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: Transcutaneous Vagal Stimulation in Knee Osteoarthritis (TRAVKO)

Eligibility criteria:
Inclusion Criteria:

          1. Women and men aged 55 and over;

          2. Medical diagnosis of osteoarthritis of the knee according to the criteria of the
             American College of Rheumatologists;

          3. Chronic pain (i.e., 3 months or more)

          4. Average pain of the last seven days of at least 30 mm on the EVA scale;

          5. Walking without technical aids or knee brace;

          6. Availability to attend an exercise program three times a week for four weeks;

          7. Access to communication via telephone;

          8. Agree to participate in the study by signing an informed consent form.

        Exclusion Criteria:

          1. Presence of the following symptoms and signs: Fever or chills, large effusions,
             paresthesias or paresis of the lower limb;

          2. Presence of medically diagnosed psychiatric or neurological diseases (cognitive
             impairment, Alzheimer's, Parkinson's, epilepsy, moderate or severe depression, bipolar
             disorders, obsessive-compulsive disorder, etc.)

          3. Neuromuscular or cardiac disorders, stroke, generalized rheumatology, diabetes
             mellitus II, morbid obesity (i.e., equal to or greater than III);

          4. Medical contraindication of physical exercise;

          5. Joint infiltration or lower limb surgery in the previous 6 months;

          6. Surgery is planned for the next 6 months;

          7. Use of oral steroids or opioids in the last 4 weeks;

          8. Conditions that affect the lower limb and/or limit its functional capacity, such as
             previous fractures in the area, deformity, joint replacement, tibial osteotomy;

          9. Participation in exercise programs in the last nine months;

         10. Inability to follow instructions.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 55 Years old.


Eligibility (NLI label): Contradiction