Assume an "all-fours" position on a mat - with arms outstretched, hands flat on the ground and knees bent to 90-degrees, and spine straight. Place a very light weight (1 pound) in the crease of one knee and hold into position by contracting the hamstring to prevent movement of the weight. Perform flexion (forward) / extension (backward movements) followed by lifting the involved leg sideways (like a male dog at a fire hydrant). Relocate the weight to the opposite leg and repeat. Try 5-10 of each movement.