Understanding Complete vs Partial AIS: What Every Person and Family Should Kno
27/10/2025
Living with a spinal cord injury (SCI) brings many questions for individuals and their families. One of the first things a doctor will mention is the term AIS — the American Spinal Injury Association Impairment Scale. Understanding this scale, and especially the difference between Complete and Partial (Incomplete) AIS injuries, can make a world of difference in how you view treatment, recovery, and daily life.
This guide will break down everything you need to know about Understanding Complete vs Partial AIS: What Every Person and Family Should Know, in simple language that anyone can follow.
What Is the AIS Scale?
The American Spinal Injury Association Impairment Scale (AIS) is a system used by doctors and rehabilitation teams to describe how much function remains after a spinal cord injury. It helps medical professionals measure how severely the spinal cord has been damaged, and what parts of the body might be affected.
AIS grades range from A to E, where A represents a complete injury (no sensory or motor function below the injury level), and E means normal motor and sensory function.
👉 Learn more about the official scale on the ASIA website.
How the AIS Scale Works
When assessing a person with SCI, doctors test motor and sensory function in various parts of the body. They check:
- Muscle strength in key muscle groups,
- Touch and pinprick sensation, and
- Reflexes in arms, legs, and trunk.
These tests determine the level of injury (which vertebra is affected) and the completeness of the injury (Complete vs Partial).
| AIS Grade | Description |
|---|---|
| A | Complete injury – no sensory or motor function below the injury. |
| B | Sensory incomplete – feeling is preserved below the injury, but no motor function. |
| C | Motor incomplete – some movement below the injury, but weak. |
| D | Motor incomplete – stronger movement below the injury. |
| E | Normal function – full motor and sensory abilities. |
Understanding Complete AIS (AIS A)
A Complete AIS (AIS A) injury means that all nerve signals are blocked below the level of the spinal cord injury. There is no sensation or voluntary movement below that point.
For example, if someone has a complete injury at the T6 vertebra, they will lose all motor and sensory function below the mid-chest area.
Key Facts About Complete AIS:
- No sensory or motor function in the lower parts of the body.
- The spinal cord is completely disrupted at the injury site.
- Recovery potential is limited, but not impossible.
- Rehabilitation focuses on maximizing independence.