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Table 2 Baseline characteristics of the patients: Demographics, self-reported symptoms (KOOS), DCE-MRI perfusion variables, and physical function

From: Exercise-induced pain changes associate with changes in muscle perfusion in knee osteoarthritis: exploratory outcome analyses of a randomised controlled trial

  Exercise therapy group Control group
Randomised (n = 31) Per-protocol (n = 16) Randomised (n = 29) Per-protocol (n = 17)
Mean (SD) Mean (SD) Mean (SD) Mean (SD)
Demographic Characteristics
 Age (years) 65.9 (8.5) 67.2 (8.2) 61.3 (7.1) 60.6 (7.2)
 Female, no (%) 27 (87) 14 (87.5) 21 (71) 12 (70.6)
 Height (m) 1.69 (0.08) 1.67 (0.07) 1.72 (0.09) 1.72 (0.11)
 Weight (kg) 81.9 (14.1) 77.3 (8.3) 83.3 (15.0) 85.8 (14.2)
 BMI (kg/m2) 28.7 (4.2) 27.7 (3.4) 28.1 (4.5) 29.0 (4.0)
KOOS
 Pain 56.5 (14.8) 52.8 (18.1) 63.3 (12.4) 61.3 (9.8)
 Symptoms 58.3 (16.8) 57.4 (18.2) 65.5 (19.5) 63.9 (17.8)
 Function in Daily Living 65.0 (14.0) 61.9 (17.3) 74.2 (13.9) 76.3 (10.9)
 Knee-Related Quality of Life 27.6 (19.2) 37.9 (15.6) 34.7 (20.9) 44.1 (16.8)
 Function in Sports and Recreation 37.1 (14.2) 25.0 (16.0) 44.2 (14.4) 37.4 (23.0)
DCE-MRI Perfusion variables
 Total Muscle VOI
  Nvoxel% 56.1 (15.7) 57.7(14.7)
  IRExNvoxel 334.0 (171.5) 386.7 (230.2)
  IRExNvoxel% 0.30 (0.15) 0.18 (0.07)
  MExNvoxel 81,491.0 (26,054.0) 91,236.6 (29,556.8)
  MExNvoxel% 72.8 (21.5) 73.4 (20.7)
 Extensor VOI
  Nvoxel% 48.6 (16.0) 45.0 (19.5)
  IRExNvoxel 98.1 (82.5) 113.0 (108.9)
  IRExNvoxel% 0.39 (0.21) 0.4 (0.3)
  MExNvoxel 16,553.4 (9817.4) 16,488.1 (10,599.5)
  MExNvoxel% 67.1 (23.7) 60.6 (27.5)
 Flexor VOI
  Nvoxel% 58.1 (16.6) 60.9 (13.8)
  IRExNvoxel 236.1 (116.1) 273.7(150.0)
  IRExNvoxel% 0.27 (0.15) 0.28 (0.16)
  MExNvoxel 64,937.5 (17,987.4) 74,748.5 (21,639.4)
  MExNvoxel% 74.3 (22.3) 76.5 (19.3)
Physical function
 Muscle strength Knee extension, Nm
  0°/s 103.1 (21.2) 124.1 (35.7)
  60°/s 81.2 (24.8) 91.0 (29.9)
  120°/s 69.3 (20.7) 86.9 (29.1)
  180°/s 60.3 (17.0) 76.9 (26.8)
 Muscle strength knee flexion, Nm
  0°/s 48.7 (17.3) 63.4 (22.8)
  60°/s 38.1 (14.6) 49.0 (20.0)
  120°/s 34.2 (13.8) 45.4 (19.7)
  180°/s 32.4 (12.1) 44.1 (17.9)
 6-min walk distance, m 494.4 (93.8) 541.2 (84.7)
  1. Abbreviations: SD Standard deviation, BMI Body mass index, KOOS The Knee Injury and Osteoarthritis Outcome Score, DCE-MRI Dynamic contrast enhanced magnetic resonance imaging, Total Muscle VOI A volume of interest consisting of the summed and averaged peri-articular knee extensor and flexor muscle ROIs, Extensor VOI A volume of interest consisting of summed and averaged ROIs of the peri-articular knee extensor muscles, Flexor VOI A volume of interest consisting of summed and averaged ROIs of the peri-articular knee flexor muscles, Nvoxel% Proportion of Highly Perfused Voxels (%), IRExNvoxel Initial Rate of Enhancement Composite Score, IRExNvoxel% Initial Rate of Enhancement Index, MExNvoxel Maximal Enhancement Composite Score, MExNvoxel% Maximal Enhancement index