31 research outputs found

    Studying movement reorganization when learning a whole-body action: Example of learning a constrained gait pattern

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    In order to better understand the process of learning a complex motor skill, an effort was done to identify principles of movement reorganization. However, many studies refuted the existence of generalized invariant “strategies” for mastering the redundant degrees of freedom and emphasized the importance of the constraints especially those linked to the task itself. We aimed to identify common characteristics in movement reorganization when 7 participants practiced (4 sessions) a new gait pattern at speeds higher than that of the preferred walk-to-run transition by placing biomechanical constraints on distal lower joints (i.e. racewalking regulations). Movement analysis was performed on kinematic variables computed from a whole-body model (VICON). First, using ANOVAs we assessed practice-related changes in spatiotemporal parameters, angular displacements and relative phases (inter-/intra-limb coordination). Results indicated an immediate reorganization incoordinative patterns (e.g., relative phases and stride frequency) accompanied by a general decrease in the initial movement variability (i.e., standard deviation of many key variables). However, the large number of studied variables made it difficult to put forward common “strategies” used by participants. Second, we ran principal component analyses (PCA) on 8 major angular displacement variables for all participants, trials and sessions. PCA were used to evaluate the coupling in the motion of body segments that synchronize in different components (dimensions), each believed to be controlled by the CNS as one unit. Results indicated that the majority of participants immediately recruited an additional task-specific control dimension compared to normal walking. Moreover, this analysis revealed a gradual synchronization of the knee joint motion with that of the early established pelvis transverse plane rotation

    Adaptive Effects of Seeing Green Environment on Psychophysiological Parameters When Walking or Running

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    Several studies have investigated the influence of perceiving colors on affective outcomes and/or performance. However, the effects of seeing colors on self-selected behaviors have received little attention from physiologists and psychologists. Therefore, the present study aimed at examining whether exposure to green and red environments could influence affective judgments, perception of effort, heart rate, and gait speeds when walking and running at a self-selected pace. Participants were randomly assigned to one of the three experimental conditions: Green, red, or white (neutral) environment. The experimental task consisted in a 20-min trial of either walking (Study 1) or running (Study 2) at the most comfortable speed on a treadmill surrounded by three large HD TV screens displaying specific properties of the studied colors. Study 1 revealed that walking in a green environment induced a significant reduction in heart rate values as compared to the red and white conditions although no differences in gait speed were found. This corroborates the calming and relaxing effect of green on the human organism. Study 2 showed that running in a green environment was associated with an increased level of perceived exertion at similar speeds (compared to other color conditions), while exposure to red induced a significant decrease in the level of tension. In both studies, the preferred gait speed was not affected by the colored environment which is discussed in relation to the energy-conservation principle. Furthermore, both studies showed that performing a 20-min walk or run at preferred pace presented beneficial mood changes. Implications of the effects of self-selected exercise under colored environments on human functioning are addressed in the discussion

    A Prototype Of Virtually Interactive Hand Activating Devise-Low Cost Portable Head Mounted System (vihad Plus) For Neurological Rehabilitation

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    Background and Purpose: Restoring function in individuals who have severe paralysis of the upper extremity secondary to stroke is challenging. Recent technologies have made it possible to use robotic devices as novel tools for assisting the therapists to provide safe and intensive rehabilitation with repeated motions. However, most of the training robots are types of Continuous Passive Motion (CPM) devices that produce slower and stereotyped movement patterns. Earlier works have shown that passive or slow movements do not significantly benefit motor improvement. Several studies reveal that even the use of ipsilateral electromyographic (EMG) pattern recognition approaches might not be practical to decode movement intention and, may negatively affect re-mapping of the neural pathways in the brain. To have a successful hand rehabilitation system, the system should be able to produce a wide variety of unpredicted and challenging movement patterns of various degrees of speed and range of motion with increasing complexity, sufficient enough to produce the necessary neurological plasticity of the affected brain. Current rehabilitation devices are not sufficient to produce such a range of complex activities which enables maximum neurological plasticity. Objective: In this work, we describe a prototype of the contralateral EMG-based Interactive Hand Activating Devise for Stroke (IHADS) system that can detect a hemiplegic person's intention for bilaterally executed hand activities using his/her surface EMG signals from the non-affected side (contralateral). Furthermore, this system can assist in bilateral hand activities through an exoskeleton attached to the hemiplegic upper extremity to initiate progressively challenging and unpredicted type of activities in a virtual reality (VR) world to obtain optimum functional recovery by inducing maximum neurological plasticity. Design: The IHADS system is made up of an embedded controller and a robotic exoskeleton, contralateral EMG sensors and a VR interface with a semi-immersed VR system, where the patient will be seeing progressively impulsive activities that would force the brain to activate the affected extremity to manipulate through the remaining neural networks and mirror neuronal system which in turn will optimize the neurological recovery. This means that the paralyzed arm will be following the motion of the healthy arm whose motion is picked up by the EMG sensors and are translated as actuation signals for the exoskeleton to execute virtually created challenging activities. Conclusion: Contralateral EMG-based 'IHADS' system is a unique, cost effective, highly innovative and portable robotic device. If incorporated into the stroke rehabilitation, this system will be capable of autonomous guidance through the use of real-time feedback from the contralateral upper limb, integrated via the VR interface and the hand activating device to make rehabilitation more intense, functional, motivating, and capable of inducing maximum neurological plasticity

    Analysis of the relationship between physical self-concept and body composition

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    Introduction: Body image is a psychological construct which refers to self-concept including self-image and feelings an individual perceives regarding his or her body. Several studies have examined how women subjectively perceive their bodies in Western cultures compared to objective measures. However, limited studies have examined this relationship among women in the Gulf region (e.g., Qatar) in which Islamic traditional clothing (i.e., Abaya) is typically adopted and possible differences in the judgment of a healthy body shape might be found. The purpose of this study was to see whether there is a connection between the objective body composition measures [i.e., body weight (BW), body height (BH), body mass index (BMI)] and the subjective measures of physical self-description. We expect to find a tendency among females in this study to estimate a thinner body image compared to their current/measured one. Methods: 97 female volunteers (18-26 years) were recruited from Qatar University. We measured their body composition (i.e., BW, BH and BMI). We used the short version of the Physical Self-Description Questionnaire (PSDQ), a multidimensional physical self-concept instrument with 11 original subscales including: body fat, health, appearance, global physical self-concept. The collected data for all variables were analyzed using Statistica software (v.12, DELL) for correlations using Pearson’s coefficients. Results: Based on the BMI results, 25.7% of the participants were classified as overweight or obese (12.3% and 13.4%, respectively). Results indicated a significant negative moderate correlation between the global physical self-concept on one side and BMI (r=-0.27) and BW (r=-2.0) on the other. Furthermore, the perceived body fat showed significant negative correlation with BMI (r=-0.57) and with BW (r=-0.52). The inter-correlation within the subscales showed that the perceived body fat was significantly correlated with appearance (r=0.25), health (r=0.16) and global physical score (r=0.34). Conclusion: Our results indicated a clear and logic relationship between perceived global physical self-concept scores and participants` body composition (i.e., negative correlation). However, an interesting result in line with our hypothesis and concerning the way participants perceived their own body fat indicates a negatively correlation with BMI and BW. In the studied population, a possible interpretation could be done based on the positive link revealed between perceived body fat, perceived appearance, perceived health and global physical score. Indeed, this could indicate that the ideal perceived body might be different and higher than norms presented in the World Health Organization classification. To get further insights on the nature of these relationships, we have started new investigations on the relationship between the other subscales of physical self-description and a comprehensive physical fitness test (ALPHA-FIT Test, UK).This publication was made possible by UREP grant #17-044-3-011 from the Qatar national research fund (a member of Qatar foundation). The statements made herein are solely the responsibility of the authors

    Muscle Strength and Glycaemic Control among Patients with Type 2 Diabetes.

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    Poor glycaemic control is associated with chronic life-threatening complications. This cross-sectional study examined whether there is an association between handgrip strength and glycaemic control among patients with diabetes. Data on 1058 participants aged 40 and older were collected from the National Health and Nutritional Examination Survey (NHANES). Muscle strength was assessed using a handgrip dynamometer, and glycaemic control was assessed using HbA1c. Handgrip strength was presented as age- and gender-specific quartiles, with participants in quartile 1 having the lowest handgrip strength and participants in quartile 4 having the highest handgrip strength. Logistic regression analyses were used to assess the association between handgrip strength and poor glycaemic control among participants with diabetes. Three models, each adjusted to include different variables, were employed. Odds ratio (OR) values revealed no association between handgrip strength and glycaemic control after adjusting for age, gender, and race in model 1. With further adjustment for sedentary activity, income-to-poverty ratio, education, and smoking, patients in quartile 4 of handgrip strength had 0.51 odds of poor glycaemic control (95% CI: 0.27-0.99). However, the reported association above vanished when further adjusted for insulin use (OR = 0.67; 95% CI: 0.35-1.28). In conclusion, findings may indicate an association between glycaemic control and muscle strength. This association may be altered by insulin use; further investigations are required.Qatar University (project No. QUST-1-CHS-2020-11

    Physical fitness and physical self-concept of male and female young adults in Qatar

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    Background Physical inactivity is high within the Qatari population, particularly within females, and school-based environments, contributing to increased morbidity and mortality. School-based physical activity (PA) outcomes may be mediated by physical self-concept. Low physical self-concept may negatively impact PA engagement, compromising childhood and adolescent physical fitness, which may translate into adulthood. Normative physical fitness data for the Qatari population is unavailable. Stratifying normative physical fitness appears prudent, to not only allow comparisons to be made worldwide, but enable informed decisions for public health policy and future interventions in the Qatari population.Scopu

    Characteristics of preferred walking patterns in young Qatari adults

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    Walking is the most natural and important activity of daily living as it refers to the primary type of terrestrial human locomotion. Analyses of gait patterns typically examine the speed and manner in which people prefer to walk. Even though humans can walk at speeds ranging from near 0 km/h to 9 km/h, they typically only use a very limited range of speeds around 4.5 km/h in their daily life (Bohannon & Andrews, 2011). The preferred walking speed (PWS) is used in clinical settings as an indicator of a person’s mobility. For example, elderly people, or those suffering from osteoarthritis prefer to walk at slower speeds. Therefore, improving their PWS is considered as a significant clinical goal. Many studies on gait analysis tried to identify the basic parameters of normal unconstrained gait in different populations. Despite the fundamental common shared characteristics, walking patterns may vary from a person to another according to several factors such as age, gender, physical characteristics, etc. In a study examining the “pace” of random pedestrians in 31 cities around the world, differences in the walking speed were found to be linked to parameters such as climate, economic variables, size of population and cities (Levine & Norenzayan, 1999). More recently, a study has put forward the impact of the cultural background on walking norms by revealing several significant differences in basic gait parameters between young Kuwaiti and Swedish adults (Al-Obaidi et al., 2003). Specifically, the authors presented the first evidence concerning walking patterns in a population from the Gulf region and proposed an interpretation to the found differences that is linked to traditional clothing and foot wear. This reveals the need for a specific normative database targeting healthy young Qataris. Creating such databases for Qatar is desirable for rehabilitation purposes for people with impaired walking patterns (e.g., elderly fallers, people suffering from stroke consequences, hemiplegia, Parkinson disease, etc). For instance, the aim of this study is to evaluate the preferred walking speed and manners in which young male and female Qatari adults walk as compared to non-Qatari participants with similar physical characteristics. To characterize walking patterns we used spatiotemporal kinematic indicators such as stride length, stride frequency and support phase duration. The associated physiological cost and perceived exertion of walking at a preferred pace will also be examined to test for possible differences. We expect to see differences between the preferred walking patterns of Qatari and non-Qatari participants as proposed by Al-Obaidi and collaborators (2003)

    Ketamine-based sedation use in mechanically ventilated critically ill patients with COVID-19: A multicenter cohort study

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    Backgrounds: Ketamine possesses analgesia, anti-inflammation, anticonvulsant, and neuroprotection properties. However, the evidence that supports its use in mechanically ventilated critically ill patients with COVID-19 is insufficient. The study's goal was to assess ketamine's effectiveness and safety in critically ill, mechanically ventilated (MV) patients with COVID-19. Methods: Adult critically ill patients with COVID-19 were included in a multicenter retrospective-prospective cohort study. Patients admitted between March 1, 2020, and July 31, 2021, to five ICUs in Saudi Arabia were included. Eligible patients who required MV within 24 hours of ICU admission were divided into two sub-cohort groups based on their use of ketamine (Control vs. Ketamine). The primary outcome was the length of stay (LOS) in the hospital. P/F ratio differences, lactic acid normalization, MV duration, and mortality were considered secondary outcomes. Propensity score (PS) matching was used (1:2 ratio) based on the selected criteria. Results: In total, 1,130 patients met the eligibility criteria. Among these, 1036 patients (91.7 %) were in the control group, whereas 94 patients (8.3 %) received ketamine. The total number of patients after PS matching, was 264 patients, including 88 patients (33.3 %) who received ketamine. The ketamine group's LOS was significantly lower (beta coefficient (95 % CI): −0.26 (−0.45, −0.07), P = 0.008). Furthermore, the PaO2/FiO2 ratio significantly improved 24 hours after the start of ketamine treatment compared to the pre-treatment period (6 hours) (124.9 (92.1, 184.5) vs. 106 (73.1, 129.3; P = 0.002). Additionally, the ketamine group had a substantially shorter mean time for lactic acid normalization (beta coefficient (95 % CI): −1.55 (−2.42, −0.69), P 0.01). However, there were no significant differences in the duration of MV or mortality. Conclusions: Ketamine-based sedation was associated with lower hospital LOS and faster lactic acid normalization but no mortality benefits in critically ill patients with COVID-19. Thus, larger prospective studies are recommended to assess the safety and effectiveness of ketamine as a sedative in critically ill adult patients

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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