Background
Hamstring injuries represent one of the most prevalent musculoskeletal injuries in athletes, with reinjury rates reaching 30%. Despite extensive research, consensus on optimal rehabilitation protocols remains elusive, with considerable heterogeneity in intervention strategies and return-to-sport frameworks. This necessitates comprehensive synthesis of contemporary evidence to inform clinical practice and identify knowledge gaps.
Objectives
To systematically map rehabilitation protocols for hamstring injury recovery, characterizing intervention components, progression criteria, outcome measures, and synthesizing evidence regarding protocol efficacy and safety across athletic populations.
Study Design & Methods
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, we conducted comprehensive searches in Scopus and PubMed databases from inception to January 2026. Search strategies combined: (1) hamstring-related terms ("hamstring injury" OR "hamstring strain" OR "posterior thigh injury") AND (2) rehabilitation terms ("rehabilitation protocol" OR "exercise therapy" OR "return to sport" OR "eccentric training"). Two independent reviewers screened 847 identified records. Inclusion criteria: randomized controlled trials, comparative studies, cohort studies examining rehabilitation interventions in athletes (aged 14-45 years) with acute or chronic hamstring injuries. Exclusion criteria: studies focusing solely on prevention, surgical interventions without rehabilitation protocols, and non-athletic populations. Data extraction encompassed study characteristics, participant demographics (age, sport type, injury severity), rehabilitation protocol components (exercise modalities, dosage, progression criteria), and outcome measures (muscle strength ratios, functional performance, return-to-sport rates, reinjury rates).
Results
Twenty-seven studies met inclusion criteria, comprising 1,847 athletes across 15 sports with hamstring injuries (Grade I-III). Mean follow-up was 18.4 ± 9.2 months. Six primary intervention categories emerged: eccentric-focused training (44.4%), multicomponent progressive programs (29.6%), proprioceptive and neuromuscular control (14.8%), novel modalities including platelet-rich plasma (7.4%), and accelerated rehabilitation (3.7%). Eccentric training, particularly Nordic hamstring exercises, demonstrated superior hamstring-to-quadriceps strength ratios (mean improvement 22.7%, range 15-34%) and reduced reinjury rates (8.3% versus 18.2%). Multicomponent programs integrating eccentric strengthening, sprint mechanics retraining, and progressive agility yielded faster return-to-sport (6.2 ± 2.1 versus 8.9 ± 3.4 weeks, p=0.003) without compromising safety. Proprioceptive training enhanced balance performance (Y-Balance improvement: 8.9 ± 3.2 cm) and athlete confidence. Critical gaps included inconsistent progression criteria (only 33% utilized objective strength benchmarks), limited biomechanical assessment reporting, and insufficient long-term surveillance beyond 12 months. Protocols incorporating objective strength benchmarks and sprint-specific loading demonstrated the most consistent return-to-sport outcomes.
Conclusions
Eccentric-focused and multicomponent progressive protocols effectively improve strength parameters, functional performance, and return-to-sport outcomes in athletes with hamstring injuries. However, substantial protocol heterogeneity and inconsistent outcome measurement highlight needs for standardized rehabilitation frameworks, validated progression criteria incorporating biomechanical and neuromuscular assessments, and prospective studies examining optimal dosage across injury severities. Future research should prioritize sport-specific pathways, reinjury mechanisms, and consensus return-to-sport guidelines.
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