Which axis runs through the body from side to side?

The frontal axis runs horizontally through the body from side to side, playing a crucial role in various movements during physical activities. This axis is significant because it allows for flexion and extension movements to occur in the sagittal plane, such as during a bicep curl or when performing squats. When the body rotates around the frontal axis, it typically involves movements that open or close the limbs towards or away from the midline of the body, which are essential in exercises that require lateral movement.

Understanding the frontal axis and its function helps in analyzing athletic performance and biomechanics, further enhancing one's ability to understand varied sports movements and training techniques.