When mechanically sound, a machine like a car or motorcycle runs smoothly with all its moving parts precisely aligned and timed to interact in a specific way. When parts don't line up or begin to break down, the mechanics of movement is compromised. In the same way, the musculoskeletal system of the human body is a mechanical system of levers that work together to produce movement. Good body mechanics plays a crucial role in safe and effective exercise.
Spinal Alignment and Stabilization
Neutral spinal alignment and stabilization are foundational to body mechanics. Neutral position is perfect postural alignment, where the spine is most stable. Soldiers stand at attention with neutral alignment because it positions joints and muscles in a way that is least fatiguing, enabling them to hold formation. The muscles of the abdomen, pelvic floor and low back make up the core and work to hold the spine in alignment during movement. Activating core muscles while exercising protects the spine from injury and holds it in its most efficient position.
Center of Gravity
NASA defines center of gravity as the average location of an object's weight. During exercise, your center of gravity shifts as your joints move thorough their range of motion, pulling you off balance if you do not compensate. To stabilize the body during standing exercise, create a broad base of support by planting the feet hip-width, knees slightly bent, abdominal muscles engaged.
Joint Alignment
For optimal body mechanics, consider how the joints align in relation to one another, in relation to equipment and in relation to the downward force of gravity. When setting up an exercise, position the body so that the primary muscle you wish to work is isolated while the rest of the body is stable. Think of your body as a towering structure and align knees, ankles and hips, wrists, elbows and shoulders so that the structure is sound and stable. When using equipment, align moving joints with the rotational axis of the machine. For example, on a leg curl machine align the knee with the machine's corresponding rotational fulcrum.
Speed and Range of Motion
A law of physics states that a body in motion will remain in motion unless acted on by an outside force. During exercise, your muscles initiate and stop movement. However, if you allow momentum or gravity to control your movement the force required to stop it will be greater, and the stress on joints and connective tissue is magnified. Moving your joints through their full range of motion in a slow and controlled fashion will result in greater gains in strength while sparing joints and connective tissue.
