By Paul Rincon
BBC News Online science staff
A sailor from a sunken ship belonging to Oliver Cromwell's navy had the upper body of a trapeze artist but bowed legs, his recovered skeleton shows.
The sailor's bones reveal he had a powerful upper body
The able seaman, who was in his early 20s, stood 157cm (5ft 2in) tall and suffered from rickets as a child.
About 80% of the man's skeleton was recovered from the wreck of the Swan, a warship that sank off the Isle of Mull in Scotland on 13 September 1653.
The results were presented at the BA Festival of Science in Exeter.
The Swan was one of a six-strong fleet of ships that were dispatched by Cromwell to capture a castle of the Royalist MacLeans of Mull and end their resistance. However, a storm sank three of the ships off the coast.
Archaeologist Dr Colin Martin said bones from the wreck had been dragged along the sea bed by crabs, but they made up 80% of the same man.
The ship was designed for a crew of 40, but "Seaman Swan" as he is known to Professor Sue Black of Dundee University, and one of the investigators on the dive, was the only skeleton recovered from the wreck.
The Swan sank in a storm in 1653
The sailor's bowed legs had been caused by the rickets he had suffered as a child. Rickets is the result of the loss of calcium and phosphate from the skeleton. The consequent softening and weakening of the bones can lead to deformities of the legs.
"For all that, he was an extremely fit and healthy man who exercised beyond comprehension. His upper body was extraordinarily well-developed," Dr Martin told the British Association's annual meeting.
It is clear from this brawny physique that the man performed rhythmic balancing work, such as setting sails and hauling on ropes. Dr Martin added that the closest present-day analogy to the man's physique was that of a trapeze artist.
However, Seaman Swan also had deformities in his hips that were seemingly caused by jumping off the equivalent of a 2m (6.5ft) wall on a regular basis.
The bones were dragged around the sea bed by crabs
After climbing most of the way down the rigging, sailors slid the last way to the deck, Dr Martin said.
The 20m (66ft) long 6.7m (22ft) wide ship now lies crushed on the sea bed. Dr Martin said the ship had collapsed "like an archaeological lasagne".
A number of fish and mammal remains were also found on the ship, providing clues to what the sailors were eating. The fish remains included a species related to cod called ling, which were much larger than any ling found around Scotland today.