Comparison in Eccentric Exercise-Induced Muscle Damage on Rate of Velocity Development among Four Limb Muscles

Abstract

It has been reported that the magnitude of eccentric exercise-induced muscle damage (EIMD) was greater and recovery of EIMD was slower following eccentric exercise of elbow flexors (EF) than the knee extensors (KE; Saka et al., 2009; Chen et al., 2010). It has recently shown that rate of velocity development (RVD) could be affected following eccentric exercise of the elbow flexors (Nguyen et al., 2009), but this cannot be generalized to the different muscles (e.g. KE) of EIMD on RVD. PURPOSE: This study tested the hypothesis that changes in RVD following eccentric exercise of elbow extensors (EE) and EF would be greater than that of knee flexors (KF) and KE. METHODS: Twenty untrained young men (21 ± 1 yrs) were randomly assigned into EF (n=5) and EE (n=5), and KF (n=5) and KE (n=5) groups, and then performed a bout of 30 maximal eccentric exercises (MAX) of EF, EE, KF and KE for the EF, EE, KF and KE groups, respectively, using their non-dominant arm or leg. Maximal isokinetic concentric strength (60°/s; peak torque, PT), RVD, range of motion (ROM) and circumference (CIR) were measured before to 5 days after MAX for each group. All data were analyzed by a two-way mixed design ANOVA. RESULTS: A significant decreases (p<.05) in PT and ROM, and increases in CIR following MAX for all groups. Changes in PT, ROM and CIR following MAX for the EF and EE groups were significantly greater than (p<.05) that of the KF and KE groups. Decreases in RVD following MAX of the EF (30 ± 14%) and EE (67 ± 14%) groups were significantly greater than that of the KF (29 ± 13%) and KE (12 ± 11%) groups (p<.05). However, there was not a significant difference between KE and KF groups, but EF group was significantly greater than EE group (p<.05). CONCLUSION: These results suggested that RVD loss was greater and the recovery was slower following maximal eccentric exercise of the EE and EF compared to the KE and KF. Thus, the difference responses of RVD to MAX between the arms and legs are possibly associated with the differences in the use of the muscles in daily activities.