The Medical Research Council Manual Muscle Testing Scale, or MRC Scale, is a scale from 0 to 5 which is used to measure muscle power. A higher numeric value was associated with higher strength. The scale was developed by the Medical Research Council in 19431.
The MRC Scale is also known as the Oxford Scale.
| Table: MRC ratings2 | |
|---|---|
| MRC Rating (0…5) |
Description |
| 0 | No activation; the muscle is completely paralyzed. |
| 1 | Minuscule activation; the muscle may twitch or move a small amount. |
| 2 | Muscle activation with full range of motion, but with the effects of gravity excluded. |
| 3 | Muscle activation with full range of motion and against the effects of gravity. |
| 4 | Muscle activation with full range of motion, against the effects of gravity, and a moderate amount of resistance. |
| 5 | Muscle activation with full range of motion and a significant amount of resistance. |
The biceps muscle, commonly referred to as the bicep, is found on the upper portion of the arm, on the anterior (front) side. It will bend the arm at the elbow, when it is activated,
For this test, the patient should be sitting upright in a chair, or at the edge of a bed or table, with their forearm resting on their own thigh.
The MRC rating for the biceps muscle would be equal to the highest achievable rating in the sequence below.
MRC 0: When asked to activate their biceps muscle, no movement of the forearm will occur. Further, it will not be possible to see or feel that the muscle has contracted at all.
MRC 1: When asked to activate their biceps muscle, very little or zero movement of the forearm will occur, but it will be possible to see or feel that the muscle has contracted.
MRC 2: An assistant should hold the patient's elbow to the side, high enough to make the upper arm horizontal; the elbow should be at the same height as the shoulder. The wrist should be likewise supported by the assistant. When asked to activate their biceps muscle, movement of the forearm will occur.
MRC 3: When asked to activate their biceps muscle, movement of the forearm will occur, but if resistance is applied by an assistant, movement is not possible.
MRC 4: When asked to activate their biceps muscle against moderate resistance provided by an assistant, movement of the forearm will occur.
MRC 5: When asked to activate their biceps muscle against significant resistance provided by an assistant, movement of the forearm will occur.
| Table: Abbreviations used for muscle groups with the MRC scale3 | |
|---|---|
| Muscle Group | Abbreviation |
| Ankle dorsiflexors | AD |
| Ankle plantar flexors | AP |
| Common finger extensors | CFE |
| Elbow extensors | EE |
| Elbow flexors | EF |
| Hip abductors | HAB |
| Hip adductors | HAD |
| Hip extensors | HE |
| Hip flexors | HF |
| Knee extensors | KE |
| Knee flexors | KF |
| Neck extension | NE |
| Neck flexion | NF |
| Shoulder abductors | SA |
| Shoulder external rotators | SER |
| Thumb flexors | TF |
| Wrist extensors | WE |
| Wrist flexors | WF |