What is the role of the crossed-extensor reflex?

The crossed-extensor reflex plays a crucial role in maintaining balance during limb withdrawal. When a painful stimulus is detected, such as stepping on a sharp object, the body initiates a withdrawal reflex to pull the affected limb away from the source of pain. However, this withdrawal can destabilize the body, as lifting one leg off the ground can lead to a loss of balance.

The crossed-extensor reflex compensates for this by activating extensor muscles in the opposite limb, allowing it to support the body’s weight and maintain balance while the injured limb is withdrawn. This coordinated response helps prevent falls and ensures that the person remains upright and stable during a potentially hazardous situation. In this way, the reflex demonstrates how the nervous system integrates sensory information and motor responses to promote safety and balance.