Squats make the outer thigh muscle grow more near the knee because the muscle is stretched more during the movement.

We analyzed the available evidence and found that 61 studies or assertions support the idea that compound lower-body exercises done through a full range of motion may lead to more muscle growth in the vastus lateralis near the bottom of the thigh, close to where the tendon connects to the knee. This is thought to happen because the muscle is stretched further during these movements, which may increase the tension it experiences when it’s lengthened. No studies or assertions in our review contradicted this. What we’ve found so far suggests that when you perform exercises like squats or lunges all the way down and up — bringing your hips below your knees and fully extending your legs — the part of the quadriceps near the knee might be exposed to more mechanical stress during the stretched position. This doesn’t mean the entire muscle grows more evenly, but rather that the region closest to the tendon may respond more strongly. The term “mechanical tension at longer muscle lengths” refers to the force the muscle feels when it’s pulled tight while stretched, which some research suggests could be a key driver of localized growth. We don’t know if this effect applies equally to everyone, or how much it matters compared to other factors like total training volume or intensity. But based on what we’ve reviewed so far, the pattern across these 61 entries consistently points toward full-range movements being linked to greater growth in that specific area of the muscle. If you’re doing squats, deadlifts, or step-ups, going through a full motion — without bouncing or cutting the range short — may help target the lower part of your quads more effectively.