Evaluation of a Home-based NMES Therapy for Knee Osteoarthritis Pain

Inclusion criteria

• Subject must provide written, informed consent before any study procedures occur. The subject should be provided with a copy of the signed Informed Consent upon signature.
• Subjects with symptomatic Kellgren-Lawrence (KL) Grade 2, 3, or 4 OA by radiograph (AP tunnel view) within 30 days prior to day 0 visit, where the K-L grades are defined as:

• Grade 0: no radiographic features of OA are present
• Grade 1: doubtful joint space narrowing (JSN) and possible osteophytic lipping
• Grade 2: definite osteophytes and possible JSN on anteroposterior weight-bearing radiograph
• Grade 3: multiple osteophytes, definite JSN, sclerosis, possible bony deformity
• Grade 4: large osteophytes, marked JSN, severe sclerosis and definite bony deformity
• Subject must have a normal tibiofemoral angle (0-8°) and a joint space width of ≥ 3mm confirmed by radiograph.
• Subjects who are between the ages of 21 - 85 years.
• Subjects must have a visual analog pain (VAS) score of at least 4 cm on a 10 cm scale for a nominated activity in the target knee at the time of screening.
• For bilateral knee osteoarthritis subjects, the visual analog pain VAS score for a nominated activity of the contralateral knee must be less than 4 cm on the VAS scale.
• Subject has access to a smartphone or tablet (Android or iOS).
• Subject must be ambulatory.
• Subject must be willing to discontinue receiving knee intra-articular injections of steroids, knee intra-articular injections of hyaluronic acid, opioids, and analgesics (except for acetaminophen up to 3000 mg/day or an equivalent) for the duration of the study.
• Subject must be willing to take acetaminophen (up to 3000 mg/day) or an equivalent as pain medication for the duration of the study.
• Subject must be willing to stop taking any pain medications 24 hours prior any scheduled study visit.
• Subject must be willing to stop receiving knee physical therapy of the target knee for the duration of the study.
• Subject must be willing to stop wearing any knee unloader brace of the target knee for the duration of the study.
• Subjects must be proficient in English.
• Subjects must be willing and able to comply with all study procedures for the duration of the clinical study

Exclusion criteria

• Subjects who have a body mass index ≥ 40 at the time of consent (at the discretion of the PI).
• Subjects with a diagnosis of inflammatory arthritis (knee rheumatoid arthritis, active gout, knee joint infection, Lyme disease, SLE, etc.).
• Subjects with a diagnosis of severe neuropathy condition for the past 6 months and under medication for treatment of the condition.
• Subjects with a diagnosis of fibromyalgia for the past year.
• Subjects who have had an injury or an acute traumatic injury to the target knee within 6 months of screening.
• Subject must NOT have had arthroscopy of the target knee within 8 weeks of randomization.
• Subjects who have had treatment of the target knee with intra-articular injections of steroids within 8 weeks of screening.
• Subjects who have had intra-articular injections of hyaluronic acid within 12 weeks of screening.
• Subjects who have had a scheduled surgery on the target knee within the study period.

(Note- Subjects who are scheduled to go under total knee replacement surgery within the next 3 months at screening will not be enrolled. Subjects that are contemplating the surgery can be included.)

• Subjects who have used electrotherapy or acupuncture for OA of the target knee within 4 weeks of screening.
• Subjects who have used Neuromuscular Electrical Stimulation (NMES) in the past year.
• Subjects with significant and clinically evident mal-alignment of the target knee (> 5 degrees varus or valgus in the target knee).
• Subjects with surgical metallic hardware in the target knee.
• Subjects who have had implanted electrical devices (cardiac pacemakers, deep brain stimulators, implantable cardiac defibrillators).
• Subjects who have contraindications to X-rays.
• Subjects with a current malignancy or who have received treatment for malignancy with the last 5 years, with the exception of resected basal cell carcinoma and squamous cell carcinoma of the skin.
• Subjects who have an active substance abuse problem (drugs or alcohol) or a history of chronic substance abuse (> 5 years).
• Subjects with skin breakdown or infection in the area where the study device will be placed (quadriceps of the target knee).
• Subjects with any chronic conditions (e.g., diabetes, hypertension, congestive heart failure, etc.) that have not been well-controlled for at least 3 months prior to screening.
• Subjects who have any ongoing litigation for worker's compensation.
• Subjects with any condition, in the opinion of the Investigator that might interfere with the evaluation of the study objectives.
• Subjects who are pregnant.
• Subject must not have participated in a clinical study within the past 12 weeks from the last day of treatment that required the use of an investigational device, drug or biologic