The degree of motor function preserved following a spinal cord injury will depend on the level of injury, and whether the injury was complete or incomplete. Muscle strengths are graded using the following Medical Research Council (MRC) scale of 0-5:
- 5 - Normal power
- 4+ - Submaximal movement against resistance
- 4 - Moderate movement against resistance
- 4- - Slight movement against resistance
- 3 - Movement against gravity but not against resistance
- 2 - Movement with gravity eliminated
- 1 - Flicker of movement
- 0 - No movement
The level of injury is the point in the spinal cord at which damage has occurred. The levels are determined by counting the nerves from the top of the spine downwards. These nerves are grouped into four different areas. These are the Cervical, Thoracic, Lumbar and Sacral areas of the spinal cord. The location of damage to the spinal cord directly determines how groups of muscles, organs and sensations will be affected.
