Interactive auditory feedback on physical movement activity can provide new insights into kinaesthetic awareness. Much existing work tends to emphasise corrective sonic feedback approaches to cyclic movements, either for enhancing or correcting faulty performance. Less explored is the application of aesthetic sonification for encouraging playful, creative expression of rhythmic actions such as walking. To aid the sonic interaction design process, some form of conceptual model of walking is required. We contribute a preliminary version of the Prefix/Suffix Extraction model, informed by previous work on gesture to sound-action chunks. By decomposing the footstep into a prefix-middle-suffix signal, we can control and explore various mappings of weight transfer through the articulation of the foot to sonic characteristics that may encourage the walker to play with their normal way of walking. A public installation of an interactive pressure-sensitive sound-generating surface acted as a proof-of-concept, with four different harmonic sound treatments resulting in noticeable variations in how members of the general public creatively engaged with their walking