- Discussion:
   - injuriy to long thoracic nerve (serratus anterior) leads to medial winging;
- injury to the spinal accessory (trapezius) leads to lateral winging;

- diff dx:
- brachial plexus injury /preganglionic injury
- serratus anterior / long thoracic nerve
- trapezius
- fascioscapulohumeral muscular dystrophy
- parsonage turner