What is the posterior chain?
The posterior chain is simply the backside of your body and its primary muscles include the lower back, gluteus maximus (glutes), hamstrings, and calves. This area is often neglected and misunderstood.
There are two main reasons why. The first reason is many people sit 8-10+ hours per day. Because of the seated position the quadriceps/psoas become adaptively short and tight, further inhibiting the glutes. The glutes then suffer amnesia to their primary role as hip stabilizer and extensor.
The second reason the posterior chain is neglected is that none of these muscles are seen in the mirror. Out of sight out of mind, we only seem to notice when we are trying on jeans or the dreaded swimsuit. May be you do strength training, yoga, or running, etc … but the glutes are not reflecting all the hard work; so the question is… are you really working them?
Although the posterior chain consists of the low back, glutes, hamstrings and calves, the focus here will be on the function and importance of the glutes. When the glutes become inhibited the posterior chain is not functioning properly. The low back and the hamstrings then have to take on the work of the glutes, and along with these muscles being overworked the IT Band, TFL plus the piriformis also take on an additional load, leading to a whole cascade of low back, hip, knee, ankle, and foot problems.
Although yoga feels good when stretching the excessively used low back and hamstrings, the majority of poses that are used in class will over stretch the posterior chain and over work the anterior chain, exacerbating the problem the people deal with all day. This is not exclusive to yoga, there other workout programs in gyms that can be just as unbalanced.
This article is going to look at the many roles of the glutes.
The glutes' role when it comes to the hip is hip extension and from a standing position this is to lift one leg behind you while standing on the other, but you must maintain the center of gravity of the ankle with the other glute. This position rarely equates to the pelvis being level.
In general when the pelvis is level in balance work you are hanging off the passive structures of the hip and continuing to weaken glutes. In the bottom half of a squat (Utkatasana) or bottom position of the lunge (Warriors), hip extension is the movement upwards to drive up out of the bottom of the pose. Hip extension is also done from the floor when in supine bridge.
The next role of the glutes around the hip is abducting the leg. This movement is moving the leg away from the mid-line of the body; an additional role at the hip is that of external rotation. The role of the glutes at the pelvis is to posterior tilt the pelvis. This is misunderstood and is often poorly executed; most people end up extending from the lumbar spine instead of from the hips.
When people cannot rotate the pelvis properly it is based off weak glutes plus short/tight quadriceps/psoas and resulting back pain. Visualize your pelvis as a bucket full of water and when in neutral, the water is going nowhere, but as the quads/psoas begin to tighten they pull the pelvis down slightly and water is now pouring out the front, this is an anterior tilt.
In a posterior tilt, water is being poured out the back, but you must be careful how you do this action because it comes from the co-contraction of the lower abdominals and the glute max, not from the lumbar spine.
The glutes' role around the spine is simple, if you don’t have strong glutes you are going to extend and flex at the spine instead. Strong glutes encourage good lifting and movement technique. The glutes also have the best leverage out of all the muscles in rotation based movements such a revolved crescent. The glutes' role around the sacrum is to provide stability through an action called force closure. Force closure is an outside force and is required if the joint has movement.
The fibers of the glutes and hamstrings attach to the sacrum and when they contract help create this force closure for stability. But there is also a mechanism called form closure. In the body this would be a fused joint but the closest example we have is the sacroiliac joint (SI-J), but still has 0.2% movement. This is why the sacrum requires the additional stability from force closure created by the glutes.
The glutes role around the anterior hip (front), when you use mainly the hamstrings without the co-contraction of the glutes, they will pull the head of the femur forward into the acetabulum (hip socket). Without the co-contraction of the glutes or if you do not have strong glutes to keep that from happening you are going to get anterior hip pain. The glutes pull backwards on the femur and track it properly in the hip socket and thus preventing anterior hip pain.
The glutes role around the knee is to help keep the knees tracking out (knees tracking on 2nd/3rd toe) when in low positions like a squat, this is when glute medius has the best leverage and becomes an internal rotator. Muscles change roles in hip extension/flexion depending on the depth.
The glutes role around the feet, are through fascia connection via the thoraco-lumbar fascia of the low back and the IT Band. The most profound expression of the glutes and feet interaction is through sprinting, but this can certainly be the case for lesser intensities even in walking and jogging. The hip extensors absorb a vast amount of braking forces to help propel the body forward. Proper glute activation and strength is necessary for force to transfer and movement to be efficient.
Because of the many roles of the glutes, they also play a role in posture and have a cascading affect. All you have to do is look at posture (forward head posture, rounded upper back, pot belly or pouchy belly, flat sagging butt) and the pain people are suffering from today and see the importance of the glutes in the ways mentioned.
What are the enemies of the glutes?
Pain in the lower body will inhibit the glutes, it is a protective mechanism. If the glutes are inhibited you won’t be able to do sudden or explosive movements, this to save whatever is injured to be repaired. The problem is that when the injury is healed the glutes don’t just magically come back on. When I test the recruitment order of the posterior chain 9 out of 10 people cannot activate the glutes, the body & brain skip right over it.
Sitting is another enemy of the glutes. When you sit all day you are in the position of hip flexion and there is adaptive shortening and tightening of the quads/psoas. When this happens, there is also an additional neurological response of shutting down the opposing muscle (the glutes); this is called reciprocal inhibition. So get up and move throughout the work day and train or practice through full range of motion to counteract what we are doing during the day.
Getting the glutes on all the time takes a multi-pronged approach; proper isolation when stretching quads/psoas; myofascial release (foam roller work), glute activation work, and working through full range of motion. I have worked to creatively incorporate these approaches from my strength training experience into a yoga flow.
References:
Bret Contreras, T-Nation
Mark Buckley, FMA Strength Training
Perry Nickelston, DC, FMS, SFMA Dynamic Chiropractor, Dynamic Chiropractor—July 15, 2011, Vol. 29, Issue 15