Your hamstrings are a group of three muscles that run from behind your knee up to your butt. Back in the day, butchers used to hang their hams for smoking by suspending the pigs from these long, ropey muscles of the posterior thigh—hence the name ham + string. (#Ew.) The hamstrings work opposite your quads to help bend your knee and extend your leg at the hip joint, and are absolutely gosh-darn critical for any sport that involves running.
Consider the following: how many professional athletes have you seen tear a quadriceps muscle? I’m guessing not many. Quad strains and tears can occur when an athlete accelerates, and generally affect the over-40 crowd—in fact, the percentage of pulled quads among football-age players is only 1.6%. In contrast, the hamstrings are injured when an athlete decelerates, and I’d bet my boots you’ve seen at least a few catastrophic hammy injuries during sporting events. Who can forget U.S. Men's National Team striker Jozy Altidore’s heartbreaking grade-two hamstring tear just 23 minutes into the 2014 World Cup? While I can’t say that Altidore’s injury cost the U.S. the World Cup title (the German team must have hamstrings of STEEL), it certainly ended his World Cup hopes for 2014—and could, sadly, affect his future success in the sport. A recent study shows that the recurrence of hamstring injury among soccer athletes is 12% to 63%, which is a staggering figure. So, one may thus conclude, if you tear your hamstring once, the likelihood that you will reinjure the same hamstring is scarily high.
What the heck is going on here? Why are the hamstrings so vulnerable to injury? And what—if anything—can be done to prevent it? First, let's unpack 3 reasons why our hamstrings tend to be more injury-prone than our quads.
1. We Face Forward
You can’t see your hamstrings when you look in the mirror. This may not sound like a legit reason as to why hammies are more frequently injured than quads, but srsly, think about it! Your hamstrings are located on the back of your body, and how often do you look in the mirror backwards? (Er, on second thought, maybe I don’t want to know...)
We are a forward-facing, forward-moving culture. We walk forward, not backward. Our eyes are located in the front of our heads, not the back. There’s a reason why people tend to overdevelop their pecs, biceps, abs, and quads—these are the most visible muscles! Think of the last time you were in a recreational gym or weight room. How many people were doing either dumbbell biceps curls or barbell bench presses? How many were on a mat doing crunches or sit-ups? How many were on the leg extension machine just cranking away on their quads? My guess is A LOT. But how about the people doing rear dumbbell flys, or stability ball hamstring curls? My guess is NOT A LOT.
Since we can’t see our posterior chain (all the muscles on the back of the body), we just don’t think about training it as often. In the biz we call the forward-facing muscles the “beach muscles.” And your hammies just don’t fall into this category. (Although they should. Healthy hamstrings are suuuper sexy.)
2. We Sit
We all know, or should by now, how bad sitting for long periods of time is for your body. Sitting too much shuts off your core muscles, shortens your hip flexors, and certainly doesn’t do much for your shoulder posture. (I hope you just pulled your shoulder blades back and down. I know I did.) But sitting can also wreak some really fascinating havoc on your hamstrings, too.
Think about the position of your hip and knee joints when you sit: both are flexed. Now, since the hamstrings cross both joints, this means both ends of the hamstrings, and both tendon attachments, are affected by the seated posture. But each end is affected differently—the top of the hamstring that crosses the hip becomes STRETCHED, while the bottom of the hamstring that crosses the knee becomes SHORTENED. So when you frequently sit for long periods, the hamstrings become overstretched in one place and short and tight in another. And this imbalance in resting muscle length and suppleness can cause some real damage—especially if your sport or workout involves running.
3. We Are Imbalanced
The body is a beautiful, balanced machine: every muscle group in the body has an equal and opposite counterpart. For every agonist muscle (or primary mover), there is an antagonist muscle (or assisting mover). During a biceps curl, for example, your biceps muscle is the agonist, contracting to produce force, while your triceps muscle is its antagonist, lengthening to allow for the contraction of the biceps.
But what if your biceps muscle was 3 times stronger than your triceps? Your arm strength would become imbalanced—which exponentially increases your risk of injury. The same principle applies to the quads and hamstrings: when your quads are working, your hamstrings are assisting, and vice versa. The problem with the relationship between quads and hammies is that muscle strength in both groups is often very, VERY off-balance.
Many runners have quads that are 30% to 40% STRONGER than their hamstrings. I’m sure you can already see how this can cause some serious problems. In a recent study published in the Journal of Strength and Conditioning Research on the relationship between your quads and hams, researchers discovered that highly-trained runners (this study was specifically performed on female runners) had a hamstrings:quad strength ratio of about 1:1—much higher than that of recreational runners. This study suggests that a balance of strength in the hamstrings and quadriceps is the real differentiating factor between trained and untrained runners, as opposed to absolute strength.
When your quads are stronger than your hamstrings it decreases the hamstrings’ ability to stabilize the knee, leaving you more susceptible to injuries like ACL tears. And because hamstring injury tends to be more frequent in women and girls than in men and boys, this leaves female athletes more susceptible to these catastrophic knee injuries. The reason for this could be related to the wider Q angle in females (see my post on valgus knees for further info), or possibly just a greater overuse of the quad muscles compared to the hamstrings. We all do squats and lunges, but how often do we deadlift? Overtraining the anterior chain or neglecting your posterior chain (or, horror of horrors, both) is a quick way to put yourself at risk for serious, sidelining injury.
Check Out Part 2 for More!
Read Part 2 of this series, which includes: how to train your hamstrings the RIGHT way, how to p/rehab your hamstrings the RIGHT way, and how to NOT tear your hamstrings during athletic competition.
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Learn more about Christye and read her other posts | @CoachChristye