The purpose of this study is to determine whether an intervention with Physical activity on prescription (PAP) to individuals in primary care with knee or hip osteoarthritis would result in effects on physical activity level, physical capacity and quality on life.

The hypothesis is that patients with osteoarthritis in hip or knee will increase their level of physical activity significantly more with a PAP intervention compared to patients who only get general advice about physical activity.

According to guidelines the recommended first-line management for people with osteoarthritis consist of exercise, information about osteoarthritis and if necessary, weight reduction. It is well documented that exercise has a positive effect on pain and physical function in these patients. Therefore, it is important to have methods to increase physical activity levels in these patients. It is not explored whether an intervention with PAP may lead to increased physical activity in patients with knee or hip osteoarthritis. The study will be a prospective, randomized, single-blind intervention study including 140 patients (70 patients/group). Patients will in a parallel design be randomized to intervention or control group. Both groups receive oral and written information about osteoarthritis and if necessary, advice on weight loss. The intervention group receives Swedish Physical activity on prescription. It is a patient-centered counselling about physical activity related to the disease. The counselling results in an individualized written prescription on physical activity including specific modes on physical activity. After three weeks, three months and six months they are offered a follow up which could be by telephone or personal meeting. During the follow up they discuss who the physical activity works out and plan new goals. The control group will receive an intervention with general advice about being active three times a week and do strength training functional during the day. Patients in the control group see the physiotherapist once.

Inclusion Criteria:

1. Patients with clinically verified osteoarthritis in knee or hip
2. Sedentary (physical activity level, less than 150 minutes of moderate-intensity or less than 75 minutes of vigorous-intensity a week) includes

Exclusion Criteria:

1. Severe pain in hip or knee when walking
2. Other serious disorders causing problems when walking
3. Back injury causing pain in the leg
4. Cruciate ligament injury in the knee which causes severe dysfunction
5. Severe menisci injury
6. Total joint replacement in hip or knee
7. Unable to understand Swedish and follow verbal visual instructions

Study population: Patients who contact primary care center because of their hip or knee osteoarthritis and which is referred to the physical therapist. Seven health centers in Gävle include patients.