Background : Photobiomodulation (laser/light) therapy has reduced skeletal muscle fatigue and improved performance in previous research. Objective: To determine if the application of a novel blue (450 nm) and red (645 nm) light-emitting diode photobiomodulation therapy patch improves muscle function and decreases perceived exertion after an elbow-flexion fatigue protocol. Participants: Thirty-four strength-trained individuals (male = 32 and female = 2, age = 22.5 [2.7] y). Methods: Participants were randomly assigned to an active or placebo treatment. On visit 1, participants’ 1-repetition maximal biceps curl was determined, and an orientation session of the fatigue task occurred to ensure no learning effects. Fifty percent of the participants’ 1-repetition maximum was used during the fatigue protocol. On visit 2, participants performed biceps curl repetitions at a speed of 25 repetitions per minute until they could not physically move the weight past 90° of elbow flexion or stay with the set pace. After the fatigue protocol, a 30-minute blue/red light (wavelength = 450 and 645 nm, peak irradiance = 9 mW/cm2, duty cycle = pulsed 33%, and fluence = 5.4 J/cm2) or sham treatment was administered based on the randomized group assignment. Immediately following, the participants repeated the fatigue protocol. The number of complete repetitions was counted, and the participants rated their perceived level of exertion on the Borg scale immediately after each fatigue bout. Results: Overall, fatigue occurred between the 2 exercise bouts (pretreatment = 44.1 [12.3] and posttreatment = 37.4 [9.6] repetitions, P = .02). However, less fatigue was noted in the number of participants of the active treatment group than the sham treatment group. During the posttreatment fatigue task, 29.4% of participants in the active treatment group improved compared to 0% in the sham treatment (P = .045). Conclusion: Nearly 30% of participants had an increase benefit during a repeated-bout fatigue task due to the blue/red light-emitting diode photobiomodulation light patch.
Justin H. Rigby and Austin M. Hagan
Justin H. Rigby and Shaylene B. Dye
A variety of cryotherapy systems may be used to cool tissues immediately after an injury. The purpose our study was to examine the effect of a 30-min application of various cryotherapy devices on skin temperatures and compression. A crossover-designed study performed in a university research laboratory was conducted. Each treatment condition was applied to the lateral ankle for 30 min on different days. HyperIce’s colder temperatures over the lateral ankle (p < .0001) would make it the treatment choice for immediate care of ankle lateral ligament injuries, but is limited due its size for larger injuries.
Stephan R. Fisher, Justin H. Rigby, Joni A. Mettler and Kevin W. McCurdy
Clinical Scenario: Cryotherapy is one of the most commonly used modalities for postexercise muscle recovery despite inconsistencies in the literature validating its effectiveness. With the need to find a more effective modality, photobiomodulation therapy (PBMT) has gained popularity because of recent research demonstrating its ability to accelerate the muscle recovery process. Focused Clinical Question: Is PBMT more effective than cryotherapy at reducing recovery time and decreasing delayed onset muscle soreness after strenuous exercise? Summary of Key Findings: Three moderate- to high-quality double-blinded, randomized, placebo-controlled trials and 2 low- to moderate-quality translational studies performed on rats were included in this critically appraised topic. All 5 studies supported the use of PBMT over cryotherapy as a treatment for postexercise muscle recovery following exercise. PBMT was superior in reducing creatine kinase, inflammation markers, and blood lactate compared with cryotherapy, following strenuous/high intensity aerobic or strength muscular exercise. PBMT was also shown to improve postexercise muscle performance and function more than cryotherapy. Clinical Bottom Line: There is moderate evidence to suggest the use of PBMT over cryotherapy postexercise to enhance muscle recovery in trained and untrained athletes. Shorter recovery times and increased muscle performance can be seen 24 to 96 hours following PBMT application. Strength of Recommendation: Based on consistent findings from all 5 studies, there is grade B evidence to support the use of PBMT over cryotherapy for more effective postexercise recovery of skeletal muscle performance.