Changes induced by eccentric training on force-velocity relationships of the elbow flexor muscles
The aim of this study was to examine the effects of a short term eccentric training period on force-velocity relationships of the elbow flexor muscles. From a muscle model, the maximal shortening velocity VO(x) and the af parameter which varies according to the curvature of the force-velocity relationship of the muscle were determined. Sixteen volunteer subjects divided into 2 groups participated in this study (Group Eccentric GE, n=8 . Group Control GC, n=8). The subjects performed, on an isokinetic ergometer, 2 maximal concentric elbow flexions at different angular velocities (60, 120, 180; 240, 300, 360 °s−1) and held maximal and submaximal isometric actions at an elbow flexion angle of 90°. Under isometric conditions, myoelectrical activity (EMG) of the biceps was recorded and quantified as a RMS value. All tests were performed before and after training sessions. Training was conducted 3 times a week for 4 weeks by the GE, and included 6×5 eccentric actions with a load of 100% of 1 RM. After training and for the GE, the af parameter and Vo(x) increased significantly (p<0.05). These changes were accompanied by a significant increase (p<0.05) of the RMS value of the maximal isometric action. This evolution towards faster characteristics for the elbow flexor muscles after training could be partly due to nervous adaptation.
Key wordsMuscle model Eccentric training Surface electromyography.
Unable to display preview. Download preview PDF.
- Friden J, Seger J, Sjöström M, Ekblom B (1983). Adaptative response in human skeletal muscle subjected to prolonged eccentric training. Int J Sports Med 4:177–183Google Scholar
- Hakkinen K, Komi PV (1983) Electromyographic changes during strength training and detraining. Med Sci Sports Exerc 15:455–460.Google Scholar
- Hill AV (1938). The heat of the shortening and the dynamic constants of muscle. Prod R See B (London) 126:138–195Google Scholar
- Komi PV and Buskirk ER (1972). Effect of eccentric and concentric muscle conditioning on tension and electrical activity of human muscle. Ergonomics 15:417–434Google Scholar
- Martin A, Martin L, Morlon B (1994). Theoretical and experimental behaviour of the muscle viscosity coefficient during maximal concentric actions. Eur J Appl Physiol 69:539–544Google Scholar
- Moritani T, deVries H (1979) Neural factors versus hypertrophy in time course of muscle strength gain. Am J Phys Med 58:115–130Google Scholar
- Moritani T (1993). Neuromuscular adaptations during the acquisition of muscle strength, power and motor tasks. J Biomech 26:95–107Google Scholar
- Nardone A, Romano C, Schieppati M (1989). Selective recruitment of high-threshold human motor units during voluntary isotonic lengthening of active muscles. J Physiol (London) 409:451–471Google Scholar