Ultrasound can be used to address unresolved questions in phonological theory. To date, some studies have shown that results from ultrasound imaging can shed light on how differences in phonological elements are implemented. Phenomena that have been investigated include transitional schwa, vowel coalescence, and transparent vowels. A study of consonant cluster phonotactics is presented as an example of how ultrasound methodology can be used to examine phonological issues. Five English speakers presented with phonotactically illegal non-words (e.g., /zgomu/) typically repaired these sequences with vowel insertion. Using ultrasound imaging, the production of these words is compared to legal sequences that are articulatorily similar, such as "succumb" and "scum" to assess the nature of the schwa found between /z/ and the following consonant. Results indicate that for some speakers, production of schwa in /zC/ sequences is not consistent with the phonological epenthesis of a schwa. Instead, speakers appear to be failing to sufficiently overlap the consonant gestures. (Contains 4 tables, 5 notes and 4 figures.)