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, hamstrings, and calves. This area is often ignored and misunderstood. Many people sit for 8-10 hours per day. Because of the seated position the quadriceps become short and tight and even impeed the glutes. The glutes then forget their primary role as hip stabilizer and extensors. Generally, the glutes have one of the highest ratios of fast twitch fibers in the whole body.
“A strong posterior chain means a strong squat and deadlift”
How does it help to support movement?
- Multifidus (spine support)
- Erector Spinae (back and spinal extension)
- Gluteal Muscles (hip extensors, femoral rotation)
- Hamstring Muscles (hip extension, knee flexion)
- Gastrocnemius or Calf (plantar flexes ankle, knee flexion)
- External Obliques (back and spine support, in tandem with anterior core)
Movement and mechanics
But even though both chain groups need to be treated equally, sedentary lifestyles, sitting at the desk and lack of proper exercise lead to suboptimal muscular activation patterns within the posterior chain due to lower crossed syndrome (LCS).
That means the hip flexors are overactive and impede the glutes. Without the contribution of the gluteus maximus to hip extension, the hamstrings and lumbar erector spinae muscles are placed under greater stress and become synergistic dominant movers.
This means that the main muscles that should be performing most of the work take a break and the few other ‘helper’ or the synergists have to take over to fill the gap. When this happens, there is marked anterior tilt of the pelvis and a stressed lordosis curve at the lumbar spine. Imagine you try to stand straight but your butt sticks out behind you, your hip is tilted forward and your gut protrudes out in front of you. This is a recipe for acute and chronic lower back pain syndromes.
To compensate for the lack of complete hip extension caused by anterior pelvic tilt, there is increased lumbar extension.
When you bend over, pick something up or stand from a seated position, you are now at a mechanical disadvantage. Instead of activating muscles in the correct movement, you would compensate and skip right over the glutes. Proper hinging at the hips and pushing the hips forward simultaneously are critical to effective posterior-chain motor control. Every muscle group needs to be flexible and strong enough to do its job, otherwise there will be an over-reliance on others to shoulder the load. This can contribute to chronic tightness, fatigue, stiffness and spasm episodes—not to mention the risk of injury when you are moving weight.