Key facts
- Score direction
- Higher is better
- Meaningful change
- The developers did not establish a universal minimal clinically important difference. Responsiveness and meaningful change should be interpreted for the specific population, follow-up interval and return-to-sport goal.
- Scoring
- Each of four activities is scored by frequency: less than once a month = 0, once a month = 1, once a week = 2, two or three times a week = 3, and four or more times a week = 4. All four values are summed for a total from…
- Time to complete
- 1 min
- Questions
- 4
- Licensing
- Licensed instrument - check copyright terms before clinical use
About the Marx Activity Rating Scale (MARS)
The Marx Activity Rating Scale measures exposure to four activities associated with high-level knee function: running, cutting, decelerating and pivoting. It asks about the person's healthiest and most active state during the previous year, which reduces the effect of a recent temporary limitation. The score describes activity frequency and functional demand rather than knee symptoms or general fitness.
Medical Specialties
Anatomic Areas
Clinical Indications
Developer Information
Developed by Robert G. Marx, Timothy J. Stump, Edward C. Jones, Thomas L. Wickiewicz, Russell F. Warren and colleagues and published in 2001. The original study reported one-minute completion, test-retest reliability of 0.97 and convergent validity with established activity scales.
Copyright & Licensing
The English scale is publicly hosted by the American Academy of Orthopaedic Surgeons, but no explicit licence authorising commercial digital reproduction was identified. Obtain written permission or rights confirmation before production publication, translation, cultural adaptation or commercial electronic administration, and cite Marx et al. (2001).
Administration Instructions
Please indicate how often you performed each activity in your healthiest and most active state, in the past year.
Scoring Methodology
Each of four activities is scored by frequency: less than once a month = 0, once a month = 1, once a week = 2, two or three times a week = 3, and four or more times a week = 4. All four values are summed for a total from 0 to 16. A valid total requires all four items. Higher scores represent more frequent participation in activities that place high functional demand on the knee; they do not necessarily represent better health.
Meaningful Change Threshold
The developers did not establish a universal minimal clinically important difference. Responsiveness and meaningful change should be interpreted for the specific population, follow-up interval and return-to-sport goal.
Score Interpretation
Understanding what your score means
activity frequency
0 - 16Higher values represent more frequent participation in high-demand knee activities. No validated severity bands or universal healthy cut-offs are established, and higher scores do not necessarily mean better health.
Subscales
This questionnaire measures multiple dimensions
Clinical Limitations & Considerations
The score measures frequency of selected high-demand knee activities, not symptoms, quality of movement, duration, intensity or general fitness. The healthiest and most active state in the past year may not reflect current activity. Age, sport choice and opportunity influence scores. The original developers did not specify missing-item imputation, so all four items are required.
Supporting Literature
Key validation and development studies for the Marx Activity Rating Scale (MARS)
- 1
Development and evaluation of an activity rating scale for disorders of the knee
Marx RG, Stump TJ, Jones EC, Wickiewicz TL, Warren RF
The American Journal of Sports Medicine, 2001
Frequently asked questions
What does a activity frequency Marx Activity Rating Scale (MARS) score mean?
A Marx Activity Rating Scale (MARS) score of 0 to 16 is classified as activity frequency. Higher values represent more frequent participation in high-demand knee activities. No validated severity bands or universal healthy cut-offs are established, and higher scores do not necessarily mean better health.
Related Outcome Measures
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Oxford Knee Score
Oxford Knee Score - a 12-item patient-reported outcome measure for assessing function and pain after total knee replacement surgery
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