What are the two main types of forces acting on the body during movement?

The two main types of forces acting on the body during movement are internal forces and external forces. Internal forces are generated by the muscles and connective tissues within the body, facilitating movement and providing stability, as they help maintain posture and support joint function. These forces are critical for the body to execute any muscular contraction, whether it is for lifting objects or maintaining balance.

External forces, on the other hand, are those that act on the body from outside sources, such as gravity, ground reactions, or contact with other objects. These forces influence how the body moves through space and interacts with the environment. For instance, gravitational force pulls the body downward, while external forces can also include friction when the feet push against the ground during walking or running.

Understanding the distinction between internal and external forces is essential in biomechanics, as it helps to analyze movement mechanics, develop training and rehabilitation programs, and improve performance while reducing injury risk.