Strengthening exercises for the trunk musculature often occur on the floor dominated by abdominal flexion or on a back extension machine to isolate the spinalis muscles. The limited range associated with varied crunches certainly activates the rectus abdominis while back extension isolates the erector spinae, but both fail to effectively enhance trunk muscle synergy and spinal stabilization in functional environments. Analysis of trunk training exercises published in the Journal of Strength and Conditioning (2010) suggests that the opposite reaction occurs when varied load locations are applied. According to the authors the body cannot isolate muscles when they are readily coordinated as maximal muscle activity occurs during single-plane tasks. Muscle activation levels are constrained during functional tasks and therefore perform in a synchronized rather than isolated manner. This explains the limited transfer of bodybuilding exercises to athletic performance.

To train the trunk musculature for improved functional task requires non-traditional approaches. Closed kinetic chain, asymmetrical loading, raised center of mass and multi-planar movements all enhance the coordination between force couples. One popular example of loading the trunk in a non-traditional manner is the overhead squat, but due to requisite skill acquisition, balance in the musculature and limitations in flexibility most people incorrectly compensate in one manner or another. In many cases the back extensor muscles and hip flexors partially take over responsibility for the trunk. Likewise, a host of muscles contribute to manage the overhead position for exercisers with tight internal rotators and latissimus dorsi muscles.

To optimize the movements that most enhance trunk performance additional work is most likely required. Closed chain movements performed through full range of motion can add stability and flexibility to better perform more challenging exercises like the overhead squat with resistance. Using varied loads and movement patterns presents stress without the need for heavy resistance. This combination allows for more emphasis on range and quality movement patterns. The following exercises are examples of non-traditional movements for improved functional performance.

Band Overhead Squat

Start	Finish

Band T Squat

Start	Finish

High-Low Squat Reach

Start	Finish

Back T Reverse Lunge

Start	Finish

Lateral Rotation with Step Back

Start	Finish

Bilateral Overhead Reach

Start	Finish

Single Arm Split Stance Y Reach

Start	Finish