Athletes are grouped according to their functional ability to perform each stroke in a process known as ‘classification’. Athletes can have a physical, visual or intellectual impairment. The rules of the Federation Internationale de Natation (FINA) are modified including-water starts for some athletes and ‘tappers’ for those with visual impairments. No prostheses or assistive devices are allowed in the pool.
Events can begin in a variety of ways. While freestyle, breaststroke and butterfly races usually commence from a starting platform, athletes can already be in the water if they would have difficulty making a diving start.
Events that start in the water, including backstroke, usually begin with athletes holding a grip installed on the starting platform. Athletes in these events can use an aid such as a belt or start while holding a string or towel in their mouth if it would be difficult to hold the grip due to a physical impairment.
The same applies to the finish line. Athletes participating in breaststroke and butterfly races, where it’s standard practice to touch the pool end wall, are permitted to touch with a part of their upper body depending on their impairment.
Athletes also adapt their technique to compensate for their impairment.