These sub-classifications are determined by medical tests performed by an opthamologist. The Functional Classification is based on a combination of the locomotor disabilities. This relates to the different classes that the competitor would compete in at a competition. Class S7 relates to the events of freestyle, backstroke and butterfly. This system can be compared to weight classifications in wrestling or rowing.
Athletes are eligible only if they fit within the parameters.
Functional swimmers are tested for classification several times throughout their swimming careers. A swimmer will be issued a classification, by a provincial classifier, when they first join the sport. They are tested again at their first national championships and again if they process to the international level. Swimmers will also be reclassified if there is a change in their locomotor skills either from trauma or progression of some disabilities, or if there is a change in the classification system. Functional tests are done both on land and in the water.