Strongest Predictors of a Positive Outcome After Physiotherapy for Knee Osteoarthritis
Strongest Predictors of a Positive Outcome After Physiotherapy for Knee Osteoarthritis
Individuals with painful knee osteoarthritis (OA) experience restricted physical function.
 Few previous studies have investigated comprehensive sets of constructs and tests to
 investigate physical function in these patients. Most single studies of knee OA patients show
 limited scope for explaining physical function in the perspective of WHO's International
 Classification of Functioning, Disability and Health (ICF) 3 levels: Body functions (the
 bodily level), Activities (individual level), and Participation (societal level). On the
 bodily level there is limited case-control knowledge on muscle strength beyond the knee and
 endurance-strength in general. On the activity level, there is similar limitation of
 biomechanical bodily features in stair climbing. On the participation level the situation is
 similar for objective performance. Measures are needed that inter-relate all three levels of
 ICF. These should also include well discriminating tests e.g. knee strength, walking, and
 activities of daily life (ADL), as well as both objective and subjective measures.

 The purpose of this study is to explore mechanisms that can explain physical function in
 patients with knee OA in primary care. The study's main and primary goal is to quantify which
 baseline factors and change scores are the strongest predictors of a positive treatment
 outcome in terms of patients' global perceived change after physiotherapy. Secondary research
 question is: which factors are the strongest predictors of a positive outcome of
 physiotherapy in knee OA, in terms of pain intensity, patient specific functional scale, and
 function in daily living?
Inclusion Criteria:

 1. Clinical and radiological osteoarthritis of the knee and referred to physiotherapists.

 2. Symptomatic daily during the last month.

 3. Symptomatic for more than one year.

 4. Able to walk up and down a flight of 10 stairs with or without walking aids.

 5. Able to walk 3 stairs up and down without walking aids.

 6. Understand Norwegian orally and in writing.

 7. Body mass index below 35.

 Exclusion Criteria:

 1. Neurological, rheumatic, orthopedic, or respiratory diagnosis, other than
 osteoarthritis of the knee which can negatively affect the walking ability, balance or
 pain.

 2. Body mass index above or equal to 35.

 3. Fracture of the femur or shank, or arthroscopic surgery in the osteoarthritic knee.

 4. Chronic generalized pain (American College of Rheumatology Criteria, 2010).

 5. Inability to understand Norwegian language.