What is the most common source of topping the ball. I video taped myself hitting the ball off the grass at the driving range with a 5 iron, and my arms seem to collapse through impact.

I've had all kinds of advice, but they mostly seem opinion based.

Does anyone know any good excercises for curing this problem, which gets much worse on the golf course when I tense up.

By the way, when I do make solid contact with the ball, it usually goes dead straight. On the driving range this happens 1 out 4 times or thereabouts.

Peder
Chelsea, QC