Shoulder elevates during hold
The target trap re-engages by shrugging, negating the stretch.
Overactive muscles
Upper trapeziusLevator scapulae
Corrective work
Foam RollUpper traps↗StretchNeck side stretch (upper trap / levator)↗StretchChin tucks↗The target trap re-engages by shrugging, negating the stretch.
Rotation substitutes for pure lateral flexion, targeting SCM rather than trap.