Chek points out in the article “The Inner Unit: A New Frontier In Abdominal Training” that research has shown that the inner unit exists under a different neurological control than the outer unit. Fitness training focuses on the outer unit to the exclusion of the inner unit. This fixation on the si pack creates an improper firing sequence for the core, which promotes ineffective breathing patterns, poor posture, postural distortions, and joint instability. When we miswire the inner unit through poor practices, exerting any type of effort can predispose the spine to force that it cannot stabilize and/or absorb. This often results in sacroiliac joint and spinal injury. When we allow the wiring to fire naturally, we seldom experience injury, even under intense stress.