I don’t think that a herniated disc is considered a major back injury. They are also very common among amateur and professional athletes who participate in strength sports.
Not trying to downplay the injury. But it’s not on the same level as things that cause paralysis or sensory deprivation.
Squatting and deadlifts are part of some paralysis rehabilitation protocols.
EDIT:
Here is Ryan Shazier.
During a Monday Night Football game against the Cincinnati Bengals on December 4, Shazier sustained what appeared to be a severe back injury after a head-on tackle. The hit left Shazier seemingly unable to move his legs. After stabilization he was taken to the hospital and the next morning revealed that he had sustained a spinal contusion. On December 7, Shazier underwent spinal stabilization surgery to secure the injured section of spine and to aid in his recovery. The surgery ended his 2017 season.
https://en.wikipedia.org/wiki/Ryan_Shazier