Patient case (clinical description): A 47-year-old woman comes to the office complaining of pain in the calf and knee when she bends down. The pain limits her activity. Her medical history is significant for osteoarthritis, for which she uses nonsteroidal anti-inflammatory drugs (NSAIDs) for the past two years. She is living with her husband and has 3 children. She doesn't smoke but drinks alcohol occasionally. Her vital signs are normal. On physical examination, there is a small effusion in the right knee. The effusion grew a little larger and she developed a tender swelling in the popliteal fossa and calf. Both the pain and swelling worsened as she bent and straightened her knee.

Patient's own account: I'm a 47-year-old woman, married with 3 kids. I don't smoke and I drink occasionally. I went to the doctor because of pain in my calf and knee when I was bending down. This has been limiting my daily activities. I have been diagnosed with osteoarthritis for which I have taken anti-inflammatory drugs for the past 2 years. The doctor saw a small fluid buildup in my right knee. This buildup became a bit bigger and I have a swollen calf. The pain is worse when I bend and straighten my knee.

Clinical trial: The Effect of Exercise on Serum Levels of Collagen and Proteoglycan in Patients With Knee Osteoarthritis (EFEX-OA-01)

Eligibility criteria:
Inclusion criteria for OA patients:

          1. Kellgren-Lawrence radiological grade of 1-3 in at least one tibio-femoral joint
             diagnosed by screening x-ray.

          2. 35 to < 75 years of age at the time of signing the informed consent form.

          3. Bodyweight > 50 and < 150 kg and a BMI in the range 18,5-35 kg/m2.

          4. Are male or female.

          5. Is able to meet for all of the four study visits and comply with the dietary and
             activity restrictions.

          6. Can give informed consent.

        Exclusion criteria for OA patients:

        Medical conditions:

          1. History of arthroscopy or intra-articular administration of corticosteroids or
             hyaluronic acid into the target knee within 6 months before screening.

          2. Kellgren-Lawrence radiological grade of 4 in at least one tibio-femoral joint

          3. Previous arthroplasty of knee or hip.

          4. Intention of having major surgery during the timeframe of this study.

          5. OA related to eg. dysplasia, aseptic osteonecrosis, acromegaly, Paget disease,
             Stickler syndrome, hemochromatosis, gout, chondrocalcinosis (pseudogout) or calcium
             pyrophosphate deposition disease.

          6. Current treatment with beta-receptor adrenergic antagonists (beta-blockers), systemic
             corticosteroid treatment in doses equivalent to > 10 mg of prednisolone per day, or
             Vitamin K antagonists, new oral anticoagulants, fractionated and non-fractionated
             heparin

          7. Active systemic infection.

          8. Active systemic inflammatory or autoimmune disease.

          9. Symptomatic occlusive arterial disease e.g. claudication intermittens.

         10. Heart failure > NYHA class II.

         11. History of transient ischaemic attack or stroke.

         12. ECG findings which, in the opinion of the investigator, compromises patient safety
             related to HRmax-test.

         13. History of coronary artery disease, myocardial infarction, or other serious
             cardiovascular disease, as evaluated by the investigator.

         14. Is not currently active athlete or a highly trained individual.

        Inclusion criteria for healthy subjects:

          1. 18 to < 75 years of age at the time of signing the informed consent form.

          2. Have a bodyweight within > 50 and < 150 kg and a BMI within the range 18,5-35 kg/m2.

          3. Are male or female.

          4. Is able to meet for all of the four study visits and comply with the dietary and
             activity restrictions.

          5. Can give informed consent.

        Exclusion criteria for healthy subjects:

          1. History of arthroscopy or intra-articular administration of corticosteroids or
             hyaluronic acid into the target knee within 6 months before screening.

          2. Previous arthroplasty of knee or hip.

          3. Intention of having major surgery during the timeframe of this study.

          4. Secondary OA e.g. because of dysplasia, aseptic osteonecrosis, acromegaly, Paget
             disease, Stickler syndrome, hemochromatosis, gout, chondrocalcinosis (pseudogout) or
             calcium pyrophosphate deposition disease.

          5. Current treatment with beta-receptor adrenergic antagonists (beta-blockers), systemic
             corticosteroid treatment in doses equivalent to > 10 mg of prednisolone per day, or
             Vitamin K antagonists, new oral anticoagulants, fractionated and non-fractionated
             heparin

          6. Any known active systemic infection.

          7. Any known active systemic inflammatory or autoimmune disease.

          8. Symptomatic occlusive arterial disease e.g. Inermittent claudication.

          9. Heart failure > NYHA class II.

         10. History of transient ischaemic attack or stroke.

         11. History of coronary artery disease, myocardial infarction, or other serious
             cardiovascular disease, as evaluated by the investigator.

         12. ECG findings which, in the opinion of the investigator, compromises patient safety
             related to HRmax-test.

         13. Is not currently active athlete or a highly trained individual.

         14. X-ray verified Kellgren-Lawrence grade 1-4.

         15. Is clinically suspected of having hip OA.

        Other exclusions (all subjects):

          1. Legal incapacity or limited legal capacity

          2. Inability to communicate or cooperate with the investigator or to comply with the
             requirements of the entire study.

          3. Are categorized as being very difficult to draw blood from, as evaluated by the
             investigator.

          4. Current alcohol abuse and/or inability to refrain from intake of alcoholic beverages
             24 hours prior to study intervention.

          5. Other factors e.g. self-reported drug abuse, which in the opinion of the investigator
             may interfere with the study conduct.

          6. Site staff, study staff members and study staff family members.

          7. Other concomitant disease compromising or otherwise significantly affecting ECM
             turnover in the opinion of the investigator
No condition on gender to be admitted to the trial.
Accepts Healthy Volunteers
Subject must be at least 18 Years old.
Subject must be at most 75 Years

Eligibility (NLI label): Entailment