Part of the answer to my last post on PFSS lies in the abdominal muscle structure & function. Here are some good excerpts from pages 40-41 of "Running- Biomechanics & Exercise Physiology Applied in Practice", Bosch & Klomp 2005.
- During functional movement, the abdominal muscles ALWAYS work together with other muscles.
- isolating the abdominal muscles during training (certainly for well trained athletes) is of limited use.
- Being able to handle a REACTIVE load is more important for abdominal muscles during running than being able to contract forcefully.
- the abdominal muscles absorb forces in repeatedly alternating diagonal lines.
Great runners need to have what Dr. Stuart McGill calls "super stiffness". Strong abs seem to have the ability to block extraneous motion in the coordination of the upper & lower extremities.