The relationship between external knee moments and muscle co-activation in subjects with medial knee osteoarthritis

Purpose: External knee moments are reliable to measure knee load but it does not take into account muscle activity. Considering that muscle co-activation increases compressive forces at the knee joint, identifying relationships between muscle co-activations and knee joint load would complement the investigation of the knee loading in subjects with knee osteoarthritis. The purpose of this study was to identify relationships between muscle coactivation and external knee moments during walking in subjects with medial knee osteoarthritis. Methods: 19 controls (11 males, aged 56.6 ±5, and BMI 25.2 ± 3.3) and 25 subjects with medial knee osteoarthritis (12 males, aged 57.3 ± 5.3, and BMI 28.2 ± 4) were included in this study. Knee adduction and flexion moments, and co-activation (ratios and sums of quadriceps, hamstring, and gastrocnemius) were assessed during walking and compared between groups. The relationship between knee moments and co-activation was investigated in both groups. Findings: subjects with knee osteoarthritis presented a moderate and strong correlation between co-activation (ratios and sums) and knee moments. Interpretation: Muscle co-activation should be used to measure the contribution of quadriceps, hamstring, and gastrocnemius on knee loading. This information would cooperate to develop a more comprehensive approach of knee loading in this population

A list of land plants of Parque Nacional do Caparaó, Brazil, highlights the presence of sampling gaps within this protected area

Brazilian protected areas are essential for plant conservation in the Atlantic Forest domain, one of the 36 global biodiversity hotspots. A major challenge for improving conservation actions is to know the plant richness, protected by these areas. Online databases offer an accessible way to build plant species lists and to provide relevant information about biodiversity. A list of land plants of “Parque Nacional do Caparaó” (PNC) was previously built using online databases and published on the website "Catálogo de Plantas das Unidades de Conservação do Brasil." Here, we provide and discuss additional information about plant species richness, endemism and conservation in the PNC that could not be included in the List. We documented 1,791 species of land plants as occurring in PNC, of which 63 are cited as threatened (CR, EN or VU) by the Brazilian National Red List, seven as data deficient (DD) and five as priorities for conservation. Fifity-one species were possible new ocurrences for ES and MG states

Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study

Background Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave. Methods This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs. Results Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; p = 0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; p ≤ 0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; p = 0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; p = 0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; p = 0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI − 0.47, 1.37, p = 0.34) and hospital (adj. difference 1.4 days; 95% CI − 0.62, 2.35, p = 0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, p = 0.24) when adjusted for covariates. Conclusions Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility. Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)

Psychophysiological reactions to experimental stress : relations to pain sensitivity, position sense and stress perception

Stress and monotonous work contribute substantially to the development of chronic musculoskeletal disorders. Yet, the pathophysiological mechanisms underlying the process, particularly the involvement of autonomic regulation, remain unclear. It has been suggested that altered motor control resulting from distorted sensory information from fatigued muscles may be an important component in the development of musculoskeletal disorders. Animal studies have shown that sympathetic nervous system activation exerts actions in skeletal muscles, such as vasoconstriction and modulation of afferent information from muscle spindles. However, few attempts have been made to address this issue in humans. Therefore, the first aim of the thesis was to investigate the impact of repetitive computer work with and without additional stressors on muscle oxygenation and position sense in the upper extremity. Assuming an important role of stress in the development of chronic musculoskeletal symptoms, one may expect open or latent manifestations of such symptoms in patients with non-specific stress-related illnesses. It is possible that sympathetic activation may influence pain perception, and that treatments aimed at reducing stress may also affect the pain experience. Thus, the second aim of the thesis was to evaluate the effects of a cognitive-behavioral training program and a physical activity program for patients with stress-related illnesses on autonomic reactivity, pain, and perceived health. First, a laboratory model of computer mouse use was characterized in terms of biomechanical exposure of the wrist, and wrist position sense was determined before and after 45 minutes of continuous mouse use. Then, the effects of performing the computer mouse work under time pressure and precision demands were determined. Autonomic activity and muscle oxygenation in the upper extremity were measured during the work, and wrist position sense was assessed before and after the work. When patients with stress-related illnesses were compared to healthy individuals in autonomic reactivity to functional tests, pressure-pain thresholds, and ratings of health, indications of a relation between autonomic reactivity and symptoms of pain was found. Hence, in a subsequent evaluation of a cognitive-behavioral training program and a physical activity program for patients with stress-related illnesses, post intervention effects on autonomic reactivity to functional tests, pressure-pain thresholds, ratings of health and return-to-work were studied during a period of 12 months after the intervention. The main findings were the following. 1) Wrist kinetics data obtained during the computer mouse work showed similarities to previously presented data for mouse-operated design tasks. 2) When time pressure and precision demands were added to the computer work, increased autonomic activity paralleled with decreased muscle oxygenation in the upper extremity was found. Wrist position sense accuracy, however, did not decrease after the work as it did when the work was performed without the additional demands. The result is intriguing, as it does not appear to be in concordance with previous animal studies. 3) Patients with stress-related illnesses showed higher autonomic reactivity to cognitive and physical laboratory tests than healthy control subjects. They also had substantially lower pressure-pain thresholds in the back, and rated poorer health and health-related behavior than the control subjects. 4) We found little difference in effect of cognitive-behavioral training and physical activity, compared to usual care, for patients with stress-related illnesses. Patients in the control group showed an improvement of about the same magnitude as in the treatment groups over the 12-month follow-up period. The present findings indicate a non-additive relation between autonomic activity during repetitive work and position sense inaccuracy. Furthermore, patients with stress-related illnesses often reported pain in the neck, shoulders, and lower back. This was associated with lower pressure-pain thresholds in the back and a modest increase in sympathetic reactivity to physical and mental tests, which might suggest a potential use of these methods in the clinical examination and rehabilitation of patients with stress-related illnesses

Responsiveness and minimal important change for the ProFitMap-neck questionnaire and the Neck Disability Index in women with neck-shoulder pain

PURPOSE: The aim was to determine the responsiveness and minimal important change (MIC) of the questionnaire ProFitMap-neck that measures symptoms and functional limitations in women with neck pain. The same measurement properties were determined for Neck Disability Index (NDI) for comparison purposes. METHODS: Longitudinal data were derived from two randomized controlled trials, including 103 and 120 women with non-specific neck pain, with questionnaire measurements performed before and after interventions. Sensitivity and specificity to discriminate between improved and not or little changed participants, based on categorization of a global rating of change scale (GRCS), were determined for the ProFitMap-neck indices and NDI by using area under receiver operating characteristic curves (AUC). Correlations between the GRCS anchor and change scores of the questionnaires were also used to assess responsiveness. The change score that showed the highest combination of sensitivity and specificity was set for MIC. RESULTS: The ProFitMap-neck indices showed similar responsiveness as NDI with AUC exceeding 0.70 (Range: ProFitMap-neck, 0.74-0.83; NDI, 0.75-0.86). The MIC in the two samples ranged between 6.6 and 13.6 % for ProFitMap-neck indices and 5.2 and 6.3 % for NDI. Both questionnaires had significant correlations with GRCS (Spearman's rho 0.47-0.72). CONCLUSIONS: Validity of change scores was endorsed for the ProFitMap-neck indices and NDI with adequate ability to discriminate between improved and not or little changed participants. Values of minimal important change were presented

Telework in academia : associations with health and well-being among staff

As the development of technical aids for telework has progressed, work has become more flexible in time and space. Among academics, the opportunity to telework has been embraced by most, but it is unclear how it relates to their health and well-being. The aim of this study was to determine how frequency and amount of telework is associated with perceived health, stress, recuperation, work-life balance, and intrinsic work motivation among teaching and research academics. An electronic questionnaire was sent to junior lecturers, senior lecturers, and professors at Swedish public universities. It included the General Health Questionnaire, Work Stress Questionnaire, items for assessing recuperation, the Basic Psychological Need Satisfaction at Work scale, and parts of Copenhagen Psychosocial Questionnaire, as well as questions about the frequency and amount of telework performed. In total, 392 academics responded to the survey. Multivariate analysis of variance showed significant differences between groups of academics with different telework frequency (p < 0.05). Univariate analyses of variance showed that ratings of stress related to indistinct organization and conflicts were higher among academics that telework several times per week or more than among academics that telework less than once per month. In regression analyses of associations between amount of telework (in hours per week) and the dependent variables, no significant effects were found. Although it cannot be concluded whether stress is a cause or an effect of frequent telework, the findings warrant further attention to academics who telework frequently

Psychophysiological reactions, stress and recuperation among telecommuting academics

Telecommuting is a working arrangement that is highly adopted among academic staff. This may be a cause or a consequence of expanding demands on productivity, efficiency and availability of academic staff. A previous study on white-collar workers at a government authority showed higher cardiovascular arousal during work at the office, but less recovery after working from home. To our knowledge, these findings have not been confirmed or refuted in other populations. As part of an ongoing study, we aimed to determine whether there is a difference in perceived stress and psychophysiological reactions during work at the central workplace (CW) compared to work performed away from the central workplace (OCW) among academic staff. In addition, recuperation after work performed at the two locations were compared. For each subject, saliva cortisol was collected regularly throughout each of two working days in the same work week (i.e., one full day CW and one full day OCW). Before and after each working day, the subjects rated their stress and fatigue on 100 mm Visual Analogue Scales (VAS) where higher values imply more stress and fatigue, and the difference in ratings within a day (i.e., after-before) was calculated. In the morning after each of the working days, the subjects rated how recuperated they felt on VAS where higher values imply more recuperation. Cortisol values were analyzed using repeated measures analysis of variance with Day (2 days) and Time of day (6 time points) as within-subjects effects. Self-ratings were compared using paired-samples T test. In all tests, the level of significance was p=0.05. Preliminary results show no significant differences between days in cortisol curves (F=0.62; p=0.685), stress (Dstress=2 for CW and -1 for OCW; p=0,604), fatigue (Dfatigue=7 for CW and 6 for OCW; p=0,837) and recuperation (51 for CW and 61 for OCW; p=0,094)

Visual Symptoms and Risk Assessment Using Visual Ergonomics Risk Assessment Method (VERAM)

A visual environment impaired by e.g. glare can cause eyestrain, visual symptoms and musculoskeletal strain. A Visual Ergonomics Risk Assessment Method (VERAM) consisting of both a subjective questionnaire and an objective risk assessment, have been used at 217 workplaces, mainly computer work. VERAM can be used to examine and prevent deficiencies and increase wellbeing as well as detecting risks in the visual work environment and suggest measures that can be used to reduce the risks. The questionnaire showed that eyestrain, visual symptoms and musculoskeletal strain are common among Swedish workers. The overall risk assessments for glare and amount of illuminance on work surface are divided into three categories, green – no risk, yellow – risk, and red – high risk. Risk of glare and insufficient illuminance was present at 66% and 49% of the assessed workplaces, respectively. When the risk of glare and illuminance levels was rated as red, the frequency of the subjective strain was higher

Psychophysiological reactivity, postures and movements among academic staff : A comparison between teleworking days and office days

The aim of this study was to determine if psychophysiological activity, postures and movements differ during telework (i.e., work performed at home) and work performed at the conventional office. We performed twenty-four-hour pulse recordings and accelerometry measurements on 23 academic teaching and research staff during five consecutive workdays, with at least one day of telework. Additionally, we conducted salivary sampling during one day of telework, and one day of office work. Heart rate and heart rate variability indices, postural exposure and cortisol concentration were analyzed using repeated measures analysis of variance with Workplace and Time (i.e., before, during and after workhours) as within-subject effects. We found a significant interaction effect of Workplace and Time in heart rate variability indices and in the number of transitions between seated and standing postures. This shows more parasympathetic activity among academic teleworkers during telework than office work, which may indicate more relaxation during telework. They had an overall sedentary behavior at both workplaces but switched between sitting and standing more often during telework, which may be beneficial for their health