Lack of running-specific strength in the lower limbs is the main reason why most runners get injured. Your hamstrings are no exception. We’ll examine what causes hamstring injuries in runners and the best way to avoid injuring your hamstrings.
In most non-running activities, a muscle is being shortened as it exerts force (e.g. performing a bicep curl). This is called a concentric contraction. However, in running, muscles are frequently being lengthened as they exert force. This action is known as an eccentric (pronounced ee-CEN-tric) contraction. Eccentric contractions are more damaging to muscles than concentric actions.
Your hamstrings undergo an eccentric contraction every time you swing your leg forward (during the swing phase of the gait cycle). They contract and pull back on the leg as it moves forward. Regardless, the leg moves ahead, resulting in eccentric strain on your hamstrings. Imagine your hamstrings being stretched to the max as they try to shorten - approximately 90 times per minutes!
Several European research studies have shown that lack of running specific (eccentric) strength is the most critical indicator of hamstring injury risk. Surprising to some, lack of hamstring flexibility had little effect on predisposition to injury. The same research concluded that improving the eccentric strength reduced the chances of hamstring injury.
The key is to strengthen muscles in a running-specific way. Concentric strength training for hamstrings, such as performing hamstring curls, is of little relevance to running and will not yield your desired result.
Two effective hamstring strengthening exercises for runners are "walking-the-dog lunges" and "bicycle leg swings". Best of all, you can perform them at home. Dr. Owen Anderson describes how to perform these exercises in the June/July 2007 issue of Running Research News:
*Walking-The-Dog Lunges.
Begin this exertion with a standing-tall alignment, with dumbbells held in your hands. Take a big step forward with your left foot, land with your heel first and with your left knee in line vertically with left foot, drop down into a lunge squat, contract your glutes and hamstrings to power back up into an erect body position, and assume a balanced, standing-tall alignment to end this first rep with your left leg. Then, take a big step forward with your right foot, follow the same procedure you used with your left leg, and you will have completed one rep on both your right and left legs. Continue in this manner, alternating legs, until each leg has lunged 10 times.
Avoid letting your torso fall forward (you should maintain a standing-tall alignment at all times). Also avoid an incomplete extension on stand-up (a failure to achieve straight leg and standing-tall alignment). Stay away from lateral movements of your legs during both the lunge and the squat."
Gradually increase to the three sets of 10 reps each.
*Bicycle Leg Swings. Requires resistance band with ankle and door attachments
To do these, stand with your weight fully supported on your left leg (initially, you may place your right hand on a wall or other support to maintain balance). Begin by flexing your right hip and raising your right knee up to waist height (your right thigh should be parallel with the ground); as you do this, your right knee should be flexed to 90 degrees or more.
Once your thigh is parallel to the ground, begin to extend your right knee (swing the lower part of your right leg forward, unflexing the knee) until your knee is nearly fully extended (your leg is nearly straight), with your right thigh still parallel to the ground. As your right knee nears full extension, allow your right thigh to drop downwards and backwards until the entire thigh and leg are extended behind your body (as if you were following through on a running stride). Your right knee should be near full extension (your leg should be basically straight) until it reaches the peak of the backswing.
As your right hip nears full extension (as you approach the end of the backswing), raise your right heel by bending your right knee; your heel should move closely towards your buttocks as you do this. As this happens, move your right knee forward until it returns to the appropriate position in front of your body, with your right thigh parallel to the ground. Repeat this entire sequence of actions in a smooth manner such that the hip and leg move through a continuous arc without stopping or pausing.
Once you are able to coordinate the movement, strive to perform the swings at a cadence of about 12 swings every 10 seconds or so (slightly faster than one swing per second). When you feel comfortable carrying out the basic routine, purchase an intermediate-strength resistance band and complete the exercise while utilizing the stretch cord (resistance band), which should be attached to your "swing" (non-support) ankle at one end and a firm post, table leg, fence, railing, or other structure (at roughly knee height) in front of you. Stand facing the post, table leg, fence, or railing, with enough distance between you and the structure so that the stretch cord significantly accelerates your leg forward during the forward-swing phase of the exercise. This enhanced forward acceleration will put your hamstrings under great eccentric stress – and will ultimately be very strengthening for your hams. Begin with 40 bicycle swings per leg, and gradually work your way up to three sets of 50 swings per leg with the stretch cord."
Performing these exercises twice weekly will not only help you prevent hamstring injury, they will make your hamstrings more resistant to fatigue, thereby improving your racing performance.
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Click on Injury Free Running for Women Over 40 for more essential information on how to prevent injury from ruining your running and racing plans.
© 2016 Savvy Runner Inc.
Bennett Cohen and Gail Gould are the Founders and Presidents of the International Association of Women Runners. For access to resources to help you reach your goals for running and racing, visit www.IAWR-Connect.com..
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