Load Redistribution in Variable Position Wheelchairs in People With Spinal Cord Injury

Abstract

Background/Objective: Tilt and recline variable position seating systems are most commonly used for pressure relief to decrease potential for skin breakdown. This study provides quantitative information on the magnitudes of loading on the seat and back during phases of tilt, recline, and standing. The objective of this study was to show that the amount of force reduction at the seat would differ across these 3 methods within their respective clinical ranges.

Participants: Six able-bodied (AB) subjects (2 men, 4 women) with a median age of 25 years, and 10 subjects (8 men, 2 women) with spinal cord injury (SCI) with a median age of 35.5 years.

Methods: Subjects sat on a power wheelchair with Tekscan pressure mats placed underneath a foam backrest and cushion. Data were collected at 5 positions for each method. Order of position and method tested were randomized. Linear regressions were used to calculate the relationships of normalized seat and backrest forces to seat and backrest angles for each chair configuration.

Results: Normalized seat loads had strong linear relationships with the angles of change in tilt, recline, and standing for both groups. Maximum decreases in seat load occurred at full standing and full recline in the SCI subjects and in full standing in the AB subjects. Loads linearly increased on the back during tilt and recline and linearly decreased during standing for both groups.

Conclusions: Standing and recline offered similar seat load reductions at their respective terminal positions. Standing also reduced loading on the backrest. Recognizing that each method had clinical benefits and drawbacks, the results of this study indicate that tilt, recline, and standing systems should be considered as a means of weight shifting for wheelchair users.     

Assessment of wheelchair driving performance in a virtual reality-based simulator

Abstract

Objective

To develop a virtual reality (VR)-based simulator that can assist clinicians in performing standardized wheelchair driving assessments.

Design

A completely within-subjects repeated measures design.

Methods

Participants drove their wheelchairs along a virtual driving circuit modeled after the Power Mobility Road Test (PMRT) and in a hallway with decreasing width. The virtual simulator was displayed on computer screen and VR screens and participants interacted with it using a set of instrumented rollers and a wheelchair joystick. Driving performances of participants were estimated and compared using quantitative metrics from the simulator. Qualitative ratings from two experienced clinicians were used to estimate intra- and inter-rater reliability.

Results

Ten regular wheelchair users (seven men, three women; mean age ± SD, 39.5 ± 15.39 years) participated. The virtual PMRT scores from the two clinicians show high inter-rater reliability (78–90%) and high intra-rater reliability (71–90%) for all test conditions. More research is required to explore user preferences and effectiveness of the two control methods (rollers and mathematical model) and the display screens.

Conclusions

The virtual driving simulator seems to be a promising tool for wheelchair driving assessment that clinicians can use to supplement their real-world evaluations.     

The Natural-Fit Handrim: Factors Related To Improvement In Symptoms And Function In Wheelchair Users

Background/Objective: People with spinal cord injury (SCI) may spend several decades using a wheelchair as their primary means of mobility. Secondary injury and a decline in independence over time are common with manual wheelchair users who, in turn, may require increased assistance as time passes. The Natural-Fit contoured hand rim has been shown to improve symptoms and function in people with SCI who use manual wheelchairs and who have experienced upper extremity pain. The objective of this study was to determine the factors associated with improved symptoms and functions.

Participants: 87 people who purchased the ergonomic wheelchair handrims. Participants were predominately men, with a median age of 51 to 55 years, median level of injury Tl 0 to T12, median time in a wheelchair of 15 years, and they had used the contoured rims for 1 to 2 years.

Methods: This was a mail survey of 217 people who purchased the rims. The survey was mailed out from the manufacturer and was anonymously returned to the physical therapy department of a university. A $10 incentive was offered for returning the survey.

Results: The majority of participants reported improvements in upper extremity symptoms, ease of wheelchair propulsion, and functional status. Longer use of the rims was associated with reported improvement in ease of wheelchair propulsion and reduction in pain in hands and wrists.

Conclusion: If a simple modification of the wheelchair can help bring about significant changes in the users' symptoms and function, this modification should be incorporated by people who use manual wheelchairs before decline in function begins. Proactive intervention may alleviate symptoms, help the person maintain maximal independence, and prolong the length of time the individual remains independent.     

A motor learning approach to training wheelchair propulsion biomechanics for new manual wheelchair users: A pilot study

Context/Objective: Developing an evidence-based approach to teaching wheelchair skills and proper propulsion for everyday wheelchair users with a spinal cord injury (SCI) is important to their rehabilitation. The purpose of this project was to pilot test manual wheelchair training based on motor learning and repetition-based approaches for new manual wheelchair users with an SCI.

Design: A repeated measures within-subject design was used with participants acting as their own controls.

Methods: Six persons with an SCI requiring the use of a manual wheelchair participated in wheelchair training. The training included nine 90-minute sessions. The primary focus was on wheelchair propulsion biomechanics with a secondary focus on wheelchair skills.

Outcome Measures: During Pretest 1, Pretest 2, and Posttest, wheelchair propulsion biomechanics were measured using the Wheelchair Propulsion Test and a Video Motion Capture system. During Pretest 2 and Posttest, propulsion forces using the WheelMill System and wheelchair skills using the Wheelchair Skills Test were measured.

Results: Significant changes in area of the push loop, hand-to-axle relationship, and slope of push forces were found. Changes in propulsion patterns were identified post-training. No significant differences were found in peak and average push forces and wheelchair skills pre- and post-training.

Conclusions: This project identified trends in change related to a repetition-based motor learning approach for propelling a manual wheelchair. The changes found were related to the propulsion patterns used by participants. Despite some challenges associated with implementing interventions for new manual wheelchair users, such as recruitment, the results of this study show that repetition-based training can improve biomechanics and propulsion patterns for new manual wheelchair users.     

Short-term influence of transfer training among full time pediatric wheelchair users: A randomized trial

Objective/Background: To describe a structured, short-term, transfer training intervention for full-time pediatric wheelchair users, investigate the impact of training on transfer skills, and to examine similarities and differences in response to training compared to those seen in adult wheelchair users.

Design: Randomized clinical trial.

Methods: Participants were first randomized into an intervention (IG) or control group (CG). After completing surveys and demographic intake forms, all participants performed two sets of level transfers (from wheelchair to bench and back to wheelchair?=?one set) at three time points. Each time point composed of two transfer sets were scored using the Transfer Assessment Instrument (TAI) and averaged to produce a final transfer score per time point. No feedback or training were given to participants prior to time points one and two however the IG received structured training prior to transfer assessment # 3. TAI scores were compared at transfer assessment #3 using a Mann-Whitney test.

Outcome measures: Transfer Assessment Instrument (TAI) and Self-Perception Profile for Children (SPPC).

Results: Intervention group participants demonstrated significant improvements among TAI scores (9.06 ± 1.01) compared to the control group (7.15 ± 1.67), P?=?0.030, d?=?1.385. No significant differences were found among SPPC scores.

Conclusion: Pediatric wheelchair users transfer skills were found to improve immediately after training with TAI score changes similar to those seen in adult wheelchair users after training. Such improvements may be a factor in long-term upper extremity preservation. Further testing is needed to examine the long-term impact of improved transfer skills.     

Evaluation Of Selected Sidewalk Pavement Surfaces For Vibration Experienced By Users Of Manual AndPowered Wheelchairs

Abstract

Background: Obstades such as bumps, curb descents, and uneven driving surfaces cause vibrations that affect the wheelchair, and in turn, the wheelchair user. Chronic exposure can cause low-back pain, disk degeneration, and other harmful effects. Little research has been conducted to assess the vibrations experienced by wheelchair users.

Objective: The purpose of this study was to conduct an evaluation of the vibration exposure du ring electric-powered wheelchair driving and mechanical energy requirements for manual wheelchair propulsion over selected sidewalk surfaces. The goal was to determine the criteria for a wheelchair-pedestrian access route that does not require excessive propulsive work or expose wheelchair users to potentially harmful vibrations.

Methods: Ten unimpaired individuals participated in this study. Six sidewalk surfaces were tested. Measured variables included power of the acceleration per octave, mechanical work to propel over surfaces, peak acceleration, and frequency at which peak acceleration occurs.

Results: For both the manual and electric-powered wheelchair, at 1 m/s, significant differences were found in peak accelerations between the seat and footrest (P < 0.0001) and between the sidewalk surfaces (P = 0.004 ). The greatest risk for injury caused by shock and vibration exposure occurs at frequ encies near the natural frequency of seated humans (4-15 Hz). The values for work required to propel over the surfaces tested were not stat istically significantly different. Besides appearance and construction, the only distinguishing characteristic was surface roughness caused by the joints.

Conclusion: When treating the poured concrete sidewalk as the standard, surfaces 2, 3, 5, and 6 compared most favorably in t erms of vibration exposure, whereas surface 4 produced mixed results. Surfaces 2, 3, 5, and 6 yielded results that were similar to the poured concrete sidewalk and could be considered acceptable for wheelchair users. in conclusion, surfaces other than the t raditional poured concrete can be used for pedestrian access routes without adding vibration exposure or reducing propulsion efficiency.     

A survey of protective cushion usage in individuals with spinal cord injury while traveling in a motor vehicle and on a commercial airliner

Abstract

Objective

While there are specific recommendations for pressure relieving cushions when seated in a wheelchair, there is a paucity of information regarding prescribed wheelchair cushions for persons with spinal cord injury (SCI) when traveling and not in their wheelchair seat. A questionnaire was designed to ascertain if individuals with SCI who are primarily wheelchair users utilize a prescribed wheelchair cushion when traveling in a motor vehicle (MV) or on a commercial airliner, as not utilizing one may be a causative factor in developing pressure ulcers.

Design and setting

Survey design in an outpatient SCI rehabilitation setting.

Participants

Full-time wheelchair users, with chronic (>1 year) SCI.

Results

Forty-two participants completed the survey, with a mean age of 39 years old and time post-injury of 10.4 years. All subjects used a prescribed wheelchair cushion when seated in their wheelchair. Twenty-seven subjects reported transferring to a MV seat (59.5% of sample), with 25 (92.6%) reporting not using a prescribed wheelchair cushion when sitting directly on the MV seat. For subjects who traveled on an airplane (n = 23–54.8%), 19 (82.6%) reported that they do not sit on a prescribed specialty cushion.

Conclusion

Persons with chronic SCI, who are primary wheelchair users, utilize prescribed wheelchair cushions when sitting in their wheelchair, but most do not utilize a prescribed wheelchair cushion when seated in a MV (if they transfer out of their chair) or on a airplane seat. Studies to determine the pressures over the bony prominences on their travel surfaces may need to be undertaken to see whether the pressures are appropriate, as they may be a source of skin breakdown.     

Relationships Among Cushion Type,Backrest Height,Seated Posture,And Reach Of Wheelchair Users With Spinal Cord Injury

Abstract

Background: Seated posture and trunk control are important factors affecting upper extremity (UE) function of wheelchair users. A stable pelvis and trunk are required to provide a base from which UE movement occurs, but, conversely, the ability to move one’s trunk and pelvis can increase functional ranges of motion. For wheelchair users, balancing sufficient trunk support with adequate trunk mobility has important functional and medical consequences.

Objective: To determine the effect of cushion and backrest height on posture and reach and to determine the relationship between posture and UE reach using a randomized 2 X 3 repeated-measures factorial design.

Methods: Twenty-two subjects with spinal cord injury were tested in 6 configurations, including 3 types of cushions (segmented air, contoured viscous fluid/foam, and air/foam) and 2 of 3 backrest heights (referenced to Tl 2, inferior scapular angle, and scapular spine) while performing unilateral and bilateral reaching tasks. Seated posture (pelvic tilt and torso angle) and American Spinal Injury Association (ASIA) score were also measured.

Results: Pelvic tilt and ASIA score were significant predictors of reach. No evidence was found indicating cushion type or backrest height affected reach or posture. No consistent patterns of posture were found across cushion types or backrest heights.

Conclusions: The posture adopted by wheelchair users is a more important influence on UE reach than are the cushion or backrest height used. Sitting with increased posterior pelvic tilt enhanced stability and permitted greater reach. Because individuals adopt different postures when using different cushions and backrest heights, clinicians should monitor posture while assessing seating and function of wheelchair users.     

A brief fall prevention intervention for manual wheelchair users with spinal cord injuries: A pilot study

Objective: To conduct a pilot study of an intervention to decrease fall incidence and concerns about falling among individuals living with Spinal Cord Injury who use manual wheelchairs full-time.

Design: Pre/post. After a baseline assessment, a structured intervention was implemented. The assessment protocol was repeated 12 weeks after the baseline assessment.

Setting: Research laboratory and community.

Participants: 18 individuals living with SCI who use a manual wheelchair full-time with an average age of 35.78?±?13.89 years, lived with SCI for 17.06?±?14.6 years; 61.1% were female.

Intervention: A 1:1, 45 minute, in-person intervention focused on factors associated with falls and concerns about falling: transfers skills and seated postural control.

Outcome measures: Participants reported fall incidence and completed the Spinal Cord Injury Fall Concerns Scale, Community Participation Indicators and the World Health Organization Quality of Life – short version (WHOQOL-BREF). Transfer quality was assessed with the Transfer Assessment Instrument (TAI) and seated postural control with the Function In Seating Test (FIST).

Results: Recruitment, assessment and delivery of the intervention were successfully completed. After exposure to the intervention, fall incidence significantly decreased, (P?=?0.047, d_{z ?}=?0.507) and FIST scores improved (P?=?0.035, d_z? =?0.54). Significant improvements were also found in the WHOQOL-BREF Physical (P?=?0.05, d_{z ?}=?1.566) and Psychological (P?=?0.040, d_{z ?}=?0.760) domains.

Conclusion: The feasibility of the structured intervention was established and the intervention has the potential to reduce fall incidence and improve quality of life among individuals living with SCI who use a wheelchair. Appropriately powered randomized controlled trials of the program are warranted.     

Development and evaluation of a gyroscope-based wheel rotation monitor for manual wheelchair users

Abstract

Objective

To develop and evaluate a wireless gyroscope-based wheel rotation monitor (G-WRM) that can estimate speeds and distances traveled by wheelchair users during regular wheelchair propulsion as well as wheelchair sports such as handcycling, and provide users with real-time feedback through a smartphone application.

Methods

The speeds and the distances estimated by the G-WRM were compared with the criterion measures by calculating absolute difference, mean difference, and percentage errors during a series of laboratory-based tests. Intraclass correlations (ICC) and the Bland–Altman plots were also used to assess the agreements between the G-WRM and the criterion measures. In addition, battery life and wireless data transmission tests under a number of usage conditions were performed.

Results

The percentage errors for the angular velocities, speeds, and distances obtained from three prototype G-WRMs were less than 3% for all the test trials. The high ICC values (ICC (3,1) > 0.94) and the Bland–Altman plots indicate excellent agreement between the estimated speeds and distances by the G-WRMs and the criterion measures. The battery life tests showed that the device could last for 35 hours in wireless mode and 139 hours in secure digital card mode. The wireless data transmission tests indicated less than 0.3% of data loss.

Conclusion

The results indicate that the G-WRM is an appropriate tool for tracking a spectrum of wheelchair-related activities from regular wheelchair propulsion to wheelchair sports such as handcycling. The real-time feedback provided by the G-WRM can help wheelchair users self-monitor their everyday activities.     

Technological advances in powered wheelchairs

During the last 40 years, there have been revolutionary advances in power wheelchairs. These unique wheelchair systems, designed for the physically immobile patient, have become extremely diversified, allowing the user to achieve different positions, including tilt, recline, and, more recently, passive standing. Because of this wide diversity of powered wheelchair products, there is a growing realization of the need for certification of wheeled mobility suppliers. Legislation in Tennessee (Consumer Protection Act for Wheeled Mobility) passed in 2003 will ensure that wheeled mobility suppliers must have Assistive Technology Supplier certification and maintain their continuing education credits when fitting individuals in wheelchairs for long-term use. Fifteen other legislative efforts are currently underway in general assemblies throughout the US. Manufacturers, dealers, hospitals, and legislators are working toward the ultimate goal of passing federal legislation delineating the certification process of wheeled mobility suppliers. The most recent advance in the design of powered wheelchairs is the development of passive standing positions. The beneficial effects of passive standing have been documented by comprehensive scientific studies. These benefits include reduction of seating pressure, decreased bone demineralization, increased bladder pressure, enhanced orthostatic circulatory regulation, reduction in muscular tone, decrease in upper extremity muscle stress, and enhanced functional status in general. In February 2003, Permobil, Inc., introduced the powered Permobil Chairman 2K Stander wheelchair, which can tilt, recline, and stand. Other companies are now manufacturing powered wheelchairs that can achieve a passive standing position. These wheelchairs include the Chief SR Powerchair, VERTRAN, and LifeStand Compact. Another new addition to the wheelchair industry is the iBOT, which can elevate the user to reach cupboards and climb stairs but has no passive standing capabilities. In addition, the physically immobile patient must be seated on an ERGODYNAMIC Seating System 2000, which is inflated by the alternating pressure compressor 8080. This seating system has a deep center seam between the two ischial-support chambers, which provides a recess for the coccyx. The pre-ischial crossbar compartment inflates during each cycle to prevent the pelvis from slipping forward. It is essential that the physician of the immobile patient order two ERGODYNAMIC Seating Systems 2000 because the patient must have an additional seating system in the case one leaks. Moreover, two compressors are necessary because each compressor must be serviced after 2500 hours of use. For the protection of the consumer, these pressure relief systems must be supplied and serviced by a Certified Rehabilitation Technology Supplier such as Wheelchair Works Inc. Despite the indisputable scientific evidence of the medical benefits of passive standing for the immobile user, few individuals have access to these revolutionary wheelchairs. Consequently, it is mandatory that the medical community, headed by specialists in physical and occupational therapy as well as rehabilitation medicine, CRTS, and manufacturers collaborate in a national education campaign to convince Medicare/Medicaid and all commercial insurance companies to approve immediately these assisted technologies. This program is essential so that the physically immobilized patient can achieve the undisputed physical benefits of passive standing.     

Measured and predicted resting energy expenditure in wheelchair rugby athletes

Objective: Report measured resting energy expenditure (REE) in wheelchair rugby athletes and evaluate agreement between REE and the prediction models of Chun, Cunningham, Harris-Benedict, Mifflin, Nightingale and Gorgey, and Owen.

Design: Cohort-based validation study.

Setting. Paralympic team training camp.

Participants: Fourteen internationally competitive athletes who play wheelchair rugby, 13 of whom had cervical spinal cord injuries (SCI).

Outcome Measures: A portable metabolic analyzer was used to measure REE following an overnight fast and dual-energy X-ray absorptiometry (DXA) was used to assess lean body mass for the prediction equations.

Results: REE in the current sample was 1735?±?257?kcal?×?day^?1 ranging from 1324 to 2068?kcal?×?day^{?1 Bhambhani Y. Physiology of wheelchair racing in athletes with spinal cord injury. Sports Med 2002;32(1):23–51.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]}. Bland–Altman analyses revealed negative mean bias but similar limits of agreement between measured REE and scores predicted by Chun, Cunningham, Mifflin, Nightingale and Gorgey, and Owen models in elite athletes who play wheelchair rugby.

Conclusion: Prediction models regressed on persons with and without SCI under-predicted REE of competitive wheelchair rugby athletes. This outcome may be explained by the higher REE/fat-free mass (FFM) ratio of current athletes compared to less active samples. Findings from the current study will help practitioners to determine nutrient intake needs on training days of varied intensity.     

Development of a universal wheelchair narrower

A wheelchair user's mobility may be hampered by narrow doorways and restricted turning spaces. Mobility may be improved by undertaking expensive building alterations in the wheelchair user's own home and work environment. However, other environments, including modes of public transport, may still present considerable difficulties. One way of improving mobility is to reduce the overall width of a wheelchair with the occupant still seated within it. This is achieved by using a clamp, known as a "wheelchair narrower" which can be fitted and operated either by the wheelchair user or an attendant. The narrower takes advantage of the inherent design of a wheelchair which permits folding for storage. A universal wheelchair narrower was manufactured and tested at Tayside Rehabilitation Engineering Services. It was designed to be used on 69% of wheelchairs issued through the National Health Service in Scotland. Tests revealed that wheelchairs could be narrowed by between 38 and 127 mm depending upon the type of wheelchair. Active wheelchair users reported that the device was particularly useful when travelling.     

Reliability and minimal detectable change of a new treadmill-based progressive workload incremental test to measure cardiorespiratory fitness in manual wheelchair users

Background: Cardiorespiratory fitness training is commonly provided to manual wheelchair users (MWUs) in rehabilitation and physical activity programs, emphasizing the need for a reliable task-specific incremental wheelchair propulsion test.

Objective: Quantifying test-retest reliability and minimal detectable change (MDC) of key cardiorespiratory fitness measures following performance of a newly developed continuous treadmill-based wheelchair propulsion test (WPT_Treadmill).

Methods: Twenty-five MWUs completed the WPT_Treadmill on two separate occasions within one week. During these tests, participants continuously propelled their wheelchair on a motorized treadmill while the exercise intensity was gradually increased every minute until exhaustion by changing the slope and/or speed according to a standardized protocol. Peak oxygen consumption (VO_2peak), carbon dioxide production (VCO_2peak), respiratory exchange ratio (RER_peak), minute ventilation (VE_peak) and heart rate (HR_peak) were computed. Time to exhaustion (TTE) and number of increments completed were also measured. Intra-class correlation coefficients (ICC) were calculated to determine test-retest reliability. Standard error of measurement (SEM) and MDC_90% values were calculated.

Results: Excellent test-retest reliability was reached for almost all outcome measures (ICC=0.91-0.76), except for RER_peak (ICC=0.58), which reached good reliability. TTE (ICC=0.89) and number of increments (ICC=0.91) also reached excellent test-retest reliability. For the main outcome measures (VO_2peak and TTE), absolute SEM was 2.27?mL/kg/min and 0.76 minutes, respectively and absolute MDC_90% was 5.30?mL/kg/min and 1.77 minutes, respectively.

Conclusion: The WPT_Treadmill is a reliable test to assess cardiorespiratory fitness among MWUs. TTE and number of increments could be used as reliable outcome measures when VO₂ measurement is not possible.     

Development of a comprehensive mobile assessment of pressure (CMAP) system for pressure injury prevention for veterans with spinal cord injury

Objective: This paper reports the iterative redesign, feasibility and usability of the Comprehensive Mobile Assessment of Pressure (CMAP) system’s mobile app used by Veterans with SCI.

Design: This three-year, multi-staged study used a mixed-methods approach.

Setting: Minneapolis VA Health Care System, Minneapolis, Minnesota.

Participants: Veterans with spinal cord injury (N?=?18).

Interventions: Veterans with spinal cord injury engaged in iterative focus groups and personal interviews, sharing their needs and desires for the CMAP app redesign. App developers used these data for the redesign. The redesigned CMAP app was tested for six-weeks in users’ homes.

Outcome Measures: Quantitative (surveys) and qualitative (interviews) methods measured feasibility for self-management of seating pressure. Qualitative data were audio recorded, transcribed, anonymized, and coded. Survey data were analyzed using summary statistics.

Results: After the CMAP system’s redesign, the in-home use interview found: (1) any tool that can assist in prevention and monitoring of skin ulcers is important; (2) the desired key features are present in the app; (3) the main barrier to CMAP use was inconsistent functionality; (4) when functioning as expected, the live pressure map was the central feature, with reminders to weight shift also of high importance. The survey found: power wheelchair users tended to score closer than manual wheelchair users to the positive response end ranges on two separate surveys.

Conclusions: Overall both the power and manual wheelchair users reported that they wanted to use the system, felt confident using the system, and that the functions of the system were well integrated.     

Burn on the buttocks caused by gel wheelchair cushion left on driver’s seat of hand control car

Context: Nowadays, people with paraplegia and quadriplegia have greater opportunities to venture into the general public. However, there is also an increased risk of associated hazards.

Findings: This report describes a 42-year-old man with paraplegia, who was insensate below the T7 level and sustained burns from sitting on a gel wheelchair cushion that had been left on the driver-side seat of a hand control car on a sunny day. Physical examination revealed deep partial-thickness burns on both his buttocks. He underwent surgical debridement and received an autologous split-thickness skin graft, and healed well.

Conclusion In modern times, the lives of people with paralysis are no longer restricted to the bed and wheelchair. Active people with spinal cord injuries inevitably diversify the use of wheelchair cushions in many ways; therefore, there is a greater possibility for the occurrence of associated hazards. This is a preventable issue, so both the user and manufacturers should recognize this potential hazard of gel wheelchair cushions.     

Ambulation and complications related to assistive devices after spinal cord injury

Abstract

Objective

To evaluate long-term health outcomes including pain intensity, pain interference, and fatigue among ambulatory persons with spinal cord injury (SCI).

Design

Prospective cohort study.

Setting

Data were analyzed at a major medical university in the southeast USA.

Participants

Participants included 783 ambulatory adults with SCI of traumatic origin, who were at least 1-year post-injury. Participants were identified through three sources of records at a large specialty hospital in the southeastern USA.

Interventions

Not applicable.

Outcome measures

Pain intensity and interference (Brief Pain Inventory) and fatigue (Modified Fatigue Impact Scale Abbreviated Version 5).

Results

Examining assistive devices used for ambulation, 66% of the population used at least one device. In the logistic model, wheelchair and cane usage were significantly related to the outcomes after controlling for age, gender, and race. Wheelchair usage 50% of the time or less was significantly related to pain intensity (odds ratio (OR) 2.05, 95% confidence interval (CI) = 1.39–3.03), pain interference (OR 2.11, 95% CI = 1.43–3.12), and fatigue (OR 1.99, 95% CI = 1.12–1.43). Additionally, unilateral cane use was significantly related to the outcomes; pain intensity (OR 1.86, 95% CI = 1.35–2.56), pain interference (OR 2.11, 95% CI = 1.52–2.93), and fatigue (OR 2.49, 95% CI = 1.52–4.08).

Conclusions

Among ambulatory persons with SCI, increased pain intensity, pain interference, and fatigue are associated with minimal wheelchair usage (50% or less) and less supportive assistive device (unilateral cane) usage.     

Measuring Tissue Perfusion During Pressure Relief Maneuvers: Insights Into Preventing Pressure Ulcers

Abstract

Background/Objective: To study the effect on tissue perfusion of relieving interface pressure using standard wheelchair pushups compared with a mechanical automated dynamic pressure relief system.

Design: Repeated measures in 2 protocols on 3 groups of subjects.

Participants: Twenty individuals with motor-complete paraplegia below T4, 20 with motor-complete tetraplegia, and 20 able-bodied subjects.

Methods: Two 1-hour sitting protocols: dynamic protocol, sitting configuration alternated every 10 minutes between a normal sitting configuration and an off-loading configuration; wheelchair pushup protocol, normal sitting configuration with standard wheelchair pushup once every 20 minutes.

Main Outcome Measures: Transcutaneous partial pressures of oxygen and carbon dioxide measured from buttock overlying the ischial tuberosity and interface pressure measured at the seat back and buttocks. Perfusion deterioration and recovery times were calculated during changes in interface pressures.

Results: In the off-loading configuration, concentrated interface pressure during the normal sitting configuration was significantly diminished, and tissue perfusion was significantly improved. Wheelchair pushups showed complete relief of interface pressure but incomplete recovery of tissue perfusion.

Conclusions: Interface pressure analysis does not provide complete information about the effectiveness of pressure relief maneuvers. Measures of tissue perfusion may help establish more effective strategies. Relief achieved by standard wheelchair pushups may not be sufficient to recover tissue perfusion compromised during sitting; alternate maneuvers may be necessary. The dynamic seating system provided effective pressure relief with sustained reduction in interface pressure adequate for complete recovery of tissue perfusion. Differences in perfusion recovery times between subjects with spinal cord injury (SCI) and controls raise questions about the importance of changes in vascular responses to pressure after SCI.