Effect of Cycling Training with Foot External Rotation on Neuromuscular Function of Vastus Medialis Oblique and Vastus Lateralis

Abstract

Cycling exercise is one of the neuromuscular training for knee joints. Recent study showed that cycling exercise with foot external rotation (ER) could induce more preferential vastus medialis oblique (VMO) activation than neutral position. Besides, it is known that neuromuscular function of the knee could be increased by the continuous training. However, the long-term training effect is still under-investigated. The purpose of this study was to determine the effect of continuous cycling training with foot ER on neuromuscular functions. Thirty male young subjects were randomly divided into neutral, ER 45° and control groups. All subjects trained three times a week for 8 weeks, each session lasted for 20 mins on cycle ergometer. The foot position in the control group was determined by subjects. Electromyography (EMG) onset time and activities of VMO and vastus lateralis (VL) were collected during ascending and descending of a stair-stepping task that was performed before and after the training. During ascending, results showed that ER 45° group had significantly smaller VMO relative VL onset time difference after training. During descending, ER 45° group had significantly smaller VMO relative VL onset time difference than neutral and control groups at post-test. ER 45° group had significantly smaller VMO relative VL onset time difference and VMO onset time. Neutral group had significantly smaller VMO relative VL onset time difference after training during descending. These results suggest that reflex response times of vastus medialis oblique of healthy male subjects could be improved after 8-week cycling training with foot ER, but VMO:VL ratio did not change significantly after training.