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Silvia Caggiari, Dan L Bader, Finn Foxell, Nicholas Pipe, Seana Couch, Abbie Turner, Peter R Worsley Clinical Academic Facility, School of Health Sciences, University of Southampton, Southampton, SO17 1BJ, UKCorrespondence: Silvia Caggiari, Clinical Academic Facility, School of Health Sciences, University of Southampton, Southampton, SO17 1BJ, UK, Email Silvia.Caggiari@soton.ac.ukPurpose: Respiratory protective equipment is widely used in healthcare settings to protect clinicians whilst treating patients with COVID-19. However, their generic designs do not accommodate the variability in face shape across genders and ethnicities. Accordingly, they are regularly overtightened to compensate for a poor fit. The present study aims at investigating the biomechanical and thermal loads during respirator application and the associated changes in local skin physiology at the skin–device interface.Materials and Methods: Sixteen healthy volunteers were recruited and reflected a range of gender, ethnicities and facial anthropometrics. Four single-use respirators were evaluated representing different geometries, size and material interfaces. Participants were asked to wear each respirator in a random order while a series of measurements were recorded, including interface pressure, temperature and relative humidity. Measures of transepidermal water loss and skin hydration were assessed pre- and post-respirator application, and after 20 minutes of recovery. Statistical analysis assessed differences between respirator designs and associations between demographics, interface conditions and parameters of skin health.Results: Results showed a statistically significant negative correlation (p < 0.05) between the alar width and interface pressures at the nasal bridge, for three of the respirator designs. The nasal bridge site also corresponded to the highest pressures for all respirator designs. Temperature and humidity significantly increased (p < 0.05) during each respirator application. Significant increases in transepidermal water loss values (p < 0.05) were observed after the application of the respirators in females, which were most apparent at the nasal bridge.Conclusion: The results revealed that specific facial features affected the distribution of interface pressures and depending on the respirator design and material, changes in skin barrier function were evident. The development of respirator designs that accommodate a diverse range of face shapes and protect the end users from skin damage are required to support the long-term use of these devices.Keywords: respiratory protective equipment, skin health, goodness of fit, interface pressure, physiological response

Joseph MH Lemmens,1 Jackie Broadbridge,1 Margaret Macaulay,1 Rowland W Rees,2 Matt Archer,2 Marcus J Drake,3 Katherine N Moore,4 Dan L Bader,1 Mandy Fader11University of Southampton, School of Health Sciences, Southampton SO17 1BJ, UK; 2Department of Urology, University Hospital Southampton NHS Foundation Trust, Southampton, SO16 6YD, UK; 3Bristol Urological Institute, Southmead Hospital, Bristol, BS10 5NB, UK; 4Faculty of Nursing, University of Alberta, Edmonton, Alberta, T6G 1C9, CanadaBackground: Penile compression devices (PCD) or clamps are applied to compress the urethra and prevent urinary incontinence (UI). PCDs are more secure and less likely to leak than pads, allowing men the opportunity to participate in short-term, vigorous activities. However, they are uncomfortable, can cause pressure ulcers (PU) and affect penile blood flow. No objective assessment of tissue health has been undertaken to assess and compare different PCD designs and to provide guidance on safe use.Objective: This study was designed to evaluate existing PCDs in terms of their physiological response and potential for pressure-induced injury.Design, setting and participants: Six men with post-prostatectomy UI tested four selected PCDs at effective pressures, in a random order, in a controlled laboratory setting.Outcome measurements and statistical analysis: Using objective methods for assessing skin injury, PCDs were measured in situ for their effects on circulatory impedance, interface pressures and inflammatory response.Results and limitations: There was evidence for PCD-induced circulatory impedance in most test conditions. Interface pressures varied considerably between both PCDs and participants, with a mean value of 137.4±69.7 mmHg. In some cases, penile skin was noted to be sensitive to loading with elevated concentration of the cytokine IL-1α after 10 mins wear, indicating an inflammatory response. IL-1α levels were restored to baseline 40 mins following PCD removal.Conclusion: Skin health measures indicated tissue and blood flow compromise during the 50 mins of testing using all PCDs. Although there was an elevation in pro-inflammatory cytokines, PCDs did not cause sustained irritation and skin health measures recovered 40 mins after PCD removal. This research indicates that application of a clamp for one hour with an equal clamp free time before reapplication is likely to be safe. Longer periods are often recommended by manufacturers but have yet to be tested.Keywords: penile, compression, clamp, urinary, incontinence, pressure

Paul Clarkson,1,2 Peter R Worsley,1 Lisette Schoonhoven,1,3 Dan L Bader11School of Health Sciences, University of Southampton, Southampton, UK; 2Southern Health NHS Foundation Trust, Calmore, UK; 3Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, NetherlandsBackground: Pressure ulcers (PUs) are a major burden to individuals, impacting their physical, mental and social wellbeing. While PU prevention is traditionally regarded as a nursing issue, an interprofessional approach has been promoted as best practice. However, little is known about current practice or the knowledge and attitudes of the wider interprofessional team (IPT).Purpose: Pre-designed questionnaires were used to explore knowledge and attitudes with healthcare staff in the community.Methods: Questionnaires were disseminated to all healthcare staff within a community healthcare Trust predominantly via an online tool. Data were analyzed using descriptive and inferential statistics.Results: The median values of all professional groups demonstrated satisfactory attitudes (>75%) and levels of knowledge (>60%) to PU prevention. However, there were differences within and between groups. Management staff demonstrated the most positive attitude to PU prevention (89%), followed by occupational therapists (OTs) and healthcare assistants (HCAs) (87%, IQR: 75%→89%). OTs demonstrated the highest scores for knowledge (69%, IQR: 62%→73%), while healthcare and rehabilitation assistants scored the lowest (58%, IQR: 58%-64%).Conclusion: This study has demonstrated that the majority of healthcare staff in a UK community setting have satisfactory levels of knowledge and attitudes in relation to PU prevention overall. Nevertheless, there were some differences between groups, albeit non-significant. There were also differences between sub-themes of the questionnaires, indicating a greater focus of pressure ulcer treatment over prevention. While PU prevention is widely regarded to be a nursing issue, these findings provide some indication of the potential for an interprofessional approach.Keywords: pressure ulcer, interprofessional, knowledge, attitudes, community, questionnaire

Peter R Worsley, Nathan D Stanger, Aran K Horrell, Dan L Bader Clinical Academic Facility, Faculty of Health Sciences, University of Southampton, Southampton, UK Background: Research has shown that up to 33% of pressure ulcers (PUs) acquired in hospitals result from the application of a medical device. Cervical collars (C-collars) have been impli-cated in causing PUs, due to the mechanical force they apply to the skin. In order to improve our understanding of collar-related PUs, the present study aimed to assess the biomechanical, biochemical, and microclimate effects of C-collar design and fitting tension. Methods: A cohort of 15 healthy volunteers was fit with two different C-collars according to the manufacturer guidelines. Two further collar tensions were also defined as loose and tight for each device. Each collar condition was applied for 15 minutes, with a 10 minute refractory period. Measurements at the device–skin interface included interface pressures, inflammatory biomarkers, microclimate, range of cervical motion, and comfort scores. Results: The interface pressures at each tissue site increased monotonically with greater collar tension (p

Peter R Worsley, George Prudden, George Gower, Dan L Bader Southampton General Hospital, Clinical Academic Facility, Faculty of Health Sciences, University of Southampton, Southampton, UK Abstract: Non-invasive ventilation is commonly used for respiratory support. However, in some cases, mask application can cause pressure ulcers to specific features of the face, resulting in pain and reduced quality of life for the individual. This study investigated the effects of mask strap tension on the biomechanical and biomarker responses at the skin interface. Healthy participants (n=13) were recruited and assigned two different masks in a random order, which were fitted with three strap conditions representing increments of 5 mm to increase tension. Masks were worn for 10 minutes at each tension followed by a 10-minute refractory period. Assessment at the device–skin interface included measurements of pressures at the nose and cheeks, temperature and humidity, a selection of inflammatory cytokine concentrations collected from sebum and scores of comfort. The results indicated significantly higher interface pressures at the bridge of the nose compared to the cheeks for both masks (p

Summary: Introduction: The mechanisms of pain reduction have not completely been established following patellar taping in subjects with patellofemoral pain syndrome (PFPS); although it might be related to alteration in the kinetics of the patellofemoral joint. Methods: Patellofemoral Joint Reaction Force (PFJRF) of eighteen subjects with PFPS and eighteen healthy subjects as controls were assessed by a motion-analysis system and one force plate. This procedure was performed on the affected knee of subjects with PFPS, before, during and finally after patellar taping during unilateral squatting. A similar procedure was also performed on the unaffected knees of both groups. Results: The mean values of PFJRF prior to taping (2025N, SD 347N) were decreased significantly following a period of taping (1720N, SD 303N) (P <0.05). There were no significant differences between the mean values of PFJRF among controls (1922N, SD 398N) and subjects with PFPS prior to taping (P >0.05) which might be due to small sample size in both groups and large variability observed in the study. Interpretation: Decreased values of PFJRF may explain the mechanism of pain reduction following patellar taping in subjects with PFPS. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate temporal changes in skin responses following exposure to moisture alone or moisture in combination with mechanical loading., Design: Comparison cohort with a repeated-measures design., Subjects and Settings: The sample comprised 12 healthy volunteers. Participants were purposely sampled from 2 different age groups; half were 32 to 39 years old and half were 50 to 62 years old. Participants identified as White, Black, or mixed; 83% (n = 10) identified as White; 8 (67%) were female., Methods: Four sites at the sacrum were challenged with the application of specimens taken from 2 absorbent products; the pad specimens were applied dry or saturated with synthetic urine (SU; pH = 8); a further site from the sacral skin was also selected and used as a control. Skin assessments were performed at different points in time: (1) 60 minutes after exposure to dry or SU-saturated pad specimens; (2) 60 minutes after exposure to pads and mechanical loading (application of pressure in the form of 45°C high sitting); and (3) 30 minutes after removal of all pads (recovery period). Outcome measures were transepidermal water loss (TEWL), stratum corneum (SC) hydration, erythema, pH, and skin inflammatory biomarkers measured at each of the time points described earlier., Results: The control site and those exposed to dry pads showed minimal time-dependent changes irrespective of the parameter investigated. In contrast, significant increases in TEWL (P = .0000007) and SC hydration responses (P = .0000007) were detected at the sites under absorbent pad specimens after saturation with SU (exposure to moisture). In some participants, TEWL and SC hydration parameters were significantly higher during pressure application. Skin pH remained in the mildly acidic range throughout the test session, and no consistent trends were observed with erythema. Skin inflammatory biomarkers also exhibited considerable variability across participants; none changed significantly over time. Significant differences (P = .02) were also detected following the exposure of moisture in combination with pressure., Conclusion: We evaluated an array of parameters to identify changes following skin exposure to 2 absorbent pads in the presence and absence of SU and mechanical loading. Analysis revealed changes in skin barrier properties in the presence of moisture and/or pressure. This observation suggests a need for frequent pad changing as well as periods of skin off-loading to protect the skin health of individuals with incontinence., Competing Interests: Disclosures: Shabira Abbas is a senior scientist at Essity AB. The other authors have no conflicts of interest., (Copyright © 2023 by the Wound, Ostomy and Continence Nurses Society.)

Background: Pressure ulcers (PUs) are chronic wounds that are detrimental to the quality of life of patients. Despite advances in monitoring skin changes, the structure and function of skin cells over the site of pressure ulcers are not fully understood., Objective: The present study aims to evaluate local changes in the properties of superficial corneocytes in category 1 PU sites sampled from a cohort of hospitalised patients., Methods: Cells were collected from a PU-compromised site and an adjacent control area and their topographical, maturation and mechanical properties were analysed., Results: Corneocytes at the PU-compromised site were characterised by higher levels of immature cornified envelopes (p < 0.001) and greater amounts of desmoglein-1 (corneodesmosomal protein) (p < 0.001) compared to the adjacent control area. The cells at the control site presented the typical ridges-and-valleys topographical features of sacrum corneocytes. By contrast, the PU cells presented circular nano-objects at the cell surface, and, for some patients, the cell topography was deformed. CEs at the PU site were also smaller than at the control site. Although differences were not observed in the mechanical properties of the cells, those of the elderly patients were much softer compared with young subjects., Conclusion: This is the first study investigating the changes in corneocyte properties in category I pressure ulcers. Superficial cells at the PU sites showed altered topographical and maturation characteristics. Further studies are required to elucidate if these changes are a consequence of early loss of skin integrity or a result of mechanical and microclimate insults to the skin surface., Competing Interests: Conflict of Interest The authors have no conflict of interest to declare., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

In acute care facilities, the detection of pressure ulcers (PUs) relies on visual and manual examination of the patient's skin, which has been reported to be inconsistent and may lead to misdiagnosis. In skin and wound research, various biophysical parameters have been extensively employed to monitor changes in skin health. Nonetheless, the transition of these measures into care settings as part of a routine clinical assessment has been limited. This study was designed to examine the spatial and temporal changes in skin biophysical parameters over the site of a category I PU, in a cohort of hospitalised patients. Thirty patients, each presenting with a category I PU, were enrolled in the study. Skin integrity was assessed at the PU-compromised site and two adjacent areas (5 and 10 cm away). Data was collected over three sessions to examine both temporal differences and longitudinal changes. Skin integrity was assessed using two biophysical parameters, namely, transepidermal water loss (TEWL) and stratum corneum (SC) hydration. In addition, the influence of intrinsic factors, namely, incontinence and mobility status, on the parameters was evaluated. TEWL values at the sites compromised by PU were statistically significantly greater (P < .001) than corresponding values at the adjacent control sites at 5 and 10 cm, which were consistent with a normative range (<20 g/h/m 2 ). By contrast, SC hydration values did not reveal clear distinctions between the three sites, with high inter-patient variation detected at the sites. Nevertheless, individual profiles were consistent across the three sessions, and the PU site was observed to be either abnormally dry or overhydrated in different individuals. No consistent temporal trend in either parameter was evident. However, intrinsic factors were shown to influence the parameters, with females, bedridden and incontinent patients presenting significantly higher TEWL and SC hydration values (P < .05). TEWL was able to identify differences in skin responses at skin sites compromised with a category I PU when compared to healthy adjacent skin sites. Accordingly, this parameter could be included in the clinical assessment for the identification of PU risk. Further studies are required to elucidate the role of hydration and skin barrier function in the development of PUs and their ability to monitor temporal changes in skin integrity., (© 2023 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

Objective: To investigate reliability and changes of in-shoe plantar pressure and shear during walking at three cadences with two insole designs. This was a precursor to the investigation of plantar loading in people with diabetes for potential foot ulcer prevention., Method: A sensorised insole system, capable of measuring plantar pressure and shear at the heel, fifth metatarsal head (5MH), first metatarsal head (1MH) and hallux, was tested with ten healthy participants during level walking. Reliability was evaluated, using intra-class correlation coefficient (ICC), while varying the cadences and insole types. Percentage changes in pressure and shear relative to values obtained at self-selected cadence with a flat insole design were investigated., Results: Mean±standard deviation of maximum pressure, medial-lateral and anterior-posterior shear of up to 380±24kPa, 46±2kPa and -71±4kPa, respectively, were measured. The ICC in ranges of 0.762-0.973, 0.758-0.987 and 0.800-0.980 were obtained for pressure, anterior-posterior and medial-lateral shear, respectively. Opposite anterior-posterior shear directions between 5MH and 1MH (stretching), and between 1MH and hallux (pinching) were observed for some participants. Increasing cadence increased pressure and anterior-posterior shear (by up to +77%) but reduced medial-lateral shear at the heel and hallux (by up to -34%). Slower cadence increased anterior-posterior shear (+114%) but decreased medial-lateral shear (-46%) at the hallux. The use of a flexible contoured insole resulted in pressure reduction at the heel and 5MH but an increase in anterior-posterior shear at the heel (+69%) and hallux (+75%)., Conclusion: The insole system demonstrated good reliability and is comparable to reported pressure-only systems. Pressure measurements were sensitive to changes in cadence and insole designs in ways that were consistent with the literature. However, our plantar shear showed localised shear changes with cadences and insoles for the first time, as well as stretching and pinching effects on plantar tissue. This opens new possibilities to investigate plantar tissue viability, loading characteristics and orthotic designs aimed towards foot ulcer prevention., Competing Interests: Declaration of interest: This study was funded by the NIHR Invention for Innovation (i4i) Programme (NIHR201315). The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. The authors have no conflicts of interest to declare.

Pressure Ulcers (PU) are a major burden for affected patients and healthcare providers. Current detection methods involve visual assessments of the skin by healthcare professionals. This has been shown to be subjective and unreliable, with challenges associated with identifying erythema in darker colour skin. Although there exists a number of promising non-invasive biophysical techniques such as ultrasound, capacitance measurements, and thermography, the present study focuses on directly measuring the changes in the inflammatory status of the skin and underlying tissues. Therefore, in this study, we aim to analyse inflammatory cytokines collected through non-invasive sampling techniques to detect early signs of skin damage. Thirty hospitalised patients presenting with Stage I PU were recruited to evaluate the inflammatory response of skin at the site of damage and an adjacent healthy control site. Sebutapes were collected over three sessions to investigate the temporal changes in the inflammatory response. The panel of cytokines investigated included high-abundance cytokines, namely, IL-1α and IL-1RA, and low abundance cytokines; IL-6, IL-8, TNF-α, INF-γ, IL-33, IL-1β and G-CSF. Spatial and temporal differences between sites were assessed and thresholds were used to determine the sensitivity and specificity of each biomarker. The results suggest significant (P < .05) spatial changes in the inflammatory response, with upregulation of IL-1α, IL-8, and G-CSF as well as down-regulation of IL-1RA over the Stage I PU compared with the adjacent control site. There were no significant temporal differences between the three sessions. Selected cytokines, namely, IL-1α, IL-1RA, IL-8, G-CSF, and the ratio IL-1α/IL-1RA offered clear delineation in the classification of healthy and Stage-I PU skin sites, with receiver operating characteristic curves demonstrating high sensitivity and specificity. There were limited influences of intrinsic and extrinsic factors on the biomarker response. Inflammatory markers provided a high level of discrimination between the sites presenting with Stage I PU and an adjacent healthy skin site, in a cohort of elderly inpatients. Indeed, the ratio of IL-1α to IL-1RA provided the highest sensitivity and specificity, indicative that inflammatory homeostasis is affected at the PU site. There was a marginal influence of intrinsic and extrinsic factors, demonstrating the localised effects of the inflammation. Further studies are required to investigate the potential of inflammatory cytokines incorporated within Point of Care technologies, to support routine clinical use., (© 2023 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

Introduction: During the COVID-19 pandemic healthcare workers (HCWs) have used respiratory protective equipment for prolonged periods, which has been associated with detrimental effects on the underlying skin. The present study aims to evaluate changes in the main cells (corneocytes) of the stratum corneum (SC) following prolonged and consecutive use of respirators., Methods: 17 HCWs who wore respirators daily during routine hospital practice were recruited to a longitudinal cohort study. Corneocytes were collected via tape stripping from a negative control site (area outside the respirator) and from the cheek which was in contact with the device. Corneocytes were sampled on three occasions and analysed for the level of positive-involucrin cornified envelopes (CEs) and the amount of desmoglein-1 (Dsg1), as indirect measurements of immature CEs and corneodesmosomes (CDs), respectively. These were compared to biophysical measurements (Transepidermal water loss, TEWL, and SC hydration) at the same investigation sites., Results: A large degree of inter-subject variability was observed, with maximum coefficients of variation of 43% and 30% for the level of immature CEs and Dsg1, respectively. Although it was observed that there was not an effect of prolonged respirator usage on the properties of corneocytes, the level of CDs was greater at the cheek than the negative control site (p < 0.05). Furthermore, low levels of immature CEs correlated with greater TEWL values after prolonged respirator application (p < 0.01). It was also noted that a smaller proportion of immature CEs and CDs was associated with a reduced incidence of self-reported skin adverse reactions (p < 0.001)., Conclusions: This is the first study that investigated changes in corneocyte properties in the context of prolonged mechanical loading following respirator application. Although differences were not recorded over time, the levels of CDs and immature CEs were consistently higher in the loaded cheek compared to the negative control site and were positively correlated with a greater number of self-reported skin adverse reactions. Further studies are required to evaluate the role of corneocyte characteristics in the evaluation of both healthy and damaged skin sites., Competing Interests: Declaration of competing interest The authors have no conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Pressure coupled with shear stresses are the critical external factors for diabetic foot ulceration assessment and prevention. To date, a wearable system capable of measuring in-shoe multi-directional stresses for out-of-lab analysis has been elusive. The lack of an insole system capable of measuring plantar pressure and shear hinders the development of an effective foot ulcer prevention solution that could be potentially used in a daily living environment. This study reports the development of a first-of-its-kind sensorised insole system and its evaluation in laboratory settings and on human participants, indicating its potential as a wearable technology to be used in real-world applications. Laboratory evaluation revealed that the linearity error and accuracy error of the sensorised insole system were up to 3% and 5%, respectively. When evaluated on a healthy participant, change in footwear resulted in approximately 20%, 75% and 82% change in pressure, medial-lateral and anterior-posterior shear stress, respectively. When evaluated on diabetic participants, no notable difference in peak plantar pressure, as a result of wearing the sensorised insole, was measured. The preliminary results showed that the performance of the sensorised insole system is comparable to previously reported research devices. The system has adequate sensitivity to assist footwear assessment relevant to foot ulcer prevention and is safe to use for people with diabetes. The reported insole system presents the potential to help assess diabetic foot ulceration risk in a daily living environment underpinned by wearable pressure and shear sensing technologies.

The present study sought to explore the impact of movement monitoring devices on risk prediction and prevention of pressure ulcers (PU) among adults. Using systematic review methodology, we included original research studies using a prospective design, written in English, assessing adult patients' movement in bed, using a movement monitoring device. The search was conducted in March 2021, using PubMed, CINAHL, Scopus, Cochrane, and EMBASE databases, and returned 1537 records, of which 25 met the inclusion criteria. Data were extracted using a pre-designed extraction tool and quality appraisal was undertaken using the evidence-based librarianship (EBL). In total, 19 different movement monitoring devices were used in the studies, using a range of physical sensing principles. The studies focused on quantifying the number and types of movements. In four studies the authors compared the monitoring system with PU risk assessment tools, with a variety of high and low correlations observed. Four studies compared the relationship between movement magnitude and frequency and the development of PUs, with variability in results also identified. Two of these studies showed, as expected, that those who made less movements developed more PU; however, the two studies also unexpectedly found that PUs occurred in both low movers and high movers. In the final two studies, the authors focused on the concordance with recommended repositioning based on the results of the monitoring device. Overall, concordance with repositioning increased with the use of a monitoring device. The synthesis of the literature surrounding bed monitoring technologies for PU risk prediction showed that a range of physical sensors can be used to detect the frequency of movement. Clinical studies showed some correlation between parameters of movement and PU risk/incidence, although the heterogeneity of approaches limits generalisable recommendations., (© 2022 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd.)

Study Design: Cohort observational study., Objectives: To examine the movement profiles of individuals with spinal cord injury (SCI) during their inpatient rehabilitative phase using continuous pressure monitoring (CPM), evaluating the trends in those with skin damage., Setting: SCI specialist rehabilitation centre in the United Kingdom., Methods: Individuals with SCI (n = 12) were assessed using CPM in the bed and chair over a 24-72 h. Pressure data was used as a surrogate for movement using both nursing interpretation and an intelligent algorithm. Clinical features were obtained including participants age, injury level, ASIA score, co-morbidities and prescribed support surfaces. Trends between movement profiles (frequency and intervals), SCI demographics and observed skin damage were assessed using cross-tabulation and histograms., Results: The data revealed significant correlations (p < 0.05) between the nursing observation and algorithm for predicting movement, although the algorithm was more sensitive. Individuals with high level injuries (C1-T6) were observed to have a lower frequency of movement and larger intervals between movements when compared to low level injuries (T7-L5) during both lying and sitting periods. The individuals observed to have skin damage were predominantly those who had both a low frequency of movement and extended gaps between movements., Conclusions: Movements for pressure relief in both the bed and chair environments were dependent on the level of injury in individuals with SCI during their inpatient rehabilitation. Distinct movement patterns corresponded with those who acquired skin damage, revealing the potential clinical applications for technologies to monitor PU risk and inform personalised care., (© 2022. The Author(s).)

Introduction: Proteins, such as cytokines and chemokines, are present in varying concentrations in a range of biofluids, with an important signalling role in maintaining homeostasis. Commercial tapes have been employed to non-invasively collect these potential biomarkers in sebum from the skin surface to examine their concentrations in conditions including acne, atopic dermatitis, and pressure ulcers. However, the identification of robust biomarker candidates is limited by the low abundance of specific proteins extracted by current methodologies. Therefore, this study was designed to develop an optimized extraction method for potential inflammatory biomarkers in sebum collected with Sebutapes., Methods: Commercial tapes (Sebutapes) coated with synthetic sebum were used to systematically evaluate the effects of chemical and mechanical stimuli on extraction efficiency. Varying concentrations of high- and low-abundance biomarkers (IL-1α, IL-6, IL-8, INF-γ, TNF-α, and IL-1RA) were used to spike the synthetic sebum samples. Methodological variables included different surfactants, mechanical stimuli, and buffer volume. Extraction efficiency was estimated using immunoassay kits from the extracted buffer., Results: The results revealed that the use of a surfactant, i.e., β-dodecyl maltoside, in addition to the mechanical stimuli, namely, sonication and centrifugation, resulted in an increased recovery of cytokines, ranging from 80% for high-abundant cytokines, such as IL-1α and IL-1RA, and up to 50% for low-abundance cytokines, including TNF-α, IL-6 and IL-8. Compared to previous methods, the new extraction protocol resulted in between a 1.5-2.0-fold increase in extraction efficiency., Conclusion: The study revealed that there was a high degree of variability in the extraction efficiency of different cytokines. However, improved efficiency was achieved across all cytokines with selective surfactants and mechanical stimuli. The optimised protocol will provide means to detect low levels of potential biomarkers from skin surface, enabling the evaluation of local changes in pro- and anti-inflammatory cytokines present in different skin conditions., (© 2022 S. Karger AG, Basel.)

N95/FFP3 respirators have been critical to protect healthcare workers and their patients from the transmission of COVID-19. However, these respirators are characterised by a limited range of size and geometry, which are often associated with fitting issues in particular sub-groups of gender and ethnicities. This study describes a novel methodology which combines magnetic resonance imaging (MRI) of a cohort of individuals (n = 8), with and without a respirator in-situ, and 3D registration algorithm which predicted the goodness of fit of the respirator. Sensitivity analysis was used to optimise a deformation value for the respirator-face interactions and corroborate with the soft tissue displacements estimated from the MRI images. An association between predicted respirator fitting and facial anthropometrics was then assessed for the cohort., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Caggiari et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Incontinence-associated dermatitis (IAD) develops from prolonged exposure of skin to urine and/or stool and represents a common complication in older adults, reducing the quality of life. Increased pH is an important etiologic factor of IAD; however, the relationship between urinary pH and skin barrier disruption remains unclear., Objective: The aim of this study is to examine the effects of synthetic urine (s-urine) at various pHs on transepidermal water loss (TEWL), stratum corneum hydration (SCH), and skin surface pH., Methods: S-urine solutions (pH 5.0-9.0) were applied to the volar forearms of 15 healthy participants for 2 h, with another site serving as the untreated control. Measurements of TEWL, SCH, and skin surface pH were obtained at baseline (BL) and after each challenge. Skin buffering capacity was also examined in 5 volunteers by recording skin pH at BL, after 2 h exposure and every 5 min for 40 min., Results: TEWL and SCH were increased following exposure to s-urine compared to BL values. Although there was a tendency for pH to increase after exposure, further investigation showed that changes are only temporal as pH value is restored to BL within 5 mins. There were no significant differences between solutions., Conclusions: This study revealed that urine disrupts healthy skin integrity; however, its effects are not pH dependent. Transient changes were observed on the acid mantle of the skin due to its innate buffering capacity. Future studies need to examine the effects of urine combined with bacteria responsible for pH elevation in patients with urinary incontinence., (© 2022 The Author(s). Published by S. Karger AG, Basel.)

Background: Skin sensitivity (SS) is a commonly occurring response to a range of stimuli, including environmental conditions (e.g., sun exposure), chemical irritants (e.g., soaps and cosmetics), and mechanical forces (e.g., while shaving). From both industry and academia, many efforts have been taken to quantify the characteristics of SS in a standardised manner, but the study is hindered by the lack of an objective definition., Methods: A review of the scientific literature regarding different parameters attributed to the loss of skin integrity and linked with exhibition of SS was conducted. Articles included were screened for mechanical stimulation of the skin, with objective quantification of tissue responses using biophysical or imaging techniques. Additionally, studies where cohorts of SS and non-SS individuals were reported have been critiqued., Results: The findings identified that the structure and function of the stratum corneum and its effective barrier properties are closely associated with SS. Thus, an array of skin tissue responses has been selected for characterization of SS due to mechanical stimuli, including: transepidermal water loss, hydration, redness, temperature, and sebum index. Additionally, certain imaging tools allow quantification of the superficial skin layers, providing structural characteristics underlying SS., Conclusion: This review proposes a multimodal approach for identification of SS, providing a means to characterise skin tissue responses objectively. Optical coherence tomography (OCT) has been suggested as a suitable tool for dermatological research with clinical applications. Such an approach would enhance the knowledge underlying the multifactorial nature of SS and aid the development of personalised solutions in medical and consumer devices., (© 2021 The Authors. Skin Research and Technology published by John Wiley & Sons Ltd.)

Liquid chromatography-mass spectrometry methods were required to afford the rapid separation and detection of purines and small organic acids. These compounds are found in sweat and sebum and are potential biomarkers for the early detection of pressures sores. Two ultra-high-performance supercritical fluid chromatography-mass spectrometry assays have been successfully developed for both classes of compounds. Separation for purines was achieved using a gradient of supercritical carbon dioxide and methanol with a 1-aminoanthracene sub 2 μm particle size column followed by positive ion electrospray ionization. Separation for organic acids was achieved using a gradient of supercritical carbon dioxide and methanol (50 mM ammonium acetate 2% water) with a Diol sub 2 μm particle size column followed by negative ion electrospray ionization. Calibration curves were created in the absence of internal standards and R 2 values > 0.96 were achieved using single ion monitoring methods for the protonated purines and the deprotonated acids. The two new assays afford rapid analytical methods for the separation and detection of potential biomarkers in human sweat leading to the early detection and prevention of pressure sores., (© 2021 Wiley-VCH GmbH.)

Despite the potential for biomechanical conditioning with prosthetic use, the soft tissues of residual limbs following lower-limb amputation are vulnerable to damage. Imaging studies revealing morphological changes in these soft tissues have not distinguished between superficial and intramuscular adipose distribution, despite the recognition that intramuscular fat levels indicate reduced tolerance to mechanical loading. Furthermore, it is unclear how these changes may alter tissue tone and stiffness, which are key features in prosthetic socket design. This study was designed to compare the morphology and biomechanical response of limb tissues to mechanical loading in individuals with and without transtibial amputation, using magnetic resonance imaging in combination with tissue structural stiffness. The results revealed higher adipose infiltrating muscle in residual limbs than in intact limbs (residual: median 2.5% (range 0.2-8.9%); contralateral: 1.7% (0.1-5.1%); control: 0.9% (0.4-1.3%)), indicating muscle atrophy and adaptation post-amputation. The intramuscular adipose content correlated negatively with daily socket use, although there was no association with time post-amputation. Residual limbs were significantly stiffer than intact limbs at the patellar tendon site, which plays a key role in load transfer across the limb-prosthesis interface. The tissue changes following amputation have relevance in the clinical understanding of prosthetic socket design variables and soft tissue damage risk in this vulnerable group., (© 2021. The Author(s).)

Incontinence-associated dermatitis (IAD) is a painful complication in elderly patients, leading to reduced quality of life. Despite recent attention, its underlying inflammatory mechanisms remain poorly understood. This study was designed to quantify the release of inflammatory cytokines in a human model of IAD. The left volar forearm of ten healthy volunteers was exposed to synthetic urine and synthetic faeces for 2 h, simulating the effects of urinary and faecal incontinence, respectively, and the subsequent cytokine response compared to that of an untreated control site. Inflammatory cytokines were collected using both the Sebutape® absorption method and dermal microdialysis and quantified using immunoassays. Results from the former demonstrated an upregulation in IL-1α, IL-1RA and TNF-α. Synthetic urine caused a higher median increase in IL-1α from baseline compared to synthetic faeces, whereas synthetic faeces were associated with significantly higher median TNF-α levels compared to synthetic urine (p = 0.01). An increase in IL-1α/IL-1RA ratio was also observed with significant differences evident following exposure to synthetic urine (p = 0.047). Additionally, microdialysis revealed a time-dependent increase in IL-1β and IL-8 following exposure of up to 120 min to synthetic urine and synthetic faeces, respectively. This study demonstrated the suitability of both sampling approaches to recover quantifiable cytokine levels in biofluids for the assessment of skin status following exposure to synthetic fluids associated with incontinence. Findings suggest some differences in the inflammatory mechanisms of IAD, depending on moisture source, and the potential of the cytokines, IL-1α and TNF-α, as responsive markers of early skin damage caused by incontinence., (Copyright © 2021 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.)

Temperature and humidity conditions at the interface between a support surface and the skin, termed microclimate, has been implicated in the development of pressure ulcers. Support surface technologies have been developed to control microclimate conditions, although only a few standard test methods exist to evaluate their performance. This study describes a combined experimental-computational approach to analyzing microclimate control systems. The study used a modified physical model protocol to evaluate two specific support surface systems involving a spacer fabric cover with i) no air flow and ii) an active fan. The physical model deposited moisture at a controlled rate for 25 min, and the microclimate conditions under the model and the surrounding area were monitored for 24 h. Using the experimental data as boundary conditions, a finite element model was developed using mass transport principles, which was calibrated using experimental results. Model inputs included mass density and mass diffusivity, resulting in an estimated absolute humidity change over time. The physical model tests revealed distinct differences between the support surfaces with and without active airflow, with the former having little effect on local humidity levels (RH>75% for 24hr). By contrast, there was a spatial and temporal change in microclimate with the active fan, with sensors positioned towards the source of airflow reaching ambient conditions within 24hr. The computational model was refined to produce comparable results with respect to both the spatial distribution of microclimate and the change in values over time. The combined experimental and computation approach was able to distinguish distinct difference in microclimate change between two support surface designs. The approach could enable the efficient evaluation of different mattress design principles to aid decision making for personalized support surface solutions, for the prevention of pressure ulcers., (Copyright © 2021 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.)

Background: Technologies have been developed to monitor changes in dermal oedema, indicative of the early signs of pressure ulcers. However, there is limited information on the effects of regional differences in tissue morphology on these sub-epidermal moisture (SEM) parameters. This study was designed to investigate the absolute SEM readings across different anatomical sites using a commercial device., Methods: Twenty-four healthy participants were recruited to evaluate basal SEM values at different bony prominences, sampled by an experienced operator., Results: Distinct differences were observed in unloaded SEM values across different anatomical sites, notably between the upper and lower extremities. A high degree of variability was observed in particular sites, such as the heels. Moreover, SEM values at certain locations revealed significant relationships with age, BMI and gender (p < 0.05)., Conclusion: The study revealed a high level of variability between and within anatomical sites in a healthy cohort of participants. Determining the changes in local skin and sub-dermal tissue status using SEM may require consideration of both site specific and individual demographic factors, with further research needed in cohorts at risk of pressure ulcers., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Skin is constantly exposed to mechanical and chemical insults, in the form of prolonged loading, overhydration or exposure to irritants. An array of non-invasive biophysical tools has been adopted to monitor the changes in skin response. The present study aims to identify a set of robust parameters sensitive to mechanical and chemical challenges to skin integrity., Materials and Methods: Eleven healthy participants were recruited to evaluate the skin response following mechanical loading, tape stripping, overhydration and chemical irritation. Forearm skin responses were recorded at baseline and at three time points following the insult. Measurements included transepidermal water loss, sub-epidermal moisture, erythema and laser Doppler imaging. Thresholds were informed by basal values, and the sensitivity of parameters to detect skin changes was evaluated., Results: High degree of variability in skin response was observed with selected biophysical parameters, such as sub-epidermal moisture, laser Doppler imaging and erythema, even in the absence of an applied insult. Temporal skin response revealed distinct response profiles during each evoked insult. Indeed, the sensitivity of the biophysical parameters was influenced by the threshold values and time point of measurement. Some statistically significant correlations were determined between the biophysical parameters., Conclusion: The study revealed that thresholds derived from single biophysical parameters were limited in detecting skin changes following insults. A complementary evaluation using combined parameters has the potential to provide a more sensitive assessment. Further research is required to identify robust biophysical parameters, to aid the early detection of skin damage in clinical settings., (© 2021 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.)

Synthetic clays are promising biomaterials for delivery of therapeutic molecules in regenerative medicine. However, before their use can be translated into clinical applications, their safety must be assessed in human volunteers. The aim of this study was to test the hypothesis that a synthetic nanoclay (LAPONITE) does not cause irritation to the human skin. To achieve this, a nanoclay gel at two different concentrations (1.5 and 3% w/v) was applied on the forearm of healthy volunteers for 24 h. 1% sodium lauryl sulfate (SLS) and 3% (w/v) polyacrylic acid were used as the positive and negative controls, respectively. The compromise in the skin barrier function was measured by trans-epidermal water loss (TEWL), erythema by spectroscopic measurements, and skin inflammatory biomarkers (IL-1α and IL-1RA) by the enzyme-linked immunosorbent assay. We found that the nanoclay caused no prolonged increase in TEWL, erythema, or induction of inflammatory cytokines. This was in contrast to 1% SLS, a known irritant, which induced significant increases in both skin erythema and TEWL. We conclude that the nanoclay is not an irritant and is thus suitable for therapeutic interventions at the skin surface.

Pressure mapping technologies provide the opportunity to estimate trends in posture and mobility over extended periods in individuals at risk of developing pressure ulcers. The aim of the study was to combine pressure monitoring with an automated algorithm to detect posture and mobility in a vulnerable population of Spinal Cord Injured (SCI) patients. Pressure data from able-bodied cohort studies involving prescribed lying and sitting postures were used to train the algorithm. This was tested with data from two SCI patients. Variations in the trends of the centre of pressure (COP) and contact area were assessed for detection of small- and large-scale postural movements. Intelligent data processing involving a deep learning algorithm, namely a convolutional neural network (CNN), was utilised for posture classification. COP signals revealed perturbations indicative of postural movements, which were automatically detected using individual- and movement-specific thresholds. CNN provided classification of static postures, with an accuracy ranging between 70-84% in the training cohort of able-bodied subjects. A clinical evaluation highlighted the potential of the novel algorithm to detect postural movements and classify postures in SCI patients. Combination of continuous pressure monitoring and intelligent algorithms offers the potential to objectively detect posture and mobility in vulnerable patients and inform clinical-decision making to provide personalized care., Competing Interests: Declaration of Competing Interest There were no conflicts of interest in this study., (Copyright © 2021. Published by Elsevier Ltd.)

Purpose: The aim of this study was to investigate the permeability of the skin following cleansing activities and its susceptibility to synthetic urine penetration., Subjects and Setting: Ten healthy volunteers (aged 22-58 years) participated in the study, which was conducted in a university bioengineering laboratory., Methods: Tape stripping and sodium lauryl sulfate were used to simulate the physical and chemical irritation exacerbated by frequent cleansing activities, respectively. An untreated site also was selected to evaluate responses of intact skin. Synthetic urine was then applied for a period of 2 hours. Measurements of transepidermal water loss and skin pH were taken at baseline and after each challenge. To quantify the permeability of the skin following exposure, desorption curves of transepidermal water loss were measured and skin surface water loss was calculated., Results: Chemically irritated skin, characterized by increased pH (7.34 ± 0.22), demonstrated an increased permeability to urine, as reflected by a significant increase in mean skin surface water loss (46,209 ± 15,596 g/m2) compared to both the intact (14,631 ± 6164 g/m2) and physically irritated (14,545 ± 4051 g/m2) skin (P = .005 in both cases). In contrast, the differences between the intact and physically irritated skin were not significant (P = .88)., Conclusion: Permeability of the skin to irritants is influenced by the status of the skin and its acid mantle. These highlight the need to reevaluate the frequency of cleansing activities, along with the choice of product in clinical settings, favoring the use of pH-balanced cleansers., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2020 by the Wound, Ostomy and Continence Nurses Society.)

Background: Pressure mapping technology has been adapted to monitor over prolonged periods to evaluate pressure ulcer risk in individuals during extended lying postures. However, temporal pressure distribution signals are not currently used to identify posture or mobility. The present study was designed to examine the potential of an automated approach for the detection of a range of static lying postures and corresponding transitions between postures., Methods: Healthy subjects (n = 19) adopted a range of sagittal and lateral lying postures. Parameters reflecting both the interactions at the support surface and body movements were continuously monitored. Subsequently, the derivative of each signal was examined to identify transitions between postures. Three machine learning algorithms, namely Naïve-Bayes, k-Nearest Neighbors and Support Vector Machine classifiers, were assessed to predict a range of static postures, established with a training model (n = 9) and validated with new input from test data (n = 10)., Findings: Results showed that the derivative signals provided a means to detect transitions between postures, with actimetry providing the most distinct signal perturbations. The accuracy in predicting the range of postures from new test data ranged between 82%-100%, 70%-98% and 69%-100% for Naïve-Bayes, k-Nearest Neighbors and Support Vector Machine classifiers, respectively., Interpretation: The present study demonstrated that detection of both static postures and their corresponding transitions was achieved by combining machine learning algorithms with robust parameters from two monitoring systems. This approach has the potential to provide reliable indicators of posture and mobility, to support personalised pressure ulcer prevention strategies., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Respiratory masks are used to deliver non-invasive ventilation for cardiorespiratory pathologies. Masks must minimize skin tissue compression while maintaining a seal at the interface. Ill-fitting masks or those applied too tightly are implicated in pressure ulcer formation. This study aimed to analyse respiratory mask goodness of fit in a cohort of face shapes. A number of parameters were identified and analysed with a novel registration protocol. In the majority of cases, mask indentation exceeded the thickness of the interface material and significant gapping was observed. The size range was most appropriate for males, with only one size suitable for females.

Background: Diabetes-Related Foot Ulcers (DRFUs) are a common and devastating consequence of Diabetes Mellitus and are associated with high morbidity, mortality, social and economic costs. Whilst peak plantar pressures during gait are implicated cited as a major contributory factor, DRFU occurrence has also been associated with increased periods of sedentary behaviour. The present study was designed aimed to assess the effects of sitting postures on plantar tissue health., Methods: After a period of acclimatisation, transcutaneous oxygen tensions (T C PO 2 ) and inflammatory cytokines (IL-1α and IL-1RA) were measured at the dorsal and plantar aspects of the forefoot before, during and after a 20-min period of seated-weight-bearing in participants with diabetes (n = 11) and no diabetes (n = 10). Corresponding interface pressures at the plantar site were also measured., Results: During weight-bearing, participants with diabetes showed increases in tissue ischaemia which were linearly correlated proportional to plantar pressures (Pearson's r = 0.81; p < 0.05). Within the healthy group, no such correlation was evident (p > 0.05). There were also significant increases in post seated weight-bearing values for ratio for IL-1α and IL-1RA, normalised to total protein, post seated weight-bearing in participants with diabetes compared to healthy controls., Conclusion: This study shows that prolonged sitting may be detrimental to plantar skin health. It highlights the need to further examine the effects of prolonged sitting in individuals, who may have a reduced tolerance to loading in the plantar skin and soft tissues., (Crown Copyright © 2020. Published by Elsevier Ltd. All rights reserved.)

Objective: Pressure ulcers are caused by prolonged mechanical loads deforming the underlying soft tissues. However, the mechanical loads for microcirculatory occlusion are unknown. The present study was designed to characterize the simultaneous response of microvascular and lymphatic structures under repeated mechanical loading., Methods: The effects of two distinct loading/unloading cycles involving (a) incremental pressures 30, 60, and 90 mmHg and (b) three repeated cycles of 30 mmHg were evaluated on a cohort of able-bodied volunteers. Microvascular response involved the monitoring of transcutaneous gas tensions, while dermal lymphatic activity was estimated from near-infrared imaging. Responses were compared during each load and recovery cycle., Results: Changes in microvascular response were dependent on the load magnitudes, with 30 mmHg resulting in a reduction in oxygen tension only, while 90 mmHg affected both oxygen and carbon dioxide values in most cases (54%). By contrast, lymphatics revealed near total occlusion at 30 mmHg. Although there were intersubject differences, temporal trends consistently revealed partial or full impairment under load, with recovery during off-loading., Conclusions: The pressure required to cause microcirculatory occlusion differed between individuals, with lymphatic impairment occurring at a lower pressure to that of microvascular vessels. This highlights the need for personalized care strategies and regular off-loading of vulnerable tissues., (© 2020 The Authors. Microcirculation published by John Wiley & Sons Ltd.)

Background: Mechanical conditioning has been widely used to attempt to enhance chondrocyte metabolism for the evolution of functionally competent cartilage. However, although upregulation of proteoglycans have been reported through the application of uniaxial compression, minimal collagen has been produced. The study is designed to examine whether alternative loading regimens, equivalent to physiological conditions, involving shear in addition to compression can enhance collagen production., Methods: Finite element models were developed to determine how the local chondrocyte environments within agarose constructs were influenced by a range of static and dynamic loading regimens. 3-D poro-viscoelastic models were validated against experimental data. In particular, these models were used to characterise chondrocyte deformation in compression with and without shear superimposed, with special reference to the formation of pericellular matrix around the cells., Findings: The models of the hydrogel constructs under stress relaxation and dynamic cyclic compression conditions were highly correlated with the experimental data. The cell deformation (y/z) in the constructs was greatest in the centre of the constructs, increasing with magnitude of compression up to 25%. The superposition of shear however did not produce significant additional changes in deformation, with the presence of PCM reducing the chondrocyte deformation., Interpretation: The use of FE models can prove important in the definition of appropriate, optimised mechanical conditioning regimens for the synthesis and organisation of mature extra cellular matrix by chondrocyte-seeded constructs. They will also provide insight into the mechanisms relating cell deformation to mechanotransduction pathways, thereby progressing the development of functionally competent tissue engineered cartilage., (Copyright © 2020. Published by Elsevier Ltd.)

Purpose: Incontinence-associated dermatitis (IAD) due to the prolonged exposure of the skin to urinary, fecal, or double incontinence represents a major clinical practice challenge. The aim of this review was to identify and critically appraise the results of published studies on the etiology and pathophysiology of IAD and highlight the current gaps in empirical evidence., Methods: Scoping literature review., Search Strategy: The electronic databases PubMed, Cumulative Index to Nursing and Allied Health Literature, MEDLINE, and Embase were searched for relevant articles published from 1996 to April 2018. Thirteen studies and review articles related to the etiology and pathophysiology of IAD were identified in our initial review, and 3 studies published subsequent to our initial review were evaluated and included in our final review., Findings: These studies suggest that several etiologic factors contribute to the development of IAD including exposure to urine, stool, or a combination of these substances (dual incontinence), the duration and frequency of exposure, frequent cleaning, and inflammatory responses. Results from the current scoping review showed that despite the increasing interest in IAD, evidence related to the underlying mechanisms causing IAD remains sparse. This paucity represents a clear gap in knowledge and indicates a need for additional research., Implications: Future studies should aim at elucidating: (1) the role of urine and its inherent pH on skin integrity, (2) the role of stool, specific digestive enzymes, and fecal bacteria on skin integrity, (3) the permeability and susceptibility of the skin to damage following frequent cleansing activities and occlusion, and (4) the specific inflammatory response triggered following exposure to urine and fecal matter.

Background: In the early stages of rehabilitation after primary amputation, residual limb soft tissues have not been mechanically conditioned to support load and are vulnerable to damage from prosthetic use. There is limited quantitative knowledge of skin and soft tissue response to prosthetic loading., Methods: An in-vivo protocol was developed to establish suitable measures to assess tissue tolerance during loading representative of early prosthesis use. Ten participants without amputation one participant with trans-tibial amputation were recruited, and pressure applied to their calf in increments from 20 to 60 mmHg. Measurements were recorded at relevant skin sites including interface pressures, transcutaneous oxygen (T C PO 2 ) and carbon dioxide (T C PCO 2 ) tensions and inflammatory biomarkers., Findings: At the maximum cuff pressure, mean interface pressures were between 66 and 74 mmHg, associated with decreased T C PO 2 values. On the release of pressure, the ischaemic response was reversed. Significant upregulation (p < 0.05) in inflammatory biomarker IL-1α and its antagonist IL-1RA were observed at all sites immediately following loading., Interpretation: The protocol was successful in applying representative prosthetic loads to lower limb tissues and monitoring the physiological response, both in terms of tissue ischemia and skin inflammation. Results indicated that the measurement approaches were sensitive to changes in interface conditions, offering a promising approach to monitor tissue status for people with amputation., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 IPEM. Published by Elsevier Ltd. All rights reserved.)

Pressure ulcers (PUs) represent a substantial burden to both patients and healthcare providers. Accordingly, effective prevention strategies should follow early detection of PUs. Anaerobic metabolites, such as lactate and pyruvate, are promising noninvasive biomarkers indicative of tissue ischaemia, one of the major mechanisms leading to PU development. The aim of this study was to investigate if the temporal release profile of these metabolites in sweat and sebum is sensitive to detect local tissue changes resulting from prolonged mechanical loads. The sacrum of healthy volunteers was subjected to two different loading protocols. After a baseline measurement, the left and right side of the sacrum were subjected to continuous and intermittent loading regimen, respectively, at a pressure of 100 mmHg. Biomarker samples were collected every 20 min, with a total experimental time of 140 min. Sweat was collected at 37 ∘ C and 80% relative humidity, and sebum at ambient conditions, from 11 to 13 volunteers, respectively. Both samples were analysed for lactate and pyruvate concentrations using ultra-high performance supercritical fluid chromatography mass spectrometry. Prior to analysis metabolite concentrations were normalized to individual baseline levels and, in the case of sweat, additional normalization was performed to an unloaded control site to account for fatigue of sweat glands. Although substantial variability was present, the temporal release profiles of both sweat and sebum metabolites reflected the applied loading regimen with increased levels upon load application, and recovery to baseline levels following load removal. Highest relative increases were 20% and 30% for sweat lactate and pyruvate, respectively, and 41% for sebum lactate. Sebum pyruvate was not present in quantifiable amounts. There was a linear correlation between the individual responses to intermittent and continuous loading. The present study revealed that metabolite biomarkers in both sweat and sebum were sensitive to the application of mechanical loads, indicative of local ischaemia within skin and soft tissues. Similar trends in metabolic biomarkers were observed in response to intermittent and continuous loading regimens in both sweat and sebum. Metabolites represent a potential means to monitor the health of loaded skin and soft tissues informing timely interventions of PU prevention., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Aim: To examine the inter-practitioner variability of repositioning for pressure ulcer prevention, the effectiveness of the intervention, and whether the provision of written guidance influenced the repositioning technique., Methods: A pre-test post-test study design was utilised. Descriptive data regarding the work history of participants was collected. Participants were invited to reposition a healthy volunteer before and after reviewing guidance detailing the 30° side-lying technique. The researchers measured the resulting turn angles and assessed offloading of bony prominences., Results: The repositioning technique varied considerably in the sample of nurse participants. Turn angles decreased following the guidance, but offloading of body sites vulnerable to pressure damage remained sporadic., Conclusion: Pressure ulcer prevention training should include practical demonstrations of repositioning. Clear guidance regarding the optimal repositioning technique for pressure ulcer prevention is needed., (Copyright © 2019 Elsevier Inc. All rights reserved.)