Shoveling catwalks, felt back pop.Treatable first aid. Pain persisted through weekend, went to Dr. 10/23/06 for eval. Eval. was back strain, Dr. recomendended phy. ther.& continue working. Increased back pain, returned to Dr. 12/12/06. Dr. rx MRI, time off for 2 weeks. Emp. was re-eval. 12/14/06, following reading of MRI,was released to return back to work 12/18/06.