So you are disabled and thinking about working within the fitness industry – here is a easy to follow guide about what qualifications you need to teach what. 
Level 2 Gym instructor qualification – comprises of x2 theory multiple choice exam papers (70% pass rate on both), x2 work books, and a practical exam. This is the minimum qualification you need to work in a gym, and is needed to progress on to most level 3 qualifications. 
Level 2 Exercise to Music qualification – comprises of x2 theory multiple choice exam papers (70% pass mark!) x2 work books & a practical exam. 

This is the minimum qualification you need to teach aerobics & most gyms now require this if you want to teach a group fitness class. 
Level 2 kids fitness same as above but means you can teach kids as well. 
Level 3 qualifications follow the same pattern and have x2 theory papers, pratical and work books, some may vary from this and will just have work books & a case study instead.

Level 3 qualifications include:

Personal Trainer (PT) 

GP Referral (rehabilitation)

Exercise for older clients

Pre/post natel

Exercise & Disability
If you are disabled & want to train to work within the industry please consider Instructability – a funded programme to train you up to become a level 2 gym instructor and level 3 exercise & Disability qualification so you can train disabled clients. You will also get a 3 month work placement in a gym. Priceless experience which can lead on to paid work. It did with me.
With this you can go on & do the practical ETM and more level 3 courses. 
CPD courses

If you want to teach group fitness classes you need to do CPD courses on what you would like to teach. Here is a few examples: Zumba, Clubbercise, insanity, bokwa, Boogie bounce, fit steps, Kettlebells, Circuits etc etc 

The more you do the more you will be able to offer & work more. 

Please go to http://www.instructability.org for more information on this. 
I started off through Instructability. I done my ETM since and I teach Zumba, Clubbercise & Boxercise classes & am a Clubbercise pro- trainer. I also do GP a Referral gym sessions. From my gym training I am now a physical disabilities outreach worker so doing the course can get you jobs outside of the industry too. 
If your disabled & interested in training to be a Clubbercise instructor please contact me via my website http://samjames.zumba.com