Please select the eligibility criteria that correspond to the clinical trial below.
Title: Wearable Pulsed Electromagnetic Fields Device in Knee Osteoarthritis Patients: a Double Blinded, Randomized Clinical Trial
Brief Summary: The aim of the study is to evaluate the efficacy of a wearable device using pulse electromagnetic fields on pain intensity reduction, measured by visual analogue score (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), in patients affected by osteoarthritis Secondary aim is the evaluate the effect on knee effusion reduction, when present and to evaluate pain intensity changes corrected by pain threshold measured by pressure algometry.


Options:
A: Inclusion Criteria:

* a diagnosis of primary OA of the knee according to the ACR criteria, including radiologic evidence of OA
* age \>40 years
* symptomatic disease for at least 6 months prior to enrollment
* persistent pain despite receiving the maximum tolerated doses of conventional medical therapy, including acetaminophen (4 gm/day) and/or a nonsteroidal antiinflammatory drug (NSAID), with persistent pain defined as a minimum mean score of 25 mm on the visual analog scales (VAS) for global pain (0-100-mm range for each) daily pain during the month prior to study enrollment
* ability to attend followup appointments

Exclusion Criteria:

* secondary causes of OA
* local or systemic infection
* diabetes mellitus
* systemic arthritis
* allergy to anesthetic agent or contrast material
* coagulopathy
* anticoagulant therapy
* had previous IA steroid injection
* avascular necrosis of bone
* patients who are on specific OA pharmacological therapy (NSAIDS, opioids) for more than 2 weeks prior enrollment
B: Inclusion Criteria:

The OA condition will be assessed by physical examination based on the clinical criteria of the American College of Rheumatology criteria. The clinical criteria consisted of pain in the knee and any three of the following:

1. aged 50 years of age or over;
2. \<=30 minutes of morning stiffness;
3. crepitus on active joint motion;
4. bony tenderness;
5. bony enlargement; or
6. no palpable joint warmth.

This classification has been reported to yield 84% specificity and 89% sensitivity for diagnosis of OA knee.

Exclusion Criteria:

1. other connective tissue diseases affecting the knee;
2. knee joint steroid injections within the preceding three months;
3. having a hearing aid or pacemaker in situ (this is to avoid possible interaction between the pacemaker and the magnetic pellets);
4. receiving AT within the preceding three months;
5. suffering from aural injuries or infections; and
6. inability to understand instructions or give consent.

The assessment is conducted by a research assistant who will receive intensive coaching on the physical assessment and therapy administration by the research team. Potential subjects will be further assessed by a registered medical practitioner who has over 15 years of clinical experience when the assessment on the OA condition by the RA and the research team is in doubt.
C: Inclusion Criteria:

* The female subjects were included if they were over 40 with knee primary grade II or III OA, based on Gupta et al radiographic criteria2, and joint or anterior knee pain for at least 3 months.

Exclusion Criteria:

* We excluded patients with a history of surgery or any invasive procedure of the affected knee, physical therapy for knee injuries or any medication that had changed in the last 3 months, other diseases changing function, and patients who presented any contraindication for PSW application, especially metallic implants, pacemakers, lack of sensitivity, or tumor.
D: Inclusion Criteria:

* 40 years of age or older
* Meet the American College of Rheumatology (ACR) clinical criteria for a diagnosis of knee OA. The ACR clinical criteria for knee OA includes knee pain plus 3 of the following 6 criteria:
* age \> 50 years,
* morning stiffness of \< 30 minutes,
* crepitus on active movement,
* tenderness of the bony margins of the joint,
* bony enlargement of the joint noted on exam,
* lack of palpable warmth of the synovium. Based on this criteria, a subject who is less than 50 years but has knee pain and 3 of the other 5 criteria would also be classified as having knee OA.

Exclusion Criteria:

* do not meet the ACR clinical criteria for knee OA,
* are scheduled for total knee arthroplasty (TKA) surgery,
* have undergone TJA surgery on any lower extremity joint,
* exhibit uncontrolled hypertension (i.e. individuals not currently taking medication for hypertension whose systolic blood pressure is greater than 140 mm Hg or diastolic blood pressure greater than 90 mm Hg at rest),
* have complaints of low back pain or other lower extremity joint pain that affects function at the time of recruitment,
* have a history of neurological disorders that would affect lower extremity function (stroke, peripheral neuropathy, parkinson's disease, multiple sclerosis, etc.),
* are women who are pregnant.

Answer: A