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Wijker BJ, de Groot S, van Dongen JM, van Nassau F, Adriaansen JJE, Achterberg-Warmer WJ, Anema JR, Riedstra AT, van Tulder MW, Janssen TWJ. Electrical stimulation to prevent recurring pressure ulcers in individuals with a spinal cord injury compared to usual care: the Spinal Cord Injury PREssure VOLTage (SCI PREVOLT) study protocol. Trials 2022; 23:156. [PMID: 35172888 PMCID: PMC8848924 DOI: 10.1186/s13063-022-06088-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 02/05/2022] [Indexed: 01/01/2023] Open
Abstract
Background Pressure ulcers (PUs) on the buttocks are among the most common secondary complications in individuals with chronic spinal cord injury (SCI). PUs can result from sitting for extended periods, disuse atrophy, increased sitting pressure and reduced circulation. Compared with usual care, activation of paralysed muscles using electrical stimulation (ES) has been shown to markedly increase paralysed muscle mass, improve circulation of skin and muscle and improve sitting pressure distribution. ES might therefore be a useful method to reduce PU incidence. Methods A multicentre randomized controlled trial (SCI PREVOLT) will be conducted with an economic and process evaluation alongside. One hundred participants with a SCI in the chronic phase and a minimal incidence of 1 PU in the last 5 years will be recruited from rehabilitation centres across the Netherlands. Participants will be stratified by centre and age and randomized to the intervention or control group. The intervention group will use ES at least 1 h/day during at least 4 times a week for 1 year next to usual care. The control group will only receive usual care. The primary outcome is the incidence of PUs, measured by a blinded person assessing the presence or absence of a PU on the buttocks on a photo made by the participant or his/her caregiver. The incidence of a PU will be evaluated every 2 weeks. Secondary outcomes include interface pressure distribution, blood flow in the profunda femoris artery, muscle thickness of the hamstrings and gluteal muscles and questionnaires about different dimensions of life, e.g. participation and quality of life. Secondary outcomes will be measured at baseline and 3, 6, 9 and 12 months after randomization. Discussion This study will assess if electrical stimulation is a (cost-)effective method to prevent PUs and reduce the risk factors of getting PUs. If ES is effective and cost-effective compared with usual care, ES could be implemented in daily treatment of individuals with a SCI. Trial registration Netherlands Trials Register NTR NL9469. Registered on 26 May 2021. Supplementary Information The online version contains supplementary material available at 10.1186/s13063-022-06088-0.
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Affiliation(s)
- Boas J Wijker
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| | - Sonja de Groot
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Rehabilitation Research Center
- Reade, Amsterdam, The Netherlands
| | - Johanna M van Dongen
- Department of Health Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Femke van Nassau
- Department of Public and Occupational Health, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Public Health Research Institute, Amsterdam, The Netherlands
| | | | | | - Johan R Anema
- Department of Public and Occupational Health, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Public Health Research Institute, Amsterdam, The Netherlands
| | - Andries T Riedstra
- Paraplegia Organization
- Dwarslaesie Organisatie Nederland (DON), Nijkerk, The Netherlands
| | - Maurits W van Tulder
- Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Thomas W J Janssen
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Rehabilitation Research Center
- Reade, Amsterdam, The Netherlands
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Valipoor S, Pati D, Stock MS, Bazuin D. Safer chairs for elderly patients: design evaluation using electromyography and force measurement. ERGONOMICS 2018; 61:902-912. [PMID: 29325515 DOI: 10.1080/00140139.2018.1427804] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 01/09/2018] [Indexed: 06/07/2023]
Abstract
A vast majority of patient fall events in hospitals involve the elderly. In inpatient care settings, despite the risk of fall, patients are encouraged to leave their bed, move around their room, and sit on their chair to progress in their healing. Despite the vital role of patient chair design in improving recovery, few studies have examined the ergonomic requirements of safe patient chairs. This study examined the impact of manipulating horizontal and vertical positions of armrests in a test chair on required physical effort during Stand-to-Sit-to-Stand (St-Si-St) transitions among 15 elderly women. Physical effort was measured using: (1) surface electromyography (sEMG); (2) force measurement by load cells; (3) video recording. Findings showed non-linear patterns of change in required physical effort due to changes in armrests' height and distance. It was also found that minimum effort is associated with armrests higher and farther apart than those in typical patient chairs. Practitioner Summary: Safe chairs are essential for inpatient recovery, yet their ergonomic features are not investigated. Impact of changes in chair armrests on required physical effort was examined using electromyography, force measurement and video recording. Armrests higher and farther apart than those in typical patient chairs may be safer for elderly patients.
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Affiliation(s)
- Shabboo Valipoor
- a Department of Interior Design, College of Design, Construction and Planning , University of Florida , Gainesville , FL , USA
| | - Debajyoti Pati
- b Department of Design, College of Human Sciences , Texas Tech University , Lubbock , TX , USA
| | - Matt S Stock
- c Department of Health Professions, College of Health and Public Affairs , University of Central Florida , Orlando , FL , USA
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Cullum N, Buckley H, Dumville J, Hall J, Lamb K, Madden M, Morley R, O’Meara S, Goncalves PS, Soares M, Stubbs N. Wounds research for patient benefit: a 5-year programme of research. PROGRAMME GRANTS FOR APPLIED RESEARCH 2016. [DOI: 10.3310/pgfar04130] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BackgroundComplex wounds are those that heal by secondary intention and include lower-limb ulcers, pressure ulcers and some surgical wounds. The care of people with complex wounds is costly, with care mainly being delivered by community nurses. There is a lack of current, high-quality data regarding the numbers and types of people affected, care received and outcomes achieved.ObjectivesTo (1) assess how high-quality data about complex wounds can be captured effectively for use in both service planning and research while ensuring integration with current clinical data collection systems and minimal impact on staff time; (2) investigate whether or not a clinical register of people with complex wounds could give valid estimates of treatment effects, thus reducing dependence on large-scale randomised controlled trials (RCTs); (3) identify the most important research questions and outcomes for people with complex wounds from the perspectives of patients, carers and health-care professionals; (4) evaluate the potential contributions to decision-making of individual patient data meta-analysis and mixed treatment comparison meta-analysis; and (5) complete and update systematic reviews in topic areas of high priority.MethodsTo meet objectives 1 and 2 we conducted a prevalence survey and developed and piloted a longitudinal disease register. A consultative, deliberative method and in-depth interviews were undertaken to address objective 3. To address objectives 4 and 5 we conducted systematic reviews including mixed treatment comparison meta-analysis.ResultsFrom the prevalence survey we estimated the point prevalence of all complex wounds to be 1.47 per 1000 people (95% confidence interval 1.38 to 1.56 per 1000 people). Pressure ulcers and venous leg ulcers were the most common type of complex wound. A total of 195 people with a complex wound were recruited to a complex wounds register pilot. We established the feasibility of correctly identifying, extracting and transferring routine NHS data into the register; however, participant recruitment, data collection and tracking individual wounds in people with multiple wounds were challenging. Most patients and health professionals regarded healing of the wound as the primary treatment goal. Patients were greatly troubled by the social consequences of having a complex wound. Complex wounds are frequently a consequence of, and are themselves, a long-term condition but treatment is usually focused on healing the wound. Consultative, deliberative research agenda setting on pressure ulcer prevention and treatment with patients, carers and clinicians yielded 960 treatment uncertainties and a top 12 list of research priorities. Of 167 RCTs of complex wound treatments in a systematic review of study quality, 41% did not specify a primary outcome and the overall quality of the conduct and reporting of the research was poor. Mixed-treatment comparison meta-analysis in areas of high priority identified that matrix hydrocolloid dressings had the highest probability (70%) of being the most effective dressing for diabetic foot ulcers, whereas a hyaluronan fleece dressing had the highest probability (35%) of being the most effective dressing for venous ulcers; however, the quality of this evidence was low and uncertainty is high.ConclusionsComplex wounds are common and costly with a poor evidence base for many frequent clinical decisions. There is little routine clinical data collection in community nursing. A prospective complex wounds register has the potential to both assist clinical decision-making and provide important research evidence but would be challenging to implement without investment in information technology in NHS community services. Future work should focus on developing insights into typical wound healing trajectories, identifying factors that are prognostic for healing and assessing the cost-effectiveness of selected wound treatments.FundingThe National Institute for Health Research Programme Grants for Applied Research programme.
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Affiliation(s)
- Nicky Cullum
- School of Nursing, Midwifery and Social Work, University of Manchester, Manchester, UK
| | - Hannah Buckley
- Department of Health Sciences, University of York, York, UK
| | - Jo Dumville
- School of Nursing, Midwifery and Social Work, University of Manchester, Manchester, UK
| | - Jill Hall
- Department of Health Sciences, University of York, York, UK
| | - Karen Lamb
- Leeds Community Healthcare NHS Trust, Leeds, UK
| | - Mary Madden
- Department of Health Sciences, University of York, York, UK
| | - Richard Morley
- Department of Health Sciences, University of York, York, UK
| | - Susan O’Meara
- Department of Health Sciences, University of York, York, UK
| | | | - Marta Soares
- Centre for Health Economics, University of York, York, UK
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Hu L, Tackett B, Tor O, Zhang J. Analysis of sitting forces on stationary chairs for daily activities. ERGONOMICS 2016; 59:556-567. [PMID: 26257071 DOI: 10.1080/00140139.2015.1080311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
No literature related to the study of sitting forces on chairs sat on by people who weighed over 136 kg was found. The Business Institutional Furniture Manufactures Association needs force data for development of performance test standards to test chairs for users who weigh up to 181 kg. 20 participants who weighed from 136 to 186 kg completed 6 tasks on an instrumented chair in the sequence of sitting down, remaining seated and rising. Effects of sitting motion, armrest use and seat cushion thickness on vertical sitting forces and centre-of-force were investigated. Results indicated hard sitting down yielded the highest sitting force of 213% in terms of participants' body weights. Armrest use affected sitting forces of normal sitting down, but not of rising and hard sitting down. Cushion thickness affected sitting forces of normal and hard sitting down and shifting, but not of rising, static seating or stretching backward situations. Practitioner Summary: Results of the sitting force and centre-of-force data obtained for this research can help furniture manufacturers develop new product performance test standards for creating reliable engineering design and manufacturing quality and durable products to meet a niche market need.
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Affiliation(s)
- Lingling Hu
- a Department of Industrial Design , Zhejiang A&F University , Hangzhou , Zhejiang , China
- b Department of Sustainable Bioproducts , Mississippi State University , Starkville , MS , USA
| | - Bob Tackett
- b Department of Sustainable Bioproducts , Mississippi State University , Starkville , MS , USA
| | - Onder Tor
- b Department of Sustainable Bioproducts , Mississippi State University , Starkville , MS , USA
| | - Jilei Zhang
- b Department of Sustainable Bioproducts , Mississippi State University , Starkville , MS , USA
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Groah SL, Schladen M, Pineda CG, Hsieh CHJ. Prevention of Pressure Ulcers Among People With Spinal Cord Injury: A Systematic Review. PM R 2014; 7:613-36. [PMID: 25529614 DOI: 10.1016/j.pmrj.2014.11.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/25/2014] [Accepted: 11/29/2014] [Indexed: 12/15/2022]
Abstract
OBJECTIVES To evaluate the literature on the effectiveness of bed and wheelchair positioning and repositioning in the prevention of pressure ulcers (PUs) in both the spinal cord injury (SCI) and non-SCI populations. DESIGN Systematic review. METHODS PubMed, CINAHL, PsycINFO, and EMBASE were queried with the subject heading terms "pressure sore," "pressure ulcer," "position or turn in bed, wheelchair," "pressure relief," and "pressure release." All study design types that assessed the effectiveness of bed and wheelchair positioning and pressure relief maneuvers in any patient group and in any setting were sought. Three independent reviewers extracted and summarized details of eligible trials using a standardized method. Two independent reviewers assessed the methodological quality of each trial using the American Academy of Neurology guidelines. When reviewers were not able to reach consensus, a third independent reviewer served as tiebreaker. RESULTS We identified 2820 publications, of which 49 met inclusion criteria. Of these publications, the subject population was 2834 (923 persons with SCI, 717 persons without SCI, and 1194 healthy control subjects). Among studies examining pressure related to position or repositioning in bed or sitting, procedures for measuring skin pressure and metabolism were highly variable by anatomic location, measurement technique, outcome measure, study site, participant characteristics, and description of position/turning for bed and seated interventions. Numerous factors can influence tissue interface pressures, and no prospective studies had been performed to determine a causal relationship between interface pressure and skin breakdown. Several studies suggest that skin response to pressure differs between subjects with and without SCI. Conflicting results and insufficient evidence for optimal bed and seated positioning and turning and pressure relief maneuvers to prevent PUs in both SCI and non-SCI populations were limiting factors. CONCLUSIONS Although there is no clear optimal positioning or turning frequency in bed, the evidence suggests avoiding the 90° lateral position because of high pressures and PU risk over the trochanters. During sitting, pressures are linearly redistributed from the sitting area during recline and tilt; however, reclining carries with it an increased risk of shear forces on this skin. The evidence does not support conclusive guidelines on positioning or repositioning techniques for PU prevention in bed or during sitting. We conclude that PU risk is highly individualized, with the SCI population at a higher risk, which demands flexible PU prevention strategies for bed/seated positioning and pressure relief maneuvers. Education has and will remain our most powerful ally to thwart this pervasive public health problem.
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Affiliation(s)
- Suzanne L Groah
- MedStar National Rehabilitation Hospital, 102 Irving St., NW, Washington, DC 20010; Department of Rehabilitation Medicine, MedStar Georgetown University Hospital, Washington, DC(∗).
| | - Manon Schladen
- MedStar National Rehabilitation Hospital, 102 Irving St., NW, Washington, DC 20010; MedStar Health Research Institute, Hyattsville, MD; Washington, DC Veterans Affairs Medical Center, Washington, DC(†)
| | - Cynthia G Pineda
- MedStar National Rehabilitation Hospital, 102 Irving St., NW, Washington, DC 20010; Department of Rehabilitation Medicine, MedStar Georgetown University Hospital, Washington, DC; MedStar Montgomery Medical Center, Olney, MD(‡)
| | - Ching-Hui J Hsieh
- MedStar National Rehabilitation Hospital, 102 Irving St., NW, Washington, DC 20010; MedStar Health Research Institute, Hyattsville, MD(§)
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A system utilizing metal hydride actuators to achieve passive motion of toe joints for prevention of pressure ulcers: a pilot study. Rehabil Res Pract 2012; 2012:541383. [PMID: 22619724 PMCID: PMC3350992 DOI: 10.1155/2012/541383] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 02/09/2012] [Accepted: 02/10/2012] [Indexed: 11/18/2022] Open
Abstract
This paper describes the influence of human toe movement on blood flow and the design of a toe joint passive motion system for preventing pressure ulcers. First, we measured lower extremity blood flow in the foot during active and passive motion of the toe to facilitate the design of new rehabilitation equipment. Also, the flexion and extension angles and the force of the toe joints were measured to determine appropriate specifications for the system. Increases in blood flow were observed at the external malleolus during movement. Flexion and extension angles and the force of the toe joints were found to differ significantly among participants. It is shown that a toe joint passive motion system can be effective in preventing pressure ulcers. On the basis of these results, a device using alloys of metal hydride (MH) as an actuator that is suitable for the system to initiate toe motion, was developed.
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Solis LR, Liggins AB, Seres P, Uwiera RRE, Poppe NR, Pehowich E, Thompson RB, Mushahwar VK. Distribution of Internal Strains Around Bony Prominences in Pigs. Ann Biomed Eng 2012; 40:1721-39. [DOI: 10.1007/s10439-012-0539-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 02/28/2012] [Indexed: 10/28/2022]
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Solis LR, Liggins A, Uwiera RRE, Poppe N, Pehowich E, Seres P, Thompson RB, Mushahwar VK. Distribution of internal pressure around bony prominences: implications to deep tissue injury and effectiveness of intermittent electrical stimulation. Ann Biomed Eng 2012; 40:1740-59. [PMID: 22354272 DOI: 10.1007/s10439-012-0529-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 02/03/2012] [Indexed: 11/27/2022]
Abstract
The overall goal of this project is to develop interventions for the prevention of deep tissue injury (DTI), a form of pressure ulcers that originates in deep tissue around bony prominences. The present study focused on: (1) obtaining detailed measures of the distribution of pressure experienced by tissue around the ischial tuberosities, and (2) investigating the effectiveness of intermittent electrical stimulation (IES), a novel strategy for the prevention of DTI, in alleviating pressure in regions at risk of breakdown due to sustained loading. The experiments were conducted in adult pigs. Five animals had intact spinal cords and healthy muscles and one had a spinal cord injury that led to substantial muscle atrophy at the time of the experiment. A force-controlled servomotor was used to load the region of the buttocks to levels corresponding to 25%, 50% or 75% of each animal's body weight. A pressure transducer embedded in a catheter was advanced into the tissue to measure pressure along a three dimensional grid around the ischial tuberosity of one hind leg. For all levels of external loading in intact animals, average peak internal pressure was 2.01 ± 0.08 times larger than the maximal interfacial pressure measured at the level of the skin. In the animal with spinal cord injury, similar absolute values of internal pressure as that in intact animals were recorded, but the substantial muscle atrophy produced larger maximal interfacial pressures. Average peak internal pressure in this animal was 1.43 ± 0.055 times larger than the maximal interfacial pressure. Peak internal pressure was localized within a ±2 cm region medio-laterally and dorso-ventrally from the bone in intact animals and ±1 cm in the animal with spinal cord injury. IES significantly redistributed internal pressure, shifting the peak values away from the bone in spinally intact and injured animals. These findings provide critical information regarding the relationship between internal and interfacial pressure around the ischial tuberosities during loading levels equivalent to those experienced while sitting. The information could guide future computer models investigating the etiology of DTI, as well as inform the design and prescription of seating cushions for people with reduced mobility. The findings also suggest that IES may be an effective strategy for the prevention of DTI.
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Affiliation(s)
- Leandro R Solis
- Rehabilitation Science Program, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
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Olesen CG, de Zee M, Rasmussen J. Missing links in pressure ulcer research—An interdisciplinary overview. J Appl Physiol (1985) 2010; 108:1458-64. [DOI: 10.1152/japplphysiol.01006.2009] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This paper surveys the literature on the etiology of sitting-acquired deep tissue pressure ulcers from three different viewpoints. The first viewpoint is identification of risk factors related to seated posture. The second viewpoint focuses on the external factors that can cause necrosis to human cells, such as ischemia and compression. The third viewpoint focuses on computational models of the human buttocks to calculate where stress concentrations occur. Each viewpoint contributes to the understanding of pressure ulcer etiology, but in combination they cover the multiple scales from cell to organism, and the combined insight can provide important information toward a full understanding of the phenomenon. It is concluded that the following three questions must be answered by future research. 1) Does compressive stress alone explain cell death, or is it necessary to consider the full three-dimensional strain tensor in the tissues? 2) How does the change in posture-induced load applied on the human buttocks change the stress distribution in the deep muscle tissue? 3) Is it possible to optimize the seated posture in a computational model to reduce the deeper tissue loads?
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Affiliation(s)
- Christian Gammelgaard Olesen
- Departments of 1Mechanical and Manufacturing Engineering and
- Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Mark de Zee
- Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - John Rasmussen
- Departments of 1Mechanical and Manufacturing Engineering and
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Linder-Ganz E, Yarnitzky G, Yizhar Z, Siev-Ner I, Gefen A. Real-Time Finite Element Monitoring of Sub-Dermal Tissue Stresses in Individuals with Spinal Cord Injury: Toward Prevention of Pressure Ulcers. Ann Biomed Eng 2008; 37:387-400. [DOI: 10.1007/s10439-008-9607-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 11/17/2008] [Indexed: 10/21/2022]
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Solis LR, Hallihan DP, Uwiera RRE, Thompson RB, Pehowich ED, Mushahwar VK. Prevention of pressure-induced deep tissue injury using intermittent electrical stimulation. J Appl Physiol (1985) 2007; 102:1992-2001. [PMID: 17272408 DOI: 10.1152/japplphysiol.01092.2006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pressure ulcers develop due to morphological and biochemical changes triggered by the combined effects of mechanical deformation, ischemia, and reperfusion that occur during extended periods of immobility. The goal of this study was to test the effectiveness of a novel electrical stimulation technique in the prevention of deep tissue injury (DTI). We propose that contractions elicited by intermittent electrical stimulation (IES) in muscles subjected to constant pressure would induce periodic relief in internal pressure; additionally, each contraction would also restore blood flow to the tissue. The application of constant pressure to the quadriceps muscles of rats generated a DTI that affected 60 ± 15% of the compressed muscle as assessed by magnetic resonance imaging. In contrast, in the groups of rats that received IES at 10- and 5-min intervals, DTI of the muscle was limited to 16 ± 16 and 25 ± 13%, respectively. Injury to the muscle was corroborated by histology. In an experiment with a human volunteer, compression of the buttocks reduced the oxygenation level of the muscles by ∼4%; after IES, oxygenation levels increased by ∼6% beyond baseline. Concurrently, the surface pressure profiles of the loaded muscles were redistributed and the high-pressure points were reduced during each IES-induced contraction. The results of this study indicate that IES significantly reduces the amount of DTI by increasing the oxygen available to the tissue and by modifying the pressure profiles of the loaded muscles. This presents a promising technique for the prevention of pressure ulcers in immobilized and/or insensate individuals.
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Affiliation(s)
- Leandro R Solis
- Dept. of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2S2
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VanSickle DP, Cooper RA, Boninger ML. Road loads acting on manual wheelchairs. IEEE TRANSACTIONS ON REHABILITATION ENGINEERING : A PUBLICATION OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY 2000; 8:371-84. [PMID: 11001517 DOI: 10.1109/86.867879] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A barrier to performing more in-depth analyzes during the wheelchair design process is a lack of dynamic reaction force and moment data, and the instrumentation to collect this data. Instrumentation was developed to collect the dynamic force and moment data. New data collections methodologies and analysis techniques were implemented to facilitate computer-aided-engineering for wheelchair designs. Data were collected during standardized wheelchair fatigue tests, while driving over a simulated road course within a laboratory, and while driving in the community. Seventeen subjects participated in this study. Based upon the three test conditions, a pseudo-statistical distribution of the force and moment data at both a caster and rear wheel was developed. The key parameters describing the distribution and the extremums of the data (minima and maxima) were compared using analysis of variance. The results showed that the force and moment distributions and extreme values were similar for the both sets of human trials (i.e., simulated road course and field trials). However, the standardized testing (i.e., wheelchair fatigue testing) differed from both human trials. The force/moment data gathered during this study are suitable for inputs in finite element analysis and dynamic modeling. Our results suggest that the fatigue tests should be modified to change the magnitude and increase the frequency of the forces and moments imparted on the wheelchair. The data reported from this study can be used to improve wheelchair standards and to facilitate computer-aided-engineer in wheelchair design.
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Affiliation(s)
- D P VanSickle
- Human Engineering Research Laboratories, VA Rehabilitation Research and Development Center, VA Pittsburgh Healthcare System, PA 15206, USA
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Abstract
The aim of this study was to gain insight about the influence of body posture on the pressure at the seat surface and to establish to what extent different seat cushions designed for incontinent patients reduce maximum pressures. Pressures were measured for 56 healthy volunteers in eight postures using four cushions. The posture in which the lowest maximum pressure was measured was the sitting-back posture with the lower legs on a rest. If the seat could not be tilted back, the maximum pressure in the upright sitting posture with the feet on the ground was significantly lower than sitting upright with the legs supported on a rest. Sliding down and slouching caused the highest maximum pressure. Regular checking of the posture and using positioning cushions should form part of any pressure-ulcer prevention protocol. The four selected cushions each have different pressure-reducing effects. A thick air cushion (Repose) has the lowest maximum pressure and is significantly better than the other cushions at reducing the high pressure when slouching or sliding down.
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14
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Burns SP, Betz KL. Seating pressures with conventional and dynamic wheelchair cushions in tetraplegia. Arch Phys Med Rehabil 1999; 80:566-71. [PMID: 10326923 DOI: 10.1016/s0003-9993(99)90201-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To compare pressure relief from a dynamic wheelchair cushion to a tilt-in-space wheelchair with conventional cushions. STUDY DESIGN Repeated measures analysis. SETTING AND SUBJECTS Spinal cord injury unit; 16 tilt-in-space wheelchair users with motor-complete tetraplegia. MAIN OUTCOME MEASURES Interface pressure at ischial tuberosities. RESULTS Mean ischial pressure with subjects seated upright on the dynamic cushion during the low ischial pressure phase was lower than tilted pressure on the gel cushion, but it was not significantly different from tilted pressure on the dry-flotation cushion (dynamic/upright, 71 mm Hg; gel/tilted, 86 mm Hg; dry-flotation/tilted, 74 mm Hg; p<.05 dynamic vs. gel). Mean ischial pressure with subjects upright on the dynamic cushion during the high ischial pressure phase was significantly greater than the gel/upright and dry-flotation/upright conditions (dynamic/upright, 157 mm Hg; gel/upright, 128 mm Hg; dry-flotation/upright, 111 mm Hg; p<.001). CONCLUSION The dynamic cushion produces similar pressure relief over the ischial tuberosities during the low pressure phase to a tilt-in-space wheelchair and conventional cushions. The dynamic cushion may be an alternative to a tilt-in-space wheelchair for some individuals.
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Affiliation(s)
- S P Burns
- Spinal Cord Injury Unit, VA Puget Sound Health Care System, Seattle Division, WA 98108, USA
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15
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Rosenthal MJ, Felton RM, Hileman DL, Lee M, Friedman M, Navach JH. A wheelchair cushion designed to redistribute sites of sitting pressure. Arch Phys Med Rehabil 1996; 77:278-82. [PMID: 8600872 DOI: 10.1016/s0003-9993(96)90112-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES Despite the diversity of wheelchair cushions currently in clinical use, pressure on bony prominences continues to be a major problem for wheelchair-bound patients, and the incidence of pressure ulcers remains high. No static surface has been reported to reduce resting pressure under the ischial tuberosities to below that of capillary pressure, which may well be the threshold for inducing tissue damage. An entirely new form of seating was designed to decrease absolute pressure using a prosthetic fitting technique analogous to a below-the-knee prosthesis. DESIGN A repeated measures randomized design was used to test differences between the experimental (TCS) and three other standard cushions. SETTING A Veterans Medical Center outpatient service. PATIENTS Wheelchair-bound volunteer subjects, n = 47, were selected who weighed more than 60kg. MAIN OUTCOME MEASURES Pressures were measured by a standard air pressure pad and also by a computer-linked array of pressure transducers. The grid was standardized and used to generate topographic maps for each site over time. These data were used to measure the seating interface pressures. RESULTS There was a significant main effect of cushion over site, F = 131 for left ischial tuberosity. Pressure were lowest while patients sat on the experimental seat and differences were significant at all time points. Using 1psi as presumed capillary pressure, frequency of success at achieving this pressure threshold was greatest for the experimental seat, p < .001. This difference persisted throughout the 30 minutes of testing. CONCLUSIONS A computerized pressure grid was developed that allowed evaluation of anatomically localized pressures. The prosthetically designed TCS displays lower seating pressures than any other cushion tested. Consistent and sustained pressures were below the postulated threshold for tissue damage.
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Affiliation(s)
- M J Rosenthal
- Geriatric Research, Education and Clinical Center, Physical Medicine and Rehabilitation Service, VA Medical Center, Sepulveda, CA 91343, USA
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Anthony D. The Assessment of the Skin of the Elderly Patient with Specific Reference to Decubitus Ulcers and Incontinence Dermatitis. J Tissue Viability 1993. [DOI: 10.1016/s0965-206x(14)80076-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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