Knee Osteoarthritis
Conditions
Keywords
Elderly
Brief summary
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.
Interventions
DEVICENeuromuscular Electrical Stimlation (NMES)
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.
Sponsors
Federal University of Rio Grande do Sul
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
50 Years to 80 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Peak torque change | Baseline and 9th intervention week | 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. |
| Electromyographic activation change | Baseline and 9th intervention week | 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. |
| Muscle architecture change | Baseline and 9th intervention week | 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). |
Countries
Brazil
Outcome results
None listed