The outward rotator muscles counterbalance both psoas and iliacus muscles.

Compensating for the narrow flexed pelvis, upper structural integrity alters in an attempt to maintain balance. The suscapularis muscles (lining the inside of the scapula) also fan open, mirroring the breadth of the iliacus muscles.

Tibialis posterior is a huge player in stabilizing and sending information from the ankle joint up the core. Stand on the ground, and gently lift up the medial arch and feel the tibialis posterior engaging right behind the tibia bone (top bone of the lower leg). You may feel the peroneals and tibialis anterior trying to join the party.

In general, we can propose the following philosophy on exercising joints: 1. When a joint is bearing a load, restrict its range of movement: stiffen the joint—engage the muscles. 2. To increase a joint’s range of movement, move it to its natural limits when it is not bearing a load: relax the muscles.