Table 1.

M-mode loading factors

	M1-mode	M2-mode	M3-mode
SOL	0.734 (0.099)	−.150 (0.112)	−0.022 (0.040)
GL	0.797 (0.052)	−0.126 (0.107)	0.017 (0.033)
GM	0.821 (0.024)	−0.174 (0.082)	0.030 (0.046)
BF	0.701 (0.080)	0.001 (0.122)	0.138 (0.062)
ST	0.644 (0.087)	0.076 (0.125)	0.062 (0.081)
TA	−0.485 (0.079)	0.549 (0.093)	0.005 (0.059)
RF	−0.418 (0.063)	0.710 (0.097)	0.024 (0.036)
VL	−0.306 (0.063)	0.757 (0.095)	0.007 (0.041)
VM	−0.234 (0.068)	0.749 (0.094)	0.008 (0.036)
TFL	−0.118 (0.082)	0.385 (0.078)	0.164 (0.127)
ESL	0.667 (0.094)	−0.142 (0.065)	0.234 (0.129)
EST	0.651 (0.093)	−0.114 (0.062)	0.241 (0.128)
RA	−0.007 (0.048)	0.165 (0.078)	0.513 (0.157)

Averaged loading factors across subjects are shown for the individual muscles. The values in parentheses represent standard errors. Significant loadings (>0.5) are shown in bold. Note the consistent patterns with dorsal muscles significantly loaded in the M1-mode and ventral muscles significantly loaded in the M2-mode. There was no significant loading for TFL because it was not consistently included in a specific mode across subjects. TA – tibialis anterior; SOL – soleus;l GL and GM – lateral and medial heads of gastrocnemius; BF – biceps femoris; SM – semitendinosus; RF – rectus femoris; VL and VM – lateral and medial vastii; TFL – tensor facsia latae; ESL and EST – lumbar and thoracic portions of erector spinae; and RA – rectus abdominis.