ANALYSIS OF EXERCISE-INDUCED MUSCLE SORENESS AND ELECTROMYOGRAPHIC CHANGES

  • T. Sato
  • M. Miyazaki
  • K. Seki

Abstract

INTRODUCTION Delayed Onset Muscle Soreness ( DOMS ) is a sensation experienced after unaccustomed exercise. It is usually first felt between 8 and 24 hours after the termination of exercise, peaks in intensity between 24 and 72 hours, and then decreases dramatically. DOMS is particularly prevalent after exercise involving unaccustomed eccentric, lengthening muscle actions and is associated with connective or contractile tissue. And shivering of local muscle groups during the cold conditions affects metabolic response and blood flow. The surface electromyogram ( EMG ) spectrum from eccentric, concentric muscle contractions under control group were studied as a factor of mechanical damage of muscle fibre and functional change of metabolic tissue. The purpose of this study was to investigate the relationship between DOMS and muscle compartment activity. METHODS Five males volunteered for this study. Subjects performed going up and down movements in time to a metronome ( 35 up 1 min ) . The right leg was going up ( concentric ), the left leg was going down (eccentric), during a 150 - 210 min period. Subject wore ankle weights (1 Kg). Subjects were asked to perceive exertion of the lower limb ( Gastrocnemius and Soleus ). The surface EMG was recorded from Gastrocnemius and Soleus, at four local muscle sites, all of eight points on the two legs. The EMG and force recordings were displayed on an oscilloscope. And subjects described scales as the perceived soreness intensity in all of the forty-eight sites on two legs after 0, 2,4,8, 12,24,48,72 hours, respectively. A simple number range was chosen, 0- 10 category - 10 as very very strong. After analog-to-digital conversion on EMGs, a data reduction was applied to mean power frequency and integrated EMG. Differences between the concentric and eccentric muscle contractions were measured with ANOVA for significance. RESULTS In the present study, going up and down exercise have it that Gastrocnemius and Soleus was main load. Recorded EMG was shown to decrease in the high - frequency bands. Then, in perceived category scale, DOMS observed greater after eccentric contraction than after concentric contraction. At 12,24 hours after exercise, eccentric was at the most intensive of DOMS. CONCLUSIONS DOMS should be considered one of the primary symptoms of most neuromuscular disorders. The EMG effects may be attributed to neural mechanisms, motor units synchronization, improved coordination, and muscle activity. REFFERENCES Gunnar A. V. Borg (1982). Psychophysical bases of perceived exertion. Med Sci Sport Exerc 14. 5:377-381 Lucille L. Smith et ,a1 (1993) The effects of static and Ballistic Stretching on Delayed Onset Muscle Soreness.