The sartorius muscle is a narrow ribbon of a muscle that winds from your hip, around the inside of your thigh, then connects at the inside of your knee. It is used during every motion of the upper leg and hip. It is especially called upon while lunging forward and driving the knee upward. Stretching the sartorius muscle requires a very specific movement.
Start on the ground supporting yourself on both knees. Your spine should be straight with your head held high.
Raise one leg so you are resting on one knee and one foot. Both knees should be bent at right angles. You will be stretching the sartorius muscle on the leg that is kneeling on the ground.
Lift both hands in the air as high as you can. Lace the fingers of both hands together then turn your hands over. Both palms should be facing the sky. Keep your hands laced together throughout the sartorius muscle stretch.
Tilt your head back and look at your hands. This should force you to lift your shoulders higher. It is important to keep your shoulders high throughout the sartorius muscle stretch.
Slide the foot you have planted on the ground slightly forward. This will open up a wider space between your foot and the knee that is resting on the ground. A few inches should suffice.
Lunge forward toward the foot that just slid forward. This will force the other thigh to extend and stretch the sartorius muscle. You should feel a pulling sensation on the top and inside of your thigh. This is the sartorius muscle extending. Perform this motion slowly. If you make a sudden, jerky motion you could cause injury.
Hold the sartorius muscle stretch for a count of five then slowly return to the starting position. Repeat the sartorius muscle stretch several times then switch legs. To make the stretch more challenging, move your forward foot further out and reach your hands higher into the air.