Injury Prevention Programmes Fail to Change Most Lower Limb Kinematics and Kinetics in Female Team Field and Court Sports: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.

ACL injury prevention programmes for female field and court sport athletes are widely promoted, partly on the idea that they change how the body moves during landing and cutting, movements linked to ACL injury risk. This systematic review and meta-analysis pooled sixteen randomised controlled trials, comparing these multicomponent programmes (often combining plyometrics, strength, and balance work) against usual training or no training, to see whether they actually altered lower-limb kinematics and kinetics. The pooled result was mostly null: no effect was detected on hip flexion, knee flexion moments, hip and knee adduction, hip internal rotation, ankle dorsiflexion, or ground reaction forces. The one change found was a small increase in knee flexion angle during landing and cutting tasks, but this was based on very low certainty evidence.

This suggests that if these programmes reduce injury risk, the mechanism may not be the biomechanical changes typically measured, or may involve variables not captured in this review.

Many team sport programmes for women include jumping, strength, and balance exercises aimed at protecting the knees, particularly the ACL, a ligament commonly injured during landing and quick direction changes. Researchers wanted to know whether these programmes actually change the way the body moves during those risky moments, since that has been one proposed explanation for why they might help. Pooling data from sixteen randomised trials with almost a thousand female athletes, the review found that these programmes generally did not change most of the movement patterns measured, things like hip and knee rotation, sideways knee movement, or the force of impact when landing.

The one exception was a small increase in how much athletes bent their knees during landing, but the evidence behind even this finding was rated very low certainty. This doesn't mean the programmes don't help prevent injury, since that wasn't what was measured here. It means that if they do help, the reason may not be the specific movement changes scientists have been focusing on and studying most often.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

This review addresses a mechanistic question underlying ACL injury prevention programming: do these programmes work, in part, because they reshape lower-limb kinematics and kinetics during landing and cutting? Clinicians recommending or delivering these programmes often assume that observed movement changes, such as reduced knee valgus or altered ground reaction forces, mediate any protective effect. Across sixteen randomised controlled trials (976 female athletes), pooled analysis found no effect on hip flexion angles and moments, knee flexion moments, hip and knee adduction angles and moments, hip internal rotation, ankle dorsiflexion, or ground reaction forces, comparing intervention programmes against usual training, sham, or no training. The single exception was an increase in knee flexion angle of 3.1 degrees (95% CI 0.8 to 5.5), but this was rated very low certainty evidence, and the remaining null findings were rated very low to low certainty. For clinical reasoning, this means the biomechanical rationale often cited for these programmes is not well supported by the pooled trial evidence, and any injury-risk benefit demonstrated elsewhere may operate through mechanisms, or measures, not captured here.

Interpretation is limited by heterogeneous, multicomponent interventions, meaning individual components cannot be isolated, and by the low certainty ratings throughout.