Oxford Scale: Difference between revisions
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=== Reliability === | === Reliability === | ||
Intraclass Correlational Coefficient (ICC) = 0.95 (0.92-0.97)<ref name=":3">Hermans G, Clerckx B, Vanhullebusch T, Segers J, Vanpee G, Robbeets C, et al. [https://onlinelibrary.wiley.com/doi/10.1002/mus.22219 Interobserver agreement of medical research council sum-score and handgrip strength in the intensive care unit.] Muscle and Nerve 2012; 45(1): 18-25.</ref> | |||
Interrater Reliability<ref name=":3" /> | |||
* Significant weakness (MRC-SS <48) = 0.68 | |||
* Severe Weakness (MRC-SS <36) = 0.93 | |||
=== Validity === | === Validity === | ||
Revision as of 20:48, 3 February 2023
Original Editor - Justin Bryan
Top Contributors - Justin Bryan and Kim Jackson
Objective[edit | edit source]
The Medical Research Council (MRC) Muscle Scale, developed by the UK Medical Research Council, is a scale of measuring the power or strength produced by muscle contraction. The scale was originally described in the paper Aids to the Investigation of Peripheral Nerve Injuries (War Memorandum No. 7), released in 1943. Measurement is scored on a 0 to 5 scale, with 5 representing maximal strength.[1]
The Medical Research Council Sum-Score (MRC-SS) was developed in the late 1980s and first described by Kleyweg, Van Der Meché, and Schmitz (1991) as a tool for assessing and tracking general muscle strength in individuals with Guillian-Barré syndrome. Currently though, the MRC-SS is a tool commonly used to determine the presence of and/or track the development of Intensive Care Unit (ICU) Acquired Weakness.[2][3]
Intended Population[edit | edit source]
This measure was originally developed for use with patients diagnosed with Guillian-Barré syndrome, including those who were considered bedbound or were receiving mechanical ventilation. Given the characteristics of this originally intended population, the MRC-SS is now more commonly in the general critical care and ICU populations, with a specific emphasis on is use as a method for identifying and tracking ICU Acquired Weakness.[2][3]
Method of Use[edit | edit source]
Assessment of the MRC-SS can be completed in a patient's hospital room in the hospital through systematic testing of strength bilaterally for six muscle groups, producing a score out of 60. If the total score achieved is below 48/60, this is a indication of the presence of ICU acquired weakness. Of note, it is crucial that the patient possess a degree of cognitive alertness that allows participation in testing. Is the patient is unable to follow basic directions, this test is likely not appropriate.[4]
| Muscle Group Tested[4] |
|---|
| Wrist Extension |
| Elbow Flexion |
| Shoulder Abduction |
| Ankle Dorsiflexion |
| Knee Extension |
| Hip Flexion |
| Muscle Grading Scores [4] | |
|---|---|
| 0 | No detectable muscle contraction (visible or palpation) |
| 1 | Detectable contraction (visible or palpation), but no movement achieved |
| 2 | Limb movement achieved, but unable to move against gravity |
| 3 | Limb movement against resistance of gravity |
| 4 | Limb movement against gravity and external resistance |
| 5 | Normal strength |
Evidence[edit | edit source]
While the MRC-SS was originally described by Kleyweg et al. in 1991, more recent studies have examined aspects of this tool as they relate to critically ill patients and the detection of ICU acquired weakness. [2][4]
Reliability[edit | edit source]
Intraclass Correlational Coefficient (ICC) = 0.95 (0.92-0.97)[5]
Interrater Reliability[5]
- Significant weakness (MRC-SS <48) = 0.68
- Severe Weakness (MRC-SS <36) = 0.93
Validity[edit | edit source]
Responsiveness[edit | edit source]
Miscellaneous[edit | edit source]
Ceiling Effect: The MRC-SS has been noted to have a ceiling effect due to the vague demarcation between the score of 4/5 and 5/5. Discrimination of the two scores as either normal (5/5) or movement against resistance (4/5) allows for a degree of subjectivity that may allow for a degree of variability among patients whose scores fall withing these ratings.[4]
Links[edit | edit source]
References[edit | edit source]
- ↑ UK Research and Innovation. MRC Muscle Scale. Available from: https://www.ukri.org/councils/mrc/facilities-and-resources/find-an-mrc-facility-or-resource/mrc-muscle-scale/ (accessed 27 Jan 2023).
- ↑ 2.0 2.1 2.2 Kleyweg RP, Van Der Meché FG, Schmitz PI. Interobserver agreement in the assessment of muscle strength and functional abilities in Guillain-Barré syndrome. Muscle & Nerve 1991; 14(11): 1103-1109
- ↑ 3.0 3.1 Connolly B, Thompson A, Moxham J, Hart N. Relationship Of Medical Research Council Sum-Score With Physical Function In Patients Post Critical Illness. American Journal of Respiratory and Critical Care Medicine 2012;185:A3075.
- ↑ 4.0 4.1 4.2 4.3 4.4 Hermans G, Van den Berghe. Clinical Review: intensive care unit acquired weakness. Critical Care 2015; 19(274): n.p.
- ↑ 5.0 5.1 Hermans G, Clerckx B, Vanhullebusch T, Segers J, Vanpee G, Robbeets C, et al. Interobserver agreement of medical research council sum-score and handgrip strength in the intensive care unit. Muscle and Nerve 2012; 45(1): 18-25.
