Human BIomechanics for Beginners: the Hip Joint

The topic today is your hip joint.

This article is part of a series that will describe how various parts of your body move. Knowing these basics will help you become aware of your movements and move better.

The topic today is your hip joint. The hip joint is the largest weight-bearing joint in the body. It supports your body weight while you are standing, walking, or running. The hip joints help you move and help you maintain your balance.

The hip joint is where your thighbone (femur) meets your pelvis to form a ball-and-socket joint. The hip joint consists of two main parts: the acetabulum and the femur.

The acetabulum is a cup-like depression on the side of the pelvic bone. It can vary in width, depth, and orientation.

The round head of the femur nestles into the acetabulum to form your hip joint. It rotates and glides within the acetabulum. The femur head is attached to the femur shaft by the femur neck.

The femur moves in the hip joint in three pairs of directions of movement:

flexion and extension (back and forth)
lateral (external) rotation and medial (internal) rotation
abduction and adduction (side to side).

And circumduction, a combination of all these movements.

Skeletal variations in the femoral neck and the hip socket affect these movements.

I love to sit in a cross-legged position (yoga lotus) in my chair or on the floor. My knees open wide and rest comfortably on the floor. You may do the same. Or you may long to do the same. And that may be possible… or not.

Is lotus pose available to you? Or even healthy for you? It depends on the shape of your hip socket and your femoral neck. Both will affect how much internal and external rotation is available in your hip joint. Lotus pose requires external rotation at the hip sockets as well as flexion and a bit of abduction.

Some hip sockets face more forward in the pelvis (acetabular anteversion). Some sockets face more to the side (acetabular retroversion). Hip socket anteversion allows more external rotation. Some femoral necks angle more upward (femoral anteversion), some more downward (femoral retroversion). Femoral retroversion makes external rotation easier. Photos illustrating these skeletal variations are available at http://paulgrilley.com/bone-photos/.

Practice can address muscles and ligaments that limit your lotus. But it cannot change the shape of your bones. It’s the end of the road when the neck of the femur comes into contact with the rim of the hip socket. Do not try to force your body into full lotus. Adapt. Sit on a yoga brick or a folded blanket or pillow to raise your hips. Place a yoga brick or a folded blanket or a pillow to support your knees.

Summing Up:

Hip joint mobility varies widely. Two important factors are the angle of the femur neck and the angle of the hip socket. Honor your skeletal structures. Find an adaptation for lotus or any pose if your hip bones get in the way.

Reference:

Bernie Clark. Lotus Pose: Destroyer of Disease, or Destroyer of Knees?, www.yogainternational.com.