Effect of eccentric exercise and delayed onset muscle soreness on the homologous muscle of the contralateral limb
Poster Presentation XML
1University of Bojnord
2هیات علمی/ دانشگاه بجنورد
Introduction: Eccentric actions induce muscle fiber damage and associated delayed-onset muscle soreness (DOMS) resulting in an impaired ability of the muscle to generate voluntary force. The presence of pain within the damaged muscle can also mediate inhibitory effects on the contralateral motor cortex which are expected to have an effect on the physical capacity of the unaffected homologous muscle in the contralateral limb. This study investigates the extent to which eccentric exercise and DOMS of the injured muscle can affect activation and performance of the non-injured homologous muscle of the contralateral limb.
Methodology: Healthy volunteers performed maximal voluntary contractions of knee extension and sustained isometric knee extension at 50% of maximal force until task failure on both the ipsilateral injured limb and the contralateral limb. Surface electromyography (EMG) was recorded from the ipsilateral and contralateral knee extensor muscles (vastus medialis, rectus femoris, and vastus lateralis).
Results: Maximal isometric knee extension force (13.7% reduction) and time to task failure (38.1% reduction) of the contralateral non-injured leg decreased immediately after eccentric exercise, and persisted 24 h and 48 h after (p<0.05). Moreover, the amplitude of muscle activity recorded from the contralateral knee extensor muscles was significantly lower during the post exercise maximal and submaximal contractions following eccentric exercise of the opposite limb (p<0.05).
Discussion: Unilateral eccentric exercise of the quadriceps can contribute to reduced neuromuscular activity and physical work capacity of the unaffected homologous muscle in the contralateral limb.
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