Background: Hamstring injuries are a common musculoskeletal disorder, particularly amongst athletes. Many factors have been associated with these injuries, including motor control and strength, soft tissue length and postural alignment. Well-established rehabilitation protocols are commonly used in the treatment of this condition, but their effectiveness remains questionable. This is an update of a Cochrane review first published in 2007.
Objectives: To evaluate the effectiveness of all rehabilitation strategies employed to promote the return to full strength, range of movement and function of those individuals presenting with all forms of hamstring injury, regardless of site, severity, onset or level of chronicity.
Search methods: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (to September 2011), the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2011 Issue 3), MEDLINE (including in-process & other non-indexed citations: 1966 to August 2011), EMBASE (1980 to September 2011), PEDro (2006 to June 2012), CINAHL (1937 to September 2011), AMED (1985 to September 2011), SPORTDiscus (1859 to February 2006), and the World Health Organisation International Clinical Trials Registry platform (April 2012).
Selection criteria: Randomised clinical trials investigating the effect of at least one rehabilitation strategy, in isolation or combination with another, compared with another strategy or control, performed on individuals presenting with hamstring injuries.
Data collection and analysis: Two review authors performed study selection. All review authors performed data extraction and assessed risk of bias. Any disagreement was resolved by discussion.
Main results: Two trials were included in the review, totaling 104 participants. One trial assessed additional (four times a day) versus once daily stretching and the other assessed exercise for movement dysfunction versus stretching and strengthening. The first trial, involving 80 elite athletes, suggested additional stretching could reduce time to return to full activity (mean difference (MD) -1.8 days, 95% confidence interval (CI) -2.1 to -1.5, P < 0.001). The second trial, involving 24 participants from a diverse sporting background, did not find conclusive evidence of a difference (MD -14.5 days, 95% CI -30.64 to 1.64, P = 0.08). It did, however, report reduced re-injury rates using exercise for movement dysfunction of 8% versus 64% (odds ratio (OR) 0.05, 95% CI 0.00 to 0.52, P = 0.01). No other outcomes relevant to this review were reported by either study: most notably pain and participant satisfaction.
Authors' conclusions: Most proposed physiotherapy techniques for rehabilitation of hamstring injuries have not been assessed using randomised trials. Those that have only have single studies with a limited range of participants and outcomes. There is limited evidence to suggest that time to recovery for elite athletes can be reduced with an increased daily frequency of hamstring stretching exercises. There is preliminary evidence from another small study of mixed ability athletes to suggest that exercise to correct movement dysfunction could reduce time to return to full activity and the risk of re-injury. Further studies are required to check these findings. Until further evidence is available, current practice and widely published rehabilitation protocols cannot either be supported or refuted.