High specific torque is related to lengthening contraction-induced skeletal muscle injury
- 1 March 2008
- journal article
- Published by American Physiological Society in Journal of Applied Physiology
- Vol. 104 (3), 639-647
- https://doi.org/10.1152/japplphysiol.00322.2007
Abstract
Animal models implicate multiple mechanical factors in the initiation of exercise-induced muscle injury. Muscle injury has been widely studied in humans, but few data exist regarding the underlying cause of muscle injury. This study sought to examine the role of torque per active muscle volume in muscle injury. Eight subjects performed 80 electrically stimulated [via electromyostimulation (EMS)] eccentric contractions of the right and left quadriceps femoris (QF) through an 80° arc at 120°/s. Specific torque was varied by applying 25-Hz EMS to one thigh and 100-Hz EMS to the contralateral thigh. Transverse relaxation time (T2) magnetic resonance images of the QF were collected before and 3 days after the eccentric exercise bouts. Injury was assessed via changes in isometric force and ratings of soreness over the course of 14 days after exercise and by determining changes in T2 and muscle volume 3 days after exercise. The 100-Hz EMS induced greater force loss (P < 0. 05), soreness (P < 0.05), change in muscle volume (P = 0.03), and volume of muscle demonstrating increased T2 (P = 0.005) than the 25-Hz EMS. In addition, injury was found to be similar across the QF in all but the most proximal regions of the QF. Our findings suggest that, in humans, high torque per active volume during lengthening muscle contractions is related to muscle injury.Keywords
This publication has 42 references indexed in Scilit:
- Effects of neuromuscular electrical stimulation parameters on specific tensionEuropean Journal of Applied Physiology, 2006
- Long-term spinal cord injury increases susceptibility to isometric contraction-induced muscle injuryEuropean Journal of Applied Physiology, 2004
- Muscle volume is a major determinant of joint torque in humansActa Physiologica Scandinavica, 2001
- Eccentric contractions require unique activation strategies by the nervous systemJournal of Applied Physiology, 1996
- Injury to Skeletal Muscle Fibers During Contractions: Conditions of Occurrence and PreventionPTJ: Physical Therapy & Rehabilitation Journal, 1993
- Mapping of electrical muscle stimulation using MRIJournal of Applied Physiology, 1993
- Magnetic resonance imaging and electromyography as indexes of muscle functionJournal of Applied Physiology, 1992
- Exercise, Muscle Damage and Fatigue*Sports Medicine, 1992
- Exercise-induced Muscle Damage, Repair, and Adaptation in Old and Young SubjectsJournal of Gerontology, 1988
- Myofibrillar Damage Following Intense Eccentric Exercise in ManInternational Journal of Sports Medicine, 1983