The conclusion from the research:
Eccentric training produces specific gains in eccentric strength, which can be observed as an increase in the eccentric-to-concentric strength ratio. This gives muscles a greater capacity to decelerate, and absorb energy. This superior ability to absorb energy is probably why eccentric training then leads to a reduction in the risk of getting a muscle strain injury. Eccentric training is therefore an essential element of strength training programs for sport.
Although conventional stretch-shortening cycle (SSC) strength training involves an eccentric phase, it decreases the eccentric-to-concentric strength ratio. During SSC training, the force you exert is lower relative to your maximum ability in the eccentric phase, than in the concentric phase, because of large strength differences between phases. This means that the concentric phase is trained comparatively harder, and concentric strength increases by more than eccentric strength.
Read the entire article here:
https://www.strengthandconditioningresearch.com/perspectives/eccentric-training-muscle-strains/