[NTG-context] Keeping section head with index

I want to put an index in its own section using \section{Index} \placeindex I cannot use \completeindex because that starts a new chapter, not section. Unfortunately, the header often gets separated from the index, being left as the last line on the page. I searched the mail archive and found a suggestion to use: \setuphead[section][before={\testpage[4]}] but this affects the vertical spacing of all section heads. Can anyone either: 1) suggest an alternative way of keeping the section head with the index, or 2) show me how to maintain the vertical spacing of headers when using the above construct. Thanks very much. Richard