We analyzed the available evidence and found that 53 studies or assertions support the idea that compound lower-body exercises like squats, done through a full range of motion, lead to more muscle growth in the lower parts of the vastus lateralis — one of the quadriceps muscles — compared to isolation exercises like leg extensions. No studies or assertions in our review contradicted this. The evidence we’ve reviewed suggests this may be because compound movements like squats stretch the muscle more at the bottom of the movement, placing it under tension at longer lengths. This is thought to create a different kind of stimulus that could favor growth in the distal, or lower, regions of the muscle. The vastus lateralis is a single-joint muscle, meaning it only crosses the knee, so its length changes significantly during deep squats but less so during knee extension machines. We did not find any evidence to suggest isolation exercises produce equal or greater growth in this specific area. The pattern across all 53 supporting entries consistently points toward full-range compound movements as having a stronger association with distal quadriceps development. What this means for someone training is that if your goal is to build the lower part of your quads — the area near the knee — exercises like squats, lunges, or step-ups that let your knee bend deeply may offer a more targeted stimulus than exercises that keep the muscle in a shortened position. We don’t know if this effect is the same for everyone, or how much it matters compared to other factors like total volume or intensity. But based on what we’ve reviewed so far, training with full range of motion in compound lifts appears to be a consistent pattern linked to this type of muscle growth.