Midline stabilization is essential for effective functional movement. Kelly Starrett, of San Francisco CrossFit, explains the essential anatomy and physiology of it in this excerpt from his one day seminar at CrossFit Santa Cruz on November 9, 2008.
The midline is the entire spine, and its stability is dependent not just on the core, but also on all the prime movers of the body, including the hip, glutes, and hamstrings. Excessive tightness in any of the prime movers will affect the core muscles, often resulting in low back pain.
There are several two-joint muscles that affect midline stability. Understanding the roles of these muscles helps in diagnosing common flaws. In this episode, Kelly talks primarily about the quadraceps and hamstrings, the main two-joint muscles of the pelvis. He also addresses the relationship between head position and hamstring flexibility.
This is the eighth of a series from Kelly on the theory and practice of stabilizing the midline in functional movement.