My Top Five Concepts for Selecting Lower Extremity Exercises For Cruciate Ligament and Patellofemoral Rehabilitation.
Rafael F Escamilla
PMID 36793575WHAT IT FOUND
Seated knee extensions place higher strain on the ACL than most weight-bearing exercises like squats and lunges.
Technique details matter: keeping knees over toes and using a forward trunk tilt reduces ligament load. Progress from low to high knee angles to control stress on the patellofemoral joint.
Key findings
01Peak ACL strain and tensile loading are greater in non-weight-bearing seated knee extensions than in most weight-bearing exercises like stair climbing and lunges.
02Patellofemoral force and stress increase as knee angle increases, so lower knee angles are preferable when minimizing joint load.
03Squatting with heels off the ground results in over three times the ACL loading compared to squatting with heels on the ground.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTs
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
This is a review of other people's data, not a direct test of clinical outcomes in patients. It focuses on biomechanical loading (strain/force), which does not always correlate directly with pain or healing rates in a clinical setting. The recommendations are based on general population biomechanics and may not apply to every individual patient's specific injury pattern.
The easy way to misread this
Do not assume that avoiding seated knee extensions entirely is necessary for all patients. The review states that while WBE generally produces less ACL strain, the specific technique and load matter. A seated knee extension with no resistance might produce similar strain to a one-leg sit-to-stand, but WBE recruits more stabilizing muscles.