140,000 Bad Backs?

If you have ever had severe back problems, you will know what I mean when I say that there can be few conditions more debilitating, life-restricting or painful. Under a year ago, I had what appeared to have become a chronic back problem - today, I am moving freely without even a twinge.

I wonder what proportion of the 140,000 have had problems but are now fully functional and are staying 'on sick' as a preference.
It may sound a tad 'big brotherish' but this is a case where certain claimants should be watched and filmed by fraud investigators.
You see someone playing tennis, golf, lifting or even carrying heavy shopping and their claim is shown up immediately as bogus.
There has to be a sense of proportion - some people on benefits are actually 'economical with the truth'.