Effects of a warm-up program on jump-landing pattern and lumbopelvic function in female basketball players with dynamic knee valgus.

Dynamic knee valgus, where the knee collapses inward during landing, is often flagged as a biomechanical risk factor for anterior cruciate ligament injury in female athletes. This trial asked whether swapping a traditional warm-up for a specific injury-prevention warm-up program, called STOP-X, could change landing mechanics and core-hip control in female basketball players who showed this valgus pattern. Thirty players were randomized to eight weeks of either the STOP-X program or their usual warm-up, and researchers measured jump-landing knee angles and a step-down test of lumbopelvic function before and after. Compared with the control group, the STOP-X group showed greater improvements in landing knee flexion, reduced initial and maximum knee valgus angles, and better lumbopelvic control on the step-down test.

Initial flexion angle did not differ between groups. The findings are interesting because they suggest a warm-up modification, rather than a separate training block, might influence movement patterns linked to injury risk, though the small sample size and short follow-up mean these results need replication before broader conclusions can be drawn.

If you're a female basketball player, you may have heard that the way your knee moves inward when you land from a jump, sometimes called dynamic knee valgus, is linked to a higher risk of a serious knee ligament injury. This study looked at whether changing the warm-up routine before practice could improve that landing pattern and the control athletes have through their hips and core. Thirty female basketball players with this knee pattern were split into two groups.

One group did a specific warm-up program called STOP-X for eight weeks, while the other kept doing their normal warm-up. Researchers then measured how the players landed from jumps and how well their hips and trunk controlled a stepping-down movement. The group that did the STOP-X warm-up showed better landing patterns and improved hip and core control compared to the group that kept their usual routine.

One landing measure, how much the knee was already bent at first contact, did not differ between groups. This was a small, short study, so it can't tell us yet whether these movement changes actually lower injury rates over time.

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

This randomized controlled trial compared an eight-week STOP-X warm-up program against a traditional warm-up in 30 female basketball players pre-screened for dynamic knee valgus using a single-leg landing test, allocated 15 per group. Outcomes were jump-landing kinematics (maximum flexion, initial valgus, maximum valgus) and lumbopelvic function via the forward step-down test, analyzed with 2x2 repeated measures ANOVA and Bonferroni post hoc comparisons. Between-group differences favored the experimental group for maximum flexion (F=20.73, P=0.001, effect size=0.42, +4.48%), initial valgus (F=90.12, P=0.001, effect size=0.76, -32.56%), maximum valgus (F=151.6, P=0.001, effect size=0.84, -52.86%), and forward step-down performance (F=22.82, P=0.001, effect size=0.44, -51.45%).

Initial flexion angle showed no statistically significant between-group difference (P=0.49, effect size=0.01). Effect sizes for valgus measures were large, suggesting a meaningful biomechanical shift, though the trial's small sample, single-sport single-sex population, and lack of reported longer-term follow-up or injury incidence data limit generalizability. The design supports a between-group causal interpretation for the significant outcomes, but whether these kinematic changes translate into reduced ACL injury rates remains untested here.