Several bones and joints are used when swinging a baseball bat, such as:
(1) radius-ulna and carpals, which are in your fingers, thumb and wrist,
(2) vertebral arches and bodies, which are in your elbows, shoulders, and spine
(3) femur, tibia and patella, which are in your hips and knees
(4) tibia-fibula and talus, which are in your ankles