Table 4.

Absolute values of muscle thickness and echogenicity for acquisition and analysis by two assessors with different levels of expertise.

Parameter	Expert	Novice	p value
Acquisition (n = 10)
Thickness - quadriceps (cm)	3.43 ± 0.87	3.47 ± 0.84	0.97
Thickness - rectus femoris(cm)	1.86 ± 0.55	1.82 ± 0.52	0.96
Echogenicity - square (AU)	77.4 ± 16.8	76.4 ± 16.7	0.98
Echogenicity - trace (AU)	69.1 ± 12.7	67.5 ± 16.1	0.94
Analysis (n = 10)
Thickness - quadriceps (cm)	3.18 ± 0.85	3.16 ± 0.88	0.99
Thickness - rectus femoris(cm)	1.67 ± 0.48	1.72 ± 0.50	0.98
Echogenicity - square (AU)	83.9 ± 18.6	81.8 ± 17.6	0.96
Echogenicity - trace (AU)	67.7 ± 14.6	65.1 ± 14.4	0.94

AU - arbitrary units. A between-measures analysis of variance was used to test for significant differences between assessors and techniques; no significant differences were found for muscle thickness or echogenicity between assessors with different levels of expertise or between techniques for muscle thickness; however, echogenicity was significantly higher when quantified by the square technique compared to the tracing technique, for both acquisition and analysis (p < 0.001). Results expressed as the mean ± standard deviation.