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Fig.1
Flow chart of the study participants included in the analysis.
Fig.2
The positions of the WIM electrodes on the left wrist and right hand during bioelectrical impedance measurement.
Fig.3
The hand-to-hand bioelectrical impedance scheme of the TTC model.
Fig.4
Arm volume multiplied by TBM/FFM ratio approximates bioimpedance: (a) Approximation of InBody 230 arm impedance. (b) Approximation of real part of bioimpedance measured with WIM.
Fig.5
(a) MAPE; (b) Coefficient of determination r2; (c) Maximal residual error. Distribution shapes were obtained during 100,000-sample bootstrap procedure. Bold lines show normal approximation curves; (d) The effect of sex and age variables on maximal residual error distribution for the single cylinder model.
Fig.6
Bland-Altman plots for WIM FFM estimate validation: (a) Single cylinder (SC) model: confidence intervals for the mean bias: (-0.874, 0.879) kg, for upper LOA: (4.380, 6.937) kg, for lower LOA: (-6.932, -4.375) kg; TTC model: for mean bias: (-0.920, 0.905) kg, for upper LOA: (4.547, 7.208) kg, for lower LOA: (-7.223, -4.562) kg. (b) Skinfold thickness calculations: confidence intervals for the mean bias: (-1.792, 0.955) kg, for upper LOA: (6.653, 10.651) kg, for lower LOA: (-11.488, -7.4918) kg.
Anthropometric, body composition and bioelectrical impedance data.
Mean ± STD
Range
Age, years
27.02 ± 10.2
18 - 56
TBM, kg
69.56 ± 11.29
45.83 - 100.95
Height, cm
171.89 ± 8.86
156.0 - 196.0
BMI, kg/m2
23.6 ± 3.97
18.17 - 38.87
Total arms
6109.06 ± 1505.04
3480.6 - 10970.2
volume, cm3
FFMDEXA, kg
50.99 ± 10.94
34.51 - 86.59
FMDEXA, %
26.77 ± 9.34
8.32 - 48.39
Re(Z)10_a, Ohm
633.13 ± 136.83
366.43 - 1001.8
Re(Z)10_b, Ohm
559.43 ± 169.33
88.28 - 866.89
Re(Z)10_c, Ohm
627.71 ± 133.16
398.16 - 964.93
Re(Z)50_a, Ohm
592.86 ± 134.54
379.79 - 914.78
Re(Z)50_b, Ohm
551.97 ± 160.0
126.64 - 889.12
Re(Z)50_c, Ohm
562.21 ± 138.21
304.83 - 831.84
Re(Z)100_a, Ohm
571.13 ± 133.97
352.69 - 881.58
Re(Z)100_b, Ohm
553.53 ± 141.96
312.6 - 890.5
Re(Z)100_c, Ohm
527.9 ± 134.54
204.77 - 799.5
Linear regression metrics for FFM estimation: two models (SC and TTC) and nine experimental conditions