Effects Of Red Light Therapy In The Development Of Elbow Isokinetic Muscle Strength And Postexercise Recovery

Object: Using LED red light (625nm) to irradiate extensors and flexors of elbow, thisresearch studied whether light treatment with specific parameters can affect isokinetic musclestrength of the elbow muscles, blood indices reflect muscle fatigue and muscle endurance.Method:20college athletes majoring in tennis participated in the study, they receivedeither placebo irradiation (control group) or red light LED irradiation (experimental group),then they received isokinetic muscle strength test for elbow extensors and flexors. Before thelight treatment, finger and venous blood samples were taken to record blood lactateconcentration and the concentration of creatine kinase in peaceful state. After red lighttreatment for10min or placebo treatment, their isokinetic muscle strength of elbow wastested in30s. And then their blood lactate concentration was tested immediately, after3min,and after5min.Result: The peak torque value of elbow extensors（42.1±8.4N-M）and the average peaktorque value(32.8±5.9N-M) in experimental group are significantly smaller than the samevalues in control group（p<0.05）. It is the same in elbow flexors, but the difference is notsignificant (p>0.05). There is no significant difference between fatigue rates of elbowextensors and flexors, but the downward trend is more significant in experimental group. Theconcentration of blood lactate rose after the test in both groups, the immediate and3minblood lactate concentration were3.9±1.0mmol/L and4.0±1.0mmol/L (experimental group);4.7±1.3mmol/L and4.6±0.9mmol/L (control group). The blood lactate concentration ofexperimental group is significantly lower than that of control group (p<0.05). Theconcentration of creatine kinase of control group is significantly lower than that ofexperimental group (352.9±76.0U/L Vs315.9±67.9U/L, p<0.05).Conclusion:1）Red LED light (625nm) treatment can significantly reduce peak torque value andaverage peak torque value of elbow extensors.2）Red LED light (625nm) treatment can not significantly affect the peak torque valueand the average peak torque value of elbow flexors 3）Red LED light (625nm) treatment can not significantly affect fatigue rate of extensorsand flexors of elbow.4） Red LED light (625nm) treatment can significantly reduce the blood lactateconcentration and the concentration of creatine kinase after isokinetic muscle strength test.