Shank - over practicing? -disregard last followup

Question
QUESTION: It doesn't happen at the driving range anymore because I limit my time to about 30 min.  After about 45 min, I would be banging away pretty consistent and then I would hit a short iron and it would happen all of a sudden. Trying all the techniques did nothing and the only cure was to completely stop.  

This also happened when I was out at the field practicing PWs.  I had to completely stop because, no matter what I tried, nothing worked.  Later that day, I went back to the park for about 5 minutes and everything was OK.

Ditto with doing short game practice - and it happened a week ago and yesterday.  I was going along for about 40 minutes and it popped up all of a sudden and got to the point where I would even shank a chip shot.  I tried the one hand drill, which worked a couple times.  Again, the only fix was to stop.   About 20 minutes later, I went to the park and had no problem pitching (I only did it about 5 minutes).

The other thing that goes along with it is that I start topping the ball or I will get it airborne and the ball gets very little distance.  The only fix is to stop practicing.

It never happens on the golf course.  I play better with a minimal warmup and by using a fairway wood off the tee for the first 3 holes.  

There is one thing... a hook is non-existant these days.  

What I'm thinking is maybe my muscles in the forearms or my wrists are tightening if I over do the practice.

ANSWER: Lou:

Perhaps, and if you get tired or lazy, you'll probably overuse your hands down at the impact area which leads to a shank.  Also, check your backswing, make sure it's not too far inside on the takeaway.  

Eddie

---------- FOLLOW-UP ----------

QUESTION: The same thing happened again today.  I was checking out a 64 degree wedge I just acquired (and was really getting a good feel for it). I was showing a guy some full shots (this is usually when it shows up), hitting them nice and straight and the shank all of a sudden happened.  I stopped, did some putts and then headed home.  I stopped by the park and was doing OK for about 10 minutes, even hitting full shots.  It happpened again.  This time I tried something with a slightly open stance: swinging along my footpath when doing pitches - the ball would go left about 5 yards.  If I would try to swing along the target line, shank.  I was doing things like checking to make sure that I was taking the club back properly.  I'm just at a loss, other than limiting my practice to no more than a half hour.

Answer
Lou:

I will bet your balance is not good.  In the forward swing, you are probably moving your weight out and into your left toe.  When that happens, you'll shank it.  You don't need to move out towards the ball very much to shank it do you?  Check your balance and make sure your footwork is good.  Your weight needs to move to the outside of your left foot, from the middle of the foot to the heel.  When you are finished, we should be able to see a couple of spikes under your left toe.  

Eddie