Wheelchairs, their securement devices, occupant restraints and transport vehicles all must functi... more Wheelchairs, their securement devices, occupant restraints and transport vehicles all must function as a system, if individuals are to safely and independently use both public and personal vehicles while remaining seated in their wheelchairs. Currently, securement systems for wheelchairs are often inadequately applied, are time consuming to use, and require the involvement of a vehicle operator or an attendant. A universal solution is needed that provides independent, quick, and safe securement. Improving accessibility and safety relies upon standardized methods being developed and adopted for interconnecting the respective technologies. The successful development of new docking-type securement devices, that eliminate several of the disadvantages of commonly used belt-type devices, depends upon standardized ways of interconnecting the wheelchair with vehicle-mounted securement hardware. The adoption and promulgation of a universal interface device (UID) standard for docking devices ...
Standardized test methods providing wheelchair cushion performance characteristics can aid cushio... more Standardized test methods providing wheelchair cushion performance characteristics can aid cushion design and selection. Assessment of the changes in performance that occur with aging provides additional information. Test methods published by the International Organization for Standardization were applied to a cohort of 21 cushions of varying design and construct to assess changes in performance due to simulated aging. Performance tests measured immersion, envelopment, stiffness, impact response and pressure distribution properties. Means pre- and post-aging are presented and changes in test outcome metrics due to aging were analyzed using linear mixed models. Statistically significant changes were found for outcome measures for each performance test. The minimum aging method simulating 18-24 months use had a significant effect on cushion performance. Changes to loaded contour depth, envelopment, pressure mapping, hysteresis, horizontal stiffness and 10% force deflection characterization test metrics indicated decreased cushion performance. The simulated aging method resulted in cushion stiffening and reduced immersion, pressure distribution and stability performance. Together, these changes may increase a user's risk for pressure injuries.
A method for designing seat support surfaces using interface pressure and soft tissue stiffness c... more A method for designing seat support surfaces using interface pressure and soft tissue stiffness criteria was evaluated. An algorithm designed to drive a rigid support surface on a programmable seating system to a shape for which the externally applied pressure is inversely related to the measured stiffness of adjacent soft tissue was evaluated on 30 elderly subjects (age 65 years or older). The resulting support surface shapes were transferred to compliant foam cushions and evaluated using interface pressure measurements. Pressure and stiffness measure- ments on the seating system indicated the surface shape control algorithm met the desired programmed criteria by achieving an inverse relationship between pressure and stiffness, as it converged to an "optimal" support surface shape. Evaluation of interface pressures on the compliant foam cushions showed that the pressure distributions on the cushions contoured to the opti- mal surface shapes were more uniform and had lower...
The purpose of a wheelchair cushion is to provide comfort and protection for wheelchair users by ... more The purpose of a wheelchair cushion is to provide comfort and protection for wheelchair users by reducing pressure at support surfaces, a function that has been effective in decreasing the risk of pressure injury [3]. Wheelchair seat cushion designs are developed to reduce risk factors for pressure injuries. With advanced technologies, cushion manufacturers continue efforts to incorporate new strategies for pressure redistribution, shear and friction reduction, and dissipation of heat and moisture. Most of the technologies focus on reducing pressure, shear, and friction. In comparison, the reduction of heat and moisture seems to have been overlooked.
Journal of neuroengineering and rehabilitation, Nov 6, 2017
Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, ... more Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a "total approach to rehabilitation", combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbias...
Archives of Physical Medicine and Rehabilitation, 2016
A convenience sample of VA TBI Model System participants contacted for annual post-injury follow-... more A convenience sample of VA TBI Model System participants contacted for annual post-injury follow-up. Sample (nZ109) was primarily male (98%) with a median age of 31 years and moderate to severe TBI (66.3%) from motor-vehicle accidents (53%). Interventions: NA. Main Outcome Measure(s): Rehabilitation Needs Survey. Results: Following literature review, common rehabilitation needs after TBI were identified and reviewed by a stakeholder panel resulting in a 21-item questionnaire. Initial administration with 109 participants resulted in a 96% completion rate and average administration time of 10 minutes. Responses were scored resulting in four classifications of needs (need met, never had need, unmet need with help received, unmet need with no help received). Preliminary responses indicate high needs in the areas of managing sequelae of brain injury (23-35%), managing daily stressors (28%), overall health improvement (22%), community reintegration (e.g., employment, school; socialization 19-24%), and case management (service coordination, informational support; 10-20%).The most infrequent needs endorsed included responses to substance misuse and relationship support items. Conclusions: Development of this measure presents a methodology for measuring rehabilitation needs in post-acute stages of TBI that may inform service needs in chronic stages of TBI. Preliminary sample indicates variability across items with high completion rate. Larger, prospective studies may be able to examine the evolving nature of rehabilitation needs following injury and indexed by participant and injury characteristics.
The Occupational Therapy Journal of Research, 1995
Surveys were sent to 403 driver evaluators and trainers throughout the United States whose client... more Surveys were sent to 403 driver evaluators and trainers throughout the United States whose clientele includes persons with disabilities, and 138 responses (35%) were received from 44 states. Most of the respondents were experienced evaluators, and 62% were occupational therapists. They were asked to report on the methods, equipment, and criteria used when assessing an individual's ability to drive. The measurement of specific driving characteristics (i.e., brake reaction time, steering force) was reported as being more important than measuring nonspecific physical characteristics (i.e., range of motion, grip strength), yet only one half of the respondents measured most of the defined driving characteristics. Most characteristics were measured through observation or a functional test rather than by using equipment. The overwhelming majority of evaluators used subjective criteria or no criteria when judging the findings of a test. Despite these results, two thirds of the evaluator...
Journal of rehabilitation research and development
Safety of motor vehicle seats is of great importance in providing crash protection to the occupan... more Safety of motor vehicle seats is of great importance in providing crash protection to the occupant. An increasing number of wheelchair users use their wheelchairs as motor vehicle seats when traveling. A voluntary standard requires that compliant wheelchairs be dynamically sled impact tested. However, testing to evaluate the crashworthiness of add-on wheelchair seating systems (WCSS) independent of their wheelchair frame is not addressed by this standard. To address this need, this study developed a method to evaluate the crash-worthiness of WCSS with independent frames. Federal Motor Vehicle Safety Standards (FMVSS) 207 test protocols, used to test the strength of motor vehicle seats, were modified and used to test the strength of three WCSS. Forward and rearward loads were applied at the WCSS center of gravity (CGSS), and a moment was applied at the uppermost point of the seat back. Each of the three tested WCSS met the strength requirements of FMVSS 207. Wheelchair seat-back stif...
The Rehabilitation Engineering Research Center on Wheelchair Transportation Safety held a state-o... more The Rehabilitation Engineering Research Center on Wheelchair Transportation Safety held a state-of-the-science workshop on wheelchair transportation. The workshop had three purposes: reviewing and documenting the status of wheelchair transportation safety, identifying deficiencies, and formulating, discussing, and prioritizing recommendations for future action. The final goal was to disseminate the workshop outcomes for utilization in formatting future research priorities. A nominal group technique was used to facilitate focused open discussion by knowledgeable persons, resulting in the identification and ranking of existing deficiencies according to priority. Participants then formulated potential short-term solutions and speculated what wheelchair transportation safety should be in the future. This document presents four white papers, prepared prior to the workshop and modified according to participant feedback, and summarizes the outcomes of the workshop. The results identify and prioritize recommendations for future action.
Regardless of the field, agenda-setting processes are integral to establishing research and devel... more Regardless of the field, agenda-setting processes are integral to establishing research and development priorities. Beginning in 1998, the National Institute on Disability and Rehabilitation Research mandated that each newly funded Rehabilitation Engineering and Research Center (RERC) hold a state-of-the-science consensus forum during the third year of its 5-year funding cycle. NIDRR's aim in formalizing this agenda-setting process was to facilitate the formulation of future research and development priorities for each respective RERC. In February 2001, the RERC on Wheeled Mobility, University of Pittsburgh, conducted one of the first such forums. The scope encompassed both current scientific knowledge and clinical issues. In preparation, expert interviews were carried out to establish the focus for the forum. Because a stakeholder forum on wheelchair technology had recently been held, opinion favored wheelchair seating as the focus and included the following core areas: seating for use in wheelchair transportation, seated postural control, seating discomfort, and tissue integrity management. The aim of this report is to present a summary of the workshop outcomes, describe the process, and increase awareness of this agenda-setting process in order to enhance future participation in a process that critically influences the field of wheeled mobility.
Archives of Physical Medicine and Rehabilitation, 2001
Objective: To evaluate the crashworthiness of commercially available hardware that attaches seat ... more Objective: To evaluate the crashworthiness of commercially available hardware that attaches seat surfaces to the wheelchair frame. Design: A low cost static crashworthiness test procedure that simulates a frontal impact motor vehicle crash. Setting: Safety testing laboratory. Specimens: Eleven unique sets of drop-hook hardware made of carbon steel (4), stainless steel (4), and aluminum (131). Interventions" Replicated seat-loading conditions associated with a 20g/48kph frontal impact. Test criterion for seat loading was 16,680N (37501b). Main Outcome Measures: Failure load and deflection of seat surface. Results: None of the hardware sets tested met the crashworthiness test criterion. All failed at less than 50% of the load that seating hardware could be exposed to in a 20g/48kph frontal impact. The primary failure mode was excessive deformation, leading to an unstable seat support surface. Conclusions: Results suggest that commercially available seating drop hooks may be unable to withstand loading associated with a frontal crash and may not be the best option for use with transport wheelchairs.
Comparative risks or benefits to wheelchair-seated pediatric occupants in motor vehicles associat... more Comparative risks or benefits to wheelchair-seated pediatric occupants in motor vehicles associated with wheelchair headrest use during rear impact were evaluated using pediatric head and neck injury outcome measures. A Hybrid III 6-year-old anthropomorphic test device (ATD), seated in identical WC19-compliant pediatric manual wheelchairs, was used to measure head and neck response during a 25 km/h (16 mph), 11g rear impact. ATD responses were evaluated across two test scenarios: three sled tests conducted without headrests, and three with slightly modified commercial headrests. Head and neck injury outcomes measures included: linear head acceleration, head injury criteria (HIC) values, neck injury criteria (N ij) values, and combined rotational head velocity and acceleration. Neck and head injury outcome measures improved by 34-70% in sled tests conducted with headrests compared to tests without headrests. Headrest use reduced N ij values and the likelihood of concussion from values above established injury thresholds to values below injury thresholds. Injury measure outcome reductions suggest lower head and neck injury risks for wheelchair-seated children using wheelchair-mounted headrests as compared to non-headrest users in rear impact. Use of relative comparisons across two test scenarios served to minimize effects of ATD biofidelity limitations.
Journal of pediatric rehabilitation medicine, 2011
Questions are often raised about whether the use of postural support devices while seated in a wh... more Questions are often raised about whether the use of postural support devices while seated in a wheelchair during travel in a motor vehicle can have potential benefits or result in harm. The benefits or harm are generally unknown as current crash-test dummies are not designed to evaluate postural supports, and there are little to no injury data for these devices in the motor-vehicle environment. Despite these limitations, guidelines and best practices can be developed for use of postural support devices during travel in a motor vehicle using basic principles of occupant protection and knowledge about injury biomechanics. This document presents guidelines and recommendations for postural support devices used on wheelchairs that also serve as seats in motor vehicles. It addresses the basic principles of safe transportation for wheelchair-seated occupants and provides guidelines and recommendations for use of specific devices during transportation.
The purpose of this document is to share typical clinical applications and to provide evidence fr... more The purpose of this document is to share typical clinical applications and to provide evidence from the literature supporting the use of wheelchairs designed to function as a motor vehicle seat that will assist practitioners in decision-making and justification. It is not intended to replace clinical judgment related to specific client needs.
Journal of rehabilitation research and development
Individuals using wheeled mobility devices (WMDs) often use them as motor vehicle seats during tr... more Individuals using wheeled mobility devices (WMDs) often use them as motor vehicle seats during transportation. Wheelchair occupant restraint systems (WORSs), consisting of upper torso and pelvic restraints, are usually mounted to the structure of transit vehicles to secure individuals within their wheelchair seats. This preliminary study attempts to evaluate the use and satisfaction of currently installed vehicle-mounted WORSs for individuals using WMD as seats in motor vehicles. A survey was conducted among 33 adults who use their WMD to travel in motor vehicles. Results from the survey showed that upper torso and pelvic restraints installed in private vehicles are quick, comfortable, and easy to use. However, WORS installed in mass transit and paratransit are often uncomfortable to wear, difficult to reach, and time-consuming to use. This preliminary study documents the growing need for developing alternative WORS that are safe, comfortable, and that allow independent usage for wh...
Pressure ulcers continue to be a common complication and costly clinical problem. Interface press... more Pressure ulcers continue to be a common complication and costly clinical problem. Interface pressure distributions between the buttocks and seat support surfaces are used clinically to evaluate the efficacy of seat cushions relative to the risk of pressure ulcer development. Soft tissue deformation, resulting in internal strain, is potentially a superior indicator of pressure ulcer risk, however, limitations of current clinical assessment technology render tissue deformation measurements inaccessible in the clinic. As an alternative, interface pressure, a parameter that is clinically accessible, is used as an indicator for potentially harmful internal stresses and strains. This task was designed to provide additional support to a research effort (Paralyzed Veterans of America, Spinal Cord Research Foundation, PVA #1503) to develop an ultrasound system that may be used to study in vivo soft tissue response to external loading on the weight-bearing human buttocks during seating, and, ...
Wheelchairs, their securement devices, occupant restraints and transport vehicles all must functi... more Wheelchairs, their securement devices, occupant restraints and transport vehicles all must function as a system, if individuals are to safely and independently use both public and personal vehicles while remaining seated in their wheelchairs. Currently, securement systems for wheelchairs are often inadequately applied, are time consuming to use, and require the involvement of a vehicle operator or an attendant. A universal solution is needed that provides independent, quick, and safe securement. Improving accessibility and safety relies upon standardized methods being developed and adopted for interconnecting the respective technologies. The successful development of new docking-type securement devices, that eliminate several of the disadvantages of commonly used belt-type devices, depends upon standardized ways of interconnecting the wheelchair with vehicle-mounted securement hardware. The adoption and promulgation of a universal interface device (UID) standard for docking devices ...
Standardized test methods providing wheelchair cushion performance characteristics can aid cushio... more Standardized test methods providing wheelchair cushion performance characteristics can aid cushion design and selection. Assessment of the changes in performance that occur with aging provides additional information. Test methods published by the International Organization for Standardization were applied to a cohort of 21 cushions of varying design and construct to assess changes in performance due to simulated aging. Performance tests measured immersion, envelopment, stiffness, impact response and pressure distribution properties. Means pre- and post-aging are presented and changes in test outcome metrics due to aging were analyzed using linear mixed models. Statistically significant changes were found for outcome measures for each performance test. The minimum aging method simulating 18-24 months use had a significant effect on cushion performance. Changes to loaded contour depth, envelopment, pressure mapping, hysteresis, horizontal stiffness and 10% force deflection characterization test metrics indicated decreased cushion performance. The simulated aging method resulted in cushion stiffening and reduced immersion, pressure distribution and stability performance. Together, these changes may increase a user's risk for pressure injuries.
A method for designing seat support surfaces using interface pressure and soft tissue stiffness c... more A method for designing seat support surfaces using interface pressure and soft tissue stiffness criteria was evaluated. An algorithm designed to drive a rigid support surface on a programmable seating system to a shape for which the externally applied pressure is inversely related to the measured stiffness of adjacent soft tissue was evaluated on 30 elderly subjects (age 65 years or older). The resulting support surface shapes were transferred to compliant foam cushions and evaluated using interface pressure measurements. Pressure and stiffness measure- ments on the seating system indicated the surface shape control algorithm met the desired programmed criteria by achieving an inverse relationship between pressure and stiffness, as it converged to an "optimal" support surface shape. Evaluation of interface pressures on the compliant foam cushions showed that the pressure distributions on the cushions contoured to the opti- mal surface shapes were more uniform and had lower...
The purpose of a wheelchair cushion is to provide comfort and protection for wheelchair users by ... more The purpose of a wheelchair cushion is to provide comfort and protection for wheelchair users by reducing pressure at support surfaces, a function that has been effective in decreasing the risk of pressure injury [3]. Wheelchair seat cushion designs are developed to reduce risk factors for pressure injuries. With advanced technologies, cushion manufacturers continue efforts to incorporate new strategies for pressure redistribution, shear and friction reduction, and dissipation of heat and moisture. Most of the technologies focus on reducing pressure, shear, and friction. In comparison, the reduction of heat and moisture seems to have been overlooked.
Journal of neuroengineering and rehabilitation, Nov 6, 2017
Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, ... more Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a "total approach to rehabilitation", combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbias...
Archives of Physical Medicine and Rehabilitation, 2016
A convenience sample of VA TBI Model System participants contacted for annual post-injury follow-... more A convenience sample of VA TBI Model System participants contacted for annual post-injury follow-up. Sample (nZ109) was primarily male (98%) with a median age of 31 years and moderate to severe TBI (66.3%) from motor-vehicle accidents (53%). Interventions: NA. Main Outcome Measure(s): Rehabilitation Needs Survey. Results: Following literature review, common rehabilitation needs after TBI were identified and reviewed by a stakeholder panel resulting in a 21-item questionnaire. Initial administration with 109 participants resulted in a 96% completion rate and average administration time of 10 minutes. Responses were scored resulting in four classifications of needs (need met, never had need, unmet need with help received, unmet need with no help received). Preliminary responses indicate high needs in the areas of managing sequelae of brain injury (23-35%), managing daily stressors (28%), overall health improvement (22%), community reintegration (e.g., employment, school; socialization 19-24%), and case management (service coordination, informational support; 10-20%).The most infrequent needs endorsed included responses to substance misuse and relationship support items. Conclusions: Development of this measure presents a methodology for measuring rehabilitation needs in post-acute stages of TBI that may inform service needs in chronic stages of TBI. Preliminary sample indicates variability across items with high completion rate. Larger, prospective studies may be able to examine the evolving nature of rehabilitation needs following injury and indexed by participant and injury characteristics.
The Occupational Therapy Journal of Research, 1995
Surveys were sent to 403 driver evaluators and trainers throughout the United States whose client... more Surveys were sent to 403 driver evaluators and trainers throughout the United States whose clientele includes persons with disabilities, and 138 responses (35%) were received from 44 states. Most of the respondents were experienced evaluators, and 62% were occupational therapists. They were asked to report on the methods, equipment, and criteria used when assessing an individual's ability to drive. The measurement of specific driving characteristics (i.e., brake reaction time, steering force) was reported as being more important than measuring nonspecific physical characteristics (i.e., range of motion, grip strength), yet only one half of the respondents measured most of the defined driving characteristics. Most characteristics were measured through observation or a functional test rather than by using equipment. The overwhelming majority of evaluators used subjective criteria or no criteria when judging the findings of a test. Despite these results, two thirds of the evaluator...
Journal of rehabilitation research and development
Safety of motor vehicle seats is of great importance in providing crash protection to the occupan... more Safety of motor vehicle seats is of great importance in providing crash protection to the occupant. An increasing number of wheelchair users use their wheelchairs as motor vehicle seats when traveling. A voluntary standard requires that compliant wheelchairs be dynamically sled impact tested. However, testing to evaluate the crashworthiness of add-on wheelchair seating systems (WCSS) independent of their wheelchair frame is not addressed by this standard. To address this need, this study developed a method to evaluate the crash-worthiness of WCSS with independent frames. Federal Motor Vehicle Safety Standards (FMVSS) 207 test protocols, used to test the strength of motor vehicle seats, were modified and used to test the strength of three WCSS. Forward and rearward loads were applied at the WCSS center of gravity (CGSS), and a moment was applied at the uppermost point of the seat back. Each of the three tested WCSS met the strength requirements of FMVSS 207. Wheelchair seat-back stif...
The Rehabilitation Engineering Research Center on Wheelchair Transportation Safety held a state-o... more The Rehabilitation Engineering Research Center on Wheelchair Transportation Safety held a state-of-the-science workshop on wheelchair transportation. The workshop had three purposes: reviewing and documenting the status of wheelchair transportation safety, identifying deficiencies, and formulating, discussing, and prioritizing recommendations for future action. The final goal was to disseminate the workshop outcomes for utilization in formatting future research priorities. A nominal group technique was used to facilitate focused open discussion by knowledgeable persons, resulting in the identification and ranking of existing deficiencies according to priority. Participants then formulated potential short-term solutions and speculated what wheelchair transportation safety should be in the future. This document presents four white papers, prepared prior to the workshop and modified according to participant feedback, and summarizes the outcomes of the workshop. The results identify and prioritize recommendations for future action.
Regardless of the field, agenda-setting processes are integral to establishing research and devel... more Regardless of the field, agenda-setting processes are integral to establishing research and development priorities. Beginning in 1998, the National Institute on Disability and Rehabilitation Research mandated that each newly funded Rehabilitation Engineering and Research Center (RERC) hold a state-of-the-science consensus forum during the third year of its 5-year funding cycle. NIDRR's aim in formalizing this agenda-setting process was to facilitate the formulation of future research and development priorities for each respective RERC. In February 2001, the RERC on Wheeled Mobility, University of Pittsburgh, conducted one of the first such forums. The scope encompassed both current scientific knowledge and clinical issues. In preparation, expert interviews were carried out to establish the focus for the forum. Because a stakeholder forum on wheelchair technology had recently been held, opinion favored wheelchair seating as the focus and included the following core areas: seating for use in wheelchair transportation, seated postural control, seating discomfort, and tissue integrity management. The aim of this report is to present a summary of the workshop outcomes, describe the process, and increase awareness of this agenda-setting process in order to enhance future participation in a process that critically influences the field of wheeled mobility.
Archives of Physical Medicine and Rehabilitation, 2001
Objective: To evaluate the crashworthiness of commercially available hardware that attaches seat ... more Objective: To evaluate the crashworthiness of commercially available hardware that attaches seat surfaces to the wheelchair frame. Design: A low cost static crashworthiness test procedure that simulates a frontal impact motor vehicle crash. Setting: Safety testing laboratory. Specimens: Eleven unique sets of drop-hook hardware made of carbon steel (4), stainless steel (4), and aluminum (131). Interventions" Replicated seat-loading conditions associated with a 20g/48kph frontal impact. Test criterion for seat loading was 16,680N (37501b). Main Outcome Measures: Failure load and deflection of seat surface. Results: None of the hardware sets tested met the crashworthiness test criterion. All failed at less than 50% of the load that seating hardware could be exposed to in a 20g/48kph frontal impact. The primary failure mode was excessive deformation, leading to an unstable seat support surface. Conclusions: Results suggest that commercially available seating drop hooks may be unable to withstand loading associated with a frontal crash and may not be the best option for use with transport wheelchairs.
Comparative risks or benefits to wheelchair-seated pediatric occupants in motor vehicles associat... more Comparative risks or benefits to wheelchair-seated pediatric occupants in motor vehicles associated with wheelchair headrest use during rear impact were evaluated using pediatric head and neck injury outcome measures. A Hybrid III 6-year-old anthropomorphic test device (ATD), seated in identical WC19-compliant pediatric manual wheelchairs, was used to measure head and neck response during a 25 km/h (16 mph), 11g rear impact. ATD responses were evaluated across two test scenarios: three sled tests conducted without headrests, and three with slightly modified commercial headrests. Head and neck injury outcomes measures included: linear head acceleration, head injury criteria (HIC) values, neck injury criteria (N ij) values, and combined rotational head velocity and acceleration. Neck and head injury outcome measures improved by 34-70% in sled tests conducted with headrests compared to tests without headrests. Headrest use reduced N ij values and the likelihood of concussion from values above established injury thresholds to values below injury thresholds. Injury measure outcome reductions suggest lower head and neck injury risks for wheelchair-seated children using wheelchair-mounted headrests as compared to non-headrest users in rear impact. Use of relative comparisons across two test scenarios served to minimize effects of ATD biofidelity limitations.
Journal of pediatric rehabilitation medicine, 2011
Questions are often raised about whether the use of postural support devices while seated in a wh... more Questions are often raised about whether the use of postural support devices while seated in a wheelchair during travel in a motor vehicle can have potential benefits or result in harm. The benefits or harm are generally unknown as current crash-test dummies are not designed to evaluate postural supports, and there are little to no injury data for these devices in the motor-vehicle environment. Despite these limitations, guidelines and best practices can be developed for use of postural support devices during travel in a motor vehicle using basic principles of occupant protection and knowledge about injury biomechanics. This document presents guidelines and recommendations for postural support devices used on wheelchairs that also serve as seats in motor vehicles. It addresses the basic principles of safe transportation for wheelchair-seated occupants and provides guidelines and recommendations for use of specific devices during transportation.
The purpose of this document is to share typical clinical applications and to provide evidence fr... more The purpose of this document is to share typical clinical applications and to provide evidence from the literature supporting the use of wheelchairs designed to function as a motor vehicle seat that will assist practitioners in decision-making and justification. It is not intended to replace clinical judgment related to specific client needs.
Journal of rehabilitation research and development
Individuals using wheeled mobility devices (WMDs) often use them as motor vehicle seats during tr... more Individuals using wheeled mobility devices (WMDs) often use them as motor vehicle seats during transportation. Wheelchair occupant restraint systems (WORSs), consisting of upper torso and pelvic restraints, are usually mounted to the structure of transit vehicles to secure individuals within their wheelchair seats. This preliminary study attempts to evaluate the use and satisfaction of currently installed vehicle-mounted WORSs for individuals using WMD as seats in motor vehicles. A survey was conducted among 33 adults who use their WMD to travel in motor vehicles. Results from the survey showed that upper torso and pelvic restraints installed in private vehicles are quick, comfortable, and easy to use. However, WORS installed in mass transit and paratransit are often uncomfortable to wear, difficult to reach, and time-consuming to use. This preliminary study documents the growing need for developing alternative WORS that are safe, comfortable, and that allow independent usage for wh...
Pressure ulcers continue to be a common complication and costly clinical problem. Interface press... more Pressure ulcers continue to be a common complication and costly clinical problem. Interface pressure distributions between the buttocks and seat support surfaces are used clinically to evaluate the efficacy of seat cushions relative to the risk of pressure ulcer development. Soft tissue deformation, resulting in internal strain, is potentially a superior indicator of pressure ulcer risk, however, limitations of current clinical assessment technology render tissue deformation measurements inaccessible in the clinic. As an alternative, interface pressure, a parameter that is clinically accessible, is used as an indicator for potentially harmful internal stresses and strains. This task was designed to provide additional support to a research effort (Paralyzed Veterans of America, Spinal Cord Research Foundation, PVA #1503) to develop an ultrasound system that may be used to study in vivo soft tissue response to external loading on the weight-bearing human buttocks during seating, and, ...
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Papers by Patricia Karg