Squats make the outer thigh muscle grow more near the knee because the muscle is stretched more during the movement.
Scientific Claim
Compound lower-body exercises performed through a full range of motion induce greater hypertrophy in the vastus lateralis near the distal tendon insertion due to increased mechanical tension at longer muscle lengths.
Original Statement
“Much more surprising was that squats resulted in more growth in the quadriceps in the sweep, the vastus lateralis. This same pattern was observed in a previous study on leg presses, and the growth in both studies was somewhat concentrated near the knee, although the finding on that was not particularly strong, statistically speaking. The reason for this is biomechanically less clear that that for the rectus femoris, but it's possible that during squats, because the quads are trained at the longer muscle length, there is more growth in the vasti than the rectus femoris.”
Context Details
Domain
exercise
Population
human
Subject
vastus lateralis muscle
Action
exhibits preferential hypertrophy at
Target
distal insertion during full-range compound movements
Intervention Details
Evidence from Studies
Supporting (2)
Exercise Selection Differentially Influences Lower Body Regional Muscle Development
This study found that exercises like the leg press, which bend your knee all the way down and up, made the big thigh muscle near the knee grow more than exercises that only straighten the knee — which matches the idea that full-range movements stretch the muscle more and help it grow better in that area.
Comparison of Muscle Hypertrophy and Strength Adaptations Induced by Back Squat and Leg Extension Resistance Exercises.
Squats made the lower part of the thigh muscle grow more than leg extensions did, which matches the idea that full-range compound exercises stretch the muscle more and build more muscle near the tendon.