Hurt leg and backside in machinery leading to sympathy (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

HARM (hurt) + ON (in cricket terminology = leg = the side of the wicket where the batter stands) + last letter (backside) of [machiner] Y . A slightly awkward definition, but to be in harmony / sympathy with someone = to share their opinions or aims.