Classification of Spinal Cord Injuries

Spinal Cord Injuries are classified based on neurological responses, touch and pinprick sensations tested in each dermatome (an area of skin that that is mainly supplied by a single spinal nerve), and strength of ten key muscles on each side of the body. The ten key muscles include:

1. C5 – Elbow flexors (biceps)
2. C6 – Wrist extensors
3. C7 – Elbow extensors (triceps)
4. C8 – Finger flexors
5. T1 – Movement of the little finger
6. L2 – Hip Flexors
7. L3 – Knee Extensors (quadriceps)
8. L4 – Ankle dorsiflexors
9. L5 – Long toe extensors
10. S1 – Ankle plantar flexors (gastrocnemius)

The American Spinal Injury Association (ASIA) devised a classification system to easily describe and categorise the extent of a spinal cord injury based on analysing the results of the tests mentioned above.  The classification system as follows: Complete – A spinal cord injury where there is no feeling or motor control below the level of injury. Incomplete – A type of spinal cord injury where there is some motor control or feeling below the level of the injury. A – Indicates a complete spinal cord injury where the patient has no sensory or motor function. B – Indicates an incomplete spinal cord injury where the patient has no motor function below the neurological level but does have sensory function. C – This classification indicates an incomplete spinal cord injury where motor function is preserved below the neurological level. A patient that fits into this category should also have more than half of the key muscles below the injury at a grade of less than 3. In other words, the muscles have full range of movement against gravity. D- This indicates an incomplete spinal cord injury where the patients’ motor function is preserved below the neurological level and half of the key muscles or more have a muscle grade of 3 or more. E – Normal motor and sensory function.