Powered Tilt/Recline Systems: Why and How Are They Used?

Design and experimental validation of a new wheelchair seat stabilization system

PURPOSE

Seat tilting wheelchair features can increase the comfort and safety of the user. Although many power wheelchairs have tilting mechanisms, they are often designed with a specific wheelchair model in mind. In this study, a design process for seat tilting mechanisms that can be applied to most rear-wheel drive wheelchair models is developed.

METHODOLOGY

Equations were developed to describe the geometrical and load constraints that were used to size the electric actuator that powers the system and define its position. Finally, the equations were used to create the seat tilting mechanism of a prototype wheelchair, which was then tested.

RESULTS

The equations yielded coherent results which showed that advantageous actuator positions from a load minimization perspective usually require dimensions that cannot be found in commercial actuators. Also, there are positions in which the load increases exponentially, which should be avoided. The tests showed that the system was able to function properly on the prototype wheelchair and that the actuator position affected the time taken for the actuator to execute different parts of the tilting movement.

CONCLUSIONS

The design process presented here was successful and modelled by general equations that can be applied to most front-wheel drive wheelchairs. It presents a low-cost option for the design of seat tilting systems, which can increase their accessibility.

User opinions about connected pressure detection systems to prevent wheelchair-related pressure injuries: An exploratory cross-sectional survey

About 1% of the world's population uses a wheelchair. Wheelchair use is a well-known risk of pressure injury. A connected pressure detection system could help to prevent this complication that is linked to long durations of sitting, provided that user expectations are understood. The aim of this study was to explore the needs of wheelchair users (WU) regarding connected pressure detection systems to prevent pressure injury. A cross-section survey-based study of WU was conducted, using an anonymous electronic questionnaire posted from July 2019 to June 2020. Eighty-eight people responded. The majority were power wheelchair users (72.7%); one third (33.0%) had already sustained a pressure injury; only 17.0% knew of the existence of pressure detection systems, nevertheless 78.4% believed that they could be useful in daily life. The feature that received the highest rating was a pressure warning alarm (4.2/5 points). The majority (71.6%) preferred reminder-alerts to be set according to their habits and not according to medical guidelines. In conclusion, pressure detecting systems were perceived as useful to prevent pressure injuries by both manual and power wheelchair users. Work is needed to inform potential users of the existence of such systems.

Clinical features of electric powered indoor/outdoor wheelchair users with spinal cord injuries: A cross-sectional study

This article aims to describe the characteristics of those with a primary diagnosis of spinal cord injury (SCI) attending a specialist wheelchair service providing electric powered indoor/outdoor chairs (EPIOCs). This cross-sectional study, with retrospective review of electronic and case note records, explores the complexities of additional clinical features associated with SCI and disability influencing prescription. Data were extracted under three themes; demographics, diagnostic/clinical information and wheelchair factors. There were 57 participants (35 men, 22 women) (mean age 53.51 ± 11.93, range 29-79 years) comprising 20 with paraplegia, 34 with tetraplegia and 3 with undocumented level. Paraplegics were significantly older than tetraplegics (p < 0.05). Thirty users had a complete SCI (mean age 49.87 ± 12.27 years) and 27 had another SCI lesion (mean age 57.56 ± 10.32 years). Those with a complete SCI were significantly younger than the rest (p < 0.02). Only 10 (9 tetraplegic) had SCI as the sole diagnosis. Twenty (15 tetraplegic) had one additional clinical feature, 14 had 2-3 (6 tetraplegic) and 13 (4 tetraplegic) had 4 or more. Ten users required specialised seating, 22 needed tilt-in-space EPIOCs while six required complex controls. The range and complexity of wheelchair and seating needs benefitted from a holistic assessment and prescription by a specialist multidisciplinary team.

Development of a Web-Based Monitoring System for Power Tilt-in-Space Wheelchairs: Formative Evaluation

Background

In order to prevent pressure ulcers, wheelchair users are advised to regularly change position to redistribute or eliminate pressure between the buttocks region and the seat of the wheelchair. A power tilt-in-space wheelchair (allowing simultaneous pivoting of the seat and the backrest of the wheelchair toward the back or front) meets many clinical purposes, including pressure management, increased postural control, and pain management. However, there is a significant gap between the use of tilt as recommended by clinicians and its actual usage. A Web-based electronic health (eHealth) intervention, including a goal setting, monitoring, reminder, and feedback system of the use of power tilt-in-space wheelchairs was developed. The intervention incorporates behavior change principles to promote optimal use of tilt and to improve clinical postprocurement follow-up.

Objective

This study aimed to conduct a formative evaluation of the intervention prototype to pinpoint the functionalities needed by end users, namely, power wheelchair users and clinicians.

Methods

On the basis of an evaluation framework for Web-based eHealth interventions, semistructured interviews were conducted with power wheelchair users and clinicians. A content analysis was performed with a mix of emerging and a priori concepts.

Results

A total of 5 users of power tilt-in-space wheelchairs and 5 clinicians who had experience in the field of mobility aids aged 23 to 55 years were recruited. Participants found the Web interface and the physical components easy to use. They also appreciated the reminder feature that encourages the use of the tilt-in-space and the customization of performance goals. Participants requested improvements to the visual design and learnability of the Web interface, the customization of reminders, feedback about specific tilt parameters, and the bidirectionality of the interaction between the user and the clinician. They thought the current version of the intervention prototype could promote optimal use of the tilt and improve clinical postprocurement follow-up.

Conclusions

On the basis of the needs identified by power wheelchair users and clinicians regarding the prototype of a power tilt-in-space wheelchair monitoring system, 3 main directions were defined for future development of the intervention. Further research with new wheelchair users, manual tilt-in-space wheelchairs, various age groups, and family caregivers is recommended to continue the formative evaluation of the prototype.

To tilt or not to tilt; the decision-making process

PURPOSE

This study's aim was to explore the complexities of how power tilt use is integrated within the context of daily life. Other studies have used mobility-type metrics of frequency, duration, and amplitude as measures of power tilt use in the context of daily life but results lack depth in explaining the complex interplay of participating in daily activities and power tilt use.

METHODS

This grounded theory study explored how power tilt was used in daily life from the perspectives of people experienced with using power tilt and therapists experienced with prescribing power tilt. Data collected from 22 in-depth interviews and five 3-day journals were analysed using a constant comparative approach.

RESULTS

The resultant substantive theory offers an avenue for examining the complex, iterative relationships of person, environment, technology and occupation that comprise daily life, influencing how power tilt is used at any point during the course of the day.

CONCLUSIONS

The knowledge generated from this research contributes to the advancement of understanding of how the decision to use tilt is integrated in daily life occupations. The theory can inform clinical practice related to individualizing power tilt use within the context of the person's own reality of daily life. IMPLICATIONS FOR REHABILITATION The decision to use tilt or not use tilt at any point during the day, is made contingent on the iterative transaction between environmental, functional and personal contexts at that point in time. Feedback from each experience where power tilt was used generates learning and knowledge about the context of power tilt use, informing subsequent occurrences where tilt use may be an option. The substantive theory generated in this study can provide an avenue to explore how and why context influences the decision-making process to foster an in-depth understanding of why tilt is chosen or not chosen to affect problems/issues/situations occurring in day-to-day life.

A Survey of Canadian Occupational Therapy Practices to Prevent Pressure Injuries Among Wheelchair Users via Weight Shifting

PURPOSE

The purpose of this study was to describe occupational therapy weight-shifting practices and explore recommended strategies for patients, healthcare staff, and family/caregivers across healthcare settings.

DESIGN

Cross-sectional survey.

SUBJECTS AND SETTING

Respondents included 97 currently practicing occupational therapists working in 5 main practice settings (ie, acute care, inpatient rehabilitation, outpatient rehabilitation, home and community care, and residential) from 9 out of 10 Canadian provinces.

METHODS

We created a 25-item questionnaire that included forced choice and open-ended queries. Items queried demographic information, weight-shifting techniques taught to patients, frequency and duration of weight shifting recommended, educational approaches used to teach weight shifting, and resources used to guide decision making. Participants were recruited via professional organizations and health authorities across Canada. Participants were excluded if they were not currently working with manual or power wheelchair users. Descriptive statistics were used to analyze quantitative data, and content analysis was used for qualitative data (responses to open-ended queries).

RESULTS

The most frequently recommended weight-shifting techniques were tilt (83.3%-92.8%), leaning to one side (47.9%-87.5%), and forward leaning (46.9%-83.3%). Study findings revealed a wide range of recommendations regarding frequency (every 10 minutes or less to >2 to 3 hours) and duration (≤30 seconds to as long as tolerated) of weight shifting. Weight-shifting interventions were most commonly guided by clinical experience (81.7%), practice guidelines (62.4%), and expertise of other team members (54.8%).

CONCLUSIONS

Results from this study highlight the need for further research to inform weight-shifting techniques and to build a more comprehensive understanding of weight-shifting education practices.

The Clinical Trials Mosaic: Toward a Range of Clinical Trials Designs to Optimize Evidence-Based Treatment

OBJECTIVE

Dichotomizing clinical trials designs into nomothetic (e.g., randomized clinical trials or RCTs) versus idiographic (e.g., N-of-1 or case studies) precludes use of an array of hybrid designs and potential research questions between these extremes. This paper describes unique clinical evidence that can be garnered using idiographic clinical trials (ICTs) to complement RCT data. Proposed and illustrated herein is that innovative combinations of design features from RCTs and ICTs could provide clinicians with far more comprehensive information for testing treatments, conducting pragmatic trials, and making evidence-based clinical decisions.

METHOD

Mixed model trajectory analysis and unified structural equations modeling were coupled with multiple baseline designs in (a) a true N-of-1 pilot study to improve severe autism-related communication deficits and (b) a small sample preliminary study of two complimentary interventions to relieve wheelchair discomfort.

RESULTS

Evidence supported certain mechanisms of treatment outcomes and ruled out others. Effect sizes included mean phase differences (i.e., effectiveness), trajectory slopes, and differences in path coefficients between study phases.

CONCLUSIONS

ICTs can be analyzed with equivalent rigor as, and generate effect sizes comparable to, RCTs for the purpose of developing hybrid designs to augment RCTs for pilot testing innovative treatment, efficacy research on rare diseases or other small populations, quantifying within-person processes, and conducting clinical trials in many situations when RCTs are not feasible.

Adult Scandinavians' use of powered scooters: user satisfaction, frequency of use, and prediction of daily use

PURPOSE

To investigate user satisfaction with characteristics of powered scooters (scooters), frequency of use, and factors predicting daily scooter use.

DESIGN

Cross-sectional.

SAMPLE

Adult scooter users (n = 59) in Denmark and Norway, mean age 74.5 (standard deviation 12.3) years.

METHODS

Structured face-to-face interviews. The NOMO 1.0, the Quebec User Evaluation of Satisfaction with assistive devices (QUEST 2.0), and a study specific instrument were used to collect data. Descriptive statistics were applied, and regression analyzes were used to investigate predictors for daily scooter use. The International Classification of Functioning, Disability and Health (ICF) served as a framework for classifying variables and guiding the investigation.

RESULTS

Satisfaction with the scooter characteristics was high with most participants being very satisfied or quite satisfied (66.1-91.5%). Most scooters were used daily (36.2%) or several times a week (50.0%). User satisfaction with safety of the scooter [odds ratio (OR) = 11.76, confidence interval (CI) = 1.70-81.28] and reduced balance (OR = 5.63, CI = 0.90-35.39) increased the likelihood of daily use, while reduced function in back and/or legs (OR = .04, CI = 0.00-0.75), tiredness (OR = .06, CI = 0.01-0.51), and increased age (OR = .93, CI = 0.87-1.00) reduced the likelihood of daily use. 52.8% of the variance was explained by these variables.

CONCLUSIONS

User satisfaction was high, and most scooters were used frequently. User satisfaction with safety, specific functional limitations and age were predictors for daily scooter use. Implications for Rehabilitation Scooters seem to be a beneficial intervention for people with mobility impairment: user satisfaction and frequency of use are high. Users' subjective feeling of safety should be secured in the service delivery process in order to support safe and frequent scooter use. Training of scooter skills should be considered in the service delivery process.

Reasons for using power tilt: perspectives from clients and therapists

PURPOSE

A power tilt wheelchair allows independence in changing body position to address a variety of needs throughout the day; however, literature and clinical practice suggest that actual use varies greatly. This grounded theory study examined how power tilt was used in daily life from the perspectives of adults who used power tilt and therapists who prescribed this technology.

METHODS

A constant comparative approach was used to collect and analyze interview data from five people who use power tilt and six therapists who prescribe this technology.

RESULTS

This paper presents the findings specific to understanding the reasons why power tilt was used, focusing on the relationships between tilt use and (1) the reasons for use, (2) the reasons for prescribing power tilt and (3) the associated amplitudes of tilt.

CONCLUSIONS

This study advances knowledge related to how power tilt is used in daily life by elucidating that how the reasons for use are conceptualized is complex. The three relationships related to the reason for power tilt use identified in this paper have the potential to influence the quality of communication about power tilt use in clinical practice between therapist and client and in research between researcher and participant. Implications for Rehabilitation: Understanding the inconsistencies and variations in how power tilt is used in daily life is dependent on exploring the reasons beyond the words or terms expressed to describe use. Reasons for tilt use are context dependent, particularly the activity occurring at the time of tilt use, the associated amplitude of tilt and the influence of other reasons occurring at the same time.

Power seat function usage and wheelchair discomfort for power wheelchair users

OBJECTIVES

To investigate correlations between power seat functions (PSFs) usage and wheelchair discomfort.

DESIGN

Quasi-experimental design: Time series design.

SETTING

In-home trial in participants' home/community.

PARTICIPANTS

Thirteen power wheelchair users who independently used power wheelchairs equipped with PSFs as their primary means of mobility.

MAIN OUTCOME MEASURES

PSF usage variables include the frequency of performing repositioning and using PSFs (tilt, recline, legrests and seat elevation), wheelchair occupancy, and driving distance. The Tool for Assessing Wheelchair disComfort (TAWC) were used to evaluate general discomfort and discomfort intensity.

RESULTS

Spearman correlation coefficient showed that the frequency of using tilt, recline, and legrest is significantly correlated with discomfort intensity. Multiple regression analysis with backward stepwise indicated that these functions can explain 43.8% of the variance (R2 = .438, F(3,33) = 8.588, P < 0.01) in the discomfort intensity score. The best-first decision tree shows that the frequency of using the legrest function was the top node, followed by recline and tilt functions. The overall accuracy of prediction with ten-fold cross validation for discomfort intensity was 79.4%.

CONCLUSIONS

For people who used power wheelchairs equipped with PSFs, correlation analysis and regression modeling provided evidence from the quantitative data that increasing the frequency of using PSFs may decrease wheelchair discomfort. Future studies should include interventions to encourage people to use their PSFs appropriately.

Rare diseases: matching wheelchair users with rare metabolic, neuromuscular or neurological disorders to electric powered indoor/outdoor wheelchairs (EPIOCs)

PURPOSE

To describe the clinical features of electric powered indoor/outdoor wheelchair (EPIOC) users with rare diseases (RD) impacting on EPIOC provision and seating.

METHOD

Retrospective review by a consultant in rehabilitation medicine of electronic and case note records of EPIOC recipients with RDs attending a specialist wheelchair service between June 2007 and September 2008. Data were systematically extracted, entered into a database and analysed under three themes; demographic, diagnostic/clinical (including comorbidity and associated clinical features (ACFs) of the illness/disability) and wheelchair factors.

RESULTS

Fifty-four (27 male) EPIOC users, mean age 37.3 (SD 18.6, range 11-70) with RDs were identified and reviewed a mean of 64 (range 0-131) months after receiving their wheelchair. Diagnoses included 27 types of RDs including Friedreich's ataxia, motor neurone disease, osteogenesis imperfecta, arthrogryposis, cerebellar syndromes and others. Nineteen users had between them 36 comorbidities and 30 users had 44 ACFs likely to influence the prescription. Tilt-in-space was provided to 34 (63%) users and specialised seating to 17 (31%). Four users had between them complex control or interfacing issues.

CONCLUSIONS

The complex and diverse clinical problems of those with RDs present unique challenges to the multiprofessional wheelchair team to maintain successful independent mobility and community living. Implications for Rehabilitation Powered mobility is a major therapeutic tool for those with rare diseases enhancing independence, participation, reducing pain and other clinical features. The challenge for rehabilitation professionals is reconciling the physical disabilities with the individual's need for function and participation whilst allowing for disease progression and/or growth. Powered wheelchair users with rare diseases with a (kypho) scoliosis require a wheelchair system that balances spine stability and movement to maximise residual upper limb and trunk function. The role of specialised seating needs careful consideration in supporting joint derangements and preventing complications such as pressure sores.

Do tilt-in-space wheelchairs increase occupational engagement: a critical literature review

PURPOSE

A wheelchair can enhance the quality of life of an individual with limited mobility, poor trunk control and stability, by enabling activity and participation and so occupational engagement. High specification wheelchairs which can tilt-in-space enable the position of users to be altered to suit activity and context. Despite tilt-in-space wheelchairs being expensive little is known about their therapeutic value.

METHODS

A critical literature review of the evidence was undertaken to evaluate whether the use of tilt-in-space increases occupational engagement. A wide ranging search strategy identified 170 articles which were screened using inclusion criteria. The eligible literature (n = 6) was analysed thematically using open coding.

RESULTS

The majority of the participants used tilt-in-space but the data was too heterogeneous to combine. Measures of occupational engagement were not used so the therapeutic value could not be assessed.

CONCLUSION

There is a lack of high quality evidence about the therapeutic benefits of tilt-in-space wheelchairs. Given the expense associated with providing these wheelchairs, and the increase in their provision, research is needed to justify provision of high specification wheelchairs to meet the occupational needs of users within the limited resources of health and social care. Implications for Rehabilitation Tilt-in-space wheelchairs. Wheelchairs are an important and essential assistive device for promoting independence and function. Suggests there are benefits for tilt-in-space wheelchairs. Identifies the need for additional large scale research.

Comparison of muscle and skin perfusion over the ischial tuberosities in response to wheelchair tilt-in-space and recline angles in people with spinal cord injury

OBJECTIVE

To compare the efficacy of wheelchair tilt-in-space and recline on enhancing muscle and skin perfusion over the ischial tuberosities in people with spinal cord injury (SCI).

DESIGN

Repeated-measures and before-after trial design.

SETTING

University research laboratory.

PARTICIPANTS

Power wheelchair users with SCI (N=20).

INTERVENTIONS

Six combinations of wheelchair tilt-in-space and recline angles were presented to participants in a random order. The testing protocol consisted of a baseline 5 minutes sitting with no tilt/recline and 5 minutes positioned in a tilted and reclined position at each of 6 conditions, including: (1) 15° tilt-in-space and 100° recline, (2) 25° tilt-in-space and 100° recline, (3) 35° tilt-in-space and 100° recline, (4) 15° tilt-in-space and 120° recline, (5) 25° tilt-in-space and 120° recline, and (6) 35° tilt-in-space and 120° recline.

MAIN OUTCOME MEASURES

Muscle and skin perfusion were assessed by near-infrared spectroscopy and laser Doppler flowmetry, respectively.

RESULTS

Muscle perfusion was significantly increased at 25° and 35° tilt-in-space when combined with 120° recline, and skin perfusion was significantly increased at 3 tilt-in-space angles (15°, 25°, 35°) when combined with 120° recline and at 35° tilt-in-space when combined with 100° recline (P<.05). Even in the positions of increased muscle perfusion and skin perfusion (25° and 35° of tilt-in-space combined with 120° of recline), the amount of muscle perfusion change was significantly lower than the amount of skin perfusion change (P<.05).

CONCLUSIONS

Our results indicate that a larger angle of tilt-in-space and recline is needed to improve muscle perfusion compared with skin perfusion. A position of 25° tilt-in-space combined with 120° recline is effective in enhancing muscle and skin perfusion of weight-bearing soft tissues at the ischial tuberosities.

Seat Adjustment Design of an Intelligent Robotic Wheelchair Based on the Stewart Platform

A wheelchair user makes direct contact with the wheelchair seat, which serves as the interface between the user and the wheelchair, for much of any given day. Seat adjustment design is of crucial importance in providing proper seating posture and comfort. This paper presents a multiple-DOF (degrees of freedom) seat adjustment mechanism, which is intended to increase the independence of the wheelchair user while maintaining a concise structure, light weight, and intuitive control interface. This four-axis Stewart platform is capable of heaving, pitching, and swaying to provide seat elevation, tilt-in-space, and sideways movement functions. The geometry and types of joints of this mechanism are carefully arranged so that only one actuator needs to be controlled, enabling the wheelchair user to adjust the seat by simply pressing a button. The seat is also equipped with soft pressure-sensing pads to provide pressure management by adjusting the seat mechanism once continuous and concentrated pressure is detected. Finally, by comparing with the manual wheelchair, the proposed mechanism demonstrated the easier and more convenient operation with less effort for transfer assistance.

Reviewing the literature on the effectiveness of pressure relieving movements

Sitting for prolonged periods of time increases seating interface pressures, which is known to increase the risk of developing pressure ulcers. Those at risk of developing pressure ulcers are advised to perform pressure relieving movements such as "pushups" or "forward leans" in order to reduce the duration and magnitude of pressure acting on the vulnerable ischial tuberosity region. The aim of this review was to synthesize and critique the existing literature investigating the effectiveness of pressure relieving movements on seating interface pressures. The twenty-seven articles included in this paper highlight the need for further research investigating the effect of recommended pressure relieving movements on the pressures around the ischial tuberosities. Furthermore, this review found that the majority of individuals at risk of developing pressure ulcers do not adhere with the pressure relieving frequency or magnitude of movements currently recommended, indicating a need for pressure ulcer prevention to be explored further.

Effect of durations of wheelchair tilt-in-space and recline on skin perfusion over the ischial tuberosity in people with spinal cord injury

OBJECTIVE

To compare the efficacy of various durations of wheelchair tilt-in-space and recline on enhancing skin perfusion over the ischial tuberosity in people with spinal cord injury (SCI).

DESIGN

Repeated-measures, intervention and outcomes measure design.

SETTING

University research laboratory.

PARTICIPANTS

Power wheelchair users with SCI (N=9).

INTERVENTIONS

Three protocols of various durations (3min, 1min, and 0min) of wheelchair tilt-in-space and recline were randomly assigned to the participants. Each protocol consisted of a baseline 15-minute sitting, a duration of 0- to 3-minute reclined and tilted, a second 15-minute sitting, and a 5-minute recovery. The position at the baseline and the second sitting was no tilt/recline of the participant and at the reclined and tilted and recovery was at 35° tilt-in-space and 120° recline.

MAIN OUTCOME MEASURES

Skin perfusion response to tilt and recline was assessed by laser Doppler and was normalized to mean skin perfusion at the baseline sitting.

RESULTS

The results showed that mean skin perfusion during recovery at the 3-minute duration was significantly higher than that at the 1-minute duration (P<.017) and mean skin perfusion was not significantly different between the 1-minute and 0-minute durations (not significant). Skin perfusion during the second sitting was significantly higher at the 3-minute duration than at the 1-minute and 0-minute durations (P<.017).

CONCLUSIONS

Our findings suggest that performing the 3-minute duration of wheelchair tilt-in-space and recline is more effective than the 1-minute duration in enhancing skin perfusion of weight-bearing soft tissues.

Towards an intelligent system for clinical guidance on wheelchair tilt and recline usage

We propose to construct an intelligent system for clinical guidance on how to effectively use power wheelchair tilt and recline functions. The motivations fall into the following two aspects. (1) People with spinal cord injury (SCI) are vulnerable to pressure ulcers. SCI can lead to structural and functional changes below the injury level that may predispose individuals to tissue breakdown. As a result, pressure ulcers can significantly affect the quality of life, including pain, infection, altered body image, and even mortality. (2) Clinically, wheelchair power seat function, i.e., tilt and recline, is recommended for relieving sitting-induced pressures. The goal is to increase skin blood flow for the ischemic soft tissues to avoid irreversible damage. Due to variations in the level and completeness of SCI, the effectiveness of using wheelchair tilt and recline to reduce pressure ulcer risks has considerable room for improvement. Our previous study indicated that the blood flow of people with SCI may respond very differently to wheelchair tilt and recline settings. In this study, we propose to use the artificial neural network (ANN) to predict how wheelchair power seat functions affect blood flow response to seating pressure. This is regression learning because the predicted outputs are numerical values. Besides the challenging nature of regression learning, ANN may suffer from the overfitting problem which, when occurring, leads to poor predictive quality (i.e., cannot generalize). We propose using the particle swarm optimization (PSO) algorithm to train ANN to mitigate the impact of overfitting so that ANN can make correct predictions on both existing and new data. Experimental results show that the proposed approach is promising to improve ANN's predictive quality for new data.

Distinct tilting behaviours with power tilt-in-space systems

PURPOSE

To characterise the use of tilt-in-space systems and to form recommendations for tilt prescription and training based upon its use.

METHOD

Wheelchair occupancy and seat position of 45 full-time power wheelchair users were monitored for 1-2 weeks using an accelerometer, occupancy switch and data logger. Demographics, pressure ulcer history, functional and physical presentations of their disability, and sensation were also documented.

RESULTS

Participants spent 12.1 h in their wheelchairs daily, with a median typical position of 8° (0°-47°). The median participant tilted every 27 min (0.1-16.6 tilts per occupancy hour). Pressure-relieving tilts (i.e. a tilt ≥30° for ≥1 min) were performed, on average, once every 10 h (0-2.2/h). Participants spent 19% of their seated time tilted past 15°. Seventeen participants utilised the tilt feature frequently and spent >20% of the time in multiple positions. The remaining participants sat in a single tilt range for >80% of the time.

CONCLUSIONS

Given the limited pressure relief compliance, alternative approaches to pressure relief and improved training may be needed for some clients. Wheelchair design and prescriptions may also need to reflect participants' preferences for sitting in small and medium tilts and changing position frequently.

The frequency of lymphedema in an adult spina bifida population

OBJECTIVE

In the United States, there are more than 100,000 people with spina bifida. There have been very few studies to date documenting the occurrence of lymphedema in the spina bifida population, despite a case series in 2001 that suggested that the occurrence may be higher than in the general population. Currently, approximately 1 million people have lymphedema in the United States. The purpose of this study was to document the occurrence of lymphedema and associated medical factors in a regional adult spina bifida population.

DESIGN

A total of 240 electronic medical records from the Adult Spina Bifida Clinic from January 2005 to August 2008 were retrospectively reviewed. Subjects were divided into two groups based on the presence or absence of lymphedema. χ² analyses were used to compare lymphedema groups with respect to history of medical comorbidities and ethnicity. Fisher exact tests were used to compare groups with respect to mobility status and the presence of power wheelchair seat functions. Mann-Whitney U tests were used to compare groups with respect to age, anatomic lesion level, employment level, and income.

RESULTS

Twenty-two (9.2%) patients had lymphedema. Mean ± SD population age was 35.1 ± 11.1 yrs. Lymphedema was associated with a history of trauma (P = 0.044), cellulitis (P < 0.001), cancer (P = 0.038), obesity (P < 0.001), wounds (P < 0.001), hypertension (P = 0.036), higher lesion level spina bifida (P = 0.049), and mobility status (P = 0.007). Hypertension and obesity were present in 38.3% and 37.5% of the total study population, respectively.

CONCLUSIONS

This is the first study to document the occurrence of lymphedema in a spina bifida patient population, which was almost 100 times higher than that in the general patient population. We also documented a high occurrence of hypertension and obesity in the total study population. These findings may help guide further prospective studies to more clearly delineate the risk factors for the development of lymphedema and to determine the appropriate therapies. Better screening, prevention and treatment algorithms are needed for hypertension and obesity in the spina bifida population.

Measuring the effect of incremental angles of wheelchair tilt on interface pressure among individuals with spinal cord injury

STUDY DESIGN

This study was a repeated measures study.

OBJECTIVES

The objective was to systematically measure the relative reduction in interface pressure (IP) at the ischial tuberosities (IT) and sacrum through 10° increments of tilt in a manual wheelchair among individuals with motor complete spinal cord injury (SCI).

SETTING

This study was carried out in Manitoba, Canada.

METHODS

A total of 18 adults with ASIA A or B level of injury were recruited through an out-patient SCI clinic. Using a standardized protocol, participants were tilted in 10° increments between 0° and 50°, and IP readings were obtained at the IT and sacrum using pressure mapping technology. Relative pressure reduction from baseline was calculated and compared between tilt angles.

RESULTS

Tilt angle had a highly significant effect on pressure reduction at the IT (P=0.000) and the cosine relationship between these variables was expressed as quadratic. Reduction in sacral pressure did not occur until 30° tilt, with increased loading at smaller tilt angles. Pressure reduction at the IT and sacrum was not significantly different for tetraplegic and paraplegic participants.

CONCLUSION

Small tilt angles are more suitable for postural control than pressure management. A minimum tilt of 30° is required to initiate unloading the sacrum and to achieve a clinically important reduction in pressure at the IT. Larger tilt angles resulted in more substantial pressure reduction than previously reported. Tilt-in-space appears to have similar benefits for individuals with paraplegia and tetraplegia.

Effect of wheelchair tilt-in-space and recline angles on skin perfusion over the ischial tuberosity in people with spinal cord injury

OBJECTIVE

To investigate the efficacy of wheelchair tilt-in-space and recline on enhancing skin perfusion over the ischial tuberosity in wheelchair users with spinal cord injury (SCI).

DESIGN

Repeated-measures, intervention, and outcomes-measure design.

SETTING

A university research laboratory.

PARTICIPANTS

Wheelchair users with SCI (N=11; 9 men, 2 women; mean ± SD age, 37.7±14.2y; body mass index, 24.7±2.6kg/m(2); duration of injury, 8.1±7.5y).

INTERVENTIONS

Protocols (N=6) of various wheelchair tilt-in-space and recline angles were randomly assigned to participants. Each protocol consisted of a 5-minute sitting-induced ischemic period and a 5-minute wheelchair tilt-in-space and recline pressure-relieving period. Participants sat in a position without tilt or recline for 5 minutes and then sat in 1 of 6 wheelchair tilted and reclined positions, including (1) 15° tilt-in-space and 100° recline, (2) 25° tilt-in-space and 100° recline, (3) 35° tilt-in-space and 100° recline, (4) 15° tilt-in-space and 120° recline, (5) 25° tilt-in-space and 120° recline, and (6) 35° tilt-in-space and 120° recline. A 5-minute washout period (at 35° tilt-in-space and 120° recline) was allowed between protocols.

MAIN OUTCOME MEASURES

Laser Doppler flowmetry was used to measure skin perfusion over the ischial tuberosity in response to changes in body positions caused by performing wheelchair tilt-in-space and recline. Skin perfusion response to wheelchair tilt-in-space and recline was normalized to skin perfusion of the upright seated position (no tilt/recline).

RESULTS

Combined with 100° recline, wheelchair tilt-in-space at 35° resulted in a significant increase in skin perfusion compared with the upright seated position (no tilt/recline; P<.05), whereas there was no significant increase in skin perfusion at 15° and 25° tilt-in-space (not significant). Combined with 120° recline, wheelchair tilt-in-space at 15°, 25°, and 35° showed a significant increase in skin perfusion compared with the upright seated position (P<.05).

CONCLUSIONS

Our results indicate that wheelchair tilt-in-space should be at least 35° for enhancing skin perfusion over the ischial tuberosity when combined with recline at 100° and should be at least 25° when combined with recline at 120°. Although smaller angles of wheelchair tilt-in-space and recline are preferred by wheelchair users for functional purposes, wheelchair tilt-in-space less than 25° and recline less than 100° may not be sufficient for effective pressure reduction for enhancing skin perfusion over the ischial tuberosity in people with SCI.

Virtual coach technology for supporting self-care

"Virtual Coach" refers to a coaching program or device aiming to guide users through tasks for the purpose of prompting positive behavior or assisting with learning new skills. This article reviews virtual coach interventions with the purpose of guiding rehabilitation professionals to comprehend more effectively the essential components of such interventions, the underlying technologies and their integration, and example applications. A design space of virtual coach interventions including self-monitoring, context awareness, interface modality, and coaching strategies were identified and discussed to address when, how, and what coaching messages to deliver in an automated and intelligent way. Example applications that address various health-related issues also are provided to illustrate how a virtual coach intervention is developed and evaluated. Finally, the article provides some insight into addressing key challenges and opportunities in designing and implementing virtual coach interventions. It is expected that more virtual coach interventions will be developed in the field of rehabilitation to support self-care and prevent secondary conditions in individuals with disabilities.

Monitoring seat feature usage among wheelchair users

To help manage pressure ulcers and adjust posture, powered wheelchairs can be equipped with seat tilt and backrest recline features. Clinicians usually prescribe these features for wheelchair users who are vulnerable to pressure sores or have difficulty changing postures, but little data has been collected to determine whether or not, and what extent, these features are used. This study examined how wheelchair users use power wheelchair seat features such as seat tilt, backrest recline, and seat elevation, during typical daily activities. A Seat Feature Data Logger (SFDL) was attached to 11 subject's wheelchairs for 10-14 days to gather data regarding daily usage of these features. The results showed that while subjects did not always use large angles of tilt and recline as many clinicians recommend, these features were used frequently and their use resulted in lower peak pressures. The information collected by the SFDL allows for a novel and quantitative description of the effectiveness and use of power seat features, and can also be used as a clinical compliance tool.

Tilted seat position for non-ambulant individuals with neurological and neuromuscular impairment: a systematic review

Objective: To determine the effects of tilt-in-space seating on outcomes for people with neurological or neuromuscular impairment who cannot walk.

Data sources: Search through electronic databases (MEDLINE, Embase, CINAHL, AMED). Discussions with researchers who are active in field.

Review methods: Selection criteria included interventional studies that investigated the effects of seat tilt on outcome or observational studies that identified outcomes for those who had used tilt-in-space seating in populations with neurological or neuromuscular impairments. Two reviewers independently selected trials for inclusion, assessed quality and extracted data.

Results: Nineteen studies were identified which fulfilled the selection criteria. Seventeen of these were essentially before–after studies investigating the immediate effects of tilting the seating. All studies looked at populations with neurological impairment, and most were on children with cerebral palsy (n = 8) or adults with spinal cord injury (n = 8).

Reviewer's conclusion: Posterior tilt can reduce pressures at the interface under the pelvis.

[Satisfaction with technological equipment in individuals with tetraplegia following spinal cord injury]

OBJECTIVE

To measure the acquisition, use and satisfaction with high technology equipment by spinal cord injured tetraplegic subjects.

DESIGN AND SETTING

A questionnaire was mailed to 102 tetraplegic subjects who were hospitalised in the rehabilitation center of Kerpape (Ploemeur, France) between 1998 and 2004, and 59 subjects responded. The questionnaire asked about the use of telephones, computers, wheelchairs and environmental controls at home.

RESULTS

When a piece of equipment was acquired, it was very often used. Patient satisfaction with equipment was 79.3%. Home phones and mobile phones were often used with options such as hands-free devices (78 and 59% respectively). A total of 64.4% of subjects acquired a manual wheelchair and 61% a power wheelchair. The most commonly acquired options on the power wheelchairs were the powered recline (73,7%) and tilt (71,1%) systems. All options were used but all were more desired than acquired. A total of 27.1% of subjects desired a pushrim-activated power-assist wheelchair, but only 15.3% had acquired one; 695% of subjects had a computer. Communication was the first use for the computer (82.5%); 49.2% of subjects had acquired an environmental control system, but 20% desired one. The first reason for lack of acquisition was financial difficulties but also accessibility and information problems. The factor that influenced the acquisition and need for equipment was the degree of spinal cord injury. No other factor reduced patient satisfaction with equipment.

CONCLUSION

Patients were satisfied with the equipment they acquired. But their needs, especially wheelchair options and environmental control systems, were not satisfied.