The volunteers completed several tests that measured trunk stability, balance, hip strength, and how easily they could move during everyday tasks. However, trunk stability declined faster than overall balance, hip strength, or mobility, especially in men. When the scientists compared the different measurements, they found that better trunk stability was closely linked with better whole-body balance. Walking and general physical activity remain valuable, but they may not fully protect the body from age-related changes in posture and balance. Building good trunk strength and body control during middle age may help delay future decline and support independence for longer.