Changes in isometric mid-thigh pull peak force and symmetry across anterior cruciate ligament reconstruction rehabilitation phases.
Johannes P J Stofberg, Kerith Aginsky, Mariaan van Aswegen and 1 others
PMID 39036284WHAT IT FOUND
The isometric mid-thigh pull test failed to reliably distinguish injured from uninjured limbs during ACL reconstruction rehabilitation.
While peak force improved over time, the injured limb was not consistently weaker than the healthy one, limiting the test's usefulness as a standalone clearance criterion.
Key findings
01The IMTP lacked sensitivity to discriminate between injured and uninjured limbs because the injured limb was not necessarily the weaker one.
02There were no statistically significant differences in peak force between the injured and uninjured limbs across rehabilitation phases, despite large effect sizes.
03The uninjured limb showed continued strength improvements in the IMTP but decreased quadriceps torque on the isokinetic dynamometer, indicating the tests measure different things.
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 was underpowered with only 15 participants, leading to high variability and a lack of statistical significance despite large effect sizes. Testing stopped at week 20, but the data suggested recovery to healthy norms would take at least 28 weeks, so the full rehabilitation trajectory was not observed. The IMTP is a compound movement that can allow other muscle groups to compensate for knee extensor weakness, potentially hiding specific deficits. The order of testing between IMTP and isokinetic dynamometry was not randomized.
Declared interests
The authors declare no financial support was received for the research, authorship, or publication.
The easy way to misread this
Do not interpret the lack of significant difference between limbs as evidence that the injured limb has recovered full strength. The study found large effect sizes and significant deficits compared to healthy controls, but the small sample size and high variability meant these differences did not reach statistical significance between limbs.