Do those funny little 'Z' shaped orthopaedic stools have a name and can anyone suggest where the 'Hunchback of Acton' (as I have become known) might obtain one? Eye thankew.
The original ones were called Balans chairs. You're best buying the best quality chair you can find - the cost is in the cushion, and as you've found out, all you weight is taken on your knees.