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.
Steering axis inclination is the number of degrees that a line drawn through the upper and lower ball joints (or strut and lower ball joint) and viewed from the front is tilted to the left or the right. This, in combination with caster, is responsible for the directional stability and self-centering of the steering.ositive caster means that the top of the upper ball joint (or strut) is tilted toward the rear of the vehicle, and negative caster means that it is tilted toward the front. A vehicle with a slightly positive caster setting will have its lower ball joint pivot slightly ahead of the tire's center.