The phenomena of downstep and contour formation are common in Bantu. In the Grassfields region their distribution is rich and often opaque (Hyman & Tadadjeu 1976). Since Voorhoeve's (1971) work on the associative construction in Medumba (Grassfields Bantu, Cameroon), the phenomenon of double-downstep and a robust use of floating tones have played an important role in the analysis of the language. Revisiting his analysis using data from recent fieldwork, it becomes clear that prosodic structure plays a role in the application of certain tone rules such as downstep and contour formation. Consonant alternations described in Voorhoeve (1965) are used to test for these prosodic boundaries. When the distribution of these consonant alternations is juxtaposed with that of the tone rules, it becomes clear that downstep is disallowed within the phonological word.