Hi, Welcome to Healthcaremagic.com. I had gone through your question I can understand your concern about your arm. As per your history you had a fall and this can be because of the legimemt or the muscle spasm. But as my opinion is concerned it can be because of the nerve compression too. Severe arm pain during night time only is associated with the cervical spondylitis or chronic muscle strain because of wrong posture. You need to visit an orthopedic expert or even a spine expert to get fully evaluated. During mean time you can take mild analgesics with muscle relaxant activity like paracetamol for pain relief. Hope my answer will help you and you can write to us further if you feel any need in future. Regards Dr Muzaffer Hussain Parray.