Final answer:
In sway back posture, certain muscles are tight such as lower back extensors and hip extensors, while others like the abdominal muscles and hip flexors are lengthened. This imbalance affects the body's center of gravity and increases the complexity of maintaining good posture. Proper ergonomics and physical exercises are important to correct these muscle imbalances.
Step-by-step explanation:
When discussing sway back posture, certain muscles are tight while others are lengthened. Muscles that are commonly tight include the lower lumbar extensors, the thoracic extensors, and hip extensors, including portions of gluteus maximus and hamstrings. On the flip side, the muscles that are commonly lengthened or weakened with sway back posture include the abdominal muscles and hip flexors. Furthermore, upper back muscles and neck extensors may also be lengthened.
This muscle imbalance is a key aspect of sway back posture, which can lead to an altered center of gravity and compensation at various levels of the spine and hip joints, resulting in increased muscle tension in certain areas and reduced tone in others. Activities like sitting for long periods without proper back support can exacerbate this issue, requiring attention to proper ergonomics and exercises to correct muscle imbalances. Maintaining good posture involves understanding the forces exerted by muscles and the complexities in the real system of muscles, bones, and joints.
The elasticity, extensibility, and contractility of muscle tissue play important roles in allowing the muscles to maintain posture and perform various movements. The intrinsic skeletal muscles of the back and neck help in the stabilization and movement of the vertebral column, while the muscles of the abdominal wall and thorax work to extend, flex, and stabilize different parts of the body's trunk, contributing both to movement and to the maintenance of correct body posture.