Page 1 of 6

Online Resource 1

Flow-diagram of subject screening and participation

Online Resource 2

Descriptive summary of continuous subject characteristics (N=103)

Variables / Mean (SD) / Range
Age, yrs. / 27.0 (5.7) / 18 – 45
Triceps fat, mm / 13.15 (5.65) / 2 – 29
Height, in. / 67.6 (3.9) / 60 – 77
Weight, lbs. / 165.3 (32.9) / 100.4 – 260.2
BMI, kg/m2 / 25.4 (4.8) / 18.9 – 41.8

BMI = body mass index

Online Resource 3

Bivariate random intercept analysis GLMM of bruise colorimetry with bruise age (hours) as fixed effect

L* / a* / b*
Fixed Effects / / p-value / AIC / / p-value / AIC / / p-value / AIC
Sex [Male] / 1.94 / 0.313 / 2882 / -0.0912 / 0.743 / 2456 / -0.398 / 0.410 / 2278
Skin Color
[Light] / 9.71 / <0.001 / 2861 / -0.0785 / 0.812 / 2448 / 0.556 / 0.336 / 2271
[Medium] / 4.04 / 0.064 / 0.795 / 0.017 / 1.56 / 0.007
Hair Color
[Blonde/Red] / 13.1 / <0.001 / 2850 / 0.258 / 0.547 / 2455 / 0.412 / 0.577 / 2275
[Brown] / 7.68 / <0.001 / 0.327 / 0.276 / 0.889 / 0.088
Handedness [Right] / -2.98 / 0.288 / 2881 / -0.348 / 0.389 / 2455 / -0.943 / 0.179 / 2276
Target Side [Right] / 0.468 / 0.809 / 2883 / -0.268 / 0.335 / 2455 / -0.122 / 0.801 / 2279
Central Clearing / 3.95 / 0.046 / 2879 / 0.150 / 0.601 / 2456 / 1.39 / 0.005 / 2271
Triceps, mm / -0.224 / 0.189 / 2886 / -0.0139 / 0.574 / 2461 / 0.0202 / 0.683 / 2284
Age, yrs / 1.91E-4 / 0.999 / 2888 / -0.0399 / 0.099 / 2458 / -0.0325 / 0.443 / 2283
BMI / -0.315 / 0.118 / 2885 / 0.00488 / 0.867 / 2461 / -0.598 / 0.238 / 2282
Bruise Size / -0.00111 / <0.001 / 2655 / 9.67E-4 / <0.001 / 2261 / -1.38E-4 / 0.051 / 2221

Note: L*: Black (L*=0) white (L*=100) axis; a*: green (-a*) red (+a*) axis; b*: blue (-b*) yellow (+b*) axis; Reference groups: Skin Color: dark; Hair Color: black.

Online Resource 4

GLMM model selection of DV L* based on AIC

AIC / Fixed Effectsa
2618 / Hrs / Size / HC
2599 / Hrs / Size / HC / SC
2591 / Hrs / Size / HC / SC / CC
2588 / Hrs / Size / HC / SC / CC / Tricep
2588 / Hrs / Size / HC / SC / CC / Tricep / BMI
2584 / Hrs / Size / HC / SC / CC / Tricep / Sex
2577 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2
2595 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2 / Hrs3
2595 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2 / Hrs*HC
2594 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2 / Hrs*SC
2587 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2 / Hrs*CC
2583 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2 / Hrs*Sex
2601 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2 / Hrs*Size
2587 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2 / Hrs*Tricep
2532 / Hrs / Size / HC / SC / CC / Tricep / Sex / Hrs2 / Spline / Hrs*Spline
2150 / Hrs / Size / HC / SC / CC / Tricep / Sex / --b / Spline / Hrs*Spline

Note: Grey effects were significant. Final model selected with AIC = 2150.

aHrs = Hours; Size = Bruise size; SC = Skin Color; CC = Central Clearing; HC = Hair Color

bIntentionally left blank

Online Resource 5

GLMM model selection of DV a* based on AIC

AIC / Fixed Effectsa
2255 / Hrs / Size / SC
2260 / Hrs / Size / SC / Age
2255 / Hrs / Size / SC / Sex
2258 / Hrs / Size / SC / Tricep
2258 / Hrs / Size / SC / Sex / Tricep
2271 / Hrs / Size / SC / Sex / Tricep / Hrs2
2277 / Hrs / Size / SC / Sex / Tricep / Hrs2 / Hrs3
2170 / Hrs / Size / SC / Sex / Tricep / Hrs*Size
2268 / Hrs / Size / SC / Sex / Tricep / Hrs*SC
2267 / Hrs / Size / SC / Sex / Tricep / Hrs*Sex
2270 / Hrs / Size / SC / Sex / Tricep / Hrs*Tricep
2185 / Hrs / Size / SC / Sex / Tricep / Hrs*Size / Hrs*SC
2185 / Hrs / Size / SC / Sex / Tricep / Hrs*Size / Hrs2
2006 / Hrs / Size / SC / Sex / Tricep / Hrs*Size / Spline / Spline*Hours

Note: Grey effects were significant. Final model selected with AIC = 2006.

aHrs = Hours; Size = Bruise size; SC = Skin Color; CC = Central Clearing; HC = Hair Color; Spine is a Dummy variable indicating measurements at Baseline and Measure 1 (approx. 30 minutes).

Online Resource 6

GLMM model selection of DV b* based on AIC

AIC / Fixed Effectsa
2212 / Hrs / Size / SC
2207 / Hrs / Size / SC / CC
2200 / Hrs / Size / SC / CC / HC
2198 / Hrs / Size / SC / CC / HC / Hand
2199 / Hrs / Size / SC / CC / HC / Sex
2203 / Hrs / Size / SC / CC / HC / Sex / Tricep
2181 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2
2179 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3
2195 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*SC
2150 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*CC
2163 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*HC
2188 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*Sex
2147 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*Size
2189 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*Tricep
2133 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*Size / Hrs*CC
2116 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*Size / Hrs*CC / Hrs*HC
2131 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / Hrs3 / Hrs*Size / Hrs*CC / Hrs*HC
2125 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / --b / Hrs*Size / Hrs*CC / Hrs*HC
2091 / Hrs / Size / SC / CC / HC / Sex / Tricep / Hrs2 / --b / Hrs*Size / Hrs*CC / Hrs*HC / Spline / Hrs*Spline
2073 / Hrs / Size / SC / CC / HC / Sex / Tricep / --b / --b / Hrs*Size / Hrs*CC / Hrs*HC / Spline / Hrs*Spline

Note: Grey effects were significant. Final model selected with AIC = 2073.

aHrs = Hours; Size = Bruise size; SC = Skin Color; CC = Central Clearing; HC = Hair Color; Hand = Handedness; Spine is a dummy variable indicating measurements at Baseline and Measure 1 (approx. 30 minutes).

bIntentionally left blank