Powered swivel seats are also available if you are unable to turn the seat yourself. This will add to the cost quite significantly and the quality can vary according to the manufacturer. As always seek independent advice and get prices from more than one source. If a powered swivel isn't necessary at the moment but could be useful in the future make sure the seat can be adapted.
A recent development is the option of a two-way powered swivel. This enables the user to get off the seat in the most convenient position at the top and bottom of the stairs. This is a costly option and isn't necessary for most people, however it can be of great use in certain circumstances. At the time of going to press only one of the manufacturers is able to provide this option.