EMG, MUSCLE CONTRACTILE FORCE AND CREATlME KINASE OF EXERCISE INDUCED STIFFENDED MUSCLE IN RABBITS

Abstract

Exercise induced muscle stiffness are often found following heavy exercise. The objective of this study was to examine the changes of EMG, maximal muscle contraction force (MMCF), and creatine kinase (CK) activity in stiff muscle. The model of exerciseinduced muscle stiffness was established by muscle contraction caused by electrical pulse. MMCF and EMG of the gastrocnemius were recorded for 15 sec. by the end and before the beginning of every section of muscle contraction. CK activity in gastocnemius homogenate was analysed. Results showed spontaneous EMG signals at the condition of no electrical stimulation, a decrease of over 60 % of control maximal muscle contraction force (cMMCF), and a loss of CK activity in stiffened muscle. It indicated that exercise-induced muscle stiffness is accompanied by structure injury.