Neuromuscular electrical stimulation (NMES) reduces structural and functional losses of quadriceps muscle and improves health status in patients with knee osteoarthritis

Abstract

Knee osteoarthritis (OA) is associated with quadriceps atrophy and weakness, so muscle strengthening is an important point in the rehabilitation process. Since pain and joint stiffness make it often difficult to use conventional strength exercises, neuromuscular electrical stimulation (NMES) may be an alternative approach for these patients. This study was aimed at (1) identifying the associations of knee OA with quadriceps muscle architecture and strength, and (2) quantifying the effects of a NMES training program on these parameters. In phase 1, 20 women with knee OA were compared with 10 healthy female, asymptomatic, age-matched control subjects. In phase 2, 12 OA patients performed an 8-week NMES strength training program. OA patients presented smaller vastus lateralis thickness (11.9 mm) and fascicle length (20.5%) than healthy subjects (14.1 mm; 24.5%), and also had a 23% smaller knee extensor torque compared to the control group. NMES training increased vastus lateralis thickness (from 12.6 to 14.2 mm) and fascicle length (from 19.6% to 24.6%). Additionally, NMES training increased the knee extensor torque by 8% and reduced joint pain, stiffness, and functional limitation. In conclusion, OA patients have decreased strength, muscle thickness, and fascicle length in the knee extensor musculature compared to control subjects. NMES training appears to offset the changes in quadriceps structure and function, as well as improve the health status in patients with knee OA. Keywords: osteoarthritis; muscle architecture; muscle strength; WOMAC; electrical stimulation Osteoarthritis (OA) is one of the major degenerative diseases and it affects elderly women more frequently than elderly men.1,2 The prevalence of OA is expected to increase dramatically in the near future due to the increased life expectancy and an increasing rate of obesity of the world population.3 The knee is the most affected joint with 13.6% of women above 60 years showing radiographic evidence of OA and/or clinical symptoms. 2OA causes erosion of articular cartilage, weakening of subchondral bone, meniscal degeneration, inflammation of the synovium, and intra-articular osteophytes. 4 These changes lead to a reduction in the range of motion, and increase in joint stiffness and pain. 5In addition to the effects on the joint structure and function, OA also has a negative effect on the musculoskeletal system. Patients with knee OA have decreased knee extensor strength compared to healthy subjects 6-10 and compared to the healthy contralateral limb.11,12 Evidence also suggests that the muscle weakness is associated with a decrease in muscle mass. 11,12However, although a reduction in muscle thickness 11 and anatomical cross-sectional area 12 have been described in OA patients, we were unable to find evidence on how muscle weakness was related to changes in other muscle architecture parameters associated with strength, such as fascicle length, and pennation angle.Fascicle length is related to the number of sarcomeres aligned in series in the ...

Phisical modalities on the functional performance in knee osteoarthritis: a sytematic review

“…Scientific evidences used in this review show that the neuromuscular electrical stimulation (NMES) may be beneficial in patients with knee OA in variables such as pain (6,(23)(24)(25)(26), physical function (6,23,25), functional performance (25,27), discomfort (6), daily living activities (6) and stiffness (23,25). Furthermore, NMES seems to compensate physiological declines occurring in the muscle of patients, acting both in structure as in function of the quadriceps (23) by means of cross-sectional area increases (23,27) and muscular strength (23,25) and also in the improvement of voluntary muscle activation when combined with an exercise program (24).…”

“…Furthermore, NMES seems to compensate physiological declines occurring in the muscle of patients, acting both in structure as in function of the quadriceps (23) by means of cross-sectional area increases (23,27) and muscular strength (23,25) and also in the improvement of voluntary muscle activation when combined with an exercise program (24). The parameters used in these studies (6,(23)(24)(25)(26)(27) varied from: 50-80Hz, 100-400μs, intensity: visible muscle contraction until the maximum tolerated, time on: 10 seconds, off time: 10-50 seconds 15-45 minutes per session, for 12-36 sessions.…”

Efeitos de oito semanas de treinamento com estimulação elétrica neuromuscular nas razões de ativação muscular / torque de idosas com osteoartrite

“…The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire 16 was used to evaluate the pain of OA subjects before and after NMES training.…”

“…Initially, subjects were seated in the chair of the dynamometer and fixed in position with Velcro strips, keeping the hip angle at approximately 90° flexion, and positioning the axis of the knee joint with the rotation axis of the dynamometer. 16 Prior to performing the tests, a familiarization procedure was performed, which consisted of two series of three concentric repetitions (angular velocities of 120°/s and 60º/s) and an isometric contraction (at an angle of 60° of knee flexion). After familiarization, torque was measured using three maximal voluntary isometric contractions (MVICTs) at an angle of 60°, and an MVICT of the knee extensor muscles (randomized) at angles of 30°, 45°, 75° and 90°.…”

“…The training consisted of three weekly sessions over a period of eight weeks, with variations in the duration of sessions (initially 18 minutes, increasing by two minutes a week, finishing at 32 minutes) and rest periods (initially 50 seconds, reduced by 10 seconds every two weeks of training, finishing at 20 seconds of rest) during the training period. 16 …”