The incidence of brachial plexus injury during vaginal delivery is around 2 in 1000 and most commonly arises in large babies (macrosomia in diabetes), twin deliveries and shoulder dystocia (difficult delivery of the shoulder after the head with compression of the shoulder on the pubic symphysis)

Erb's palsy

• Most common type of obstetric brachial plexus palsy

Aetiology

• Injury to the upper (C5 + C6) nerve roots resulting in loss of motor innervation of the deltoid, supraspinatus, infraspinatus, biceps and brachilais muscles

Clinical features

• Injury leads to internal rotation of the humerus (from unopposed subscapularis) and may lead to the classic waiter’s tip posture

Management

• Physiotherapy is required to prevent contractures early on and prognosis is predicted by the return of biceps function by 6 months with good outcome in 80‐90% of cases
• Surgical release of contractures and tendon transfers may be required if no recovery

Klumple's palsy

Aetiology

• Lower brachial plexus injury (C8 + T1 roots) caused by forceful adduction

Clinical features

• Injury results in paralysis of the intrinsic hand muscles +/‐ finger and wrist flexors and possible Horner’s syndrome (due to disruption of the first sympathetic ganglion from T1)
• The fingers are typically flexed (due to paralysis of the interossei and lubricals which assist extension at the PIP joints)

Management

• Prognosis is poorer than for Erb’s palsy with less than 50% recovery and there is no specific treatment