Overhead arm bends during the hinge
The locked-out overhead position is the defining feature; bending means shoulder instability.
Overactive muscles
Upper trapeziusPec minor
Corrective work
Foam RollUpper traps↗StretchLevator scapulae stretch↗The locked-out overhead position is the defining feature; bending means shoulder instability.
The movement is a lateral hip hinge not a squat; knees should stay soft not bent deeply.