A3 (classification)

A3 is an amputee sport classification used by the International Sports Organization for the Disabled (ISOD) for people with acquired or congenital amputations. A3 classified sportspeople have both legs amputated below knee. Their amputations impact their sport performance, including having balance issues, increased energy costs, higher rates of oxygen consumption, and issues with their gait. Sports people in this class are eligible to participate in include athletics, swimming, sitting volleyball, archery, weightlifting, badminton, lawn bowls, sitzball and wheelchair basketball.

This class is for people who have both legs amputated below knee. This classification is sometimes abbreviated as B/K. In competing in other sports, this class may have a different name:

Lawn bowls: LB1, LB2.

Sitting volleyball: Open.

Sitzball: Open.

Ten-pin bowling: TPB8, TPB9.

Cerebral palsy: CP4.

Wheelchair basketball: 4 point player, 4.5 point player.

The nature of a person's amputations in this class can effect their physiology and sports performance. Because of the potential for balance issues related to having an amputation, during weight training, amputees are encouraged to use a spotter when lifting more than 15 pounds (6.8 kg). Lower limb amputations effect a person's energy cost for being mobile. To keep their oxygen consumption rate similar to people without lower limb amputations, they need to walk slower. People in this class use around 41% more oxygen to walk or run the same distance as some one without a lower limb amputation.

People in this class can have a number of problems with their gait. There are a number of different causes for these issues, and suggested ways to modify them. For a gait that has abrupt heel contact, the cause can be excessive heel lever. This can be fixed by realigning their prosthetic foot. For jerky knee motions, the cause could be a loose socket in the knee or inadequate suspension. In that case, the socket might need replacing or they may need to realign the prosthesis. If they have prolonged heel contact, the cause could be problems with the heel lever in their prosthesis or a worn out heel. These are fixed by increasing heel stiffness or realigning the prosthesis. In some cases, prolong heel contact or knees remaining fulling extended is a problem with training in how to use the prosthesis. Another issue might be foot drag. This can be caused by an ill fitting prosthesis that can be fixed by shortening the length of the prosthesis. Some people in this class could have uneven length strides. This can be a result of problems with hip flexion or insecurity about their walk. Both are fixed by physical therapy.

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