Most men with spinal cord injury cannot ejaculate during sexual intercourse.
The spinal cord is involved with two phases of the ejaculatory process. The first allows semen to move into the urethra. The second allows that semen to be pushed out of the urethra. For all of this to happen, chemical messages need to travel between the brain and the genitals via the spinal cord. But when a man has spinal cord injury, this travel is impaired.