Finding an accurate and affordable method to quantify muscle size following spinal cord injury (SCI) could provide benefits clinically and in research settings. The purpose of this study was to validate the use of anthropometric measurements versus magnetic resonance imaging (MRI) to evaluate muscle cross-sectional area (CSA) and develop a field equation to predict muscle CSA specific to the SCI population. Twenty-two men with chronic (>1yr) motor complete SCI participated in the current study. Anthropometric measurements, including mid-thigh circumference and anterior skinfold thickness (SFT), were taken on the right thigh. The anthropometric muscle cross sectional area (Muscle CSAanthro) was predicted using the following equation: [π (r -SFT /2)2; r = thigh circumference/2π]. MRI analysis yielded whole thigh CSA (Thigh CSAMRI), mid-thigh muscle CSA (Muscle CSAMRI), mid-thigh absolute muscle CSA after subtracting intramuscular fat and bone (Muscle CSA-IMFMRI), subcutaneous adipose tissue (SATT) measured at one site as well as at 4-sites and bone CSA. Anthropometric measurements were correlated to the thigh CSAMRI (r2=0.90, SEE=17.6cm2, P<0.001). Muscle CSAanthro was correlated to muscle CSAMRI (r2=0.78, SEE=16.6cm2, P<0.001) and muscle CSA-IMFMRI (r2=0.75, SEE=17.6cm2 P<0.001). A single SFT was correlated to the polar 4-site SATT (r2=0.78, SEE=0.37cm, P<0.001). The average femur CSA and average IMF CSA derived from MRI led to the following field equation: Muscle CSApredicted = π[(Thighcircum/2π) - (SFT/2)]2 - 23.2. Anthropometric measurements of muscle CSA exhibited a good agreement with the gold standard MRI method and led to the development of a field equation for clinical use after accounting for bone and IMF.
- spinal cord injury
- body composition
- magnetic resonance imaging
- skeletal muscle
- Copyright © 2016, Journal of Applied Physiology