I normally have a tight pec minor and bicep on one side (“Deep Front Arm Line” in myofascial train theory). I did some simple tricep activation on that side (it’s usually switched off), and the tension was reduced significantly.

Hence the lesson is: we need a combination of appropriate neurological activation as well as myofascial techniques in order to create balanced muscular activation and optimal functional movement throughout the body.

Myofascial tension is a consequence of both mechanical/structural effects as well as neurological factors.