Designing a novel protocol to investigate mechanisms of falls in children with cerebral palsy, informed by lived experiences

Introduction Children with cerebral palsy (CwCP) regularly fall (35% fall daily), yet reasons for their falls are not well understood [1]. Stability and changes in walking behaviour of CwCP when negotiating challenging walking environments (e.g. uneven surfaces) have been accurately measured in laboratory settings [2], however these have not captured the real-world fall-risk that CwCP face daily. Walk-along interviews are a useful approach to capture the meaningful lived experiences of children whilst they are walking outside in challenging environments [3,4]. Previously, we co-designed a novel walk-along interview protocol by engaging with CwCP[5]. Real-world insights gathered from these walk-along interviews could enable us to design bespoke research protocols that explore the mechanisms of daily falls in CwCP. Research question How do lived experiences of CwCP inform the development of a bespoke lab-based protocol to investigate the mechanisms of falls? Methods Twelve CwCP (GMFCS I to III, 6 diplegia, 6 hemiplegia, 12±3 years old) and their parents took part in tailored walk-along interviews in which they discussed everyday fall experiences based on environments encountered on an outdoor walk. Chest-mounted cameras (Kaiser Baas X450) and wireless microphones (RODE GO II) captured environments and conversations. Walk-along interviews were analysed in NVivo using interpretive description[6]. Key insights from interviews (e.g. previous fall experiences) were used to determine the types of environments to be included in a bespoke walking protocol for assessing mechanisms of falls. Four CwCP and their parents were consulted about the findings from walk-along interviews to support protocol design. Results Walk-along interviews revealed that falls most often result when environmental challenges (“bumpy” surfaces) and sensory challenges (being “distracted” or “not looking”) are present together. Discussing previous falls or trips (Fig. 1) with CwCP and their parents informed the design of a bespoke walkway to investigate mechanisms of falls in challenging environments. The walkway includes common environmental challenges that cause falls (grass potholes and uneven pavements). To emulate the sensory challenges reported during walk-along interviews, randomly selected trials over the bespoke walkway will include a virtual distraction imitating noises and images of a busy street. Consultations with CwCP suggested these virtual distractions should include dogs barking and cars driving on busy roads. Discussion We have designed a bespoke protocol that replicates the challenging environmental features and distractions faced daily by CwCP. Our protocol is unique because it was informed by the lived experiences of CwCP and their parents during novel walk-along interviews. We will next investigate, using 3D motion capture, potential indicators of high fall-risk (e.g. foot placement, decreased margins of stability) in CwCP compared to typically developing children when negotiating the bespoke walkway with and without distractions. With our protocol, we hope to identify fall-risk behaviours when CwCP negotiate replica real-world environments, to inform future fall prevention programmes.