I have nerve damage in my arm and hands due to a car accident and a brachial plexus injury. my question is will my arm movement be limited later on?

For sometime : Your arm movement will be limited for sometime ,brachial plexus injury takes a year or two to resolve ,but you should be persistent with physical therapy

Persistance: Be aggressive about physical therapy, avoid smoking, and make sure your diet has adequate B vitamins and other supplements to optimize nerve health. Remember that it a long ongoing process and stay committed to recover.