Date of Publication


Degree Type

Honors Thesis


Kinesiology, Sport Studies and Physical Education

First Advisor

Dr. Timothy Henry, Director, Athletic Training Program, Associate Professor, Department of Kinesiology, Sports Studies, and Physical Education


This study was centered on low level laser therapy (LLLT) and its effects on delayed onset muscle soreness (DOMS). DOMS is an inflammatory response in muscle tissue characterized by pain, stiffness, and fatigue in the muscle post-exercise. DOMS results from bouts of eccentric exercise (the lengthening phase of muscle contraction). Symptoms usually reach their peak intensity between 24 and 72 hours post-exercise and subside within 5-7 days. LLLT is a type of therapeutic modality which is used to treat body dysfunctions by introducing light energy into the body. LLLT has been gaining popularity as a new treatment for DOMS, but little research has been done on its actual effectiveness. This study will add to the body of research on LLLT and compare the efficacy of LLLT to a traditional treatment for DOMS, consisting of ice immersion and stretching.

Thirty participants were included in the study; ten in the LLLT treatment group, ten in the ice immersion and stretching group, and ten in a placebo group. DOMS was induced in the bicep muscle of each participant using a standard and accepted protocol and the first treatment immediately followed. Baseline measures of pain and active range of motion were taken and those measures were repeated every 24 hours post-treatment to monitor the development and recess of DOMS over 5 days. Those receiving cold immersion submerged their arm into a cold whirlpool up to the axilla level. The water was between 12.8˚ and 18.3˚C and the treatment lasted twenty minutes. Once they came out they completed 3 x 30 seconds for each of three bicep stretches. LLLT treatment was delivered at different points up the bicep for a duration of twenty seconds at each spot. The placebo group seemed to receive the same treatment as the LLLT group, but no light was actually emitted from the treatment head so there were no therapeutic interventions in the muscle.