Effect of seated posture on interface pressure in children who are able-bodied and who have myelomeningocele

Purpose. The objective of this study was to investigate the relationship between sitting position and interface pressure distribution in seated children. Method. Fifteen able-bodied children and 15 children with myelomeningocele complete paraplegia, aged 7 to 18 years were included in the study. The body-seat interface pressure was measured with the QA pressure measurement system. Four sitting positions typically used to reduce body-seat interface pressure position (recline, tilt, combined and lean forward) were compared to a neutral position. Results. Test/re-test Pearson correlation coefficients were greater than 0.94 for maximum pressure and greater than 0.88 for mean pressure at all test positions (p < 0.0001) and, for the risk area (defined as the percentage of sensors which recorded pressures greater than 40 mm Hg.) varied from 0.62 to 0.85 (p < 0.0005). Maximum pressures for the myelomeningocele group were significantly higher than those recorded for able-bodied subjects in the neutral, combined and lean forward positions (p < 0.001). For the able-bodied subjects, maximum pressures at the combined (p < 0.001), tilt (p < 0.05) and lean forward (p < 0.0001) positions were significantly lower than those measured at the neutral position. For the myelomeningocele subjects, maximum pressure at all tested positions was significantly lower than at the neutral position (p < 0.05). Conclusions. The results point to the importance of measuring body-seat interface pressure for each wheelchair user and of using the information to customize wheelchair utilization.