Hello. I am a 47 year old male who has recently developed a problem with the muscles in my left arm (Bicep and forearm ), where the muscles have lost strength and are periodically painful. Other unusual side effects are, after sleeping my arm tends to lock at the elbow , radiating pain outwards in both direstions to the 2 connecting muscles. I have also noticed the ring finger on my left hand is swollen, starting from around the same time these other symptoms began. I contacted my GP and he seemed stumped, giving me a 10 day supply of anti inflammitories. The symptoms had subsided to a degree during that period but not entirely. Any suggestions what the cause may be?