Table 4.

Varimax rotated principal axis factor loadings for scaled peak isometric forces of selected lower extremity muscles, considering subjects performing below median walking speeds in the habitual and fast gait conditions. Results suggest unique contribution of the ankle plantar flexor peak isometric force to habitual gait performance and knee extensor peak isometric force to fast gait performance in this subgroup of subjects with inclusion body myositis.

Habitual gait speed less than median value
	Factor 1	Factor 2
Hip flexors	.957	.086
Hip extensors	.494	.204
Knee flexors	.672	.100
Knee extensors	−.041	−.343
Ankle plantar flexors	.222	.860

Fast gait speed less than median value
	Factor 1	Factor 2
Hip flexors	.951	−.153
Hip extensors	.566	−.003
Knee flexors	.632	−.159
Knee extensors	.036	.782
Ankle plantar flexors	.244	−.355