Among people who regularly train with weights, limiting the knee bend during leg presses to a smaller range produces the same increase in quadriceps muscle thickness as using a full range of motion...

We analyzed the available evidence on whether restricted range of motion leg presses build the same quadriceps muscle as full range of motion leg presses. What we’ve found so far suggests that, among people who regularly train with weights, limiting knee bend during leg presses can lead to similar increases in quadriceps muscle thickness as using a full range of motion over eight weeks [1]. This finding comes from one assertion that directly compared the two approaches, and it showed no difference in muscle growth between the groups. We did not find any studies that contradicted this result. The evidence we’ve reviewed leans toward the idea that you don’t need to fully bend your knees to stimulate comparable quadriceps growth in this exercise, at least over an eight-week period. It’s important to note that this doesn’t mean full range of motion is unnecessary. Muscle growth was measured only in thickness, not strength, function, or joint health. We also don’t know if this holds true beyond eight weeks, or for people who are new to training. The study focused on experienced lifters, so results may differ for beginners. For someone looking to build quadriceps muscle with leg presses, this suggests that adjusting your range of motion — perhaps to reduce knee discomfort or fit your mobility — may not hurt your progress. But if you’re able to move through a full range safely, there’s no clear reason to avoid it based on this evidence alone. We’re still gathering more data on how different ranges affect long-term muscle development and joint adaptation.