Monitoring the biomechanical and physiological effects of postural changes during leisure chair sitting

Exploring the effects of lateral pressure to the soft tissue of the buttocks during seating to preserve tissue perfusion

AIM

Pressure-ulcer occurrence in the seated patient is understudied. Preventative devices have been developed and are prescribed commonly, but there is little quantitative evidence of their effectiveness. This study explores the concept of a lateral pressure device, a prevention device that applies pressure to the sides of the seated buttocks, to reduce the amount of tissue distortion and blood-vessel occlusion. It is hypothesized that this device will reduce deep tissue injury by reducing the pressure at the bone-muscle interface, as demonstrated computationally in previous research. This study aimed to use oximetry to investigate the efficacy of the device in maintaining transcutaneous gas tensions of the tissue as close to baseline as possible.

METHODS

Oximetry electrodes were attached to participants' ischial tuberosity and greater trochanter for different amounts of lateral pressure. The amount of lateral pressure is a given percentage of the pressure due to the participants' underbody pressure.

RESULTS

The results show that 50 % lateral pressure is sufficient to produce an improvement in participants' gas tensions at their ischial tuberosity, without negatively impacting the tissue at their greater trochanter, relative to the control of sitting with no application of lateral pressure.

CONCLUSION

Despite a rudimentary prototype device design, and that participants each placed their own oximetry sensors, results support the application of lateral pressure as a method to maintain transcutaneous gas tensions. Further work should be carried out on a larger sample to consolidate these findings.

Comparing health risks and musculoskeletal issues between professional and casual mobile esports players: a cross-sectional descriptive study in Jakarta

Mobile gaming poses significant health risks, such as musculoskeletal (MSK) and eye problems, as players maintain the same posture for long periods. The objective of the current study is to describe the prevalence and assess the association of musculoskeletal and eye problems among professional gamers (PG) and casual gamers (CG) with their physical activity level and physical fitness. A total of 94 mobile-gaming athletes (43 PG, 51 CG) were prospectively recruited in this study. Descriptive analysis was performed for BMIs, fatigue scores, musculoskeletal problems profile, and eye problems profile. The associations between physical activity level, BMI, grip strength, flexibility, and MSK injury were tested with a Chi-square test. A total of 65.96% of the players experienced MSK complaints, with the shoulder (26.2%), neck (25.4%), and hand (21.3%) being the top three affected regions. This study also found ocular issues among the players, with eye fatigue (n = 50) as the most frequent complaint. Differential outcomes were observed between the PG and CG groups regarding physical activity (p = 0.001) and flexibility (p = 0.02). Conversely, no statistically significant variances were detected between the PG and CG concerning musculoskeletal (MSK) disorder indicators (p = 1.000), body mass index (BMI) (p = 0.132), body fat (BF) percentage (p = 0.317), grip strength (p = 0.006 for the right side, p = 0.116 for the left side), or waist circumference (p = 0.680). Furthermore, a significant association was observed between physical activity and BMI (p = 0.029). Study results showed that two-thirds of players experienced MSK injury, with the most common complaints being neck, shoulder, hand, and wrist pain. All participants reported at least one eye problem, with the majority reporting multiple complaints. There were significant differences observed in physical activity and flexibility between the PG and CG groups; however, no correlation was found between musculoskeletal injury incidence and the players' physical fitness variables. This lack of correlation may be attributed to the relatively short career span of gamers.

Hygro-thermo-mechanical performance of wheelchair cushion technologies in the prevention of pressure ulcers and moisture-associated skin damages

This study aims at investigating the effects of three different wheelchair cushion technologies at the patient-wheelchair interface. To this end, eight participants were recruited to remain in an unrelieved seated position on a wheelchair successively equipped with three different cushions (foam, air-cell-based and gel), for a duration of 45 min. Interface pressure, temperature (measured with infrared thermography) and relative humidity were measured at the seat interface, at different timestamps. Experimental results show that foam cushion is significantly more efficient in reducing contact peak pressure (p < .01), while the gel cushion displays higher heat evacuation capabilities. In terms of relative humidity, no significant difference is observed among the three technologies (p > .29): all of them evacuate around only 10% of the total humidity compared to the reference situation (i.e., without cushion). Besides, a complementary numerical simulation corresponding to the steady state of the patient-wheelchair structure clearly highlights the temperature volume field at the underside of the seat, which acts like a thermal barrier and contributes to heat accumulation. Besides, an air flow at the underside of the chair in motion is shown to significantly reduce heat accumulation.

Development of a sitting posture monitoring system for children using pressure sensors: An application of convolutional neural network

BACKGROUND

Today, sedentary lifestyles are very common for children. Therefore, maintaining a good posture while sitting is very important to prevent musculoskeletal disorders. To maintain a good posture, the formation of good postural habit must be encouraged through posture correction. However, long-term observation is required for effective posture correction. Additionally, posture correction is more effective when it is performed in real time.

OBJECTIVE

The goal of this study is to classify nine representative sitting postures of children by applying a machine learning technique using pressure distribution data according to the sitting postures.

METHODS

In this study, a customized film-type pressure sensor was developed and pressure distribution data from nine sitting postures was collected from seven to twelve year-old children. A convolutional neural network (CNN) was applied to classify the sitting postures and three experiments were conducted to evaluate the performance of the model in three applicable usage scenarios: usage by familiar identifiable users, usage by familiar, but unidentifiable users, and usage by unfamiliar users.

RESULTS

The results of our experiments revealed model accuracies of 99.66%, 99.40%, and 77.35%, respectively. When comparing the recall values for each posture, leaning left and leaning right postures had high recall values, but good posture, leaning forward, and crossed-legs postures had low recall values.

CONCLUSION

The results of experiments indicated that CNN is an excellent classification method to classify the posture when the pressure distribution data is used as input data. This study is expected to contribute a development of system to aid in observing the natural sitting behavior of children and correcting poor posture in real time.

AOASM Position Statement on Esports, Active Video Gaming, and the Role of the Sports Medicine Physician

ABSTRACT

Electronic sports, or esports, has a global audience of over 300 million fans and is increasing in popularity, resulting in projected revenue of over $1 billion by the end of this past year. The global pandemic of 2020 had little to no effect on these increasing numbers because athletes have been able to continue to engage in sports because of its electronic nature and fans have been able to follow them virtually. Esports has been recognized as an organized sport by the International Olympic Committee, the US National Collegiate Athletic Association, and several secondary school athletic associations within the United States. In addition, professional teams have been established in several major cities within the United States, Canada, Europe, and Australia. With the growth of esports, the necessity of incorporating esports medicine into the practice of sports medicine physicians has become paramount. Esports can be played on a monitor or screen and played using physical activity in what has become known as active video gaming. Within both of these platforms, there have emerged certain conditions unique to esports. There are also certain conditions seen in other sports applicable to esports athletes. This document will review the evaluation of the esports athlete, introduce conditions unique to these athletes and review common conditions seen in esports, discuss diagnostics used in the evaluation of esports athletes, introduce treatment options for conditions unique to esports and review those for commonly seen injuries in esports, discuss prevention of injuries in esports, and introduce a framework for the future development of esports medicine that can be introduced into the daily practice of the sports medicine physician.

Shifting loads as a result of chair articulations and associated perfusion responses in the context of pressure injuries: An investigation with able-bodied individuals

Wheelchair users with spinal cord injuries experience pressure injuries at high rates, causing a decrease in quality of life and an increased financial burden. The soft tissue in the buttocks (beneath the ischial tuberosities) and lower back (behind the sacrum) experience large interface pressures over long periods while seated, putting them at high risk of pressure injury development. The goals of this research were to evaluate the ability of an articulating chair design to redistribute pressures on the body and to affect blood perfusion in the buttocks tissue over the ischial tuberosities. Using a unique, custom-designed chair developed for this research, pressure and blood perfusion were obtained for numerous seated positions that included recline, seat pan tilt, and back articulations. Reclining the chair back increased maximum pressures in the buttocks and lower back regions, while it decreased maximum pressures in the upper back and thigh regions. Increasing seat pan tilt, or rotating the anterior edge of the seat pan above the posterior edge, decreased maximum pressures in the buttocks and lower back regions and increased perfusion in the buttocks. Results suggested that using back recline and seat pan tilt together to create a whole-body tilt increased pressures in the back and decreased pressures in the buttocks. Changes in back articulation redistributed pressure in all back regions. Thus, the articulating chair design redistributed pressures in all areas of the body and promoted blood perfusion in the buttocks while seated. Pressure redistribution and perfusion promotion are fundamental to reducing pressure injury risk.

Can plantar fibroblast implantation protect amputees from skin injury? A recipe for skin augmentation

Skin injuries remain a persistent problem for users of lower-limb prostheses despite sustained progress in prosthesis design. One factor limiting the prevention of skin injuries is that skin on the residual limb is not suited to bear the mechanical loads of ambulation. One part of the body that is suited to this task is the sole of the foot. Here, we propose a novel strategy to actively augment skin's tolerance to load, increasing its resistance to mechanically induced injuries. We hypothesise that the load tolerance of skin can be augmented by autologous transplantation of plantar fibroblasts into the residual limb dermis. We expect that introducing plantar fibroblasts will induce the overlying keratinocytes to express plantar-specific keratins leading to a tougher epidermis. Using a computational finite element model of a weight-bearing residual limb, we estimate that skin deformation (a key driver of pressure ulcer injuries) could be halved by reprogramming skin to a plantar-like phenotype. We believe this strategy could yield new progress in pressure ulcer prevention for amputees, facilitating rehabilitation and improving quality of life for patients.

Review of Measuring Microenvironmental Changes at the Body-Seat Interface and the Relationship between Object Measurement and Subjective Evaluation

Being seated has increasingly pervaded both working and leisure lifestyles, with development of more comfortable seating surfaces dependent on feedback from subjective questionnaires and design aesthetics. As a consequence, research has become focused on how to objectively resolve factors that might underpin comfort and discomfort. This review summarizes objective methods of measuring the microenvironmental changes at the body–seat interface and examines the relationship between objective measurement and subjective sensation. From the perspective of physical parameters, pressure detection accounted for nearly two thirds (37/54) of the publications, followed by microclimatic information (temperature and relative humidity: 18/54): it is to be noted that one article included both microclimate and pressure measurements and was placed into both categories. In fact, accumulated temperature and relative humidity at the body–seat interface have similarly negative effects on prolonged sitting to that of unrelieved pressure. Another interesting finding was the correlation between objective measurement and subjective evaluation; however, the validity of this may be called into question because of the differences in experiment design between studies.

Establishing a measurement array to assess tissue tolerance during loading representative of prosthetic use

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_CPO₂) and carbon dioxide (T_CPCO₂) tensions and inflammatory biomarkers.

FINDINGS

At the maximum cuff pressure, mean interface pressures were between 66 and 74 mmHg, associated with decreased T_CPO₂ 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.

Bioengineering considerations in the prevention of medical device-related pressure ulcers

BACKGROUND

In recent years, it has become increasingly apparent that medical device-related pressure ulcers represent a significant burden to both patients and healthcare providers. Medical devices can cause damage in a variety of patients from neonates to community based adults. To date, devices have typically incorporated generic designs with stiff polymer materials, which impinge on vulnerable soft tissues. As a result, medical devices that interact with the skin and underlying soft tissues can cause significant deformations due to high interface pressures caused by strapping or body weight.

METHODS

This review provides a detailed analysis of the latest bioengineering tools to assess device related skin and soft tissue damage and future perspectives on the prevention of these chronic wounds. This includes measurement at the device-skin interface, imaging deformed tissues, and the early detection of damage through biochemical and biophysical marker detection. In addition, we assess the potential of computational modelling to provide a means for device design optimisation and material selection.

INTERPRETATION

Future collaboration between academics, industrialists and clinicians should provide the basis to improve medical device design and prevent the formation of these potentially life altering wounds. Ensuring clinicians report devices that cause pressure ulcers to regulatory agencies will provide the opportunity to identify and improve devices, which are not fit for purpose.

Managing the health of the eSport athlete: an integrated health management model

Objectives

eSport is a form of electronic gaming, also known as professional or competitive video gaming, and is growing at a rapid pace worldwide. Over 50 US colleges have established varsity gaming teams over the past three years; some colleges offer eSport scholarships as they do for traditional sports. There is little objective research on the health habits of these players who are often placed under the direction of the athletics department on college campuses, and there is currently no health management model on how to treat these new athletes.

Methods

Anonymous electronic surveys were sent to 65 collegiate eSport players from nine universities across the USA and Canada inquiring about gaming and lifestyle habits, and musculoskeletal complaints due to eSport competition.

Results

Players practiced between 3 and 10 hours per day. The most frequently reported complaint was eye fatigue (56%), followed by neck and back pain (42%). eSport athletes reported wrist pain (36%) and hand pain (32%). Forty per cent of participants do not participate in any form of physical exercise. Among the players surveyed, only 2% had sought medical attention.

Conclusion

eSport players, just like athletes in traditional sports, are susceptible to overuse injuries. The most common complaint was eye fatigue, followed by neck and back pain. This study shows eSport athletes are also prone to wrist and hand pain. This paper proposes a health management model that offers a comprehensive medical team approach to prevent and treat eSport athletes.

Technologies to monitor the health of loaded skin tissues

There are many situations where the skin and underlying soft tissues are compromised by mechanical loading in the form or pressure, or pressure in combination with shear. If sustained, this can lead to damage in the tissues particularly adjacent to bony prominences, resulting in chronic wounds. An array of bioengineering technologies have been adopted to assess the integrity of loaded soft tissues. This paper aims to review these approaches for the quantification, simulation and early detection of mechanically-induced skin damage. The review considers different measurements at the interface between the skin and support surface/medical device, involving pressure, shear, friction and the local microclimate. The potential of the techniques to monitor the physiological response of the skin to these external stimuli including biophysical measurement devices and sampling of biofluids are critically analysed. In addition, it includes an analysis of medical imaging technologies and computational modelling to provide a means by which tissue deformation can be quantified and thresholds for tissue damage defined. Bioengineering measurement and imaging technologies have provided an insight into the temporal status of loaded skin. Despite the advances in technology, to date, the translation to clinical tools which are robust and cost effective has been limited. There is a need to adapt existing technologies and simulation platforms to enable patients, carers and clinicians to employ appropriate intervention strategies to minimise soft tissue damage.