Hi Maggie,
Great question! I agree that when initially thinking about a plexus injury, we think about an extended arm. However, when the brachial plexus is injured, nerve roots that innervate the biceps (C5, C6) and the triceps (C6, C7, C8) can both be injured. Many kids can get an elbow contracture because the nerve damage to the elbow extensors is worse than the damage to the elbow flexors, causing a muscle imbalance. This ultimately causes the flexors to shorten over time and a contracture to form. This doesn’t happen in all kids, so an elbow extension orthosis isn’t always necessary…just something to keep in your toolbox if you notice a contracture forming and especially if it is creeping up on 30° or greater. Check out this article for some more interesting background information: https://www.sciencedirect.com/science/article/abs/pii/S0894113023001308
Jessica
