Too much of an effort
Andrew Flintoff is fighting hard to be fit in time for the Ashes, much like Rafael Nadal, who is struggling with an injury ahead of Wimbledon
Both injuries are structural rather than accidental: they are long-term, perhaps even inevitable injuries. No one, given Flintoff's muscular action, can slam down his leg on slabs of hardened mud, over after over, day after day, year after year, without putting immense pressure on his joints.