Fig. 1

Relative contractile response, electrical current and muscle strength during NMES. a Relative contractile response decreases between day 1 and day 7 without reaching statistical significance. b Upper extremities show a significantly higher response rate to NMES on days 1, 2, 3, 4, 5 and 7 in comparison to lower extremities. c Muscle strength and contractile response for all muscle groups separately. M. vastus lateralis shows the lowest response to NMES. d Electrical current required to elicit a muscle contraction remains unchanged between day 1 and day 7. e A significant difference in electrical current required to elicit a muscle contraction can be observed on days 2, 3, 4, 5 and 6 when comparing upper and lower extremities. f Muscle strength increase for both extremities between first awakening and ICU discharge does not reach statistical significance. g The increase in muscle strength between first awakening and ICU discharge reaches statistical significance for lower extremities. All values are shown as median and interquartile range. Statistical significance was calculated via Mann-Whitney U test or Wilcoxon signed-rank test as appropriate. A p < 0.05 is indicated by "+" in b and e. ICU = intensive care unit; MRC = Medical research council