A1 (classification)

For athletics competitions that use the IPC athletics classification system, this class competes in T54, F56, F57 and F58.[1][4][16]

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.[1] 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.[1] 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.[17] Runners in this class can have lower metabolic costs compared to elite runners over middle and long distances.[17] 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.[1] 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.[1]

A study comparing the performance of athletics competitors at the 1984 Summer Paralympics found there was no significant difference in performance in times between women in A1, A2 and A3 in the discus, women in A1 and A2 in the javelin, women in A1 and A2 in the 100 meter race, men in A1, A2 and A3 in the discus, men in A1, A2, A3, A4, A5, A6, A7, A8 and A9 in the javelin, men in A1, A2 and A3 in the shot put, men in A1 and A2 in the 100 meter race, and men in A1, A2, A3 and A4 in the 400 meter race.[18] Double below the knee amputees also have a competitive advantage when compared to double above the knee amputees.[19] From the 2004 Summer Paralympics to the 2012 Summer Paralympics, there was no significant changes in performance times put up by male sprinters in 100 meter, 200 meter and 400 meter events.[19]

In general, track athletes with amputations should be considerate of the surface they are running on, and avoid asphalt and cinder tracks.[1]

The wheelchair basketball classification system used by the IWBF is open to people from this class. Those with hip articulations are generally classified as 3 point players, while those with slightly longer leg stumps in this class are 3.5 point players.[8] Despite wheelchair basketball having been around since the first Paralympic Games, amputee players from this class were first allowed to be classified and participate internationally in 1983 following the creation of a functional classification system in Cologne, Germany by Horst Strokhkendl. Players from this class first competed at the 1983 Gold Cup Championships.[20] In the United States under the old classification system used by the NWBA, members of this class who had hip articulations would compete in class 2.[21]

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  Potential amputation profile of a person in this class and their related wheelchair basketball classification
• 
  Potential amputation profile of a person in this class and their related wheelchair basketball classification
• 
  Potential amputation profile of a person in this class and their related wheelchair basketball classification

People in this class tend to be classified in cycling events as LC4. The class is for cyclists with an impairment in both legs.[5]

People in this class tend to be classified as LW skiers. The International Paralympic Committee defined that class as "Competitors with severe disabilities in both lower limbs ... The typical disability profile of the class is double above-knee amputation."[22] While skiing, they may use a prosthesis.[22] In the Biathlon, skiers in this class can use a rifle support while shooting.[23]

People with amputations are eligible to compete in swimming at the Paralympic Games.[17][24] A1 swimmers may be found in several classes. These include S4, S5 and S6.[25] Swimmers in this class have a similar stroke length and stroke rate comparable to able bodied swimmers.[26] Prior to the 1990s, this class was often grouped with other amputee classes in swimming competitions, including the Paralympic Games.[18]

Other sports people in this class are eligible to compete in include sitting volleyball, archery, and weightlifting.[2][18] In both archery and sitting volleyball, different classes of amputees have historically competed against each other as one class for people with amputations or people who have a minimal disability level.[2][5][18] In the case of weightlifting, amputees have also traditionally been grouped together, with divisions being based on weight instead.[18] In powerlifting, only A1 and A3 are eligible as classes but they are categorized by weight, not classification type.[27] They can also participate in badminton. When playing in a wheelchair, they compete as W3. Another sport open to people in this class is lawn bowls. A1 competitors can be classified as LB1. This is a sitting class.[28] Ten pin bowling is also open to people in this class. They compete in the TPB8 class.[29] In wheelchair fencing, they are often classified as 3s, assuming they have enough stumps to assist in maintaining their balance.[10]

Sitzball, the precursor to sitting volleyball, is another option. It is open to A1 to A9 classified players along with anyone who might be classified as "les autres" or who have lesser amputations that would not qualify them for ISOD classification. It is not open to people with spinal cord injuries. Play is open, with no requirements as to which types of disabilities are on the court at any time.[28]

Rowing is another sport open to people with amputations. In 1991, the first internationally accepted adaptive rowing classification system was established and put into use. People from this class were initially classified as A2 for people with double amputations.[30]