Shazier's latest milestone: Three-foot box jump

Shazier does box jump with ease (0:19)

Ryan Shazier shares an update from his recovery process with a video of him doing a box jump. (0:19)

Ryan Shazier has hit many milestones since he suffered a severe spinal injury that threatened his ability to walk.

But the Pittsburgh Steelers linebacker just shared maybe his best yet: executing a box jump, clearing what appears to be about three feet.

Asked via text about the viral video on his Instagram, Shazier told ESPN that he has been aiming for this one for "a while."

Shazier, the two-time Pro Bowler who was carted off the field Dec. 1 in Cincinnati after a tackling attempt and had spinal stabilization surgery in the days after, has executed the jumps in stages, according to Shazier's father, Vernon.

"The first boxes were a lot lower than that," he said. "It all began with just trying to jump -- no box. It slowly graduated to what you see in that video."

The Shazier family has hundreds of rehab videos, and he publicly shares milestones. Paralysis was a concern in the days after the injury, but since then, Shazier has retaught himself to walk, drive a car, jog and lift weights.

Shazier's contract for 2019 tolled at a minimum salary, giving him one more year toward NFL pension. He might not be playing, but he serves as inspiration inside the Steelers facility. Asked recently about the Steelers' move to keep him on the roster with the physically unable to perform (PUP) designation, coach Mike Tomlin said the decision was simple -- because "it's Ryan Shazier."

Vernon Shazier said his family doesn't keep track of dates and times of milestones but simply "get up every day and go to war."

"He's grinding every day. It's been very intense," he said. "He's come a long way but has a long ways to go. We're grateful for the progress he's achieved. He's been dedicated to doing all he can to make as much progress as he can. We don't have a ceiling, just working day to day.

"You know how the journey began, so to see him do that is very encouraging."