English to Lithuanian Art/Literary Poetry & Literature Vilkolakių transformacija

Esmė tokia, kad į kalėjimą pasodintas vyras virsta vilkolakiu. Kad ir kiek galvočiau, nesuprantu kas vyksta su jo keliais :(
Šiek tiek konteksto:
The changes come on gradually in the first minute, but then they quicken. He arches his back, his legs pressed against the floor, but he reaches back with his head, breathes hard and the shuddering stops, his legs still and streched out. His stiffled moan rises over the grating click as his knees flex and unhinge, bending backwards. The arms go slower, the bones in hi shoulders grind like an arthritic joint, trying to find a position.