The increased performance benefit associated with muscle contractions that take place during SSCs has been the focus of much research in order to determine the true nature of this enhancement.
It has been postulated that elastic structures in series with the contractile component can store energy like a spring after being forcibly stretched.
[1] Since the length of the tendon increases due to the active stretch phase, if the series elastic component acts as a spring, it would therefore be storing more potential energy.
[2] This research is further supported by Roberts et al.[3] However, other studies have found that removing portions of these series-elastic components (by way of tendon length reduction) had little effect on muscle performance.
The results of these often contradictory studies have been associated with improved efficiencies for human or animal movements such as counter-movement jumps and running.