Effects of trunk anterior tilt and knee joint flexion angle changes on muscle activity in the lower limb muscles.
Hideaki Muraoka, Toshiaki Suzuki
PMID 34177111WHAT IT FOUND
In healthy men, tilting the trunk forward and bending the knees changed which leg muscles worked.
Hamstrings and glutes fired harder as the trunk leaned forward, while the calf muscle worked harder when the knee was straight. This helps therapists choose exercises that target specific muscles.
Key findings
01Tilting the trunk forward increased activity in the hamstrings, especially when the knees were straight.
02Bending the knees increased activity in the quadriceps and calf muscles.
03The vastus lateralis (part of the quad) did not change with trunk tilt, but the rectus femoris did.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTs
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What it does not show
The study only included healthy young men, so results may not apply to women, older adults, or people with pain or disability. Pelvic tilt angle was not measured, so slight differences in pelvic position might have affected muscle activity. Inter-rater reliability was not tested because only one researcher measured the muscle activity. The study measured muscle activity, not strength or functional improvement, so it does not prove these positions make patients stronger.
Declared interests
The authors declared no conflict of interest.
The easy way to misread this
Do not assume these muscle activation patterns apply to patients with pain or disability. The study was done on healthy young men, and pelvic position was not controlled, which can change which muscles work.