One very important job of your hip muscles is to maintain the alignment of your leg when you move. One of the primary hip muscles, the gluteus medius, plays an especially important stabilizing role when you walk, run, or squat. The gluteus medius attaches your thigh bone to the crest of your hip. When you lift your left leg, your right gluteus medius must contract in order to keep your body from tipping toward the left. And when you are standing on a bent leg, your gluteus medius prevents that knee from diving into a “knock knee” or “valgus” position.
Weakness of the gluteus medius allows your pelvis to drop and your knee to dive inward when you walk or run. This places tremendous strain on your hip and knee and may cause other problems too. When your knee dives inward, your kneecap is forced outward, causing it to rub harder against your thigh bone- creating a painful irritation and eventually arthritis. Walking and running with a relative “knock knee” position places tremendous stress on the ligaments around your knee and is a known cause of “sprains”. Downstream, a “knock knee” position puts additional stress on the arch of your foot, leading to other painful problems, like plantar fasciitis. Upstream, weak hips allow your pelvis to roll forward which forces your spine into a “sway back” posture. This is a known cause of lower back pain. Hip muscle weakness seems to be more common in females, especially athletes.
You should avoid activities that cause prolonged stretching of the hip abductors, like “hanging on one hip” while standing, sitting crossed legged, and sleeping in a side-lying position with your top knee flexed and touching the bed. Patients with fallen arches may benefit from arch supports or orthotics. Obesity causes more stress to the hip muscles, so overweight patients may benefit from a diet and exercise program. The most important treatment for hip abductor weakness is strength training. Hip strengthening is directly linked to symptom improvement. Moreover, people with stronger hip muscles are less likely to become injured in the first place.