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Grading of functional weakness
What is the Grading of functional weakness?
The most widely used system was developed by the Medical Research Council (MRC) of Great Britain.
The MRC system grades strength from 0 to 5. The addition of a plus (+) or minus (−) further quantifies strength:
- 0. No movement
- 1. Trace movement
- 2. Able to move, but not against gravity
- 3. Able to move full range against gravity
- 4. Able to move against some resistance
- 5. Normal strength
In addition, the clinician may observe the patient performing the following maneuvers to look for subtle weakness:
• Arise from a chair with arms folded
• Walk the length of the examining room on toes, on heels, and tandem
• Hop on either foot
• Perform deep knee bends
• Climb a step
• Horizontally abduct arms and reach the vertex of the head
• Lift up the head from a table
• Arise from supine position with hands overhead
• Lift head and shoulders, and extend the neck while in a prone position
Sources
Medical Research Council: Aids to the Examination of the Peripheral Nervous System . London: W.B. Saunders, 2000.
