Miner walked down the walkway ramp to the boat dock and stepped from ramp to dock (an 8"" tall riser ht.)Felt back pain. Did not slip or fall . We took him to E.R. Diagnosis was muscle spasms or sprain. Adm. and injection, 2 Rx's , told to stay home today and apply ice. Can repot to work on 7/21/11 if feeling ok.