Hip to Be Square
During a yoga class, it's not uncommon to be instructed to stretch your hamstrings, tighten your abdominals, or engage your quadriceps (front thigh muscles). But can you remember the last time you heard a teacher mention your hip adductors? Given that they are one of the largest muscle groups in the legs, you would think they play a big part in yoga poses. And they do.
They are active and essential in standing poses, inversions, and arm balances, and they are stretched in standing and seated forward bends. If the hip adductors are such an integral part of so many poses, why do they languish in relative obscurity? My guess is that one reason is the complexity of their actions, and another is their location—they're found deep in the inner groin and along the inner thigh. The other thigh muscle groups, the quadriceps in front and the hamstrings in back, are much better known and discussed, but for many yoga practitioners the size, location, and function of the adductors remain mysterious.
One day many years ago, when I was a physical therapy student, I was quite surprised when I came upon a picture of the three thigh muscle groups. It was a cross section of the thigh, about halfway between the knee and the hip. The surprise was that the adductors were noticeably larger than the hamstrings and just about as big as the quadriceps.
This revelation got me thinking about the adductors' purpose. Why do they need to be almost as large as the quads, whose action we know to be crucial for everyday activities such as walking up inclines, climbing stairs, and rising from chairs?
Before we dig into the function of the adductors, let's clarify their exact location. There are five adductors, and they all originate on the pubic bones and the ischial tuberosities (sitting bones). Two of the adductors, the pectineus and the adductor brevis, are quite short and insert on the back of the upper femur (thighbone). The adductor longus and adductor magnus are longer and larger, and insert at the back of the thighbone, on the middle and lower part of the shaft. The longest adductor, the gracilis, inserts below the knee, on the inner upper tibia (shinbone).
Together, all five of these muscles adduct the hip; in layman's terms, they pull the thighs together. Several of them also have good leverage to flex the hip, pulling the thigh and torso toward each other. The other actions of the adductors are quite complicated. Depending on the position of the leg, they may also help rotate the thighbone internally or externally in the hip socket, or help extend the hip. (A hip is in extension when the upper leg is in line with or slightly behind the torso.)
Your adductors are quite easy to feel with your own hands. Start by lying down on your back with your legs out straight, and slide the tips of your right fingers down your belly until you can feel your right pubic bone. Then move your fingers about an inch and a half out to the right and about an inch down into your right groin. Squeeze your thighs together and you will feel the large adductor tendon become firm as the muscles pull it taught. If you continue this squeezing action, you should be able to trace the firm shape of the contracting muscles most of the way down to your knee.