Post-Trial Feedback Alters Landing Performance in Adolescent Female Athletes Using a Portable Feedback System.
Thomas W Kernozek, Drew Rutherford, Becky Heinert and 6 others
PMID 33604138WHAT IT FOUND
One session of portable feedback cut landing forces by nearly 30% and improved knee alignment in adolescent female athletes.
These changes persisted during a dual-task test, though the study did not track long-term retention or actual injury rates.
Key findings
01Peak vertical ground reaction force decreased significantly from baseline to post-test, with a large effect size.
02Knee-to-ankle separation ratio increased significantly, indicating less knee valgus, with a moderate effect size.
03Improvements in both force and alignment persisted during a dual-task transfer test, though effect sizes were smaller than at post-test.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The study measured changes in biomechanics during a single session, not whether these changes prevent actual ACL injuries or last beyond a few days. The drop landing and dual-task tests may not fully replicate the complex, unpredictable demands of actual sports competition. There was no control group, so it is unclear how much of the improvement was due to the feedback versus simple practice or expectation.
Declared interests
The authors present no conflict of interest.
The easy way to misread this
Do not assume these biomechanical changes will prevent ACL injuries or persist long-term. The study only measured immediate performance during a single session and did not track injury outcomes or retention over time.