According to Grey Cook of Functional Movement Solutions at the 2007 National Strength and Conditioning Association’s (NSCA) Mid Atlantic Regional Clinic, “research has shown that people with the least amount of back pain have the weakest low back muscles and people with the most back pain have the strongest low back muscles.” With most muscle groups, we gain strength by flexion and extension through weight bearing movements (e.g. the biceps with dumbbell curls). The low back muscles cannot be trained this way due to the incredible amount of stress this puts on the lumbar vertebrate (lower spine). In our postural movements we perform ranges of motion while keeping the shoulder blades squeezed back and performing the movement with an over-exaggerated posture. This teaches and trains the low back to transfer the energy and stress to other parts of the body such as the glutes, hamstrings, and upper back muscles. Proper posture and/or body alignment takes energy away from the movement, as the body was designed to have most stress placed in the muscles and away from the joints (Cook, 2003). This relieves the lumbar vertebrate from stress and therefore promotes less of a risk for back pain.
Good posture is also the key to shoulder stability. When someone has their shoulders slumped forward all day, this results in the shoulder joint being out of place and highly stressed at all times, which can result in head, neck, and shoulder pain (Griegel-Morris, et al, 1992). It is, therefore, easy to comprehend that many shoulder injuries are often caused due to poor posture on a daily basis (e.g. someone may walk around with their shoulders forward all day and then go out and swing a tennis racket, resulting in a shoulder injury and they blame the swinging of the racket when it was actually due to walking around with poor posture and putting stress on the shoulder joint over a prolonged period of time).