The hamstring muscles (biceps femoris, semitendinous, semimembranous) are located at the back of the thigh extending from the buttocks to the knee. They are a prime mover in running gait, working extremely hard as they lengthen (eccentric contraction) to slow the leg down at the end of the swing phase. This quick and powerful eccentric contraction is essential to running and running fast, although it can also make the hamstring susceptible to injury.
Athletes who tear or strain a hamstring muscle can easily tell you the day and time it happened along with immediate symptoms of pain, a pop and possibly bruising. This most frequently occurs during intense interval or track workouts. Just as common is the athlete who experiences a more gradual onset of pain without a specific, known cause. In this instance, diagnosis becomes more challenging, and it may be necessary to seek a physical examination to determine if it’s a pelvic stress fracture, sciatica, piriformis syndrome, hamstring tendinosis/tendinitis, sacroiliac joint dysfunction, etc.
You can prevent hamstring injuries by focusing on muscle strengthening, hip stability exercises and balanced lower extremity flexibility, such as in these exercises below.
Romanian deadlift with twist: Keep your back flat and lean forward until you feel a stretch in the hamstrings. Tighten glutes and push hips forward to return to standing. Bend back down at the hips, with a twist to the right and then left. Make it harder: Add weight.
Supine ball hamstring curls: Lie on your back with your ankles on a stability ball. While keeping abdominals tight lift pelvis and roll the ball in. Hold the ball in position for 1–2 seconds and then slowly lower back out to starting position. Make it harder: Do the curl with a single leg.