The effect of knee flexion angles and ground conditions on the muscle activation of the lower extremity in the squat position.
Dongwook Han, Subin Nam, Jihun Song and 2 others
PMID 29184305WHAT IT FOUND
Squatting deeper on stable ground increased vastus medialis and tibialis anterior muscle activity compared to shallower angles.
Switching to an unstable balance pad did not change muscle activity at any depth.
Key findings
01On stable ground, vastus medialis muscle activation was greater at knee flexion angles of 90° and 100° than at 70°.
02On stable ground, tibialis anterior muscle activation was greater at 100° than at 70°.
03There was no difference in muscle activation for the vastus medialis, biceps femoris, tibialis anterior, or gastrocnemius when comparing stable ground to unstable ground.
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 included only 15 young, healthy female college students, so the results may not apply to older adults, males, or patients with musculoskeletal impairments. The squats were performed as a held, paused posture for 5 seconds rather than dynamic movement, which may not reflect functional squatting. Muscle activation was measured in millivolts (mV) without reporting effect sizes or clinical meaningfulness thresholds.
The easy way to misread this
Do not assume that performing squats on an unstable surface like a balance pad increases lower extremity muscle activation. The study found no difference in muscle activity between stable and unstable ground conditions.