1.1.2 stretch shortening cycle A level pe

Dynamic contraction

Muscle changing length under contraction

The 3 stages of the stretch shortening cycle

1. Eccentric contraction: Muscle lengthens and elastic energy is stored 2. Amortization: Motor neurons fire from the spinal cord to muscles 3. Concentric contraction: Muscles contract and elastic energy is released

static contraction

The length of the muscle does not change but the tension does in the process

eccentric contraction

This involves a muscle lengthening under tension. When a muscle contracts eccentrically it is acting as a brake. E.g the downward phase of a squat, the quadriceps is lengthening

cocentric contraction

This involves the muscle shortening under tension e.g the upward phase of a squat