Cerebral palsy (CP) is the most common childhood-onset disability, with a prevalence of nearly 500 000 children and an incidence of 10 000 new diagnoses annually in the USA.¹ Children with CP often experience delays across multiple developmental areas.² Dynamic systems theory suggests that global delays are due to restrictions in everyday perceptual motor skills and social experiences secondary to mobility limitations.³ Because development occurs from the interaction of multiple components within a person, task, and environment, these components interact when a child attempts to problem-solve or complete a task.³ Therefore, perceptual motor experiences in early childhood are critical for cognitive, social, and communication development.⁴ Children with CP classified in Gross Motor Function Classification System (GMFCS) level V experience the greatest limitations in self-initiated mobility and are described as dependent for transportation, having limited head and trunk postural control and limited movement of arms and legs.² Worldwide estimates suggest that about 85% of people with CP align with levels I to IV, while 15% align with level V.⁵ Children in GMFCS level V often rely on dependent mobility rather than self-initiated mobility, which can limit exposure to these dynamic learning experiences, globally affecting their participation and function long term.⁶

Powered mobility devices can assist in enhancing such exposure while increasing initiation, self-exploration, and participation during early childhood.⁷ Historically, there have been limited powered mobility devices for children under 3 years old.⁸ One option that aimed to fill this gap in mobility technology, which first emerged in the late 1980s but gained greater popularity in the 2010s, were modified ride-on cars (MROCs).⁹ These are commercial products modified for access and supportive seating with easy-to-press activation switches, polyvinyl chloride pipes, swimming kickboards, pool noodles, harnesses, and Velcro, which cost approximately US$200.⁸ A newer option, the Explorer Mini (Permobil AB, Timrå, Sweden) is a USA Food and Drug Administration-cleared device commercially released in 2020.¹⁰ The Explorer Mini is for children with disabilities aged 12 to 36 months, can be used in a seated or standing position, has a midline 360-degree joystick for driving, and costs approximately US$2700.¹⁰ Both of these devices increase self-initiated mobility for children with disabilities in early childhood through unique mechanisms.^{11, 12}

Yet, young children in GMFCS level V continue to be denied opportunities for self-initiated mobility despite the acknowledged right of all children to mobility, play, and the technologies that support enactment of these rights.¹³ There is a perception that these children may not be purposeful and safe drivers and therefore may not benefit from use.⁷ However, access to powered mobility devices can provide opportunities to explore ‘tool use learning’, environmental exploration, and developmental gains.⁷ The extent of these potential benefits is unknown because there is limited research that includes children in GMFCS level V aged under 3 years. Limitations in previous studies include small sample sizes (ranging from one to nine participants), single sessions of device exposure were conducted before the release of the Explorer Mini, or did not distinguish outcomes from children in GMFCS level V from other GMFCS levels.^14-17

Rather than solely focusing on the achievement of driving skills, changes in participation and learning may be more meaningful measurements for children in GMFCS level V. Participation in activities of daily living is critical for children to acquire new skills, attain competence, establish meaningful relationships, and achieve quality of life.^18-22 Research related to the participation of children with disabilities suggest that to fully benefit from participation, the child must: (1) take part into something or with someone; (2) feel included; (3) have some control over what they are taking part in; and (4) be engaged in something that is personally meaningful.²⁰ Therefore, caregiver perspectives about how their child uses powered mobility devices may provide a meaningful insight into participation.

An understanding of caregiver perceptions about perceived barriers to using MROCs and the Explorer Mini may contribute to the development of strategies to promote dosage adherence in interventions and inform clinical practice and device recommendations for families who have many factors to consider when choosing a device. Therefore, the purpose of the current study was to describe caregiver experiences, perceived changes in participation, barriers, and benefits, as well as device preferences across a 16-week trial with both devices for children with CP aged under 3 years classified in GMFCS level V.

METHOD

This study was part of a multisite, mixed-methods, doubly counterbalanced, randomized, AB crossover clinical trial (see the protocol paper for the full trial description).^{23, 24} This qualitative study was conducted using a phenomenological framework by interviewing caregivers whose children in GMFCS level V took part in the study.²⁵ This approach provides an analytical perspective focused on understanding a core set of shared experiences of individuals involved in a particular phenomenon.²⁵ All study procedures were approved by a single institutional review board and reliance agreement with the University of Washington Human Subjects Division. Written informed consent and caregiver permission were obtained before the study activities.

Procedures

Data collection occurred over a 16-week period in the home setting according to the study protocol.²³ Each child completed an 8-week trial period using each device, a Fisher-Price Lightening McQueen (Fisher-Price, East Aurora, NY, USA) 6 V MROC and the Explorer Mini with no washout period and randomized device order. A functional profile assessment was completed by caregivers at the initial visit based on descriptors from the GMFCS,² Mini-Manual Ability Classification System, Communication Function Classification System, and Mini-Eating and Drinking Ability Classification System (Appendix S1).²⁶

GMFCS levels were stable over time for children older than 2 years.²⁶ However, for children under 2 years, the GMFCS should be used with caution because children's functional abilities may still change during this rapid developmental stage.²⁶

Semi-structured interviews were conducted using an interview guide (Figure 1) to understand caregiver perceptions on the benefits and barriers per device, changes to their child's participation, and overall device preference. Questions related to participation were assessed for how they fitted into the six experiential aspects of participation previously suggested in the literature.²² The interviews lasted 20 to 30 minutes and occurred at baseline, mid-study, and at study completion, with data from interviews mid-study and at study completion (after device exposure) used for the current analysis. All 20 interviews were audio-recorded, transcribed verbatim, and de-identified by the research team. The first author reviewed all transcripts to ensure consistency and caregivers were invited to review their transcripts if desired. Researcher positionality is included in Figure 1.

Data analysis

The first author used first impression and summative memos to describe the main points of the interviews, emerging concepts, and reflections after transcription. The first author coded all the data, which were reviewed by the other authors. The NVivo qualitative coding software (Lumivero, Denver, CO, USA)²⁷ was used for data analysis. The coding process included using a constant comparative method to create open codes and focused codes of each caregiver's transcripts until data saturation occurred and themes emerged (Figure 2).²⁵ An e-mail summary of the themes was shared with caregivers as a form of member checking to ensure accuracy and avoid misrepresentation of the data.²⁵

Matrix coding queries were then conducted to assess patterns and response frequency in the data. These queries consisted of assessing what barriers, benefits, and participation topics were reported for each of the devices, the MROC and the Explorer Mini (see Appendix S2 for the codebook). Attributes were assigned to the device used at the time of the interview (MROC or Explorer Mini). A frequency count was conducted to show the number of occurrences of each response by each caregiver (Figures 3-5). Frequency counts can show emergent patterns in the data and help identify common themes. All changes to codes and themes were tracked using an audit trail.

RESULTS

Out of the 10 caregivers, seven preferred the Explorer Mini and three preferred the MROC. However, caregivers reported that eight of the children preferred the Explorer Mini and two preferred the MROC. Four themes emerged. One related to the perceived benefits and barriers of each device (ease and convenience is essential) and three related to perceived changes in participation: (1) autonomy enacted through mobility; (2) belonging and being present; and (3) participation as an area of growth.

DISCUSSION

This study offered a unique opportunity to address a critical knowledge gap in powered mobility literature for enhancing participation in young children with CP classified in GMFCS level V. Caregivers expressed numerous benefits and challenges to their child's use of both devices, yet consistently described how the opportunity to trial the devices enhanced participation in the form of autonomy and belonging, growth potential, engagement, and making new developmental connections. These responses align with previous literature describing the multifaceted components of defining and enacting meaningful participation for children with disabilities.^{20, 22}

Regarding device preference, most caregivers and children in this study preferred the Explorer Mini. One theme showed that caregivers want devices that are easy and convenient. This echoes research indicating that families experienced barriers to using a MROC in real-world settings.²⁸ Caregivers reported barriers most prevalently related to the device, environment, but also related to child-related barriers (i.e. health, tolerance, and abilities) and caregiver-related barriers (i.e. physical requirements, time, and motivation).²⁸ Similarly, caregivers in this study most frequently reported device barriers such as size, weight, positioning, and steering, but provided unique examples based on the device. For example, caregivers reported that the Explorer Mini was easier to use and that their children tolerated this device better; however, those who preferred MROCs noted it was better for outdoor driving environments. This highlights the importance of a multimodal mobility perspective where caregivers and children can choose the right device for the right environment based on their needs and preferences.^{8, 29} This perspective may be especially useful for pediatric therapists who work with this population and aligns with previous work, which suggests that device preference is complex and influenced by caregiver and child factors.^{17, 30}

The results of this study align with dynamic systems theory showing that the task (mobility) is influenced by the individual (level of function) and the environment (device characteristics).³ Clinicians have an opportunity to educate families about these factors and relevant device features or modifications that will contribute to successful use of powered mobility. Factors such as positioning, the child's abilities to steer, and caregiver goals for participation can help inform decisions for which device(s) are best. Education can also be provided to mitigate known barriers, such as easier ways for device transport, locating accessible environments in their community, or sharing activities to perform in the device. This can also be a valuable opportunity to educate families about the expectations of device use (i.e. exploration and participation rather than goal-directed driving).

A strength of this study was its centering on the lived experience of caregivers and children in GMFCS level V. Focusing on this population is critical given that they have been systemically excluded from powered mobility research and practice because of inclusion criteria based on a threshold of functional ability (i.e. can sit with support), a perception of the necessity for ‘readiness’ requirements of device access, or the focus of pediatric rehabilitation on the skill of walking above other functional skills.^{8, 29} This is also the largest study to focus exclusively on young children in GMFCS level V (n = 10) within the context of a powered mobility intervention, which begins to fill a critical knowledge gap. Caregivers underscored the importance of self-initiated mobility for their children in GMFCS level V, including an emphasis on how mobility facilitates autonomy and belonging through participation.

A significant limitation of this study is that while our sample was diverse in terms of participant ethnicity, neighborhood environment, socioeconomic status, and functional profiles, all caregivers interviewed were females (mothers); it is unknown if differences in perception may be mediated by sex. Other demographic factors did not explicitly arise among participant responses, but these probably intersect alongside childhood disability in unique ways that may have influenced caregiver experiences with powered mobility devices and should be explored further. Another limitation is that data were primarily collected during the summer and autumn months (June through November) and may have influenced device use patterns both outdoors and indoors. This limitation was partially mitigated through counterbalancing device order among participants. Lastly, all researchers who collected data are pediatric physical therapists, which may be a limitation. Researchers attempted to remain neutral regarding feelings about powered mobility use for each child. However, caregivers may have experienced acquiescence bias and felt the need to respond more positively about powered mobility than they truly felt due to this power dynamic. To mitigate this bias, the researchers engaged in unconditional positive regard for positive and negative participant responses, explicitly sought opposing perspectives, engaged in reflexivity, and acknowledged positionality when interpreting the words of caregivers.

Future directions of research should compare these results to other children in this study classified in different GMFCS levels. Additionally, future research addressing how children in GMFCS level V learn to use powered mobility may inform the design and implementation of interventions. Research has assessed if children in GMFCS level V can use powered mobility devices,^{11, 15-17} but there is limited information that addresses the methods and expectations for teaching powered mobility skills, as well as the potential participation benefits noted by the caregivers in this study. Future research could further assess participation as an outcome, differences in access methods (joystick vs switch) for children in GMFCS level V at varying Mini-Manual Ability Classification System levels, or evaluate outcomes if multi-week trials of powered mobility devices became a national standard of care.

In conclusion, children in GMFCS level V were able to use both powered mobility devices throughout the study, with an overall preference for the Explorer Mini. Caregivers reported several benefits and barriers related to both devices, but overall found that their child was successful in using powered mobility, with positive contributions to participation, autonomy, belonging, and recognized participation, as well as mobility as an area of growth. This is one of the first studies to provide caregiver feedback related to the newly available Explorer Mini device. Children with CP, regardless of GMFCS level, deserve equitable access to powered mobility to promote self-initiated mobility skills. Including qualitative caregiver perspectives among other outcome measures appropriate for assessing mobility and participation outcomes for children with CP can be a powerful tool to leverage in future translational research.