The Uptake of Nordic Hamstring Exercise Program for Injury Prevention in Major League Soccer and Its Barriers to Implementation in Practice

Context: It is well demonstrated that Nordic hamstring (NH) program has poor compliance across European soccer clubs, but little is known about its implementation in Major League Soccer (MLS). The authors aimed to investigate MLS hamstring prevention practices and compliance with the NH program and understand the reasons for its inclusion or exclusion. Design: A cross-sectional electronic survey was completed by 24 of the 26 (92%) MLS top-division soccer clubs. Methods: The survey, based on the Reach, Efficacy, Adoption, Implementation, and Maintenance framework, was sent to team medical staff. Medical staff were also asked for opinions on barriers to implementation. Results: Eighteen clubs (75%) reported a formal hamstring injury prevention program, with eccentric exercises (94%; 95% CI [confidence interval], 74%-99%), high-speed running (94%; 95% CI, 74%-99%), and NH exercises (89%; 95% CI, 67%-97%) the most common strategies adopted. Fifteen clubs partially implemented the NH program, but only 5 (21%; 95% CI, 9%-40%) completed the full program and were classed as compliant. A total of 20 respondents reported that player perception and muscle soreness (83%; 95% CI, 64%-93%) were barriers to the implementation of the NH program. On a 5-point Likert scale, respondents "partially agreed" (4.13 [0.80]) that the NH exercise could substantially reduce injuries and would be "effective" at their own club (3.88 [0.61]). Conclusions: The NH exercise was valued, but negative player perception and muscular soreness were identified as barriers to implementing the full program. Manipulation of volume and frequency should inform future "effectiveness" research to prospectively assess such modifications in the context of MLS.