Abnormal Upper Cervical Stability with Arm Raise Part 2/2
When the upper neck muscles are off line because of traumatic injury to the joints or upper neck ligaments, the upper neck can become unstable on the head. In this case, the trapezius muscle kicks in as a secondary stabilizer of the head. However, this no longer works when that muscle is being used to lift the arms above the head. So the head becomes unstable in hands above the head.