A1 is an amputee sport classification used by the International Sports Organization for the Disabled (ISOD) for people with acquired or congenital amputations. This class is for sportspeople who have both legs amputated above the 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.
Definition
This class is for people who have both legs amputated above the knee. This classification is sometimes abbreviated as A/K. In competing in other sports, this class may have a different name:
Performance and physiology
The nature of a person's amputations in this class can effect their physiology and sports performance. 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 120% more oxygen to walk or run the same distance as someone 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 involves the knee buckling, there are a number of causes including the heel being too firm, excessive heel leverage, incorrect alignment of the prosthetic knee or weak hip extensions. All but the last can be fixed by making adjustments to the prosthetic. The last is fixed by doing more gait training. If the prosthetic foot is rotating at heel strike, the cause is likely a poor socket fit or rotation. This is fixed by adjusting the socket.
Prosthetic fitting and functionality in this class can differ depending on where, between the knee and hip, the amputation exists. The lower the amputation, the greater the lever the prosthetic user has using prosthesis and the more control they have in its usage. The higher the amputation, the less control they have. This can result in problems with balance.
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 .
Governance
This classification was set up by ISOD, with the current version adopted in 1992 and then modified in 1993. IWAS was created following the merger of ISOD and International Stoke Mandeville Games Federation (ISMGF) in 2005. Subsequently, IWAS became the classification governing body for some amputee sports. In a few cases for wheelchair events run by IWAS, CP-ISRA parallel classes may be used to allow wheelchair using amputees to compete in these events. In the case of A2, this means that CP3 sportspeople from CP-ISRA may be in their class.
Sports
People in this class are more likely to participate in wheelchair sports than other amputee classes.
Athletics
For athletics competitions that use the IPC athletics classification system, this class competes in T54, F56, F57 and F58.
People in this class use a prosthetic limb when competing in athletics. It has four parts: a socket, a knee, a shank and a foot. Above the knee amputees have difficulty using standard able-bodied sprint actions because of the differences in their functional muscle mass. As a result, they often use a specialized sprinting technique called “Leg-Over-Leg”. This technique involves using hip extensions to avoid deceleration caused by the prosthetic leg hitting the ground. Use of a specially made carbon fibre running prosthetic leg assists runners in this class in lowering their heart rate compared to using a prosthetic not designed for running. Runners in this class can have lower metabolic costs compared to elite runners over middle and long distances. In shot put, people in this class often plant their left leg against the toe board when they begin the glide stage of their throw. Double amputees have difficulty using a starting block in track events because they cannot align their legs with the block in the standard way. They often use different starting positions as a result.