Essentially the quads initiate the movement by extending the knees .
从本质上发起的圣城延长膝盖的运动。
To keep things in quads , we 'll be removing edges in pairs .
为了让所有的面保持四方状态,我们需要成对移除边线。
The report explains how to safely reduce the risk of knee injuries by wearing the right shoes , stretching the quads and hamstrings before exercise , and being mindful during exercise .