Shoulders shrug on the pull
Upper traps elevate; rear delts and mid-traps underactivate.
Overactive muscles
Upper trapeziusLevator scapulae
Corrective work
Foam RollUpper traps↗StretchLevator scapulae stretch↗Upper traps elevate; rear delts and mid-traps underactivate.
Partial range limits the rear delt peak contraction; use lighter load for full range.