5 Reasons You Keep Getting Hamstring Strains

March 17, 2019

by Cathe Friedrich

Hamstring strains are painful and inconvenient. But, if you’ve exercised for many years or played sports, you’ve probably had one at some point in your active life. Compared to other muscle groups, hamstring strains are more likely to be recurrent and they can take a significant amount of time to heal. You see repeated hamstring strains in active people at all levels, including professional athletes. Among athletes, football and soccer players are at higher risk, as are sprinters. Even at the professional level, hamstring injuries tend to be common and recurrent injuries and a source of frustration at all levels of physical performance.

Why are hamstring strains so prevalent and why is a strained hamstring more like to keep coming back? Most importantly, can you prevent them?

Hamstring Anatomy

The function of your hamstrings is to extend your legs behind you and to bend your knees. The hamstrings also generate the power you need when you sprint or jump. Collectively, the hamstrings are made up of three muscles: the biceps femoris, the semimembranosus, and the semitendinosus. The biceps femoris is the largest of these muscles and the muscle most likely, of the three, to be injured or strained. Health professionals grade hamstring strains from one to three depending on the severity, with one being the mildest form of injury and three the most serious. If you develop a grade one hamstring strain, the muscle is only overstretched and recovery will likely be relatively rapid. Any tears are at the microscopic level. With grade two, the hamstring muscles are partially torn while a grade three strain involves tearing of the muscle throughout all of its layers.

Why are hamstring strains so common? Some factors that increase the risk of a hamstring strain you have little control over. They tend to occur more frequently with age and are more common if you’ve had a previous hamstring injury or play a sport that places you at high risk. However, you have control over some of the factors that increase the risk of hamstring strains. Let’s focus on some of these.

Strength Imbalances

One factor that predisposes you to hamstring strains is a strength imbalance between the quadriceps, the muscles in the front of the thighs, and the hamstrings in the back. In other words, in people susceptible to hamstring strains, the hamstring muscles are often weaker than the quads. The standard approach to weight training can actually make this strength imbalance worse. That’s because many lower body exercises athletes do, including squats, target the quads more than the hamstrings. So, you may be inadvertently strengthening your quads more than your hammies and creating a strength imbalance. The solution is to shift the balance of your lower body training more heavily toward your hamstrings.

Your Hamstrings Aren’t Flexible Enough

Tight, inflexible hamstrings also increase the odds of developing a hamstring injury. Runners are prone toward hamstring tightness and also frequently develop hamstring strains. One way to ease hamstring tightness is to add lying hamstring stretches to your routine. Certain yoga poses, including downward dog, are also helpful for easing hamstring tightness. In addition, foam rolling can help with inflexible hamstrings. The signals the foam roller sends to your nervous system as the roller applies pressure tells the muscles to relax and lengthen.

Your Glutes Are Too Weak

There’s an epidemic of glute weakness in society due to long periods of sitting. In fact, a sizeable portion of the chair-sitting population has an anterior pelvic tilt due to tight hip flexors and weak glutes. How does that raise the risk of hamstring strains? If your glutes are weak, your hamstrings tighten up to help stabilize your hips. Normally, strong glutes will do the job, but the hamstrings take over when your glutes are weak. Don’t just focus on strengthening and stretching your hamstrings, work on strengthening your glutes too. You can do this by adding more glute-focused exercises like glute bridges and hip thrusts to your routine.

You’re Doing High-Risk Exercises When You Aren’t Conditioned Enough

Certain exercises, like plyometric moves that require jumping and sprinting, are high-risk activities for your hamstrings. Before doing these types of movements, build up a baseline level of fitness, strength, and mobility in your posterior chain. Sprinting is high risk because the hamstrings are eccentrically contracting during the latter part of a leg swing. Decelerating from a run is high risk too as you eccentrically contract your hamstrings as you slow down or stop.

One way to lower your risk before doing these activities is to do eccentric strength training exercises for your hamstrings. Eccentric exercises are where you extend the phase in which the muscles are lengthening against resistance. Exercises you can use to work on eccentric hamstring strength are unilateral deadlifts and “good mornings.” Physical therapists often use Nordic hamstring curls to eccentrically strengthen the hamstrings in clients. Eccentric training is important because it increases the strength of the muscles when they’re lengthened, the time they’re most vulnerable to injury.

You’re Training When Your Muscles Are Cold or Too Fatigued

If you’ll be jumping or sprinting, it’s even MORE important that you do a thorough warm-up. If you launch into a sprint with cold muscles, you’re greatly raising your risk of straining a hamstring muscle. Make sure you’re doing at least a 5-minute dynamic warm-up to raise your body temperature and warm up the muscles you’ll be working. Likewise, don’t overwork your hamstrings to the point of exhaustion and then do a high-risk exercise like sprinting.

The Take-Home Message

Prevention is the best medicine. Balanced training will help you avoid strength imbalances that contribute to injuries of all types. Also, not accumulating excessive fatigue in your hamstrings will help reduce the risk of developing a strain that can take up to a month to heal. If you’ve had hamstring strains or injuries in the past, focus on eccentrically strengthening your hamstrings and building strength in your glutes. Just as importantly, don’t do high-risk exercises, like sprinting, when you haven’t built up a baseline level of fitness. All in good time!

References:

· OrthoInfo.com. “Hamstring Muscle Injuries”

· J Orthop Sports Phys Ther. 1992; 16 (1): 12‐18.

· American J Sports Med, 2015;43(2):377-384.

· J Orthop Sports Phys Ther. 2010 Feb; 40(2): 67–81.