Interventions for preventing lower limb soft-tissue injuries in runners

Lower limb soft-tissue injuries are common in runners. Most running-related injuries are overuse injuries and the causes of these injuries are often multifactorial. Prevention strategies attempt to target modifiable risk factors. We included 25 trials with 30,252 participants in this review. Only three of the trials recruited runners from the general population, and one recruited soccer referees. Nineteen trials involved service personnel (Army, Marines, Naval personnel etc) undertaking basic training which includes intensive periods of running, along with other activities. Two trials were conducted in prisons.

The included trials tested four categories of interventions: exercises, modification of training schedules, use of orthoses, and footwear and socks.

In the following results, where there is "no evidence" that an intervention worked, the results were compatible with either a reduction or an increase in the number of soft-tissue injuries.

There is no evidence that improving physical attributes by exercises (stretching or conditioning exercises) reduces lower limb soft-tissue injuries.

With regards to the modification of training schedules, there is no evidence that a longer training programme with a gradual increase in the amount of running is more effective than a shorter training programme for preventing injuries in novice runners training for a four-mile recreational run. Having a longer build-up in training intensity may even result in an increase in sore shins in people undergoing military training. There is limited evidence from two poor quality trials conducted in prisons for the effectiveness of decreased frequency or duration of running but these results may not apply to runners in general, or military recruits.

Knee braces may reduce the frequency of anterior knee pain. Custom-made biomechanical insoles may be more effective than no insoles for reducing shin splints (medial tibial stress syndrome) in military recruits. There is no evidence to support the use of shoe insoles for the reduction of other lower limb soft-tissue injuries, whether they are individually prescribed to suit foot shape or off-the-shelf.

There is no evidence that running shoes prescribed to suit individual foot shape are better than standard running shoes for preventing injuries in military recruits.

Overall, the evidence for the effectiveness of interventions to reduce lower-limb pain and injury after intensive running is very weak. More trials, designed, conducted and reported to contemporary standards, would be required to confirm these findings, especially in recreational or competitive runners, rather than military recruits.

Authors' conclusions: 

Overall, the evidence base for the effectiveness of interventions to reduce soft-tissue injury after intensive running is very weak, with few trials at low risk of bias. More well-designed and reported RCTs are needed that test interventions in recreational and competitive runners.

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Background: 

Overuse soft-tissue injuries occur frequently in runners. Stretching exercises, modification of training schedules, and the use of protective devices such as braces and insoles are often advocated for prevention. This is an update of a review first published in 2001.

Objectives: 

To assess the effects of interventions for preventing lower limb soft-tissue running injuries.

Search strategy: 

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (March 2011); The Cochrane Library 2010, Issue 4; MEDLINE (1966 to January 2011); EMBASE (1980 to January 2011); and international trial registries (17 January 2011).

Selection criteria: 

Randomised or quasi-randomised trials evaluating interventions to prevent lower limb soft-tissue running injuries.

Data collection and analysis: 

Two authors independently assessed risk of bias (relating to sequence generation, allocation concealment, blinding, incomplete outcome data) and extracted data. Data were adjusted for clustering if necessary and pooled using the fixed-effect model when appropriate.

Main results: 

We included 25 trials (30,252 participants). Participants were military recruits (19 trials), runners from the general population (three trials), soccer referees (one trial), and prisoners (two trials). The interventions tested in the included trials fell into four main preventive strategies: exercises, modification of training schedules, use of orthoses, and footwear and socks. All 25 included trials were judged as 'unclear' or 'high' risk of bias for at least one of the four domains listed above.

We found no evidence that stretching reduces lower limb soft-tissue injuries (6 trials; 5130 participants; risk ratio [RR] 0.85, 95% confidence interval [95% CI] 0.65 to 1.12). As with all non-significant results, this is compatible with either a reduction or an increase in soft-tissue injuries. We found no evidence to support a training regimen of conditioning exercises to improve strength, flexibility and coordination (one trial; 1020 participants; RR 1.20, 95% CI 0.77 to 1.87).

We found no evidence that a longer, more gradual increase in training reduces injuries in novice runners (one trial; 486 participants; RR 1.02, 95% CI 0.72 to 1.45). There was some evidence from a poor quality trial that additional training resulted in a significant increase in the number of naval recruits with shin splints (one trial; 1670 participants; RR 2.02, 95% CI 1.11 to 3.70). There was limited evidence that injuries were less frequent in prisoners when running duration (one trial; 69 participants; RR 0.41, 95% CI 0.21 to 0.79) or frequency (one trial; 58 participants; RR 0.19, 95% CI 0.06 to 0.66) were reduced.

Patellofemoral braces appear to be effective for preventing anterior knee pain (two trials; 227 participants; RR 0.41, 95% CI 0.24 to 0.67).

Custom-made biomechanical insoles may be more effective than no insoles for reducing shin splints (medial tibial stress syndrome) in military recruits (one trial; 146 participants; RR 0.24, 95% CI 0.08 to 0.69).

We found no evidence in military recruits that wearing running shoes based on foot shape, rather than standard running shoes, significantly reduced rate of running injuries (2 trials; 5795 participants; Rate Ratio 1.03, 95% CI 0.93 to 1.14).