muscle spasm
"I was riding a Segway last weekend and unfortunately crashed and burned.  Fell on my right side.  Right now pretty black and blue. Had a lot of high intensive muscle spasms including entire upper right back area radiating around to upper chest and abdomen.  Each lasted several seconds.  Doctor prescribed 5mg Diazepam tabs up to 8 per day. Only needed four a day to start and spasms showed remarkable improvement within two days. Still have some at night when reclining or turning but I believe this will subside within a week instead of weeks.  The doctor sure knew what he was doing."