96, 0.96 and 0.98). When the sum of the unilateral values was compared with the bilateral values, the ML presented significant difference for the leg extension movements (p = 0.04) and elbow flexion (p = 0.03). The same behavior was not observed in the leg flexion movement (p = 0.75). This result may be explained due to the lower load increment - two kilos and a half - in this last movement in relation to the previous movements - five kilos. Despite most subjects were right-handed, no unilateral differences were observed in ML, although not all subjects were trained. The sum of the unilateral results was higher in 9.8% and 4.0% for leg extension and elbow flexion movements, respectively, when compared with that previously obtained, showing a probable central limitation on the motor coordination of a complex movement performed at maximal speed and with high load. However, in the leg flexion movement, the sum of the unilateral results was lower that the sum of the bilateral results (-0.6%), indicating a possible learning of the movement and adaptation to training with weights from twelve weeks on.