Part of a safe stretch program is setting the goal of enhancing joint mobility (flexibility) while maintaining joint stability (strength). (womenshealthandfitness.com.au)
If you have any concerns about shoulder joint stability, don't lower the bar so far that the top part of the arm falls much below parallel. (verywellfit.com)
This increases the amount of compression force on the joints, which is good for joint stability. (kingofthegym.com)