I have measures sitting height in Somalia and Ethiopia. The procedure is described in the article reporting the data: Standing height was measured to the nearest 0.1 cm using portable height boards of standard construction using standard methods (Boelaert et al. 1995). Sitting height was measured to the nearest 0.1 cm using portable height boards of standard construction placed on tables. Children were measured with the backs of the knees resting on the edge of the table, thighs horizontal, back straight, buttocks and scapula against the height board, hands on their knees, looking straight ahead and breathing normally (Schilg and Hulse 1997). This deviates from best practice in that the feet were not supported and the measurement was not routinely taken when the child had exhaled fully (Schilg and Hulse 1997). We used tables which we borrowed from local health centres, schools, council officers, or from local leaders. I cannot recall any problem finding tables in any of the 200+ villages in which we have done this. I do not think you will find it difficult to find tables to use. If you do then you could travel with a collapsible table. You could use the approach you suggest as long as you report that was what you did. I would do a small study measuring the same children both ways so that you can adjust your measurement if needed. This would be a matter of finding a correction using ordinary least squares linear regression. A sample size of 60 or so should suffice. You would use corrected sitting height when calculating the SSR. We used the following eligibility criteria: (age >= 24 months AND age <= 59 months) OR (height >= 85 cm AND height >= 110 cm) We used maternal report for age and a marked stick for height. We did not measure younger children since the measurements are more difficult.

Thank you very much for your rapid answer.

Very happy to help.

Did you ever collect the SSR data from South Sudan?