November 17, 2017 - Amanda Iiams, MA, NKT 3, PMA-CPT, CSCS, ACE

The Deep Six, Turnout and Pilates

The deep six! Powerful muscle group which is aligned in the transverse plane. An easy way to remember them is PGOGOQ; Piriformis, Gemellus Superior, Obturator Internus, Gemellus Inferior, Obturator Externus and Quadratus Femoris

The textbook definition for this muscle group is external rotation of the femur at the hip- concentric contraction model. Concentric contraction is external rotation as the muscles shorten.

Performance definition is deceleration of internal rotation of femur at the hip- eccentric model. Eccentric contraction is the muscles lengthen under load as the femur internally rotates. The deep six are lengthening as they move from external rotation into internal rotation to slow the movement. 

Athletes of all kinds need mobile hip rotators to achieve the flexibility needed to decelerate the internal rotation. However, every step we take when walking has an internal rotation component. Each step drives the hip into internal rotation and the deep 6 must lengthen under load to decelerate this motion, requiring them to be strong and mobile.

When the hip is excessively turned out in gait, the forefoot can become overly everted which causes the big toe to hit the ground sooner, the calcaneus compensates by supinating to lift the big toe. This can cause stress to the 5^th metatarsal.

Humans are set up for failure because inherently the deep six are tight and therefore weak (tight muscles are usually weak not strong) and external factors increase the problem (ahem- teaching turnout in Pilates).

Tight, weak hip rotators lead to decreased internal rotation of the hip which also results in increased rotation of the tibia. This increases torque at ACL, increases the demand on the IT band, and causes the patellofemoral to be out of sync. The Achilles tendon tries to compensate.  This impact is seen and felt at the ankle, knee and hip; ankle sprains, post tibialis tendonitis (looks a lot like plantar fasciitis), hamstring strains, meniscus issues, pain in the hip, tightness. 

The take-away?

• Assess mobility in both external and internal rotation and eccentric strength at deep six
• Increase internal rotation mobility and eccentric strength of deep six
• Look to the deep six not just knee or ankle for issues at these locations