The musculoskeletal system, including muscles, bones, and joints, plays a key role in maintaining body posture and balance. The muscles work together to support the body in an upright position and help stabilize joints during movement. The vestibular system in the inner ear also plays a crucial role in balance by providing information to the brain about the body's position in space. Additionally, the visual system and proprioception (the body's sense of its own position) contribute to maintaining balance. Regular physical activity, including exercises that target core strength and balance, can help improve posture and balance.