Effects of Neuromuscular Electrical Stimulation (NMES) in Patients With Knee Osteoarthritis

Study Overview
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Brief Summary
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The purpose of this study is to determine the effects of neuromuscular electrical stimulation (NMES) on neuromuscular and functional parameters in elderly with knee osteoarthritis. The hypothesis is that NAMES is able to strengthen the quadriceps muscle and to improve healthy status of elderly with knee osteoarthritis.

Official Title
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Diagnosis and Treatment of Muscle Inhibition of the Extensor Muscles of the Knee in Elderly

Conditions
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Knee Osteoarthritis

Intervention / Treatment
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* Device: Neuromuscular Electrical Stimlation (NMES)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: women, minimum age of 50 years; clinically diagnosed with knee OA; no contraindications to execute maximal knee extension tests (e.g., cardiorespiratory complications); no previous musculoskeletal or joint injuries besides knee OA; no hip or knee surgery; no neurological problems.

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Neuromuscular Electrical Stimulation (NMES)<br>The intervention was performed with subjects seated on a regular chair (hip and knee angles maintained at approximately 908), 3 times/week for a period of 8 weeks. NMES parameters included: rectangular biphasic symmetric current, pulse duration of 400 ms and stimulation frequency of 80 Hz. | Device: Neuromuscular Electrical Stimlation (NMES)<br>* The intervention was performed with subjects seated on a regular chair (hip and knee angles maintained at approximately 908), 3 times/week for a period of 8 weeks. NMES parameters included: rectangular biphasic symmetric current, pulse duration of 400 ms and stimulation frequency of 80 Hz.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak torque change | Maximal isometric knee extensor torques were obtained on an isokinetic dynamometer (Biodex System 3; Biodex Medical Systems). Participants were positioned on the dynamometer according to the manufacturer's recommendations. After a warm-up and a familiarization session, each subject executed three maximal isometric knee extensor contractions with the knee fixed at a flexion angle of 60o. Each contraction lasted for 5 s and a 2-min interval was observed between consecutive contractions. | Baseline and 9th intervention week | 
| Electromyographic activation change | An eight channel EMG system (AMT-8, Bortec Biomedical Ltd., Canada) connected to a Windaq data acquisition system (Dataq Instruments Inc., USA) was used during the maximal isometric and concentric knee extensor contractions. EMG signals were obtained following the recommendations by Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles with respect to skin preparation and electrode positioning. Passive bipolar electrodes (Meditrace - 100; Ag/AgCl; inter-electrode distance = 2.2 cm) were placed on the skin covering the rectus femoris, vastus lateralis and vastus medialis muscles. A reference electrode was placed on the medial surface of the tibia. EMG signals were digitized with a sampling frequency of 2000 Hz per channel with a 16 bits analogue-to-digital board DI-720 (Dataq Instruments Inc., USA) and stored for further analysis. | Baseline and 9th intervention week | 
| Muscle architecture change | An ultrassound system (SSD 4000, 51 Hz, ALOKA Inc., Japan) with a linear array probe (60 mm, 7.5 MHz), was used to determine the thickness, fascicle length, and pennation angle of the vastus lateralis muscle. Ultrassound images were obtained at rest with the subject sitting on the chair of an isokinetic dynamometer (Biodex System 3; Biodex Medical Systems, Shirley, NY) with the hip and knee flexed at 85o and 90o, respectively. All images were captured in the sagittal plane of vastus lateralis (at midway between the lateral condyle of the femur and the greater trochanter). The ultrasound probe was positioned in the approximate direction of the vastus lateralis muscle fibers (long axis with respect to the limb). | Baseline and 9th intervention week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Elderly