Jacob Bullard steps off a box as part of his physical therapy at WashU, Monday, Dec. 16, 2024, in St. Louis. (AP Photo/Jeff Roberson)

Jacob Bullard leaps in the air as part of a physical therapy exercise at WashU, Monday, Dec. 16, 2024, in St. Louis. (AP Photo/Jeff Roberson)

Physical therapist Tyler Detmer, right, works with patient Jacob Bullard at WashU, Monday, Dec. 16, 2024, in St. Louis. (AP Photo/Jeff Roberson)

Physical therapist Tyler Detmer, left, works with patient Jacob Bullard at WashU, Monday, Dec. 16, 2024, in St. Louis. (AP Photo/Jeff Roberson)

Jacob Bullard warms up on an elliptical machine while undergoing physical therapy at WashU, Monday, Dec. 16, 2024, in St. Louis. (AP Photo/Jeff Roberson)

Physical therapist Tyler Detmer, right, watches as patient Jacob Bullard uses a leg press machine at WashU, Monday, Dec. 16, 2024, in St. Louis. (AP Photo/Jeff Roberson)

Jacob Bullard lifts a weight as part of his physical therapy at WashU, Monday, Dec. 16, 2024, in St. Louis. (AP Photo/Jeff Roberson)