found this on Poliquins site (i belive he's had over 400 athletes in the olympics)

Fixing the Flaws – Part 1
April 20, 2005
By: Eric Cressy

A Look at the Ten Most Common Biomechanical Weak Links in Athletes continued...




"3. Lack of Overall Core Development: If you think I'm referring to how many sit-ups an athlete can do, you should give up on the field of performance enhancement and take up Candyland. The "core" essentially consists of the interaction among all the muscles between your shoulders and your knees; if one muscle isn't doing its job, force cannot be efficiently transferred from the lower to the upper body (and vice versa). In addition to "indirectly" hammering on the core musculature with the traditional compound, multi-joint lifts, it's ideal to also include specific weighted movements for trunk rotation (e.g. Russian twists, cable woodchops, sledgehammer work), flexion (e.g. pulldown abs, Janda sit-ups, ab wheel/bar rollouts), lateral flexion (e.g. barbell and dumbbell side bends, overhead dumbbell side bends), stabilization (e.g. weighted prone and side bridges, heavy barbell walkouts), and hip flexion (e.g. hanging leg raises, dragon flags). Most athletes have deficiencies in strength and/or flexibility in one or more of these specific realms of core development; these deficiencies lead to compensation further up or down the kinetic chain, inefficient movement, and potentially injury. "