American swimmer Victoria Arlen is free to compete in the London Paralympics following an assessment of her impairment.

The International Paralympic Committee originally ruled after an evaluation in London on Monday that Arlen's impairment no longer fit a classification.

The U.S. Paralympic Committee launched an appeal, leading to Arlen being reassessed by the IPC. After providing information absent from the first evaluation, the IPC said in a statement Thursday that she can remain in the sport classifications in which she was entered.

However, the IPC added that the "class allocation is subject to any modification that may be made following observation in competition.''

It means Arlen will take part in the heats of the S6 400-meter freestyle on Saturday, her first event of the games.

The 17-year-old Arlen of Exeter, N.H., returned to swimming last year after a neurological virus affected her spinal cord in 2006 and left her in a vegetative state for two years. She set world records for the S6 100 and 400 in the U.S. trials this year.

Swimmers are allocated into classes between 1 and 14, with 1-10 containing those with a physical disability. Class 1 is the most severe and class 10 the least.

The IPC also said Thursday that 40 athletes had their classifications changed before the start of the games. Two of those are American swimmers Justin Zook and Mallory Weggemann, who have won 10 Paralympic golds between them.

The U.S. Paralympic Committee appealed the decision but it was rejected Wednesday, meaning they will have to compete against more able-bodied swimmers.

The IPC typically reclassifies athletes ahead of major championships.

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