ideomotor

Ideomotor effect occurs when a complex motor task, such as snowboarding, is performed effortlessly without conscious attention. It is a consequence of a brain memorizing certain movements through repetition and sending a signal to muscles to automatically perform these movements without much conscious effort.

Isometric contraction occurs when muscle length stays the same, such as when knees are fixed in a bend position.

Eccentric muscle contraction occurs in action sports when centrifugal energy is absorbed by muscles in a loaded position. Alpine Trainer^TM  simulates this energy absorption by applying muscle contraction created by bending hip, knee and ankle joints against the resistance element of the machine.