The straight leg raise is an important exercise for the quadriceps muscle and is beneficial for recovery after knee surgery and for patients with atrophy of the quadriceps muscle (i.e., the muscle group in front of the thigh) due to lower extremity disease. Straight leg raise exercise diagram: Note: Straighten the thigh and lower leg completely, raise the lower limb until the heel leaves the bed about 25 cm, hold it in this position for 5 seconds, and then slowly lower it, so it is a standard action. Each exercise should be done at least 20-50 such movements, and at least 4 times a day such exercise movements. The total number of exercises per day is not less than 200 movements.