Free online Marx Activity Rating Scale calculator

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Marx Activity Rating Scale calculator

About the score:

The Marx Scale consists of four questions concerning four activities or actions: running, cutting, deceleration, and pivoting. The patient or survey respondent is asked to report on the frequency with which they performed the activity in their healthiest state within the past year.

It is designed to be completed in less than one minute. The questionnaire is focused on actions that may be affected by disorders of the knee.

Original and Validation Literature:

Marx, Robert G., et al. “Development and evaluation of an activity rating scale for disorders of the knee.” The American journal of sports medicine 29.2 (2001): 213-218.

Additional Literature:

Collins, Natalie J., et al. “Measures of knee function: International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form (KOOS‐PS), Knee Outcome Survey Activities of Daily Living Scale (KOS‐ADL), Lysholm Knee Scoring Scale, Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Activity Rating Scale (ARS), and Tegner Activity Score (TAS).” Arthritis care & research 63.S11 (2011).

Kanakamedala, Ajay C., Allen F. Anderson, and James J. Irrgang. “IKDC Subjective Knee Form and Marx Activity Rating Scale are suitable to evaluate all orthopaedic sports medicine knee conditions: a systematic review.” Journal of ISAKOS: Joint Disorders & Orthopaedic Sports Medicine (2016): jisakos-2015.

About the score developer:

The Marx Activity Rating Scale was developed by Robert G. Marx, MD, an orthopedic surgeon specializing in shoulder and knee surgery. Dr. Marx practices at the Hospital for Special Surgery in New York where he is the Director of the Foster Center for Clinical Outcomes Research. As director of the Foster Center, Dr. Marx is involved in research that aims to improve patient care.

To view his publications, please visit PubMed.

To view his personal webpage, please visit