Acommon visual behavior is the âhead jerk.â This motion is generally observedwhen an individual otter approaches a raft of sea otters. The approaching otternoses and sniffs the other otters while jerking its head from side to side.
Axis tilt is the vertical angle at which the ball rotates. Axis tilt is what is commonly known as spin. Axis tilt is determined by the position of the thumb during the release. If the hand turns too early, the thumb exits on top of the ball. Bowlers with a high degree of axis tilt will be able to see the top of their hand during the release and follow through.
If youâre having trouble understanding the concept of the axis of rotation, here is a great primer on this somewhat complex concept. Learn about the three axes of rotation and the various types of movements that occur at different types of joints. Axis of rotation can be a complex concept to grasp. It is not visible or tangible. It is an imaginary line that is the pivotal/rotational point at a joint. Movement in the planes occurs around this point and it is perpendicular to the planes, meaning that both linesâthe plane and the axisâcreate a right (90Â°) angle. Just as there are three planes of motion, there are three axes of rotation: the anterior-posterior axis, the mediolateral axis and the longitudinal axis. Joints rotate in these axes, allowing movement to occur in the planes.