This advice-column-style blog for SLPs was authored by Pam Marshalla from 2006 to 2015, the archives of which can be explored here. Use the extensive keywords list found in the right-hand column (on mobile: at the bottom of the page) to browse specific topics, or use the search feature to locate specific words or phrases throughout the entire blog.
This slide is from my class on improving intelligibility in apraxia, dysarthria, and low cognitive skills. Research has demonstrated that diphthongs and glides are learned very early and that children with phonological impairment rarely have trouble with them. However, it has been my experience that most clients with apraxia, dysarthria, and low cognitive skills do have trouble with them. Typically these children reduce these early sequences down to single vowels, and they often use the schwa instead of the correct vowel. This means that they are not moving the jaw, lips, and tongue to their fullest extent, and are resorting to the vowel with the simplest movement requirements.