Final answer:
Good posture maintained by physical activity prevents back strain, while bad posture can cause excessive back muscle exertion leading to postural deformity.
Step-by-step explanation:
The relationship between physical activity and postural deformity is intricate and directly impacts overall health. Regular physical activity ensures that muscles remain strong and balanced, which is critical for maintaining good posture. When the center of gravity is directly above the pivot point in the hips, it helps avoid back strain and damage to the spine's discs. In contrast, poor posture can cause the body's center of gravity (cg) to move away from this pivot point, creating a clockwise torque around the hips that back muscles must counteract. This leads to overexertion of the back muscles, which have a small mechanical advantage, resulting in muscle strain and increased risk of postural deformity.
Figures illustrating the effects of good and bad posture make it clear that the positioning of the body's cg is critical. Well-distributed physical exercise helps maintain the balance needed for good posture, hence preventing maladjustment and reducing the likelihood of postural deformity. Rather than allowing patterns of physical activity to deviate from natural habits, which could impair health, it is important to engage in exercises that strengthen the musculoskeletal system, particularly the core muscles that support the spine. Additionally, the use of ergonomically designed furniture can help maintain proper postural alignment, reducing the risk of developing deformities associated with prolonged sitting or standing in unbalanced positions.