Lots of useful stuff here

http://benefitsnow.co.uk/esa/l…..bility.asp Lots of useful info on here

The limited capability for work test is the first part of the assessment process for Employment and Support Allowance. Those who fail the test will not be awarded ESA and will need to consider applying for Jobseekers' Allowance instead.
Employment and Support Allowance page index

Introduction to Employment and Support Allowance (ESA)
The limited capability capability for work assessment
The limited capability for work-related activity assessment
The work-focused health related assessment
The work-focused interview
Employment and Support Allowance payment rates
Employment and Support Allowance sanctions
Employment and Support Allowance contributory conditions
Income-related Employment and Support Allowance
Calculating income for Employment and Support Allowance (IR)
Calculating capital for Employment and Support Allowance (IR)
Employment and Support Allowance and residence in Great Britain
Employment and Support Allowance and young people



Once you have completed and returned the initial claim form, a DWP decision maker will look at your application to see if you have given enough information to demonstrate that you have a limited capability for work and for work-related activity. If the decision maker needs more information you will be sent form ESA 50 which asks questions about your physical and mental function.

Disability Alliance advises that you should indicate that you can't do things if they cause you "too much pain or discomfort", it also advises that if tasks are so tiring or painful that you could not repeat it withn a reasonable time then you should treated as not able to do it. This advice is based on Commissioner's decision in case refCIB/14587/96 (word doc.)