Hamstring injuries are a common problem for athletes who include sprinting as part of their training program or sport. This type of injury makes it difficult to jump, land, sprint or change directions quickly. And if you pull or tear your hamstring, the recovery time is brutal. It can land you on the bench for weeks.
Before you work to prevent this game-ending injury, first learn how it can happen.
How Hamstring Injuries Occur
Your hamstrings perform several major functions during sprinting. As your foot leaves the ground, the hamstring pulls your foot up toward your hip. As you swing your leg forward, it slows how fast your lower leg moves, which keeps you from hyperextending your knee. The hamstring muscle also helps drive your foot back toward the ground.
Typically, pulls or tears occur when the lower leg is swinging forward and the hamstring is trying to slow it down. The injury is caused by a lack of eccentric strength—i.e., the strength of the muscle while it is lengthening.
Protect yourself and your hamstrings with these two simple tips:

• Avoid Leg Curls. They’re great for making your hamstrings bigger, but Leg Curls also have a tendency to make the  muscle shorter. This is definitely a problem. If you want to avoid pulling your hamstring muscles, Leg Curls should not be in your program.
• Sprint on the balls of your feet. When you sprint heel to toe, you use your hamstrings to “brake” every time your heel hits the ground. This not only places extra strain on the hamstring, it’s bad for speed. To avoid the issue, sprint on the balls of your feet, making a “pawing” motion.

There are several exercises that you should include in your strength and conditioning program to strengthen your hamstrings and protect them from injury:

Romanian Deadlifts
Stand up with the barbell in your hands and take a shoulder-width grip. Place your feet hip-width apart. Stick your chest out and pull your shoulders back. Unlock your knees. From here, keeping your arms straight, push your hips back and slide the bar down your thighs. When it has moved as far down as your flexibility allows with good form, reverse direction to your start position.
Good Mornings
Stand up with the barbell on the back of your shoulders. Place your feet hip-width apart with your knees unlocked. Stick your chest out and pull your shoulders back. From this position, push your hips back and lean forward. Keep moving forward as far as your flexibility allows with good form, then reverse direction to your start position.
Physioball Hip Raises
Lie on your back with your heels on top of a physioball. Roll the ball out until your legs make a 45-degree angle with the ball. Keeping your heels on the ball and your legs straight, lift your hips off the ground. Lower and repeat.
Perform each of the above exercises during your lower-body workouts for three to five sets of eight to 12 repetitions. And for the Romanian Deadlifts and the Good Mornings, make sure you:

• Keep your chest out and shoulders back—this protects your lower back
• Keep your knees soft, but perform the movements from your hips. This focuses the exercises on your glutes and hamstrings
• Keep your weight on your heels. This is important for balance

Photo:  theaustralian.com.au
John M. Cissik is the president of Human Performance Services, LLC, which helps athletics professionals solve their strength and conditioning problems. He has worked with all levels, produced four videos, written 10 books and more than 70 articles on strength and speed training. For more information, follow him on Twitter (@yourhpservices).