Final answer:
The conventional bowling grip uses the thumb, middle finger, and ring finger, providing control through abduction, flexion, and extension movements at the finger joints and stability through thumb opposition.
Step-by-step explanation:
The conventional bowling grip involves the use of three fingers: the thumb, middle finger, and ring finger. When gripping the bowling ball, these fingers are inserted into the three holes specifically drilled for this purpose. The thumb occupies the first hole, and the middle and ring fingers are inserted into the remaining two holes, respectively. This grip allows for abduction and flexion at the metacarpophalangeal joints and extension at the interphalangeal joints of the three middle fingers, which provides control and stability to the ball during the release.
Upon bowling, the thumb exits first, followed by the middle and ring fingers, which execute the final spin and lift necessary for pin action. The opposition movement of the thumb towards the fingers also plays a crucial role in providing a firm grasp on the bowl. This grip technique is similar to various day-to-day actions such as catching a ball or manipulating objects, which require coordinated movements and stability offered by the said joints and opposition of the thumb.