Torso rolls back during raise
Body rotation substitutes for pure shoulder abduction, removing deltoid isolation.
Overactive muscles
Upper trapeziusPec minor
Corrective work
Foam RollUpper traps↗StretchUpper trap doorframe stretch↗Body rotation substitutes for pure shoulder abduction, removing deltoid isolation.
Arm shortens to reduce the lever, making the movement easier and less effective.
Partial ROM that never challenges the deltoid at its full arc of abduction.