He was carrying an extension lead and tripped over it, the silly bugger. He landed on his lower back, slightly to the right of his spine.
It was painful for a few days but no sign of damage (no bruise or swelling). From around Wednesday he had a wee bump, and it was a bit more painful.
He raked the (large) lawn yesterday and cleared away the leaves and now has much more pain and it has swelled up even more.
What do you think?