Impact of Wheelchair Seating Systems on Scoliosis Progression for Children With Neurologic and Neuromuscular Disorders: A Retrospective Study of Custom-Contoured Wheelchair Seating and Modular Wheelchair Seating.

OBJECTIVES: To retrospectively evaluate the comparative effect of 2 wheelchair seating systems, Custom-Contoured Wheelchair Seating (CCS) and Modular Wheelchair Seating (MWS), on scoliosis progression in children with neuromuscular and neurologic disorders and to determine any predictors for scoliosis progression. DESIGN: Longitudinal, retrospective cohort study. SETTING: A national health service regional posture and mobility service. PARTICIPANTS: Nonambulant pediatric wheelchair users with neuromuscular and neurologic disorders (N=75; 36 men, 39 women; mean age at seating intervention, 10.50±3.97y) issued CCS and MWS by the South Wales Posture and Mobility Service from 2012-2022. INTERVENTIONS: Two specialized wheelchair seating systems, CCS and MWS. MAIN OUTCOME MEASURES: A generalized least squares model was used to estimate the effect of seat type on Cobb angle over time. RESULTS: Of the 75 participants enrolled, 51% had cerebral palsy. Fifty were issued CCS and 25 were issued MWS. Baseline Cobb angle was 32.9±18.9° for the MWS group and 48.0±31.0° for the CCS group. The generalized least squares model demonstrated that time since seating intervention (χ2=122, P<.0001), seating type (χ2=52.5, P<.0001), and baseline scoliosis severity (χ2=41.6, P<.0001) were predictive of scoliosis progression. Condition was not a strong predictor (χ2=9.96, P =.0069), and sex (χ2=5.67, P=.13) and age at intervention (χ2=4.47, P=.35) were not predictive. Estimated contrasts of medical condition with seat type over time demonstrated smaller differences between MWS and CCS over time. Predicted scoliosis velocity was found to attenuate with use of CCS over time compared with MWS, although scoliosis deteriorated regardless of intervention. CONCLUSIONS: Our findings showed pediatric wheelchair users with neurologic and neuromuscular disorders prescribed CCS showed greater mitigation of scoliosis progression over time compared with those issued MWS.

The clinical effectiveness of custom-contoured seating for wheelchair users with neuromuscular disorders: a scoping review.

Despite its widespread use, the clinical effectiveness of custom-contoured wheelchair seating for individuals with neuromuscular disorders remains unclear. A scoping review was conducted using PubMed, Scopus, and Web of Knowledge databases in November 2021 and updated April 2022. A total of 17 full text articles were included. Discussion themes were grouped based on three outcomes of interest: (1) posture and musculoskeletal deformity, (2) quantitative measures of body structures and functions, and (3) qualitative perceptions, opinions, and quality of life indicators. This review highlighted the lack of literature exploring the impact of custom-contoured seating on cardiopulmonary function, pressure injury management, and upper limb function; although, there was no indication that risk is increased compared to alternative seating and it performed well in terms of perceived user satisfaction, comfort, and function. The findings also demonstrated immediate benefits to postural alignment, although, the longitudinal effect on progression of musculoskeletal deformity compared to alternative seating is more ambiguous. This review aimed to scope the evidence-base for custom-contoured seating for wheelchair users with neuromuscular disorders to synthesize information from the existing literature, inform current practice, and identify knowledge gaps for further experimental investigation.

Goodness of fit of probability distributions for sightings as species approach extinction.

Estimating the probability that a species is extinct and the timing of extinctions is useful in biological fields ranging from paleoecology to conservation biology. Various statistical methods have been introduced to infer the time of extinction and extinction probability from a series of individual sightings. There is little evidence, however, as to which of these models provide adequate fit to actual sighting records. We use L-moment diagrams and probability plot correlation coefficient (PPCC) hypothesis tests to evaluate the goodness of fit of various probabilistic models to sighting data collected for a set of North American and Hawaiian bird populations that have either gone extinct, or are suspected of having gone extinct, during the past 150 years. For our data, the uniform, truncated exponential, and generalized Pareto models performed moderately well, but the Weibull model performed poorly. Of the acceptable models, the uniform distribution performed best based on PPCC goodness of fit comparisons and sequential Bonferroni-type tests. Further analyses using field significance tests suggest that although the uniform distribution is the best of those considered, additional work remains to evaluate the truncated exponential model more fully. The methods we present here provide a framework for evaluating subsequent models.

Impact of the single point of access referral system to reduce waiting times and improve clinical outcomes in an assistive technology service.

The introduction of a single point referral system that prioritises clients depending on case complexity and overcomes the need for re-admittance to a waiting list via a review system has been shown to significantly reduce maximum waiting times for a Posture and Mobility (Special Seating) Service from 102.0 ± 24.33 weeks to 19.2 ± 8.57 weeks (p = 0.015). Using this service model linear regression revealed a statistically significant improvement in the performance outcome of prescribed seating solutions with shorter Episode of Care completion times (p = 0.023). In addition, the number of Episodes of Care completed per annum was significantly related to the Episode of Care completion time (p = 0.019). In conclusion, it is recommended that it may be advantageous to apply this service model to other assistive technology services in order to reduce waiting times and to improve clinical outcomes.