The following case study examines the muscle and fat thickness of the trunk in a 25-year-old, former collegiate gymnast. Previous studies have quantified total and regional skeletal muscle mass using magnetic resonance imaging and muscle volume and distribution using ultrasound. However, to the best of our knowledge, the distribution and symmetry of skeletal muscle and subcutaneous adipose tissue (AT) of the anterior and posterior trunk have never been investigated. Ultrasound was used to identify skeletal muscle and AT thickness of 143 data points on the anterior portion of the trunk and 140 data points on the posterior portion of the trunk. Muscle thickness values in the anterior trunk ranged from 0.5 to 5.6 cm, and muscle thickness of the posterior trunk ranged from 0.6 to 6.6 cm. Total muscle volume of the trunk was 2935 and 4195 cm(3) for the anterior and posterior portions, respectively. The total predicted muscle mass in the anterior and posterior trunk was 7.4 kg. This case study begins to provide a picture of the distribution and symmetry of skeletal muscle and AT of the trunk. Future studies are necessary to confirm these findings and examine relationships among different populations.