You can’t brag about your best stretching time, you don’t get to write your stretch PR on the wall, and there is no immediate “Fran”-like gratification that you are really tough. And despite the fact that flexibility is one of the ten CrossFit pillars of complete, well-balanced fitness. Increasing flexibility potential remains the ungreased squeaky wheel of most athletes’ training programming. According to the ten general physical skills list, flexibility is allegedly as important as power or strength. So why don’t we take it more seriously? Because, typically, we simply fail to frame flexibility in terms that are important to us: increasing performance.
Lacking flexibility in crucial areas has a crushing impact on your athletic abilities; to say nothing of the host of pains and problems that inflexibility predisposes you to. If you know you have tight hips, calves, hamstrings, quads, thoracic spine, or shoulders and aren’t actively, aggressively striving to fix them, then you must be afraid of having a bigger squat, faster rowing splits, or a more explosive second pull. If you are tight and a CrossFitter, you are missing a huge opportunity to get better, stronger and faster. There are many areas of restriction in the typical athlete, but it makes sense to begin a discussion about flexibility and performance at perhaps the most commonly neglected and profoundly underaddressed area of the body, the hamstrings.
Before examining a few movements that are greatly affected by short hamstrings, we should touch on a few salient points about anatomy and function. Every athlete should know that the hamstrings are both a hip extensor (they help extend the thigh, or open the hip) and a lower leg flexor (they bend the knee). The important piece of information here is that the hamstrings cross both the knee and the hip. Hamstrings are two-joint muscles. This means that tight hamstrings will affect the knee and also the hip and back. This is important because most of the typical musculoskeletal complaints involving the knee, hip, or back typically have short hamstrings as a confounding variable. That is, explosive hip-based movements will often have consequences at the knee because taking up a lot of slack at one end of the muscle (the hip) will steal length from the other side (the knee). And this is true the other way around as well. In fact, muscles that are too short to stretch to meet the functional demands of a desired movement are said to be passively insufficient.
For example, it is well known that the quadriceps (also a two-joint muscle) help stabilize the pelvis and control the eccentric loading that occurs in the knee in, say, squatting. The quads also play a role in straightening the lower leg, of course, but that task is and should be the chief domain of the hamstrings and glutes through hip extension. Now if an athlete’s hamstrings are too tight or aren’t of sufficient length to allow full extension of the lower leg (knee) when the hip is loaded in a flexed position (i.e., rowing, deadlifting, running), then the quads have to overcome the passive insufficiency of the hamstrings and also bear their load to boot. Not only does this typically predispose the athlete to possible knee pain and future pathology, but it is the equivalent of driving your quadriceps around with a gigantic hamstring brake on.
(CFSD)