A spinal cord transection occurs when the spinal cord is completely severed, disrupting the communication between the brain and the rest of the body. The spinal cord is like a highway for nerve signals—sensory information travels from the body to the brain, while motor commands move from the brain to the muscles. When this pathway is cut, the signals can no longer travel past the site of injury. As a result, any sensation below the level of the injury is lost, leading to numbness and loss of feeling. The severity and location of the transection determine the extent of numbness. For example, an injury higher up in the spinal cord, such as in the cervical region, can affect a larger portion of the body, potentially leading to numbness in the arms, trunk, and legs. In contrast, a lower injury may only affect the legs and lower body.
Numbness happens because sensory nerves, which carry information like touch, temperature, pain, and pressure, cannot deliver their messages to the brain. Even though the sensory receptors in the skin still work, their signals are blocked at the site of the spinal injury. Similarly, motor signals from the brain can’t reach the muscles, leading to paralysis or weakness below the injury level. Over time, the body may also develop secondary changes such as muscle atrophy and loss of reflex control. Unfortunately, spinal cord nerve tissue does not regenerate easily, so the effects of a complete transection are usually permanent. Rehabilitation focuses on maximizing function, preventing complications, and improving quality of life through therapies, adaptive equipment, and sometimes surgical interventions. Understanding why numbness occurs highlights the critical role the spinal cord plays in every sensory and motor function of the body. 
