Paralympics·CBC Explains

How impairment classification works at the Paralympic Games

Canada won its first two medals of the Tokyo Paralympics on Day 1 in S10 and C4 events. If you were wondering what that means, here's an explainer on how Paralympic athletes are classified within their sports based on impairment.

Canada continues to win medals in Tokyo — but what does that mean?

Canada's Keely Shaw won bronze in the women's C4 3,000-metre individual pursuit at the Tokyo Paralympics on Wednesday. (Charly Triballeau/AFP/Getty Images)

Canada won its first two medals of the Tokyo Paralympics in Japan on Day 1.

First, track cyclist Keely Shaw earned bronze in the C4 3,000-metre individual pursuit. Then, Aurélie Rivard swam to the same medal in the S10 50m freestyle.

That's mostly straightforward — two medals, and the Games weren't even 24 hours old — but what are those letter/number modifiers that precede the event name?

The simple answer is that they indicate classification. There are 10 impairments that make athletes eligible to compete in the Paralympics — eight are physical, one is visual and one is intellectual.

Eligible impairments

  • Impaired muscle power
  • Impaired passive range of movement
  • Limb deficiency
  • Leg length difference
  • Short stature
  • Hypertonia (increased muscle tension)
  • Ataxia (unco-ordinated movement due to damaged central nervous system)
  • Athetosis (continual slow involuntary movements)
  • Impaired vision
  • Intellectual impairment

In sports such as swimming and athletics, there are categories available for all 10 forms of impairments. But in others such as goalball, only the visually impaired compete. Things are made even easier in the latter as all athletes are blindfolded, making the playing field even and eliminating the need for classification.

But swimmers are organized into different categories depending on the severity of their disability. The S10 category in which Rivard swims is for those with minimal physical impairments. The 25-year-old Canadian, for example, was born with an underdeveloped left hand. 

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In Shaw's case, the C4 classification could include athletes with a below-knee amputation and a prosthesis on one leg. Shaw herself has left-side paralysis.

In general, a higher number denotes a less severe disability. The S1 category in swimming mostly includes athletes who use a wheelchair and/or have significant loss of muscle control in their arms, legs and hands. Likewise, cycling's C1 is reserved for those with the most severe physical limitations.

Each sport also has its own minimum impairment criteria, where international federations determine on a case-by-case basis if athletes are eligible to compete. It's up to those evaluators to classify eligible athletes, too.

As different sports require different skills, eligibility and classification can vary for those with similar impairments.

And so Rivard did not just win bronze in the 50m freestyle — she won in the S10 category. The race will also be contested in S4, S6, S8, S11 and S13. Nos. 11-13 represent visual impairment, with 14 standing as the intellectual impairment category.

Classification can also be broken down by discipline: S indicates freestyle, butterfly and backstroke; SB is breaststroke; and SM represents individual medley. Other sports follow similar methods as well.

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