- Erb palsy (Erb's paralysis): paralysis from injury to the upper trunk (C5 and C6 roots) of the brachial plexus at Erb's point, producing a characteristic limb deformity.
Erb's Point
- Erb's point: region of the upper trunk where the C5 and C6 roots join, giving off the suprascapular nerve and nerve to subclavius before dividing into anterior and posterior divisions.
Erb's point, formation of the upper trunk Erb's point, formation of the upper trunk.
Etiology and Mechanism
- Cause: excessive increase in the angle between the head and the shoulder, as in a fall onto the shoulder (e.g., from a horse) or traction on the arm during a difficult birth.