Purpose: Torso surface topography has reliably detected scoliosis severity. A quantification of torso shape patterns associated with healthy spines is important as a basis for scoliosis screening, monitoring progression, and evaluating treatment methods. The study objective was to examine differences in torso surface geometry associated with age and gender in healthy children.

Method: Seventy normal healthy adolescents were recruited into 3 age groups (8–11, 12–14, 15–18 years), with a goal of equal representation across groups. All consenting subjects met inclusion criterion of no history of back or neuromotor problems, and BMI ≤ 30. Torso surface topography was obtained with Inspeck optical digitizers (InSpeck Ltd., Montreal, PQ) using standard clinical protocols. Subject arm span, height, weight and activity level was recorded. Subjects stood within a positioning frame, while five scans (5s/scan) were acquired. Three-dimensional models of each torso scan were generated. Torso shape was quantified with indices based on established spine-torso shape relations in scoliosis patients. Statistical analyses (p=0.05) were performed for 4 indices: principal axis of orientation, back surface rotation (BSR), rib prominence and quarter area at S1; L3, T12& T7vertebral levels.

Results: Two groups based on gender resulted in similar age distributions with males (Group 1, n = 31) having mean age of 12.76 ± 0.07 years; and females (Group 2, n=39) having mean age 12.64±0.17 years. No statistically significant differences in torso indices were found between the entire female and male groups. When stratified by group, significant differences were obtained between the youngest male group (8–11, n=9) and both the youngest (8–11, n=8) and middle (12–14, n=18) aged females. The quarter surface areas at T7 for the youngest males were statistically significantly different from females of similar age (p=0.036), and from the next older age group (p=0.025). The BSR (p=0.033) and rib prominence (p=0.038) at the L3 level were also significantly different between the youngest males and middle aged females.

Conclusion: General torso shape indice curves can be developed for healthy children, based on a combined database of males and females. However, differences in several torso indices are present between the youngest males and the same and middle age group females.