stretchshorteningcyklussen

The stretch-shortening cycle (SSC) is a fundamental neuromuscular mechanism that describes the interaction between eccentric (lengthening) and concentric (shortening) muscle actions. It is a rapid sequence of an eccentric contraction followed immediately by a concentric contraction of the same muscle. This cycle is crucial for generating more force and power than a purely concentric contraction alone.

The SSC is often described as having three distinct phases. The first phase is the eccentric phase, where the muscle lengthens under tension, storing elastic energy in the musculotendinous unit. The second phase is the amortization phase, which is the brief transition period between the eccentric and concentric actions. A short amortization phase is generally associated with greater force production. The third phase is the concentric phase, where the muscle shortens, releasing the stored elastic energy and contracting to produce movement.

This mechanism is prevalent in many everyday activities and athletic movements, such as running, jumping, throwing, and kicking. It allows for more efficient and powerful movements by utilizing the body's elastic properties. The ability to effectively utilize the stretch-shortening cycle is a key determinant of athletic performance in power- and speed-oriented sports. Training methods often focus on improving the efficiency of the SSC, which can lead to enhanced explosiveness and reduced energy expenditure during repetitive movements.