The Thigh & Hip
HE HIP IS THE MOST STABLE JOINT in the body. It’s well protected, as it lies deep inside the body, surrounded by muscle on all sides. It holds together very well, and it allows a lot of motion—front to back, side to side, and rotation. The joint is formed by the end of the thighbone, the femur, which inserts into the lower part of the pelvis, that thick ring of bone that anchors all manner of muscles and bones and provides a transition from your body’s torso to your legs. Imagine a butterfly resting flat in a collector’s display box—the pelvis looks something like that. The body of the butterfly corresponds to the lower part of the spinal column, which descends between the two “wings” of the pelvis to taper into the tailbone, or coccyx. Like the butterfly’s wings, the pelvis is wider on top andnarrower toward the bottom. You can feel the top portion of your pelvis—it’s where you hang your skirt orpants—but not the bottom, which is deeply embedded in muscle and flesh. And that’s good. It helps tokeep the hip joint safe from most injuries.
The stability of the hip comes from thedesign of the joint itself. It’s truly a ball and socket,with a deep socket in the pelvis and a lovely, roundball at the end of the femur. In contrast to the kneeand shoulder, other large joints with a wide rangeof motion, the hip doesn’t depend on muscles andligaments to hold it together. It’s designed to holdtogether on its own. There are few substantial liga-ments in the hip, and the muscles that surround itserve to move it rather than keep it from fallingapart. So there are few joint problems in the hip.Injuries tend to show up in the muscles and ten-dons themselves.
The ringlike structure of the pelvis, all thatbone, makes it ideal as a muscle attachment. Ap-propriately enough, the muscles of the spine andabdomen, above, begin at the pelvis, as do the hipmuscles, the hamstrings, and part of the quadri-ceps, below. Except for the gluteal muscles in thebuttocks, which are large and allow you to rotate,extend, and abduct your legs or pull them apart,these muscles in the hip tend to be smaller thanthose in the thigh, shorter and fatter, more suitedfor precision work like rotation and stabilization.But they’re no less important than the bigger muscles. Many problems around the hip arise from these short muscles being forced to do things other thanwhat they’re supposed to be doing.
The thigh is not much more than a big bone surrounded by big muscles. The bone, the femur, is thelargest in the body, and at least half of the thigh, the entire front portion, is dominated by the quadriceps, thebody’s largest muscle. Almost the whole back of the thigh is taken up by the hamstrings, and the upper insideis defined by the groin muscles, or adductors. These big muscles are responsible for big, propulsion-typemovements, like walking, running, and going up and down stairs and hills. All knee bending, as well as allknee straightening, comes from the thigh muscles. You depend on the thigh muscles to adduct, or pull yourlegs together, and to stabilize your hip as well. They’re very strong and absolutely necessary for the mostbasic needs of most sports, not to mention simply getting around from day to day. There aren’t many subtlethings about the thigh.
Interestingly, however, the largest and most powerful muscle in the thigh, the quadriceps, is sosensitive that no other muscle in the body atrophies more quickly when it’s not used, as after an injury, ormisused. As we discussed in chapter 5, “The Knee,” lack of quadriceps strength can be at the heart of amyriad of problems, and it’s as easy to have weak quadriceps as strong ones. Something to watch outfor.
|+ WARNING +|
|If You Experience Any of TheseConditions, Seek Medical Help|
|+ Pain in the upper thigh, hip, or groin that recurs every time you run, dance, jump;+ Pain in the hip that radieates down the thigh and lower leg;|
+ Pain in the hip accompanied by numbness or tingling of the lower leg or foot;
+ Pain that awakens you at night or keeps you from going to sleep;
+ Having your hip collapse under you while you’re walking or running.