Evaluation of exercise-induced muscle damage by surface electromyography

Area of Science:

• Sports Medicine
• Exercise Physiology
• Biomedical Engineering

Background:

• Exercise-induced muscle damage (EIMD) is a common concern for athletes.
• Current assessment methods, like serum creatine kinase (CK), are invasive and delayed.
• There is a need for non-invasive, instant methods to evaluate EIMD.

Purpose of the Study:

• To explore the feasibility of using surface electromyography (sEMG) as a non-invasive, instant method for assessing EIMD.
• To investigate the correlation between sEMG parameters and serum CK levels following different exercise types.

Main Methods:

• Thirteen male college athletes participated in the study.
• Serum CK levels were measured post-eccentric and endurance exercise.
• Surface electromyography (sEMG) was recorded during isokinetic knee movements using a Biodex system.

Main Results:

• Positive correlations were found between serum CK at 24-48h post-eccentric exercise and sEMG AREA before exercise (r=0.69-0.64, P<0.01-0.05).
• Zero crossing rate (ZCR) of sEMG post-exercise negatively correlated with serum CK at 48h (r=-0.63 to -0.59, P<0.05).
• Mean power frequency (MPF) and ZCR of sEMG at 6h post-endurance exercise positively correlated with serum CK at 24h (r=0.73-0.69, P<0.05).

Conclusions:

• Serum CK levels, an indicator of EIMD, are associated with sEMG AREA after eccentric exercise.
• sEMG's ZCR shows promise as a predictor of muscle damage following endurance exercise.