A very good drill for you would be to hit shots with a ball under the outside edge of your right foot (or a 2/4 or similar) and focus on maintaining the flex in your right knee.

You will get a good sense for how flexible you are or aren't very quickly and this will likely be a help to maintaining your spine angle and head position. Drill this with a heavy club/two clubs held together and with your eyes closed and hold your finish to check your balance. This will help show if your setup posture/clubfitting is out of alignment quite quickly because you won't be able to hold your finish in balance.

Thanks for all the good advice guys.

Just to give a quick update since i've been exprimenting with what people have said.

Keeping my rear end back has definitely helped but i'm not convinced it's the whole story.

I've tried your drill Edz and i must admit i don't feel as flexable as i thought i was. To give a bit of background i haven't had the oportunity to play much in the last four years through being at university. I've just graduated and am looking to start playing more seriously again. I'm fairly tall 6 foot 3 inches, and do have tight hanstrings. I doubt it's related but when i was 14 (23 now) and playing all the time i did have some lower back trouble. I suffered from this for a few years till i changed my swing. I used to have a very aggressive body action through the ball combined with a lazy right leg.

If it is the case that i'm struggling due to flexability what are my options? A few people have mentioned club fitting and posture. What would this entail?

You might consider a lesson with a videotape of your swing. It will provide much faster diagnostics than trial and error.

I wish I was 23 again! (I'm 68)
 

Sounds like you should join a gym. The golf swing appears to rotate the arms around the body but in reality they only raise and low the club. In case the gym doesn't allow golf swing practise (mine doesn't), you can stand erect and practice lifting the arms over the right shoulder, wrist cock -- the whole nine yards, then the downswing, the release etc to the floor, and then raising your arms over the left shoulder into the finish. It's a great way to loosen up those sore joints. Oh to be 23 again :)

Perhaps if I have time, I could put up my stretching routine on the fitness section. I wouldn't mind getting others opinions on it too.

Danny,

The phrase above and your reference to tension on "lifting your arms" in your previous post are the clues to the cause of your problem.

The back swing is a positional move and NOT a power generator - we hit the ball on the down swing.

Try making an easy back swing that stops at the Top - hands shoulder high, roughly.

Searching for additional power by going on from the Top and raising the arms, your body and head in the process is your self-diagnosed problem.

Swing back shorter and easier, then cram on the power only after you have made a smooth transition to the down swing.

Club head speed between parallel back and parallel forwards on the down swing only should be your objective.