Efficacy of rehabilitation (lengthening) exercises, platelet-rich plasma injections, and other conservative interventions in acute hamstring injuries: an updated systematic review and meta-analysis

Br J Sports Med. 2015 Sep;49(18):1197-205. doi: 10.1136/bjsports-2015-094879. Epub 2015 Jul 21.


Background: Our 2012 review on therapeutic interventions for acute hamstring injuries found a lack of high-quality studies. The publication of new studies warranted an update.

Objectives: To update and reanalyse the efficacy of conservative treatments for hamstring injury.

Data sources: PubMed, EMBASE, Web of Science, Cochrane library, CINAHL and SPORTDiscus were searched till mid-February 2015.

Study eligibility criteria: Randomised controlled trials (RCTs) on the effect of conservative interventions versus a control group or other intervention for hamstring injuries (HI) were included.

Data analysis: The search results were screened independently by two authors. Risk of bias assessment was performed using a modified Downs and Black scale with a maximum score of 28. Meta-analysis was performed, where possible.

Main results: 10 RCTs (526 participants), including 6 new RCTs, were identified. Two RCTs were of good/excellent quality, the rest were fair or poor (median Downs and Black score 16 (IQR 9)). Meta-analysis of two studies on rehabilitation (lengthening) exercises showed a significantly reduced time to return to play (HR 3.22 (95% CI 2.17 to 4.77), p<0.0001) but no difference in risk of re-injury. Meta-analysis of three studies investigating platelet-rich plasma (PRP) showed no effect when compared to control (HR 1.03 (95% CI 0.87 to 1.22), p=0.73). Limited evidence was found that progressive agility and trunk stability training may reduce re-injury rates.

Conclusions: Meta-analysis showed superior efficacy for rehabilitation exercises. PRP injection had no effect on acute hamstring injury. Limited evidence was found that agility and trunk stabilisation may reduce re-injury rates. The limitations identified in the majority of RCTs should improve the design of new hamstring RCTs.

Keywords: Hamstring; Injuries; Physiotherapy; Platelet-Rich Plasma; Review.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Adult
  • Athletic Injuries / rehabilitation*
  • Exercise Therapy / methods*
  • Female
  • Humans
  • Injections, Intramuscular
  • Male
  • Muscle Stretching Exercises / methods
  • Muscle, Skeletal / injuries*
  • Platelet-Rich Plasma*
  • Randomized Controlled Trials as Topic
  • Return to Sport
  • Young Adult