The term "eccentric phase" refers to a specific part of a movement or exercise where the muscle is lengthening while still under tension. Full definition
Since this is about primal - what is the primal justification for having more strength in eccentric phase of muscle contraction? (marksdailyapple.com)
For the first 2 weeks, every front squat was performed with a 5 second eccentric phase. (rugbystrengthcoach.com)
In contrast, there was no difference in gastrocnemius muscle activity between the concentric and eccentric phases when performing the narrow stance high foot placement. (strengthandconditioningresearch.com)