IT'S ALL IN THE HIPS

Which muscles first come to your mind when thinking about core stability?  For many people the abdominals are synonymous with the core.  Although the abdominals are certainly part of the puzzle, in order to improve athleticism and prevent injury, many more pieces are needed.

One really great description of the core is a  “ … muscular box with the abdominals in the front, paraspinals and gluteals in the back, the diaphragm as the roof, and the pelvic floor and hip girdle musculature as the bottom” (Akuthota, Ferreiro & Fredericson, 2007).

I covered the abdominals in my last post “Your Abdominals from the Inside Out”.  This post will expand on the core musculature by focusing on the hips and pelvic girdle.  The pelvic girdle holds a position of critical importance when it comes to the kinetic chain.  It is common to see reference to the “lower kinetic chain” (foot, ankle, knee & lumbopelvic hip girdle) and the “upper kinetic chain” (lumbopelvic hip girdle, spine, shoulder, elbow, hand).  The hips and pelvis are the important center link of this chain and play a crucial role in stabilizing the trunk and pelvis in movement and in transfer of force between the upper and lower body.

If you’ve ever watched a professional baseball player, tennis player or golfer you know that it really is all in the hips!  Optimal flexibility and strength in the muscles that support the hips & pelvis coupled with body awareness and endurance is a winning combination for injury prevention and success in any sport.

The bones of the hip joint and pelvic girdle include the three fused bones of the pelvis (ilium, ishcium, pubis), the sacrum (which is actually 5 fused vertebrae at the base of the spine), and the femur.

The joints include the symphysis pubis (where the two pubic bones come together at the front of the pelvis), the two sacroiliac joints (where the sacrum comes together with the ilium at the back of the pelvis), and the hip joint.  The hip joint is a ball and socket joint.  The “ball” is the head of the femur bone.  The “socket” is called the acetabulum and is formed by all three of the pelvic bones (ilium, ischium & pubis).

The first two joints, symphysis pubis & sacroiliac, have very little movement.  The third, the hip joint, allows for movement in a variety of planes.  The muscles that move the hip joint can be divided into the following categories:

Hip Flexors                                                                Hip Extensors

Psoas                                                                           Gluteus maximus

Iliacus                                                                          Hamstrings

Rectus Femoris                                                          

Sartorius

Muscles of the medial compartment of the thigh (pectinius, adductor longus, adductor brevis, gracilis)

Adductors                                                                   Abductors

Adductor brevis                                                          Gluteus medius

Adductor longus                                                         Gluteus minimus

Adductor magnus & minimus

Pectineus

Gracilis

Obturator externus

Lateral Rotators                                                        Medial Rotators

Obturators (internus & externus)                                Gluteus medius

Gemelli (superior & inferior)                                      Gluteus minimus

Piriformis

Quadratus femoris

___________________________________________________________

HIP FLEXORS

________________________________________________________

GLUTEUS MAXIMUS 

GLUTEUS MEDIUS

 __________________________________________________________

LATERAL ROTATORS (credit: www.iadms.org)

_____________________________________________________

ADDUCTORS

____________________________________________________

Due to the central location of the hips and pelvis in the kinetic chain, imbalances in the strength and flexibility of the hip muscles can result in misalignment and injury farther up and down the kinetic chain.

A great example of this is the effect of weak gluteal muscles on the knee and foot.  If gluteus medius and gluteus minimus (our primary hip abductors) are weak, the femur will tend to adduct and internally rotate.  If you follow this down the kinetic chain, the knee will fall into a “knock-kneed” position and proper knee tracking will be disturbed, the foot will tend to pronate.  The smaller leg muscles are not able to make up for the weakness of the gluteal muscles and a number of injuries (IT band syndrome, achilles tendionosis, plantar fasciitis, & shin splints) can result along the lower kinetic chain. 

Since over activity of the adductor muscles coupled with weakness of the gluteal muscles is one of the most common imbalances that can lead to injury lets look at a couple of exercises you can easily add to your fitness routine to help prevent this imbalance.

The gluteal muscles are primarily hip extensors and abductors.  Exercises that involve extending your leg behind you and lifting your leg to the side will target these muscles.  The tricky part, especially in people who have trouble accessing these muscles, is making sure the gluteal muscles are doing the work.  Your abdominals are the key to keeping your pelvis and spine stable during hip extension work.

Here is a nice pictorial of the “Bird-Dog” or “all fours” exercise from ACE fitness http://www.acefitness.org/exerciselibrary/14/bird-dog

Although it looks quite simple, I would suggest starting this exercise lifting your leg only.  Then progress by taking your opposite hand on to your abdominals while you lift your leg.  This is a great way to provide some sensory feedback as to the stability of your spine and pelvis.  Your “hip-bones” (the bones you feel protruding on the front of your pelvis) should stay in the same vertical plane as your pubic bone to maintain neutral pelvis, and you should feel your abdominals pulling in toward your spine.

You can then add abduction by maintain the height of your leg and moving it away from the midline of your body.  Again, try this with your opposite hand on your abdominals to help police the stability of your spine and pelvis as well as the depth of your abdominal contraction.

Lunges are a fantastic exercise for simultaneously strengthening and stretching the hip adductors.  Here is a video link demonstrating a very basic lunge. http://www.ehow.com/video_2365368_do-basic-lunge-leg-exercise.html

Training all of the muscles of the hip in a way that balances strength and flexibility will not only prevent local injury but will also help to maintain alignment and prevent injury along the whole length of the kinetic chain.

Akuthota, V.A., Ferreiro, T.M. Fredericson, M. (2007) Core stability exercise principles. Current Sports Medicine Reports, 7(1), 39-44.

Geraci M.C. (1994) Rehabilitation of pelvis, hip and thigh injuries in sports. Physical Medicine & Rehabilitation Clinics of North America, 5, 157-73.

Geraci, M.C., Brown, W. (2005) Evidence-Based treatment of hip and pelvic injuries in runners. Physical Medicine & Rehabilitation Clinics of North America, 16, 711-747.

Lloyd-Smith, R., Clement, D.B., McKenzie, D.C., et.al. (1995) A survey of overuse and traumatic hip and pelvis injuries in athletes. The Physician and Sportsmedicine, 13, 131-41.

Sciascia, A., Cromwell, R. (2012) Kinetic chain rehabilitation: a theoretical framework. Rehabilitation Research and Practice, 2012, 1-9.