
Sen. Mark Kirk practices walking with the help of a cane, a harness and a staff member at the Rehabilitation Institute of Chicago during intensive therapy for a stroke suffered nearly a year ago. The photo, taken from a video, was provided by Mr. Kirk’s office.

Sen. Mark Kirk practices walking with the help of a cane, a harness and a staff member at the Rehabilitation Institute of Chicago during intensive therapy for a stroke suffered nearly a year ago. The photo, taken from a video, was provided by Mr. Kirk’s office.

Zac Vawter kicks a soccer ball with an experimental “bionic leg” as biomedical student Aaron Young makes adjustments at the Rehabilitation Institute of Chicago. The software engineer, 31, will put the leg to the ultimate test Sunday when he attempts to climb 103 flights of stairs at Chicago’s Willis Tower. (Associated Press)

Sen. Mark Kirk, Illinois Republican, talks with staff at the Rehabilitation Institute of Chicago last month. After suffering a stroke in January, the lawmaker recovered at the rehabilitation center. He has been allowed to go home. (Rehabilitation Institute of Chicago via Associated Press)

Sen. Mark Kirk, Illinois Republican, talks with staff at the Rehabilitation Institute of Chicago last month. After suffering a stroke in January, the lawmaker recovered at the rehabilitation center. He has been allowed to go home. (Rehabilitation Institute of Chicago via Associated Press)

In this photo taken Feb. 24, 2010, Bazelais Suy rests next to a motivational sign after attempting to stand at the Rehabilitation Institute of Chicago, as he recovers from surgery to repair his shattered spine. Suy is a Haitian student activist whose spine was crushed when a university building collapsed in Haiti's catastrophic earthquake last January. He was airlifted to Chicago for six months of intensive rehabilitation and recently returned to Haiti with hopes of helping rebuild the country. (AP Photo/M. Spencer Green)

In this photo taken Feb. 24, 2010, Bazelais Suy grimaces in pain as he attempts to stand at the Rehabilitation Institute of Chicago while recovering from surgery to repair his shattered spine. Suy is a Haitian student activist whose spine was crushed when a university building collapsed in Haiti's catastrophic earthquake last January. He was airlifted to Chicago for six months of intensive rehabilitation and recently returned to Haiti with hopes of helping rebuild the country. (AP Photo/M. Spencer Green)

In this photo taken Feb. 24, 2010, a therapist helps Bazelais Suy stand with parallel bars at the Rehabilitation Institute of Chicago while recovering from surgery to repair his shattered spine. Suy is a Haitian student activist whose spine was crushed when a university building collapsed in Haiti's catastrophic earthquake last January. He was airlifted to Chicago for six months of intensive rehabilitation and recently returned to Haiti with hopes of helping rebuild the country. (AP Photo/M. Spencer Green)

In this photo taken Feb. 24, 2010, in Chicago, Bazelais Suy works with therapist Kate Silverman, and translator Ilyas Bourchid at the Rehabilitation Institute of Chicago while recovering from surgery to repair his shattered spine. Suy is a Haitian student activist whose spine was crushed when a university building collapsed in Haiti's catastrophic earthquake last January. He was airlifted to Chicago for six months of intensive rehabilitation and recently returned to Haiti with hopes of helping rebuild the country. (AP Photo/M. Spencer Green)