Hamstring Contractions During Squats

The squat is a full-body exercise that works the muscles of your legs, hips and core, including the hamstring muscles on the back of your thigh. While squats can help to strengthen your hamstrings, the hamstrings play a relatively small role in the exercise. The prime movers in the squat are the quadriceps muscles on the front of the thigh and the gluteus maximus muscle of the buttocks.

  1. Hamstrings

    • You have three hamstring muscles, all located on the back of your thigh. All three attach to your sitting bone, or ischial tuberosity, on the back of your pelvis. Two of the hamstrings -- the semitendinosus and the semimembranosus -- insert onto your inner shin bone, or tibia. The third hamstring -- the biceps femoris -- inserts onto the fibula, the long, thin bone on your outer shin. When the hamstrings contract, they flex, or bend, your knee and extend, or straighten, your hip.

    Squats

    • To perform a squat, start standing with your feet a little wider than hip-width apart. Hinging at your hips, push your pelvis back to begin the movement. Continue to lower your pelvis toward the floor, bending your hips and knees, until your thighs are parallel to the floor. Keep your spine extended and chest lifted. Track your knees in the direction of your toes, maintaining equal weight between your heels and toes. Stand up, extending your hips and knees, to return to the starting position. Placing a barbell across your upper back or holding dumbbells in your hands will add to the resistance.

    Hamstring Activity

    • While there is some hamstring activity during a squat, the contribution of the hamstrings to the movement is relatively small. A 1999 study in "Medicine and Science in Sports and Exercise" found that squats primarily work the quadriceps and gluteus maximus muscles, with much less activity in the hamstrings. A study from the same year in the "Journal of Strength and Conditioning Research" noted that squats elicit much less hamstring contraction than do some other leg exercises, such as leg curls and stiff-legged deadlifts.

    Program Considerations

    • Before beginning your strength-training workout, warm up thoroughly with light aerobic exercise, incorporating dynamic movements of your hips and legs. To build strength, choose a resistance that allows you to complete two to four sets of eight to 12 repetitions with good form. To build endurance, aim for sets of 15 to 20 repetitions. Rest two to three minutes between sets, and allow at least 48 hours between workouts. To stretch your hamstrings, lie on your back. Extend one leg toward the ceiling, wrapping a towel around your foot. Use the towel to draw your leg toward your chest until you feel a stretch in the back of your thigh. Hold for 10 to 30 seconds, then repeat with the other leg.