The problem with this is that these stretches most effectively target the proximal (Upper) portion of the quad without accounting for the distal or lower portion around the knee which is actually responsible for the pain.
The distal knee fibers are responsible for extending the knee and are most effectively stretched by bending the knee as well as loading in to knee valgus and pronation.
That's right, these movements are not evil but absolutely necessary to fully stretch and then awaken these muscles so they know when to contract and let go. Here are three awesome active stretches I like to do just that: . 1️⃣Single leg heel slides- Notice as I slide forward my knee deliberately drifts toward my big toe and in to valgus. This is not a collapse but a controlled reach until I feel a gentle stretch or my heel leaves the ground. . 2️⃣Lateral heel slides- Same intent as #1, but these exercise places greater focus on finding foot pronation. 3️⃣ Forward knee drives- The classic knee drive, but details are crucial here. As our foot hits the ground and moves toward pronation, we must also anterior tilt the pelvis which I am intentionally doing in this video. . Try any of these drills with traditional quad stretching or as part of your warm up before squatting or lunging.