Objective To determine the reliability of anthropometric and body composition measurements in children with special needs.

Design Observational study.

Setting Specialist support schools (primary and secondary) in Manchester, UK.

Participants 53 children with moderate-to-severe learning disability; 30 non-standers (14 boys) and 23 standers (15 boys). Mean ages were 11 years (range 3–20) for non-standers and 12.4 years (range 8–19) for standers.

Measures Anthropometric measures included: height/length, segmental measures, weight, skinfolds, body circumferences and body composition estimated from bioelectrical impedance analysis (BIA). These were measured twice, 2–4 weeks apart.

Main outcome measures Reliability was assessed using the technical error of measurement (TEM).

Results The TEM for height and supine length was 0.55 cm for standers and 2.47 cm for non-standers, respectively. For non-standers, the TEMs for knee height and tibial length were 0.81 and 1.57 cm, respectively. The TEM for weight was 0.55 kg for standers and 0.75 kg for non-standers. For skinfold thickness, the TEM was smaller for non-standers than standers. The TEM for mid-upper arm circumference for standers and non-standers was 0.91 and 0.82 cm, respectively. The TEM for BIA in standers and non-standers was 34.7 and 54.1 Ω, respectively. Some measurements, including waist circumferences, were difficult to obtain reliably.

Conclusions Anthropometric and body composition measurements were feasible to obtain in children with special needs. However, the reliability of these measures differs between non-standers and standers and should be considered when choosing appropriate measures.