Final answer:
To do a lateral split, the legs must perform a series of complex movements involving lateral rotation, lateral flexion, and actions by the lateral compartment of the leg. These actions allow the legs to extend outward substantially while maintaining balance and proper alignment.
Step-by-step explanation:
The initial movement of the legs to do a lateral split involves several actions of the muscles and joints in the lower body. Specifically, the motion requires the muscles that move the back of the lower legs up toward the buttocks, which occurs similarly to when you kneel. Furthermore, it necessitates the action of the muscles that assist in moving the thigh both diagonally upward and outward, actions that can be associated with lateral rotation and lateral flexion.
For successful completion of a lateral split, the muscles must also have the ability to lower the thigh, performing an inward twist of the thigh and lower leg. These actions require good flexibility and strength in the lateral compartment of the leg, which not only lowers the sole of the foot to the ground, as when foot-tapping or jumping, but is also responsible for bending the inside of the foot downward, which could be crucial for maintaining balance during the maneuver.