my son is 19 years old. at work he hurt his back he lifts about 50 to 100 lbs. hes been to work doctors therapy and through test .therapy told him he had a twisted vetabrate.he went to an orthapedic he did an mri he said he has a dry disk.something he must of had . but he has never had any problem before please let me know what could cause this.hes to return to work in 5 days and he cant even lift. i dont want him to be hurt worse. thank you