Session Information
Date: Sunday, October 21, 2018
Title: Orthopedics, Low Back Pain and Rehabilitation Poster – ACR/ARHP
Session Type: ACR/ARHP Combined Abstract Session
Session Time: 9:00AM-11:00AM
Background/Purpose: Neuromuscular electrical stimulation (NMES) is a viable intervention to improve impaired muscle function of patients with rheumatoid arthritis (RA). However, there is limited evidence about dose-response of NMES to promote muscle function in these patients. The purpose of this study was to investigate the dose-response relationship between NMES and muscle function in patients with RA and to establish the minimal NMES intensity to promote improvements.
Methods: This was a secondary analysis of pre to post NMES intervention from a randomized study. Participants were adults diagnosed with RA. Participants underwent 36 NMES treatment sessions for the quadriceps muscles over 16 weeks. Muscle function was assessed pre- and post-intervention by the following 3 measures: quadriceps cross-sectional area and muscle quality were quantified using computed tomography, and strength via an isokinetic dynamometer. NMES intensity was calculated in percentage dividing NMES-elicited quadriceps muscle torque by maximum voluntary isometric contraction (MVIC). Improvements in muscle function were calculated using paired samples t-test. Dose-response relationship was determined using curve estimation regression statistics. The minimum NMES intensity was defined as the one sufficient to significantly improve all muscle function measures.
Results: Twenty-four subjects (48 legs) participated (75% female, 58[8] years old, and BMI of 32[7] kg/m2). Quadriceps cross-sectional area, muscle quality and strength improved pre-post intervention (p<.001) (Table 1). Associations between NMES and muscle quality (r2=0.20) and strength (r2=0.23) were significant, but between NMES and muscle cross-sectional area was not (r2=0.02). The minimum NMES intensity necessary to improve all measures of muscle function ranged from 11% to 20% of MVIC (Table 2).
Conclusion: The minimum NMES intensity for significant gains in muscle function is around 15%. Larger NMES intensities may promote better muscle quality and strength in patients with RA.
Table 1: Muscle function pre and post NMES.
|
Variables |
Baseline |
Follow-up |
Change |
95% CI of Change |
|
Quadriceps Cross-sectional Area (cm2) |
48.8 (8.5) |
52.4 (8.5) |
3.6 (2.8) |
2.8; 4.4 |
|
Quadriceps muscle quality (HU) |
45.9 (4.6) |
47.4 (5.1) |
1.5 (2.3) |
0.8; 2.2 |
|
Quadriceps Strength (Nm) |
144.6 (33.9) |
158.6 (36.3) |
14.1 (19.8) |
8.3; 19.9 |
Table 2: NMES dose-response of quadriceps muscle function outcomes.
|
Intensity (% MVIC) |
Muscle Cross-sectional Area |
Muscle Quality |
Muscle Strength |
|||
|
Change in cm2 |
95% CI |
Change in HU |
95% CI |
Change in Nm |
95% CI |
|
|
1 to 10 (n=8) |
3.23 |
1.85; 4.61 |
0.15 |
-0.89; 1.18 |
1.16 |
-7.60; 9.91 |
|
11 to 20 (n=7) |
3.43 |
2.40; 4.45 |
1.18 |
0.42; 1.95 |
11.08 |
4.60; 17.57 |
|
21 to 30 (n=13) |
3.59 |
2.45; 4.74 |
1.87 |
1.01; 2.73 |
17.63 |
10.37; 24.89 |
|
31 to 40 (n=6) |
3.80 |
2.61; 4.99 |
2.40 |
1.51; 3.29 |
22.56 |
15.01; 30.12 |
|
41 to 50 (n=4) |
3.98 |
2.76; 5.19 |
2.58 |
1.67; 3.49 |
24.12 |
16.41; 31.83 |
|
51 to 60 (n=10) |
4.15 |
2.34; 5.96 |
2.48 |
1.12; 3.84 |
22.89 |
11.39; 34.38 |
To cite this abstract in AMA style:
Almeida GJ, Khoja SS, Piva SR. Dose-Response Relationship between Neuromuscular Electrical Stimulation and Muscle Function in Patients with Rheumatoid Arthritis [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/dose-response-relationship-between-neuromuscular-electrical-stimulation-and-muscle-function-in-patients-with-rheumatoid-arthritis/. Accessed .« Back to 2018 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/dose-response-relationship-between-neuromuscular-electrical-stimulation-and-muscle-function-in-patients-with-rheumatoid-arthritis/