Examination of postural dependence in subcutaneous fat thickness measurement using a caliper

Standing is commonly used as the standard position for skinfold-based subcutaneous fat thickness measurement; however, the feasibility and reliability of alternative positions remain unclear.

Ten healthy men participated. Subcutaneous fat thickness was measured at the lumbar and medial calf regions using a metal caliper. Measurements were obtained in standing, sitting, prone, side-lying, and supine positions, except for the lumbar region. Each posture was measured three times in one session by the same examiner, and participant-level means were used for analysis. Intra-rater reliability was assessed using ICC(1, 1) and ICC(1, 3).

Participant-level means ranged from 3.7 to 4.0 mm in the lumbar region and from 4.2 to 4.4 mm in the lower leg. ICCs exceeded 0.90 in both regions. A main effect of posture was observed in the lumbar region, whereas the Greenhouse-Geisser-corrected main effect was not significant in the lower leg. Post hoc differences were found only between standing and side-lying and between standing and prone positions in the lumbar region, with Cohen's d values of 0.19 and 0.16, respectively.

Subcutaneous fat thickness measurements obtained using a metal caliper showed very high intra-rater reliability across postures. Although small posture-related differences were observed, particularly in the lumbar region, the magnitude of these differences appeared to be of limited practical relevance in healthy young men. Alternative measurement postures may be considered when standing measurement is difficult, although further validation in other populations is required.