Summary of best evidence for prevention and control of pressure ulcer on support surfaces.

The aim of this study was to summarise the best evidence for the prevention and control of pressure ulcer at the support surface based on the site and stage of the pressure ulcer in order to reduce the incidence of pressure ulcer and improve the quality of care. In accordance with the top-down principle of the 6 S model of evidence-based resources, evidence from domestic and international databases and websites on the prevention and control of pressure ulcer on support surfaces, including randomised controlled trials, systematic reviews, evidence-based guidelines, and evidence summaries, was systematically searched for the period from January 2000 to July 2022. Evidence grading based on the Joanna Briggs Institute Evidence-Based Health Care Centre Evidence Pre-grading System (2014 version), Australia. The outcomes mainly embraced 12 papers, including three randomised controlled trials, three systematic reviews, three evidence-based guidelines, and three evidence summaries. The best evidence summarised included a total of 19 recommendations in three areas: type of support surface selection assessment, use of support surfaces, and team management and quality control.

How effective is alternating pressure (active) air surfaces for preventing pressure ulcers? A Cochrane Review summary with commentary.

BACKGROUND: Pressure ulcers may develop in people with impaired mobility, sensation, or cognition. Alternating pressure (active) air beds, overlays and mattresses are commonly used to prevent pressure ulcers. OBJECTIVE: This Cochrane Review aimed to determine the effects of alternating pressure (active) air beds, overlays or mattresses compared with any support surface in preventing pressure ulcers. METHODS: The population addressed was people at risk of and with existing pressure ulcers. Studies comparing alternating pressure (active) air surfaces with any beds, overlays or mattresses were included. The outcomes studied were pressure ulcer incidence, patient support-surface-associated comfort, adverse events, health-related quality of life and cost-effectiveness. RESULTS: There were 32 studies with a total of 9058 participants. There is low certainty evidence that alternating pressure (active) air surfaces compared with foam surfaces may reduce the incidence of pressure ulcers. It is uncertain whether there is a difference in the proportion of people developing new pressure ulcers between alternating pressure (active) air surfaces and reactive water-filled, fibre, air, gel or standard hospital surfaces. CONCLUSION: The use of alternating pressure (active) air surfaces may reduce the incidence of pressure ulcers compared to foam surfaces. However, it is uncertain if it is superior to reactive air surfaces, water surfaces and fiber surfaces in preventing pressure ulcers.

Impact of seating and mobility services for individuals with disabilities in Peru.

The purpose of this study is to critically analyze the perceived impact of seating and mobility services, provided by occupational therapists using an ISL model, from the perspective of the recipients of services in Peru. A quantitative, cross-sectional survey design was implemented using a survey that was developed based on areas of occupation outlined by the OTPF-4, translated into Spanish, and administered by an in-country partner via SurveyMonkey. More than 85% of respondents (n = 133) indicated they "agree" or "strongly agree" that receiving services had an overall positive impact on their life, ability to complete ADLs, social interaction, community mobility and participation, overall health, and sense of confidence and well-being; responses were generally "neutral" regarding impact on employment and education. The results support the potential of collaborative ISL, specific to the provision of seating and mobility, to improve occupational performance from the perspective of service recipients in Peru.

Creating a consumer-friendly resource to assist persons with Amyotrophic Lateral Sclerosis (ALS) in navigating the power wheelchair selection process.

Persons living with Amyotrophic Lateral Sclerosis (ALS), a fatal neurodegenerative disease, are often asked to make important decisions regarding power wheelchair (PWC) selection soon after receiving a diagnosis. There is currently a paucity of consumer-friendly information to aid clients living with ALS in better understanding the long-term functional implications of decisions made during the PWC selection process. The purpose of this action research project was to identify the specific considerations and choices required during the PWC selection process to use as the basis for creating a concise, educational video tool that emphasizes functional independence and self-advocacy for clients living with ALS. Semi-structured interviews of a panel of expert stakeholders were conducted to isolate important considerations for PWC selection in clients living with ALS. Qualitative data were collected through coded interviews and used to prioritize themes that were incorporated into an educational video. Once the draft video was created, the expert panel was provided time to review and critique the video prior to the creation of a professional quality video. Major themes identified and analyzed included environmental considerations, PWC component options, self-advocacy, and transportation. The video resource aims to be a resource for beginning a conversation about PWC options to make the PWC evaluation and selection process less daunting for clients and their caregivers.

Effects of simulated aging on cushion performance measured using standardized laboratory test methods.

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 of test outcome metrics pre- and post-aging are presented, and changes in the metrics due to aging are 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 systematic review of the effectiveness of pressure relieving cushions in reducing pressure injury.

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

Prevalence of pressure injuries and the management of support surfaces (mattresses) in adult intensive care patients: A multicentre point prevalence study in Australia and New Zealand.

BACKGROUND: Pressure injuries (PIs) are a patient safety issue that impact patient outcomes. Intensive care unit (ICU) patients are at high risk of PIs. OBJECTIVES: To report the prevalence and classification of documented PIs in adult ICU patients, the use of pressure injury risk assessment tools, and support surface management as a part of the prevention of PIs. METHODS: This was a prospective, single-day, multicentre, cross-sectional study of patients aged ≥ 16 years admitted to adult ICUs in Australia and New Zealand (ANZ), August 2016 as part of the Australian and New Zealand Intensive Care Society Clinical Trials Group (ANZICS-CTG) Point Prevalence Program. FINDINGS: Data were collected on 671 patients (58% male) in 47 ICUs. The mean [standard deviation] age and weight were 60.2 years [17.2 years] and 82.1 kg [29.7 kg], respectively, with a severity of illness score (Acute Physiology and Chronic Health Evaluation [APACHE] II) of 18.2 [8.4]. PIs were reported in 10% (70/671) of patients. Patients with a PI had a mean APACHE II score of 22.5 [standard deviation; 7.7], and 57.1% (40/70) met the criteria for sepsis on the study day. There were 107 PIs documented on the study day (N = 107) in the 70 patients with nearly half of PIs present on ICU admission (46.7%; 50/107). The sacrum was the most common location for PIs (28.9%; 31/107) and then the heels (15.9%; 17/107). All units routinely use a risk of PI assessment tool and were cared for on an active or reactive support surface. Patients with a PI were more often moved to an active support surface. CONCLUSIONS: The prevalence rate was reported at 10% for PIs for adult intensive care patients on the study day. More than half of the patients with a PI had signs of sepsis on the study day and a higher severity of illness, and more were cared for on active support surfaces. Most PIs were located at the sacrum and then the heels. All clinical sites routinely used a PI risk assessment tool.

Superfícies de suporte para prevenção de lesão por pressão no período intraoperatório: revisão sistemática com metanálise / Support surfaces for prevention of pressure ulcer in the intraoperative period: Systematic review with meta-analysis

No período intraoperatório, a lesão por pressão é um evento adverso que pode acometer o paciente cirúrgico. O planejamento e a implementação de cuidados para prevenção deste tipo de lesão são cruciais para a melhoria da qualidade da assistência prestada e da segurança do paciente. As superfícies de suporte são medidas que redistribuem a pressão e controlam o microclima e podem ser utilizadas para prevenção de lesão por pressão. O objetivo do estudo foi avaliar as evidências disponíveis na literatura sobre superfícies de suporte efetivas para prevenção de lesão por pressão em pacientes, no período intraoperatório. Trata-se de revisão sistemática conduzida pautada nas recomendações da Colaboração Cochrane. A busca dos estudos primários foi realizada nas seguintes bases de dados: PubMed; Cumulative Index to Nursing and Allied Health Literature; Cochrane Central Register of Controlled Trials, Embase, Literatura Latino-Americana e do Caribe em Ciências da Saúde, Scopus e Web of Science. A amostra da revisão sistemática foi composta por 10 estudos primários, sendo seis ensaios clínicos randomizados e quatro estudos não randomizados. A síntese dos resultados da revisão foi realizada na forma descritiva e por meio de metanálise. Para análise do risco de viés dos ensaios clínicos randomizados foi empregada a ferramenta gratuita denominada Revised Cochrane risk-of-bias tool for randomized trials (RoB 2). Para avaliar a qualidade metodológica dos estudos não randomizados foi adotada a ferramenta para estudo quase experimental, denominada JBI Critical Appraisal Checklist for Quasi-Experimental Studies. A qualidade das evidências foi avaliada por meio do Grading of Recommendations Assessment, Development and Evaluation (GRADE). Na comparação das superfícies de suporte de baixa tecnologia com o cuidado usual (colchão padrão de mesa cirúrgica), a metanálise demonstrou que não existe diferença estatisticamente significante entre as intervenções investigadas (RR = 0,88; IC95%: 0,30-2,39). Nesta comparação houve a inclusão de dois ensaios clínicos randomizados, sendo que o teste estatístico de inconsistência de Higgins indicou alta heterogeneidade entre os estudos (I2 = 83%). Além disso, a qualidade das evidências, por meio do sistema GRADE, foi considerada muito baixa (confiança muito limitada na estimativa do efeito), indicando que provavelmente a condução de outras pesquisas poderá alterar a estimativa do efeito. Na comparação das superfícies de suporte de alta tecnologia com as superfícies de baixa tecnologia, a metanálise evidenciou que existe diferença estatisticamente significante entre as intervenções investigadas, sendo as superfícies de suporte de alta tecnologia as mais efetivas (RR = 0,17; IC95%: 0,05-0,53). Nesta comparação houve a inclusão de três ensaios clínicos randomizados, sendo que a heterogeneidade entre os estudos foi leve (I2 = 0%). A qualidade das evidências foi considerada moderada (confiança moderada no efeito estimado), uma vez que dois ensaios clínicos randomizados foram avaliados com alto risco de viés. Frente ao exposto, recomenda-se a condução de ensaios clínicos bem delineados para testar superfícies de suporte para prevenção de lesão por pressão, principalmente as de alta tecnologia, no período intraoperatório.

In the intraoperative period, pressure ulcer is an adverse event that can affect the surgical patient. The planning and implementation of care to prevent this type of injury is crucial for improving the quality of care provided and for patient safety. Support surfaces are measures that redistribute pressure and control the microclimate and can be used to prevent pressure ulcer. This study aimed to evaluate the evidence available in literature on effective support surfaces for prevention of pressure ulcer in patients, during the intraoperative period. This is a systematic review conducted based on the recommendations of the Cochrane Collaboration. The search for primary studies was performed in the following databases: PubMed; Cumulative Index to Nursing and Allied Health Literature; Cochrane Central Register of Controlled Trials, Embase, Latin American and Caribbean Literature in Health Sciences, Scopus and Web of Science. The systematic review sample consisted of 10 primary studies, with six randomized clinical trials and four non-randomized studies. The synthesis of results was performed through descriptive meta-analysis. The free tool called Revised Cochrane risk-of-bias tool for randomized trials (RoB 2) was used to analyze the risk of bias in randomized clinical trials. A tool for quasi-experimental study, called JBI Critical Appraisal Checklist for Quasi-Experimental Studies, was adopted to assess the methodological quality of non-randomized studies. The quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). When comparing low-tech support surfaces with the usual care (standard operating table mattress), the meta-analysis demonstrated that there is no statistically significant difference between the investigated interventions (RR=0.88; 95%CI: 0.30-2.39). In this comparison, two randomized clinical trials were included and the Higgins inconsistency statistical test indicated high heterogeneity between studies (I2 = 83%). In addition, the quality of the evidence, through the GRADE system, was considered to be very low (limited confidence in the estimate of the effect), indicating that the conduct of further research is likely to alter the estimate of the effect. When comparing high-tech support surfaces with low-tech surfaces, the meta-analysis showed that there is a statistically significant difference between the investigated interventions, with high-tech support surfaces being the most effective (RR=0.17; 95%CI: 0.05-0.53). In this comparison, three randomized clinical trials were included and the heterogeneity between the studies was mild (I2 = 0%). The quality of the evidence was considered moderate (moderate confidence in the estimated effect), since two randomized clinical trials were evaluated with a high risk of bias. In view of the above, it is recommended to conduct well-designed clinical trials to test support surfaces for the prevention of pressure ulcer, especially high-tech ones, during the intraoperative period.

Prevention of pressure injuries in critically ill children: A preliminary evaluation.

AIMS: To evaluate a prevention strategy implemented to reduce incidence and severity of positioning related pressure injuries affecting pediatric patients in a pediatric critical care unit. Secondary objective was to evaluate compliance with preventive recommendations. BACKGROUND: The skin in infants or children has important physiological and anatomical differences compared with adults. Further, factors such as the immaturity of the skin and limited activity and mobility in pediatric critical care unit, along with the pressure exerted by medical devices, increases the risk of pressure ulcers in infants and children. The most effective preventive measures specific to this intensive care population need to be evaluated. MATERIAL AND METHODS: Quasi-experimental before-after study with consecutive sampling. The effectiveness of the care bundle implementation was evaluated based on the latest evidence (intervention group) versus the application of non-standardized care (control group). Pediatric patients up to 14 years old at risk of suffering from pressure injuries and who were admitted more than 48 h in a pediatric intensive care unit (level III) participated. For the collection of data, two computer programs and the hospital clinical records of each participant were consulted. The data collection period was 6 months per group (pre and post intervention). RESULTS: A sample of 110 patients was obtained (50 control group and 60 intervention group). The cumulative incidence in pediatric patients exposed to the risk of pressure injuries was reduced from 16% to 13.3%; and in the subgroup of patients with prolonged stay (≥28 days), the incidence was reduced from 55.55% to 20%. In the intervention group, category III and IV pressure ulcers were completely reduced. In addition, the total number of pressure injuries decreased by 21.43%. The care bandle recommendations with the highest level of adhesion recorded were: skin inspection, application of hyperoxygenated fatty acids and use of a special support surface. The main risk factor found during the study was the prone position (p < 0.05). CONCLUSIONS: The application of a care bundle for prevention can be an effective solution to reduce the number and severity of LPPs in an intensive care unit. The most vulnerable subgroup of patients may benefit from the application of these resources.

An exploration of nursing home residents' experiences of a non-powered static air mattress overlay to prevent pressure ulcers.

Pressure ulcers are injuries to the skin and underlying tissue and are associated with a negative impact on well-being and health-related quality of life. This explorative, qualitative study aimed to explore the true meaning of elderly nursing home residents' perspectives and critical success factors when implementing a new non-powered static air mattress overlay to prevent pressure ulcers. Individual, loosely structured interviews were conductedin 12 nursing homes in Flanders, the Northern region of Belgium, a convenience sampling of 14 nursing home residents were selected based on the following eligibility criteria: high risk for pressure ulcer and/or with category 1 pressure ulcer, being bedbound and/or chair-bound, aged >65 years, and use of an alternating air pressure mattress previous to the application of the non-powered static air mattress overlay. Interviews were conducted in the participants' personal rooms between June 2017 and March 2018. Interviews included broad, open-ended questions, to invite and encourage participants to openly discuss their perspectives and experiences. Participants were interviewed once during the 14-day observation period between day 3 and day 14. All interviews were audio-recorded and fully transcribed by an experienced transcriber. Interviews were read several times to reveal emerging patterns and were marked with codes into NVivo 10 qualitative data analysis software. During the process, (sub) themes were discussed by the authors until a consensus was reached. Three main themes emerged from the analysis process: rest and sleep; mobility; and discomfort and pain associated with the use of the support surface. Themes were divided into multiple subthemes: motion, noise, sensation, repositioning, and transfer in and out of bed. Through interviews, critical success factors associated with the implementation were identified, including the lack of information and time needed to evaluate the functionality and effects of a new mattress overlay. Implementation of a non-powered static air mattress overlay to prevent pressure ulcers has a far-reaching impact on nursing home residents' experiences. This study provides insight into the true meaning of patients' perspectives by focusing on learning from the patients' experiences that provide valuable information for healthcare professionals and other stakeholders.

Developing a process for assessing equivalency of wheelchair cushion pressure redistribution performance.

For wheelchair users who are at risk for developing pressure ulcers, cushion prescription seeks to address tissue integrity. Because many designs of wheelchair cushions exist, a need exists to estimate their performance in supporting the body. The objective of this research was to develop an approach to assess the equivalency of cushions with respect to their pressure redistribution performance.Two instrumented compliant buttock models, differing in form, were used in the evaluation. Stress and strain parameters were used to characterize load-bearing performance. A cohort of 8 wheelchair cushions was compared to a standard reference material, HR45 foam. Each cushion was measured using both models under two loading conditions.The use of compliant buttock models that are capable of measuring both stress and strain parameters offer greater capability in measuring load-bearing performance compared to previously described methods. The proposed approach was able to evaluate cushion performance and use a logic-based approach to define whether or not a cushion was equivalent to the HR45 material. Additional study is needed to further validate the approach and to define the thresholds and criteria used to define cushion equivalency.

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

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

Data-mining analysis of the provision of mobility devices in the United States with emphasis on complex rehab technology.

The objective of this study was to describe the provision of wheeled-mobility equipment from the perspective of a large equipment supplier in the United States. The records of clients who were prescribed a mobility device over a 6-month period were randomly sampled to product a dataset of 1,689 clients. Analysis was limited to descriptive statistics and measures of relationships. The majority of the clients were adults (72%) and female (58%) with 62% receiving a manual wheelchair. The majority of interventions (58%) included some contribution from the client or client's family. Overall, 86% of all prescribed wheelchairs were classified as complex rehab technology (CRT). About half (52%) of all interventions involved a therapist. Therapist involvement was 2.5 times more likely during CRT interventions compared to standard durable medical equipment (StdDME). The project provides a novel description of mobility-related equipment provision using a large retrospective dataset. The analysis demonstrates the utility of analyzing a large number of client interventions. The capabilities of such analyses have business, clinical, and policy implications. Combining the data available from suppliers with prospective collection of client-specific information, such as outcomes, would be a more powerful means to assess the provision of wheeled-mobility equipment.

Support surfaces for the treatment and prevention of pressure ulcers: a systematic literature review.

OBJECTIVE: Changes in technology have resulted in a lack of clarity regarding the comparative effectiveness between active and reactive support surfaces in the prevention and treatment of pressure ulcers (PUs). The purpose of this literature review was to evaluate the comparative effectiveness of active and reactive mattresses for prevention and treatment of PUs. METHOD: A literature search was completed using CINAHL, Medline Plus, Scopus, Cochrane Library and PubMed databases, as well as reference lists. A temporal limiter was placed excluding studies published before 2000 due to changes in care standards and support surface technology. RESULTS: Of the 33 articles included, nine were systematic/literature reviews and 24 were randomised controlled trials (RCTs). There was a consensus that pressure mattresses are an effective prevention and treatment strategy, however comparisons of the two types were often inconclusive or conflicting. Studies were conducted in acute, sub-acute or residential facilities, with no studies in a domiciliary setting. The majority of studies were rated as moderate quality with significant methodological limitations. CONCLUSION: Further research is needed to investigate the use of support surfaces in a domiciliary setting with an appropriate methodology aimed at minimising the limitations described in the existing literature.

Prevention of pressure ulcers with a static air support surface: A systematic review.

The aims of this study were to identify, assess, and summarise available evidence about the effectiveness of static air mattress overlays to prevent pressure ulcers. The primary outcome was the incidence of pressure ulcers. Secondary outcomes included costs and patient comfort. This study was a systematic review. Six electronic databases were consulted: Cochrane Library, EMBASE, PubMed (Medline), CINAHL (EBSCOhost interface), Science direct, and Web of Science. In addition, a hand search through reviews, conference proceedings, and the reference lists of the included studies was performed to identify additional studies. Potential studies were reviewed and assessed by 2 independent authors based on the title and abstract. Decisions regarding inclusion or exclusion of the studies were based on a consensus between the authors. Studies were included if the following criteria were met: reporting an original study; the outcome was the incidence of pressure ulcer categories I to IV when using a static air mattress overlay and/or in comparison with other pressure-redistribution device(s); and studies published in English, French, and Dutch. No limitation was set on study setting, design, and date of publication. The methodological quality assessment was evaluated using the Critical Appraisal Skills Program Tool. Results were reported in a descriptive way to reflect the exploratory nature of the review. The searches included 13 studies: randomised controlled trials (n = 11) and cohort studies (n = 2). The mean pressure ulcer incidence figures found in the different settings were, respectively, 7.8% pressure ulcers of categories II to IV in nursing homes, 9.06% pressure ulcers of categories I to IV in intensive care settings, and 12% pressure ulcers of categories I to IV in orthopaedic wards. Seven comparative studies reported a lower incidence in the groups of patients on a static air mattress overlay. Three studies reported a statistical (P < .1) lower incidence compared with a standard hospital mattress (10 cm thick, density 35 kg/m3 ), a foam mattress (15 cm thick), and a viscoelastic foam mattress (15 cm thick). No significant difference in incidence, purchase costs, and patient comfort was found compared with dynamic air mattresses. This review focused on the effectiveness of static air mattress overlays to prevent pressure ulcers. There are indications that these mattress overlays are more effective in preventing pressure ulcers compared with the use of a standard mattress or a pressure-reducing foam mattress in nursing homes and intensive care settings. However, interpretation of the evidence should be performed with caution due to the wide variety of methodological and/or reporting quality levels of the included studies.

What makes a good head positioner for preventing occipital pressure ulcers.

Patients who are stationary endure prolonged soft tissue distortions and deformations at contact areas between their body and the support surface, which may lead to the onset of pressure ulcers (PUs) over time. A novel technology for patient positioning employs innovation in materials science, specifically viscoelastic materials with shape memory properties that compose the Z-Flo™ head positioner (Mölnlycke Health Care, Gothenburg, Sweden). Head positioners are generally known to reduce the occurrence of PUs in scalp tissues and the ears, but quantitative assessments of their biomechanical efficacy are missing in the literature. To determine potential differences in mechanical loads formed in the soft tissues of the back of the head while in contact with 2 head positioner types, Z-Flo vs flat medical foam, we developed 2 comparable finite element model configurations, both including the same 3-dimensional adult head. For both model variants, stresses in skin and fat peaked at the occiput. The skin at the back of the resting head is subjected to greater stress values with respect to fat; however, the Z-Flo positioner reduced the exposure of both skin and fat tissues to elevated stresses considerably (by a factor of 3) compared to the medical foam support. We found the Z-Flo device effective in reducing tissue loads at the surface of the head as well as internally in scalp tissues, with a particular strength in reducing internal tissue shear. The Z-Flo device achieves this protective quality through highly effective immersion and envelopment of the back of the head, generated in the process of manual moulding of the device in preparation for use. Additional protection is achieved through the viscoelastic response of the filling material of this positioner, which relaxes promptly and considerably under the weight of the head (by more than 2-fold within approximately 1 s) as opposed to the elastic recoil of the foam that pushes back on scalp tissues.

Correlation of ISO 16840-2:2007 impact damping and hysteresis measures for a sample of wheelchair seating cushions.

Hysteresis and impact damping measures were made on 37 wheelchair seating cushions according to ISO 16840-2:2007 Wheelchair seating-Part 2: Determination of physical and mechanical characteristics of devices intended to manage tissue integrity-seat cushions. These measures were then correlated using Spearman and Pearson correlations to investigate the relationship between them. Correlations were also conducted on the subset of cushions comprising only those with planar foam construction. Correlation between the hysteresis measures (h250 and h500) and the mean number of rebounds greater in amplitude than 10% of the peak acceleration amplitude (R10%) were weak, as were the correlations between the hysteresis measures and the mean peak first rebound acceleration (aa). Correlations between hysteresis and the mean peak second rebound acceleration (a2), and also hysteresis and the ratio of first and second peak (a2:aa) however were moderate. Results demonstrate that the relationship between these two measures is complex. The assertion implicit in ISO 16840-2:2007 is that the two measures are related, but this study shows that these should not be assumed to be equivalent or used interchangeably.

Comparing the effects of 3 different pressure ulcer prevention support surfaces on the structure and function of heel and sacral skin: An exploratory cross-over trial.

Special support surfaces are key in pressure ulcer prevention. The aim of this study was to measure the effects of 3 different types of mattresses (reactive gel, active alternating air, basic foam) on skin properties of the sacral and heel skin after 2 hours loading. Fifteen healthy females (median age 66 years) were included. Transepidermal water loss, skin surface temperature, erythema, stratum corneum hydration, epidermal hydration, skin extensibility, elastic function, and recovery as well as skin roughness parameters were measured under controlled room conditions before loading, immediately after loading, and 20 minutes post-loading in the supine position on the different mattresses. The highest increases in transepidermal water loss, skin temperature, and erythema were observed for the foam mattress after loading, indicating higher deformation and occlusion. Cutaneous stiffness decreased in all 3 groups, indicating structural changes during loading. There was a substantial decrease of mean roughness at the heel skin in the foam group, leading to a flattening of the skin surface. Study results indicate that the type of support surface influences skin structure and function during loading. The gel and air mattress appeared to be more protective compared with the foam mattress, but the differences between the gel and air were minor.

Deep tissue loads in the seated buttocks on an off-loading wheelchair cushion versus air-cell-based and foam cushions: finite element studies.

For wheelchair users, a common injury is a sitting-acquired pressure ulcer (PU) which typically onsets near the interface between the ischial tuberosity (IT) and the overlying soft tissues. The risk of developing PUs can be reduced considerably if an adequate cushion is placed on the wheelchair in order to protect tissues from PUs by minimising interface mechanical loads between the body and cushion and also, exposure to internal soft tissue loads. In this work, we studied the biomechanical performances of an off-loading (OL) cushion with limited adjustability, in comparison to a standard foam cushion and a fully adjustable air-cell-based (ACB) cushion. These different cushion design approaches were methodologically and quantitatively analysed and compared here using a finite element (FE) modelling framework. We determined the internal mechanical deformations, strains and stresses in soft tissues of the seated buttocks during symmetric sitting, in a specific anatomy of a person with a spinal cord injury that was acquired during sitting in an open, magnetic resonance imaging configuration. Our results have shown that strains and stresses in muscle, fat and skin tissues are orders of magnitude lower for the ACB cushion with respect to the standard foam and OL cushions. The OL cushion design has taken the approach of protecting at-risk sites of the buttocks by transferring local internal tissue loads away from the ITs and towards the greater trochanters, at the price of increasing exposure to internal tissue loads at sites other than the ITs. The ACB cushion design, however, has taken a different approach, that is, immersion and envelopment of the entire buttocks structure, which is useful for minimising the exposure to internal tissue loads throughout the whole buttocks. Quantifying performances of wheelchair cushions using FE modelling provides insights into deep tissue loads, which is essential for informed decision-making in developing sitting solutions for individuals at risk, as well as for patient groups.

Impact of wheelchair seat height on neck and shoulder range of motion during functional task performance.

Wheelchair users are at high risk for developing repetitive stress injuries (RSI) of the cervical spine and glenohumeral joints due to increased demands on active range of motion (AROM) when performing functional tasks from a seated position. The addition of a seat elevation device may alleviate the risk factors that lead to the development of RSI. However, there are no studies which establish that wheelchair seat height impacts upon arthrokinematic requirements at vulnerable joints. Additionally, Medicare and most insurance carriers do not cover the cost of power seat elevators because this feature has not been shown to be a "medical necessity." This study examined differences in AROM at the cervical spine and glenohumeral joint during performance of two functional tasks while seated in a wheelchair with the seat elevation feature at minimum and maximum height. Results revealed statistically significant differences in AROM requirements for cervical extension and shoulder abduction between the two wheelchair seat heights. These findings provide preliminary support for the value of the power seat elevation function in minimizing the risk of RSI at the shoulder complex and cervical spine in wheelchair users.