Abstract
We developed an eccentric contraction induced electrical stimulation (ES) training system. The purpose of this study was to investigate whether the eccentric contraction induced ES enhance the knee extension torque compared with typical ES. Twenty-two young untrained men (age: 23 ± 3 years) in the acute response trial (single training) and seven untrained men in the long period training trial (for 6 weeks) were studied. We measured muscle thickness and knee extension torque evoked by ES with eccentric contraction training system (ES + ECC) or ES alone for the quadriceps muscle of men. The levels of pain and discomfort were evaluated using numeric rating scale (NRS) and heart rate variability. The knee extension torque of ES + ECC was higher than that of ES alone in the acute response trial. There were no significant differences in the levels of pain and discomfort between ES and ES + ECC. Additionally, ES + ECC training for 6 weeks was effective on the quadriceps muscle thickness and knee extension torque. In contrast, the ES alone training failed to increase muscle thickness and knee extension torque. These results suggest that eccentric contraction induced ES would have the potential to become an effective intervention to promote muscle strengthening.
Highlights
Resistance exercise can be effective for muscle strengthening [1]
The electrical stimulation (ES) alone training failed to increase muscle thickness and knee extension torque. These results suggest that eccentric contraction induced ES would have the potential to become an effective intervention to promote muscle strengthening
The intraclass correlation coefficients (ICC) for the test-retest reliability of the muscle thickness measurements were 0.991 for the vastus intermedius; these results indicated a high degree of reproducibility in measuring muscle thickness of these muscles
Summary
Resistance exercise can be effective for muscle strengthening [1]. Exercise involving eccentric contractions has a greater effect for muscle strengthening because the high intensity of muscle loading can be generated eccentric contraction compared to concentric or isometric contractions [3] [4]. The previous studies have suggested that eccentric exercise has advantages compared with concentric training, e.g., increases in peak torque and strength-related performance parameters [5] [6]. Eccentric exercise might have an efficient exercise for muscle strengthening compared to concentric or isometric exercise
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
