Which part of the rider's body is described as being from the waist to the knee, including the seat and inner thigh?

The base of support refers to the area of the body that provides stability and balance while riding. In the context of horseback riding, this is specifically the region from the waist to the knee, which encompasses the seat and inner thigh. This area is crucial for maintaining an effective riding position and allows the rider to connect with the horse through their legs, thereby enhancing communication and balance. A strong base of support helps riders to absorb the horse's movements and maintain their posture, which is essential for effective riding.

In contrast, the balance zone typically refers to the overall area that helps maintain dynamic equilibrium, but it is not specifically defined by the waist to knee. The center of gravity relates to the point where weight is evenly distributed, but it does not pertain to a specific section of the rider's body. Upper body position indicates how the upper part of the rider’s body is oriented; however, it excludes the lower body's role in providing support and balance while riding.