A Guide to Hip Anatomy

The hip joint is one of the largest joints in the body and is a major weight-bearing joint.  It is one of the most important joints in the human body as it allows us to walk, run, and jump.   It bears our body’s weight and the force of the strong muscles of the hip and leg.  Still, the hip joint is also one of our most flexible joints and allows a greater range of motion than all our other joints in the body, except for the shoulder.
                                                                             Inline image 1
The hip joint is made up of two bones: the pelvis and the femur (the thignbone).  It is ball and socket joint, the “ball” is the rounded end of the femur (also called the femoral head) and the “socket” is a concave depression in the lower side of the pelvis (also called the acetabulum).  The femoral head fits into the acetabulum to form the hip joint.
                                          Inline image 4
Muscles and Tendons
The motion of the ball and socket is controlled by several very powerful muscles which attach to the bones.
  • Gluteus Maximus (Glutes) – the large, strong muscles that attach to the back of your hip bones and comprise the buttocks. It is regarded as one of the strongest muscles in the human body and is responsible for the movement of the hip and thigh.
  • Gluteus Medius – Works to provide rotation of the thigh outward, from the center of the body
  • Adductor muscles – Located the inside of your thigh.  This muscle group is used to stabilize left to right movements of the trunk.
  • Illiopsoas muscle (Psoas major & Illiacus)- A hip flexor muscle that attaches to the upper thigh bone.  It is the strongest of the hip flexor and it flexes, laterally rotates, and adducts the hip.
  • Piriformis – Located from the front part of the sacrum and connected at the back part of the hip joint. Laterally rotates the femur with hip extension and abducts the femur with hip flexion.
  • Pectineus – Located at the front of the upper and inner thigh. It is one of the muscles primarily responsible for hip flexion.  It also adducts the thigh.
Hip Mobility
Our joints, limbs, and muscles, all working together, is what moves our body.  Different people will have different levels of mobility in different areas of the body.  The most common deficiency resides in the hips.  People have forgotten (or don’t know) how to use their hips the way evolution designed them to be used.  For example, instead of sitting  back with their hips to pick something up, followed by a hip extension to bring it up, they’ll bend at the waist and lift with the lower back.   You can get away with poor hip mobility for awhile, but eventually, injury is waiting to happen.
Sitting.  We all sit too much.  Sitting impacts hip mobility in two major ways:
  • It weakens the glutes
  • It shortens the hip flexors
Both your glutes and your hip flexors are important in the activation of the hips so when they are weak or inactive, they lower back takes over.  The spine is there for support and stability and with poor hip mobility brought on by excessive sitting and a weak posterior, your hip extension is no longer sufficient  and comes in the lower back.
Our hips are obviously designed to generate a ton of power!  The ligaments, the tendons, the musculature, and the bones are all dense, hardy, and robust and they’re made for activity and mobility – but too many are selling their hips short.  When this happens, we tend to lean on our other joints and muscles (like knees and spine) to pick up the slack, often times causing injury.
Restoring hip mobility
  • Should reduce or eliminate lower back and or knee pain stemming from overcompensation.
  • Improve your power output by allowing you to full engage your posterior chain
  • Improve the strength and power of your hip extension
  • Will improve our rotational stretching (instead of rotating with the lumbar spine!)
Remember, everyone will have different levels of mobility in their hips, but this is a great place to start to get the alignment of the rest of the body correct and take the strain away from other parts of the body.