If the stretches experiences any low back discomfort, stop and place a pillow under the hips to reduce the stress on the hips and start again. When contracting the hamstring it might go into spasm because of the new shortened position. To resolve this stretch the hamstring prior to starting. This stretch includes the four major muscle that make up the quadricep, the vastus medialis, lateralis and intermedius and the rectus femoris.
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