Self-reported knee pain and disability among healthy individuals: reference data and factors associated with the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS-Child.
To develop normative reference data for the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS-Child, as well as investigate socio-demographic, psychological and physical factors associated with knee pain and disability among healthy adults.



The KOOS or KOOS-Child (each containing five subscales) was administered to participants aged 8-101 years within the 1000 Norms Project, an observational study of 1000 self-reported healthy individuals. Self-efficacy, physical activity, body mass index (BMI), lower limb alignment, knee frontal plane projection angle (FPPA), knee range of motion (ROM), knee and hip strength, six-minute walk, 30-second chair stand and timed up and down stairs tests were collected. KOOS data were dichotomised using established cut-off scores and logistic regression analyses were conducted for each subscale.



Socio-demographic characteristics were similar to the Australian population. Normative reference data were generated for children (8-17 years) and adults (18-101 years). Female adults were up to twice as likely to report knee pain, symptoms and sport/recreation (Sport/Rec) limitations compared to males (P < .05). Older age, lower self-efficacy, greater BMI, varus lower limb alignment, lower knee flexion ROM and lower hip external rotation (ER) strength were independently associated with knee pain and disability among adults.



Age- and gender-stratified reference data for the KOOS and KOOS-Child have been developed to guide interpretation of results in practice and research for individuals with knee disorders. Psychological and physical factors are linked with self-reported knee pain/disability among adults, and longitudinal studies to investigate causation are required.
Arthritis and Musculoskeletal Research Group, Faculty of Health Sciences, University of Sydney, Australia. Electronic address: jennifer.baldwin@sydney.edu.au.
J N
JN
Baldwin
Arthritis and Musculoskeletal Research Group, Faculty of Health Sciences, University of Sydney, Australia.
M J
MJ
McKay
Arthritis and Musculoskeletal Research Group, University of Sydney, Australia.
M
M
Simic
Arthritis and Musculoskeletal Research Group, Faculty of Health Sciences, University of Sydney, Australia.
C E
CE
Hiller
Arthritis and Musculoskeletal Research Group, Faculty of Health Sciences, University of Sydney, Australia; Department of Health Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia.
N
N
Moloney
Arthritis and Musculoskeletal Research Group, Faculty of Health Sciences, University of Sydney, Australia.
E J
EJ
Nightingale
Arthritis and Musculoskeletal Research Group, Faculty of Health Sciences, University of Sydney, Australia; Paediatric Gait Analysis Service of New South Wales, Sydney Children's Hospitals Network (Randwick and Westmead), Australia.
J
J
Burns
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018771:Arthralgia / Q000209:etiology*; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000503:physiopathology; D000071066:Patient Reported Outcome Measures; D011379:Prognosis; D011788:Quality of Life; D016059:Range of Motion, Articular / Q000502:physiology; D012016:Reference Values; D057566:Self Report; D055815:Young Adult
Disability evaluation; Knee; Physical fitness; Self-report; Surveys and questionnaires