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

A systematic review of the effectiveness of pressure relieving cushions in reducing pressure injury

This systematic review seeks to gather and analyze the evidence on wheelchair pressure relieving cushions, and report on the optimal materials and designs for reducing pressure injury risk. The following research question guides this study: Which wheelchair cushions best reduce pressure injury risk? PIs continue to impact the health and function of wheelchairs users with significant mobility impairments. Pressure relieving cushions are typically prescribed to provide pressure relief in the pre-wound, wound, and post-wound phases. Presently, no published reviews analyze all of the commonly available cushion materials. Most comparison studies typically address a specific population such as spinal cord injury, or only a few styles of cushion design/materials. Results suggest air-cell cushions provide optimal pressure relief and shear reduction. Furthermore, small sample single cohort studies suggest off-loading cushions provide superior pressure relief beyond that of air-celled cushions but require additional research for greater generalizability.

Using high-resolution imaging to study the impact of the Kalogon wheelchair cushion on blood flow in the gluteal area

AIM OF THE STUDY

This study investigated how the air-bladder offloading mode of the Orbiter by Kalogon wheelchair cushion (Orbiter) affected blood flow in the gluteal region of non-disabled subjects. The hypothesis was that the cushion's offloading mode would improve blood flow, resulting in reduced reactive hyperemia when compared to the static setting, or Loaded Control (LC). Furthermore, the study proposed a technique using a high-resolution image laser speckle contrast system to measure blood flow in the gluteal area.

METHODS

Two procedures were carried out, one with the participant sitting on a cushion in LC, and the second, the cushion was set to offloading mode. Blood flow was measured through data imaging after each procedure. Three trials were performed, starting and ending in different cushion bladders. Customized algorithms were used to select regions of interest on the images for calculations. The Wilcoxon Signed-Rank Test was conducted to compare the offloads and loaded control values of each region of interest. Results were considered significant at α = 0.05.

RESULTS

Ten healthy, non-disabled adults participated in the study, seven females and three males. There were no significant differences among the participants. However, results showed that seven subjects tended to decrease reactive hyperemia in the offload sequence of trial when the last two bladders offloaded were the sacrum followed by the right ischial tuberosity.

CONCLUSIONS

The high-resolution imager showed that the Orbiter Offloads helped reduce reactive hyperemia in seven subjects, potentially improving blood flow. More research is necessary to comprehend the mechanisms of these effects fully.

Identification of wheelchair seating criteria in adults with neuromuscular diseases: A Delphi study

BACKGROUND

Adults with neuromuscular diseases like spinal muscular atrophy or Duchenne muscular dystrophy require full-time use of a wheelchair (WC) and perform all activities of daily living in a sitting position. Optimal configuration of the WC and seating system is essential to maintain the health and quality of life of users. However, few recommendations for configuration exist. The aim of this study was to identify and select 10 WC seating criteria that ensure an optimal sitting posture for health and quality of life.

METHODS

A four round Delphi method was used to collect the opinions of WC users and health professionals (HP), separately. First, the HP were asked if they believed that different criteria would apply to each disease. Then the HP and SMA II and DMD WC user experts responded to electronic surveys in 4 rounds.

RESULTS

Overall, 74 experts took part: 31 HP, 21 WC users with SMA II and 22 WC users with DMD. In total, 52% of HP believed that different criteria would apply to each disease. Ten criteria were identified by the HP for SMA II and 10 for DMD. Of the 40 criteria selected, 30 (75%) were common to each panel. Six topics were similar across panels: comfort, access to the joystick, prevention of pain, stability, pressure management and power seat functions. However, power seat functions did not reach consensus between HP and WC users (30-33% of agreement for HP and 93-100% for the WC user panels, p < 0.001).

CONCLUSION

Adults with SMA II and DMD had similar WC seating needs. Therefore, the same recommendations can be applied to these groups. Further research is necessary to understand the impact of cost on the prescription of power seat functions by health professionals.

Determining frictional properties of pants and cushion cover materials using human soft tissue and a rigid sled and how they affect seated shear forces

Shear forces on the buttocks while seated are directly linked to friction, yet the frictional properties at the seat interface are unknown. Shear forces are one of the factors related to increase risk of pressure injury formation. The goals of this study included determining coefficients of friction between three cushion covers and two clothing fabrics using a mechanical system as well as human participants and to evaluate the impact of the cushion covers on shear loading on the buttocks while seated. A chair with separate seat pan tilt and back recline movements was built and instrumented with reflective markers and a load cell. A motion capture system and load cell were used to determine the angles of seat pan tilt at which the sled and participants started sliding, as well as shear forces at three recline angles for three cushion covers (vinyl, one-layer nylon, and two-layer nylon). Results showed the vinyl and two-layer nylon cushion covers respectively had the largest and smallest coefficients of friction for both pants materials. The coefficients of friction calculated with the human participants and rigid sled were within 10% of each other, demonstrating similar results. Further, increasing back recline increased shear load on the buttocks, while the two-layer nylon cover reduced shear forces seen on the buttocks. This work furthers the understanding of shear loading on the buttocks, will aid in the protocols for reducing pressure injuries, and suggests that coefficients of friction found using rigid bodies may be applied to deformable bodies.

Quantitative Measurement of the Pressure and Shear Stress Acting on the Body of a Wheelchair User Using a Wearable Sheet-Type Sensor: A Preliminary Study

To provide a safer sitting environment for wheelchair users, it is important to quantitatively measure the forces acting on the contact surface between the seat and the person in the wheelchair. In addition to the pressure acting on the buttocks, shear forces have received particular attention in recent years; however, measuring shear force is more difficult than measuring pressure. To obtain this measurement, a thin and flexible sensor that can be used in a natural state on a wheelchair is needed. Therefore, we constructed a measurement system using our previously developed wearable sheet-type sensor (0.9 mm thick). In this study, preliminary tests were conducted using human dummies before testing on humans. Sensors were placed in four locations on the humanoid dummy's back and buttocks, and the electric wheelchair was tilted and reclined five times each. The results showed that the sensor output pattern was reproducible and valid enough to proceed to the next step. However, the shear force in the internal and external directions was greater than expected, which indicates that the equipment and testing methods must be reviewed. On the basis of the results obtained in this preliminary study, preparations will be made for testing on human subjects.

Effect of Tilt-in-Space and Reclining Angles of Wheelchairs on Normal Force and Shear Force in the Gluteal Region

Healthcare workers need to educate patients regarding proper sitting positions to prevent pressure injuries in the elderly and disabled. The purpose of this study was to investigate the differences in normal and shear force in the gluteal region using the combination of tilt-in-space and reclining functions of wheelchairs. Twelve healthy subjects were recruited. Protocols for 15 wheelchair tilt-in-space and reclining angles, including three reclining angles (0°, 10°, and 20°) and five tilt-in-space (0°, 5°, 10°, 15°, and 20°), were randomly assigned. To measure the amount of normal and shear force applied to the gluteal region while sitting on a wheelchair, a force plate was placed on the seat to measure the seat reaction force. For statistical analysis, a two-factor analysis of variance, with tilt-in-space and reclining, was performed for each normal and shear force. The normal force showed a significant decrease with increased reclining angle. For the shear force combined with sagittal and lateral components, the 10° tilt-in-space showed a significant decrease compared to other conditions. The combination of 20° reclining and 10° tilt-in-space angles may decrease both normal and shear force in the gluteal region while sitting. These findings may help wheelchair-dependent individuals avoid pressure injuries.

Pressure redistributing static chairs for preventing pressure ulcers

BACKGROUND

Sitting can be viewed as a therapeutic intervention and an important part of a person's recovery process; but the risk of ulceration must be mitigated. Interventions for ulcer prevention in those at risk from prolonged sitting include the use of specialist cushions and surfaces, especially for wheelchair users. Whilst there is interest in the effects of different pressure redistributing cushions for wheelchairs, the benefits of pressure redistributing static chairs, compared with standard chairs, for pressure ulcer development in at-risk people are not clear.

OBJECTIVES

To assess the effects of pressure redistributing static chairs on the prevention of pressure ulcers in health, rehabilitation and social care settings, and places of residence in which people may spend their day.

SEARCH METHODS

In June 2021 we searched the following electronic databases to identify reports of relevant randomised clinical trials: the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid Embase and EBSCO CINAHL Plus (Cumulative Index to Nursing and Allied Health Literature). We also searched clinical trials registers for ongoing and unpublished studies, and reference lists of relevant systematic reviews, meta-analyses and health technology reports. There were no restrictions by language, date of publication or study setting.

SELECTION CRITERIA

We sought to include published or unpublished randomised controlled trials that assessed pressure redistributing static chairs in the prevention or management of pressure ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection. We planned that two review authors would also assess the risk of bias, extract study data and assess the certainty of evidence according to GRADE methodology.

MAIN RESULTS

We did not identify any studies that met the review eligibility criteria, nor any registered studies investigating the role of pressure redistributing static chairs in the prevention or management of pressure ulcers.

AUTHORS' CONCLUSIONS

Currently, there is no randomised evidence that supports or refutes the role of pressure redistributing static chairs in the prevention or management of pressure ulcers. This is a priority area and there is a need to explore this intervention with rigorous and robust research.

Shifting loads as a result of chair articulations and associated perfusion responses in the context of pressure injuries: An investigation with able-bodied individuals

Wheelchair users with spinal cord injuries experience pressure injuries at high rates, causing a decrease in quality of life and an increased financial burden. The soft tissue in the buttocks (beneath the ischial tuberosities) and lower back (behind the sacrum) experience large interface pressures over long periods while seated, putting them at high risk of pressure injury development. The goals of this research were to evaluate the ability of an articulating chair design to redistribute pressures on the body and to affect blood perfusion in the buttocks tissue over the ischial tuberosities. Using a unique, custom-designed chair developed for this research, pressure and blood perfusion were obtained for numerous seated positions that included recline, seat pan tilt, and back articulations. Reclining the chair back increased maximum pressures in the buttocks and lower back regions, while it decreased maximum pressures in the upper back and thigh regions. Increasing seat pan tilt, or rotating the anterior edge of the seat pan above the posterior edge, decreased maximum pressures in the buttocks and lower back regions and increased perfusion in the buttocks. Results suggested that using back recline and seat pan tilt together to create a whole-body tilt increased pressures in the back and decreased pressures in the buttocks. Changes in back articulation redistributed pressure in all back regions. Thus, the articulating chair design redistributed pressures in all areas of the body and promoted blood perfusion in the buttocks while seated. Pressure redistribution and perfusion promotion are fundamental to reducing pressure injury risk.

Key Components Related to Pressure Injury Formation: An Initial Investigation Into Pressure Distribution and Blood Perfusion Responses in Wheelchair Users

Soft tissue around bony prominences in the buttocks and back are high-risk areas prone to the development of pressure injuries. From a clinical perspective, prevention of pressure injuries all together is the ideal situation. Unfortunately, prevalence rates still reach 47% with recurrence rates even higher. The goals of this study were to evaluate the effects of a series of wheelchair movements, some that currently exist in commercial wheelchairs and some new, on interface pressures and perfusion under the buttocks. Twenty-seven chair positions were obtained by varying back recline, seat pan tilt, and articulation of two supports along the back. Although back recline is commonly taught by therapists to be used as a pressure relieving posture, results indicated an increase in pressures under the ischial tuberosities and sacral areas in reclined positions. Articulation of the back supports produced changes in posture moving from an "erect" to "slouched" position. These movements successfully shifted pressures across back regions. Seat pan tilt was effective in shifting pressures off the ischial tuberosity regions. Additionally, in a portion of the participants, seat pan tilt consistently increased perfusion under the ischial tuberosity region. The findings of this research suggest that movements other than back recline should be considered to more effectively alter interface pressures, particularly in high-risk regions like the sacrum and ischial tuberosities.

Pressure distribution in tilting and reclining wheelchairs with an air cushion: A pilot study

Study aim: The aim of this study was to determine the optimal angle for maximizing pressure distribution in two types of wheelchairs (tilting and reclining) while using a ROHO cushion, which offers relatively effective pressure distribution.

Material and methods: This study enrolled 28 male and female college students who understood the purpose of the study and agreed to participate. This study aimed to determine the optimal angle for tilting and reclining wheelchairs when using a ROHO cushion at angles of 10°, 20°, and 30° with tilted wheelchairs and 90°, 110°, and 130° with reclining wheelchairs.

Results: The analysis showed that an improved pressure distribution when a tilting wheelchair was used versus a reclining one. A reclining position of ≥110° and a tilt angle of ≥20° led to significant pressure-reducing effects.

Conclusion: The results of this study will help wheelchair users or their guardians to select the optimal wheelchair angle when changing their posture to prevent bedsores. Although no slippage was observed in our study, it is important to remember the proper back position to prevent unnecessary slippage.

The relationship between torso inclination and the shearing force of the buttocks while seated in a wheelchair: Preliminary research in non-disabled individuals

The shearing force acting upon the contacting surface of the buttocks while seated in a wheelchair has been linked to the development of pressure ulcers. However, the actual causative factors have not been examined in detail. In an attempt to clarify the nature of this problem, we developed a specific measurement system. In preparation for future clinical applications, we conducted preliminary testing in non-disabled individuals. As a result, we were able to discover a number of issues related to this system and our measurement methods. Although we only evaluated a limited number of typical sitting postures, we were able to record the buttocks shearing force reference values for non-disabled individuals. Our results suggest that regardless of posture, a backward-directed shearing force occurs below the ischial tuberosity in non-disabled individuals in seated positions. This force seemed to increase as the individual leaned forward. Meanwhile, tilting the torso to one side seemed to be associated with an increase in the shearing force working in the opposite direction. We hope that these findings can be utilized for reference purposes in future research among non-disabled individuals.

Nonnegative matrix factorization for the identification of pressure ulcer risks from seating interface pressures in people with spinal cord injury

The purpose of this study was to predict and visualize pressure ulcer risks by using a novel approach of extracting computational features from seating interface pressures in people with spinal cord injury (SCI). In conventional clinical practice, seating interface pressure assessments rely on descriptive statistics of pressure magnitude. In this study, rank-2 nonnegative matrix factorization (NMF) was applied to the seating interface pressure maps during loading and pressure-relieving conditions in 16 people with SCI. The NMF basis images were used for visual interpretation and computational prediction of pressure ulcer risks. The two NMF basis images encapsulated pressure concentration and pressure dispersion, respectively. The first basis converged on the ischial tuberosity under both seating conditions, whereas the second basis converged anterior to the ischial tuberosity during loading and converged on the coccyx during unloading. The classification yielded 81.25% overall accuracy. In general, higher ulceration risk was associated with higher and lower activations of the first and second bases, respectively. The NMF pipeline yielded promising performance. Basis visualization affirmed the importance of lower ischial pressure and higher distribution dispersion while also revealing that clinical practice may currently be underestimating the importance of coccygeal pressure in response to pressure-relieving activities. Graphical abstract.

Implementing local cooling to increase skin tolerance to ischemia during normal seating in people with spinal cord injury

The purpose of this study was to investigate the effectiveness of local cooling in reducing reactive hyperemia after ischemia at the ischial tuberosities for people with spinal cord injury (SCI) during normal seating. The degree of the reactive hyperemic response is indicative of the extent of cellular stress caused by the ischemia. We hypothesized that reactive hyperemic skin blood flow (SBF) responses will be lower when local cooling is implemented by the wheelchair seat cushion. This study used a repeated measures design, and each subject underwent two conditions: normal seating with temperature control 'on' (cooling) and 'off' (non-cooling) for 30 min. Twenty-three participants with traumatic SCI were recruited. SBF and skin temperature were collected before, during and after seating. SBF signals were processed with short-time Fourier analyses to examine the underlying vascular control mechanisms, including the following (corresponding frequency bands): metabolic (0.0095-0.02 Hz), neurogenic (0.02-0.05 Hz), and myogenic (0.05-0.15 Hz) spectral densities. Our results showed that with cooling, skin temperature decreased (range -0.4 ~ -3.1 °C, p = 0.002), and reactive hyperemia parameters (normalized peak SBF and perfusion area) were reduced (p = 0.02, p = 0.033, respectively). In addition, changes in normalized peak SBF (non-cooling - cooling) was moderately correlated with changes in normalized metabolic and neurogenic spectral densities. Our findings suggested that local cooling has a positive effect on reducing the cellular stress caused by ischemia during normal seating. Metabolic and neurogenic SBF control mechanisms may play a minor role. Further exploration of the effect of temperature control on pressure injury prevention is warranted.

The relationship between pressure offloading and ischial tissue health in individuals with spinal cord injury: An exploratory study

Objectives: To compare thickness and texture measures of tissue overlying the ischial region in able-bodied (AB) individuals vs. individuals with spinal cord injury (SCI) and to determine if there is a relationship between pressure offloading of the ischial tuberosities (IT) and tissue health in individuals with SCI. Design: Exploratory cross-sectional study. Setting: University setting and rehabilitation hospital. Outcome Measures: Thickness and texture measurements from ultrasound images of tissues overlying the IT were obtained from AB individuals (n = 10) and individuals with complete or incomplete traumatic and non-traumatic SCI American Spinal Injury Association Impairment Scale (AIS) classification A-D (n = 15). Pressure offloading was measured in individuals with SCI and correlated with tissue health measurements. Results: The area overlying the IT occupied by the muscle was significantly greater in the SCI when compared with AB cohort. The area occupied by the muscle in individuals with SCI appeared to lose the striated appearance and was more echogenic than nearby skin and subcutaneous tissue (ST). There was no correlation between offloading times and thickness, echogenicity and contrast measurements of skin, ST and muscle in individuals with SCI. Conclusion: Changes in soft tissues overlying the ischial tuberosity occur following SCI corresponding to the loss of striated appearance of muscle and increased thickness of the area occupied by the muscle. Further studies using a larger sample size are recommended to establish if thickness and tissue texture differ between individuals with SCI who sustain pressure injuries vs. those who do not.

Dynamic changes in seating pressure gradient in wheelchair users with spinal cord injury

Pressure ulcer interventions are commonly assessed with measures of seating interface pressure, such as peak pressure gradients (PPGs). Decreases in PPG magnitudes may reduce pressure ulcer risk by decreasing tissue deformation and increasing tissue perfusion of at-risk weight-bearing tissues. Changes in PPG directions, which have previously been overlooked in the seating pressure literature, may provide a transient increase in blood flow to at-risk tissues, even if the PPG magnitude and location remain the same. The purpose of this study was to assess both PPG components in response to combinations of wheelchair tilt and recline angles. Thirteen power wheelchair users were recruited into the study. Six combinations of wheelchair tilt (15°, 25°, and 35°) and recline (10° and 30°) were tested in random order. Each combination was tested with 5-min upright sitting, 5-min tilt and recline, and 5-min maximal pressure relief recovery. Changes in PPG magnitudes and PPG directions under the left ischial tuberosity were computed for the six angle combinations. The findings in this study suggested that when combining wheelchair tilt and recline, the recline function may be particularly useful in reducing PPG magnitudes, while the tilt function may be particularly useful in manipulating PPG directions.

Evaluation of the effect of different sitting assistive devices in reclining wheelchair on interface pressure

Background

Reclining wheelchair users often add one or more sitting assistive devices to their wheelchairs, but the effect of these additional sitting assistive devices on the risk of pressure ulcers has rarely been investigated. This study examined the four modes of reclining wheelchair without and with different sitting assistive devices, namely the back reclined mode, the lumbar support with back reclined mode, the femur upward with back reclined mode, and the lumbar support with femur upward with back reclined mode, in terms of their effects on human-wheelchair interface pressure.

Methods

This study recruited 16 healthy participants to undergo the aforementioned four modes in random order and have their human-wheelchair interface pressure measured. The initial setting of experimental reclining wheelchair backrest was pushed backward to reach a 150° recline. The data on interface pressure were collected for 5 s while the participant maintained a stable sitting position. The contact area, average pressure, and peak pressure on the back area, ischial area, and femur area were recorded and calculated.

Results

Among all tested modes, the lumbar support with femur upward with back reclined mode provided the most significant reduction in stress load on the ischial area (P ≤ 0.010) and shifted part of the load to the femur area (P ≤ 0.009).

Conclusions

This study quantified the effects of and differences between various reclining wheelchair–sitting assistive device combination modes. These findings are useful for the decision-making processes of rehabilitation physicians, wheelchair users, and manufacturers.

Trends of reactive hyperaemia responses to repetitive loading on skin tissue of rats - Implications for pressure ulcer prevention

Tissue recovery is important in preventing tissue deterioration, which is induced by pressure and may lead to pressure ulcers (PU). Reactive hyperaemia (RH) is an indicator used to identify people at risk of PU. In this study, the effect of different recovery times on RH trend is investigated during repetitive loading. Twenty-one male Sprague-Dawley rats (seven per group), with body weight of 385-485 g, were categorised into three groups and subjected to different recovery times with three repetitive loading cycles. The first, second, and third groups were subjected to short (3 min), moderate (10 min), and prolonged (40 min) recovery, respectively, while fixed loading time and pressure (10 min and 50 mmHg, respectively). Peak hyperaemia was measured in the three cycles to determine trends associated with different recovery times. Three RH trends (increasing, decreasing, and inconsistent) were observed. As the recovery time is increased (3 min vs. 10 min vs. 40 min), the number of samples with increasing RH trend decreases (57% vs. 29% vs. 14%) and the number of samples with inconsistent RH trend increases (29% vs. 57% vs. 72%). All groups consists of one sample with decreasing RH trend (14%). Results confirm that different recovery times affect the RH trend during repetitive loading. The RH trend may be used to determine the sufficient recovery time of an individual to avoid PU development.

Pressure Mapping of a Standard Hospital Recliner and Select Cushions With Healthy Adults: A Comparative Study

PURPOSE

The aim of the study was to compare the degree of pressure created when healthy adult volunteers sat on a hospital recliner chair in various positions and on various cushions.

DESIGN

Comparative cross-sectional study.

SUBJECTS AND SETTING

Thirty-four healthy subjects were recruited from the community, an urban city in a rural area of Eastern North Carolina.

METHODS

Interface pressure measurements were taken by the investigators for each subject sitting on a standard hospital recliner under each of the following conditions: no cushion, foam cushion, nonadjustable air cushion, nonadjustable air/foam cushion, and adjustable air cushion. Subject positions, upright sitting and reclined, were randomly selected. Analyses consisted of data visualizations by investigators and univariate statistics. For each surface, mean pressure, peak pressure, and Pressure Area Index (PAI) were obtained and compared. Inferences were drawn from a repeated-measures analysis-of-covariance model.

RESULTS

Subject position was not associated with any of the measures for each surface after adjusting for other variables (average pressure P = .1094, maximum/peak pressure P = .1318, PAI P = .4336). Subject weight, the type of surface, and their interaction do impact the results (average pressure, maximum/peak pressure, and PAI, P < .0001). The foam cushion had the highest mean and average interface pressures and the lowest PAI. The nonadjustable air and air/foam cushions performed most similarly to each other, showing lowest mean and average interface pressures and the highest PAI.

CONCLUSION

Position of a hospital recliner chair in the 2 positions studied had no association with interface pressure outcomes; therefore, other methods of pressure redistribution need to be utilized by clinicians. Based on the results of this study, clinicians may need to reevaluate the type of cushion used in the acute hospital setting, as a standard foam cushion was found to increase interface pressures when compared to other cushions and a standard hospital recliner.

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.

Effects of different seat cushions on interface pressure distribution: a pilot study

[Purpose] The purpose of this study was to evaluate pressure redistribution on the supporting area of healthy volunteers when using different cushions. [Subjects and Methods] Twenty healthy individuals ranging in age from 19–23 years old and 20 older adults age 60 or above participated in the study. All participants lived in urban communities in South Korea. Group differences according to gender, age, and cushion types were analyzed with one-way analysis of variance and post-hoc analysis. [Results] Statistically significant differences in peak pressure and mean pressure were identified between age, gender, and cushion types. Peak pressure and mean pressure were higher on firm surfaces and on the air cushion than other cushion types. The pressure ratio was lower when an air cushion was used in the buttock area and was higher when it was used under the thighs compared to that in other conditions. [Conclusion] This study showed that interface pressure can be distributed differently depending on what cushions are used. Therefore, when using seat cushions, individuals should seek advice to help them choose the appropriate cushion for their needs.

Reliability of the special support system for sitting pressure redistribution

[Purpose] This study investigated the reliability of the Special Support System. [Subjects and Methods] Eighteen female and 14 male volunteers participated in this study. Participants were asked to sit on the Special Support System with their chins tucked in, spines straight, pelvis neutrally positioned, and their hands placed on their thighs. They were also asked to flex their hips, knees, and ankles to approximately 90 degrees and to put their feet flat on the floor. The total contact area, mean total pressure, as well as mean and peak pressures of each quadrant were each measured 15 times. Test-retest reliability was analyzed for inflated air pressure, and pressure redistribution values by using intraclass correlation coefficients. [Results] The intraclass correlation coefficient was greater than 0.89 for inflated air pressure and greater than 0.92 for total contact area, mean total pressure, and each quadrant’s mean and peak pressure. [Conclusion] The findings suggest that the Special Support System is reliable and can be used as an alternative method for redistributing sitting pressure.

Development of theory-based knowledge translation interventions to facilitate the implementation of evidence-based guidelines on the early management of adults with traumatic spinal cord injury

RATIONALE

Optimal, early management following a spinal cord injury (SCI) can limit individuals' disabilities and costs related to their care. Several knowledge syntheses were recently published to guide health care professionals with regard to early interventions in SCI patients. However, no knowledge translation (KT) intervention, selected according to a behaviour change theory, has been proposed to facilitate the use of SCI guidelines in an acute care setting.

OBJECTIVES

To develop theory-informed KT interventions to promote the application of evidence-based recommendations on the acute care management of SCI patients.

METHODS

The first four phases of the knowledge-to-action model were used to establish the study design. Knowledge selection was based on the Grading of Recommendations Assessment, Development and Evaluation system. Knowledge adaptation to the local context was sourced from the ADAPTE process. The theoretical domains framework oriented the selection and development of the interventions based on an assessment of barriers and enablers to knowledge application.

RESULTS

Twenty-nine recommendations were chosen and operationalized in measurable clinical indicators. Barriers related to knowledge, skills, perceived capacities, beliefs about consequences, social influences, and the environmental context and resources theoretical domains were identified. The mapping of behaviour change techniques associated with those barriers led to the development of an online educational curriculum, interdisciplinary clinical pathways as well as policies and procedures.

CONCLUSIONS

This research project allowed us developing KT interventions according to a thorough behavioural change methodology. Exposure to the generated interventions will support health care professionals in providing the best care to SCI patients.

Development of an algorithm to predict comfort of wheelchair fit based on clinical measures

[Purpose] The purpose of this study was to develop an algorithm to predict the comfort of a subject seated in a wheelchair, based on common clinical measurements and without depending on verbal communication. [Subjects] Twenty healthy males (mean age: 21.5 ± 2 years; height: 171 ± 4.3 cm; weight: 56 ± 12.3 kg) participated in this study. [Methods] Each experimental session lasted for 60 min. The clinical measurements were obtained under 4 conditions (good posture, with and without a cushion; bad posture, with and without a cushion). Multiple regression analysis was performed to determine the relationship between a visual analogue scale and exercise physiology parameters (respiratory and metabolism), autonomic nervous parameters (heart rate, blood pressure, and salivary amylase level), and 3D-coordinate posture parameters (good or bad posture). [Results] For the equation (algorithm) to predict the visual analogue scale score, the adjusted multiple correlation coefficient was 0.72, the residual standard deviation was 1.2, and the prediction error was 12%. [Conclusion] The algorithm developed in this study could predict the comfort of healthy male seated in a wheelchair with 72% accuracy.

Taking Control: An Exploratory Study of the Use of Tilt-in-Space Wheelchairs in Residential Care

Tilt-in-space (TIS) wheelchairs are common in residential care, but little empirical evidence exists regarding how they are used by residents and staff in these settings. As part of a larger study exploring the use of wheeled mobility in these facilities, we conducted a substudy to examine how TIS wheelchairs are used in practice and to explore the experiences of the residents who use them. We conducted a series of three participant observations and interviews with 6 residents or their family members and interviewed 10 staff. Our analysis identified taking control as the main overarching theme, subsuming two subthemes: promoting comfort and mobilizing to participate. Findings suggest that power TIS wheelchairs enable user control, whereas manual TIS wheelchairs promote staff control. These findings illustrate how TIS wheelchairs may enable or inhibit occupational engagement and suggest that vigilance is necessary to prevent their use as a restraint.

Effect of tilt and recline on ischial and coccygeal interface pressures in people with spinal cord injury

OBJECTIVE

Clinicians commonly recommend that power wheelchair users with spinal cord injury perform wheelchair tilt and recline maneuvers to redistribute seating loads away from the ischial tuberosities. However, ischial pressure reduction may be accompanied by coccygeal pressure increases. Although the coccyx is among the most common sites of pressure ulcers, few studies have reported coccygeal interface pressure. The purpose of this study was to investigate both ischial and coccygeal interface pressures in response to changes in wheelchair tilt and recline angles.

DESIGN

Thirteen power wheelchair users were recruited into this study. Six combinations of wheelchair tilt (15, 25, and 35 degrees) and recline (10 and 30 degrees, corresponding to traditional recline conventions of 100 and 120 degrees, respectively) angles were tested in random order. Each combination was tested with 5 mins of upright sitting, 5 mins of tilt and recline, as well as 5 mins of maximal pressure relief recovery. Peak pressure indices were calculated at the ischial and coccygeal sites.

RESULTS

Ischial pressures monotonically decreased in response to increasing combinations of tilt and recline. Increments of 15 degrees of tilt did not produce significant differences under either recline angle, whereas increments of 25 degrees of tilt produced significant differences under both recline angles. Coccygeal pressures increased in response to the four smallest (of six) combinations of tilt and recline, whereas they decreased in response to the largest two combinations.

CONCLUSIONS

Ischial pressures seemed to be redistributed to the coccyx in response to the four smallest angle combinations and redistributed to the back support in response to the two largest angle combinations. Future work should confirm this pressure redistribution to the back support and determine the back support locations of redistribution.

Development of intelligent model for personalized guidance on wheelchair tilt and recline usage for people with spinal cord injury: methodology and preliminary report

Wheelchair tilt and recline functions are two of the most desirable features for relieving seating pressure to decrease the risk of pressure ulcers. The effective guidance on wheelchair tilt and recline usage is therefore critical to pressure ulcer prevention. The aim of this study was to demonstrate the feasibility of using machine learning techniques to construct an intelligent model to provide personalized guidance to individuals with spinal cord injury (SCI). The motivation stems from the clinical evidence that the requirements of individuals vary greatly and that no universal guidance on tilt and recline usage could possibly satisfy all individuals with SCI. We explored all aspects involved in constructing the intelligent model and proposed approaches tailored to suit the characteristics of this preliminary study, such as the way of modeling research participants, using machine learning techniques to construct the intelligent model, and evaluating the performance of the intelligent model. We further improved the intelligent model's prediction accuracy by developing a two-phase feature selection algorithm to identify important attributes. Experimental results demonstrated that our approaches held the promise: they could effectively construct the intelligent model, evaluate its performance, and refine the participant model so that the intelligent model's prediction accuracy was significantly improved.

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.

Investigation of peak pressure index parameters for people with spinal cord injury using wheelchair tilt-in-space and recline: methodology and preliminary report

The purpose of this study was to determine the effect of the sensel window's location and size when calculating the peak pressure index (PPI) of pressure mapping with varying degrees of wheelchair tilt-in-space (tilt) and recline in people with spinal cord injury (SCI). Thirteen power wheelchair users were recruited into this study. Six combinations of wheelchair tilt (15°, 25°, and 35°) and recline (10° and 30°) were used by the participants in random order. Displacements of peak pressure and center of pressure were extracted from the left side of the mapping system. Normalized PPI was computed for three sensel window dimensions (3 sensels × 3 sensels, 5 × 5, and 7 × 7). At least 3.33 cm of Euclidean displacement of peak pressures was observed in the tilt and recline. For every tilt angle, peak pressure displacement was not significantly different between 10° and 30° recline, while center of pressure displacement was significantly different (P < .05). For each recline angle, peak pressure displacement was not significantly different between pairs of 15°, 25°, and 35° tilt, while center of pressure displacement was significantly different between 15° versus 35° and 25° versus 35°. Our study showed that peak pressure displacement occurs in response to wheelchair tilt and recline, suggesting that the selected sensel window locations used to calculate PPI should be adjusted during changes in wheelchair configuration.

Effects of wheelchair cushions and pressure relief maneuvers on ischial interface pressure and blood flow in people with spinal cord injury

OBJECTIVE

To investigate the effectiveness and interactions of 2 methods of pressure ulcer prevention, wheelchair cushions and pressure relief maneuvers, on interface pressure (IP) and blood flow of the buttocks.

DESIGN

Within-subject repeated measures.

SETTING

Rehabilitation center.

PARTICIPANTS

Wheelchair users with a spinal cord injury or disorder (N=17).

INTERVENTIONS

Participants performed 3 forward leans and 2 sideward leans with different degrees of lean while seated on each of 3 different wheelchair cushions.

MAIN OUTCOME MEASURES

IP measured with a custom sensor and blood flow measured with laser Doppler flowmetry were collected at the ischial tuberosity.

RESULTS

Pressure relief maneuvers had a significant main effect on the ischial IP (P<.001); all maneuvers except for the small frontward lean resulted in a significant reduction in IP compared with upright sitting. Blood flow significantly varied across postures (P<.001) with flow during upright sitting and small forward leans being significantly lower than during the full and intermediate leans in both the forward and sideward directions.

CONCLUSIONS

The results of the study highlight the importance of positioning wheelchair users in a manner that facilitates in-seat movement. Regardless of the cushion being used, the pressure relief maneuvers resulted in very large reductions in IPs and significant increases in buttock blood flow. Only the small frontward lean was shown to be ineffective in reducing pressure or increasing blood flow. Because these pressure relief maneuvers involved postural changes that can occur during functional activities, these pressure relief maneuvers can become a part of volitional pressure relief and functional weight shifts. Therefore, clinical instruction should cover both as a means to impart sitting behaviors that may lead to better tissue health.

Skin blood flow dynamics and its role in pressure ulcers

Pressure ulcers are a significant healthcare problem affecting the quality of life in wheelchair bounded or bed-ridden people and are a major cost to the healthcare system. Various assessment tools such as the Braden scale have been developed to quantify the risk level of pressure ulcers. These tools have provided an initial guideline on preventing pressure ulcers while additional assessments are needed to improve the outcomes of pressure ulcer prevention. Skin blood flow function that determines the ability of the skin in response to ischemic stress has been proposed to be a good indicator for identifying people at risk of pressure ulcers. Wavelet spectral and nonlinear complexity analyses have been performed to investigate the influences of the metabolic, neurogenic and myogenic activities on microvascular regulation in people with various pathological conditions. These findings have contributed to the understanding of the role of ischemia and viability on the development of pressure ulcers. The purpose of the present review is to provide an introduction of the basic concepts and approaches for the analysis of skin blood flow oscillations, and present an overview of the research results obtained so far. We hope this information may contribute to the development of better clinical guidelines for the prevention of pressure ulcers.

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.

Wheelchair tilt-in-space and recline does not reduce sacral skin perfusion as changing from the upright to the tilted and reclined position in people with spinal cord injury

OBJECTIVE

To investigate the effect of various wheelchair tilt-in-space and recline angles on sacral skin perfusion in wheelchair users with spinal cord injury.

DESIGN

Repeated-measures, intervention and outcomes measure design.

SETTING

University research laboratory.

PARTICIPANTS

Power wheelchair users with spinal cord injury (N=11).

INTERVENTIONS

Six protocols of various wheelchair tilt-in-space and recline angles were randomly assigned to the participants: (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. Each protocol consisted of a 5-minute upright sitting and a 5-minute tilted and reclined period.

MAIN OUTCOME MEASURES

Skin perfusion over the sacrum (midpoint between the right posterior superior iliac spine and the adjacent spinous process) and right ischial tuberosity was measured using laser Doppler flowmetry.

RESULTS

Sacral skin perfusion did not show a significant difference in all 6 protocols of various tilt-in-space and recline angles when changing from an upright to a tilted and reclined position (not significant). However, as previously reported, skin perfusion over the ischial tuberosity showed a significant increase at 15°, 25°, and 35° tilt-in-space when combined with 120° recline and at 35° tilt-in-space when combined with 100° recline (P<.008).

CONCLUSIONS

Our results indicate that wheelchair tilt-in-space and recline enhances skin perfusion over the ischial tuberosities without reducing sacral skin perfusion when changing from an upright to a tilted and reclined position.

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.

Enhanced phase synchronization of blood flow oscillations between heated and adjacent non-heated sacral skin

The study of skin microcirculation may be used to assess risk for pressure ulcers. It is observed that local heating causes an increase in blood flow of not only the heated skin, but also in the adjacent non-heated skin. The underlying physiological mechanism of this indirect vasodilation of the non-heated skin remains unclear. We hypothesized that blood flow oscillations (BFO) in the adjacent non-heated skin area synchronize with BFO in the heated skin, thus inducing a vasodilatory response. We investigated BFO in the heated and adjacent non-heated skin (12.1 ± 1.2-cm distance) on the sacrum in 12 healthy participants. The ensemble empirical mode decomposition (EEMD) was used to decompose blood flow signals into a set of intrinsic mode functions (IMFs), and the IMFs with power spectra over the frequency range of 0.0095-0.02, 0.02-0.05, and 0.05-0.15 Hz were chosen as the characteristic components corresponding to metabolic, neurogenic, and myogenic regulations, respectively. Then, the instantaneous phase of the characteristic components was calculated using the Hilbert transform. From the time series of phase difference between a pair of characteristic components, the epochs of phase synchronization were detected. The results showed that myogenic and neurogenic BFO exhibited self-phase synchronization during the slower vasodilation of the heated skin. In the non-heated skin, the degree of synchronization of BFO is associated with the changes in blood flow.

Influence of different types of seat cushions on the static sitting posture in individuals with spinal cord injury

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

To evaluate the efficacy of the Postural Assessment Software PAS/SAPO in the posture analysis of individuals with spinal cord injury (SCI) during sitting position and to analyze if the use of different types of seat cushions-gel and foam, with no cushion-can interfere in the individual's posture during sitting position.

SETTING

Centre of Rehabilitation at the University Hospital (FMRP-USP), Ribeirão Preto, Brazil.

METHODS

Eight individuals, four paraplegics and four tetraplegics with SCI and 20 healthy individuals participated in the study. Photos were taken of individuals in the sitting position using foam, gel cushions and with no cushion. They were analyzed using the PAS/SAPO. The alignment of the anterior-superior iliac spine (ASIS) and the posterior pelvic tilt were evaluated from the angle formed between the ASIS and the greater trochanter of the femur.

RESULTS

The group of healthy individuals presented the best postural alignment when compared with the group with SCI, both for the ASIS alignment (P<0.05) and for the degree of posterior pelvic tilt (P<0.05). No significant differences were found in the variables analyzed when the seat cushions were compared.

CONCLUSION

The different types of cushions did not alter the sitting posture; however, individuals with SCI showed worse postural alignment than the healthy individuals. PAS/SAPO was demonstrated to be useful for postural assessment.

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.

Development of intelligent model to determine favorable wheelchair tilt and recline angles for people with spinal cord injury

Machine-learning techniques have found widespread applications in bioinformatics. Such techniques provide invaluable insight on understanding the complex biomedical mechanisms and predicting the optimal individualized intervention for patients. In our case, we are particularly interested in developing an individualized clinical guideline on wheelchair tilt and recline usage for people with spinal cord injury (SCI). The current clinical practice suggests uniform settings to all patients. However, our previous study revealed that the response of skin blood flow to wheelchair tilt and recline settings varied largely among patients. Our finding suggests that an individualized setting is needed for people with SCI to maximally utilize the residual neurological function to reduce pressure ulcer risk. In order to achieve this goal, we intend to develop an intelligent model to determine the favorable wheelchair usage to reduce pressure ulcers risk for wheelchair users with SCI. In this study, we use artificial neural networks (ANNs) to construct an intelligent model that can predict whether a given tilt and recline setting will be favorable to people with SCI based on neurological functions and SCI injury history. Our results indicate that the intelligent model significantly outperforms the traditional statistical approach in accurately classifying favorable wheelchair tilt and recline settings. To the best of our knowledge, this is the first study using intelligent models to predict the favorable wheelchair tilt and recline angles. Our methods demonstrate the feasibility of using ANN to develop individualized wheelchair tilt and recline guidance for people with SCI.