An isotonic contraction occurs when a muscle changes length while generating a constant tension. This type of contraction is essential for movements such as lifting weights or performing everyday activities. During isotonic contractions, the muscle shortens (concentric contraction) or lengthens (eccentric contraction) while maintaining a steady force. Isotonic contractions are crucial for physical activities and are often contrasted with isometric contractions, where the muscle length remains unchanged despite tension. Understanding isotonic contractions helps in designing effective exercise programs and rehabilitation strategies for individuals looking to improve their strength and mobility.