BACKGROUND: Hospital stays are associated with high levels of sedentary behavior and physical inactivity. To objectively investigate physical behavior of hospitalized patients, these is a need for valid measurement instruments. The aim of this study was to assess the criterion validity of three accelerometers to measure lying, sitting, standing and walking. METHODS: This cross-sectional study was performed in a university hospital. Participants carried out several mobility tasks according to a structured protocol while wearing three accelerometers (ActiGraph GT9X Link, Activ8 Professional and Dynaport MoveMonitor). The participants were guided through the protocol by a test leader and were recorded on video to serve as reference. Sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) were determined for the categories lying, sitting, standing and walking. RESULTS: In total 12 subjects were included with a mean age of 49.5 (SD 21.5) years and a mean body mass index of 23.8 kg/m2 (SD 2.4). The ActiGraph GT9X Link showed an excellent sensitivity (90%) and PPV (98%) for walking, but a poor sensitivity for sitting and standing (57% and 53%), and a poor PPV (43%) for sitting. The Activ8 Professional showed an excellent sensitivity for sitting and walking (95% and 93%), excellent PPV (98%) for walking, but no sensitivity (0%) and PPV (0%) for lying. The Dynaport MoveMonitor showed an excellent sensitivity for sitting (94%), excellent PPV for lying and walking (100% and 99%), but a poor sensitivity (13%) and PPV (19%) for standing. CONCLUSIONS: The validity outcomes for the categories lying, sitting, standing and walking vary between the investigated accelerometers. All three accelerometers scored good to excellent in identifying walking. None of the accelerometers were able to identify all categories validly.
DOCUMENT
a b s t r a c t Prolonged sitting can cause health problems and musculoskeletal discomfort. There is a need for objective and non-obstructive means of measuring sitting behavior. A ‘smart’ office chair can monitor sitting behavior and provide tactile feedback, aiming to improve sitting behavior. This study aimed to investigate the effect of the feedback signal on sitting behavior and musculoskeletal discomfort. In a 12- week prospective cohort study (ABCB design) among office workers (n ¼ 45) was measured sitting duration and posture, feedback signals and musculoskeletal discomfort. Between the study phases, small changes were observed in mean sitting duration, posture and discomfort. After turning off the feedback signal, a slight increase in sitting duration was observed (10 min, p ¼ 0.04), a slight decrease in optimally supported posture (2.8%, p < 0.01), and musculoskeletal discomfort (0.8, p < 0.01) was observed. We conclude that the ‘smart’ chair is able to monitor the sitting behavior, the feedback signal, however, led to small or insignificant changes. © 2017 Elsevier Ltd. All rights reserved.
LINK
OBJECTIVE: The aim of this study was to explore the longitudinal relationship between sitting time on a working day and vitality, work performance, presenteeism, and sickness absence.METHODS: At the start and end of a five-month intervention program at the workplace, as well as 10 months after the intervention, sitting time and work-related outcomes were measured using a standardized self-administered questionnaire and company records. Generalized linear mixed models were used to estimate the longitudinal relationship between sitting time and work-related outcomes, and possible interaction effects over time.RESULTS: A significant and sustainable decrease in sitting time on a working day was observed. Sitting less was significantly related to higher vitality scores, but this effect was marginal (b = -0.0006, P = 0.000).CONCLUSIONS: Our finding of significant though marginal associations between sitting time and important work-related outcomes justifies further research.
DOCUMENT
Stroke is the second most common cause of death and the third leading cause of disability worldwide,1,2 with the burden expected to increase during the next 20 years.1 Almost 40% of the people with stroke have a recurrent stroke within 10 years,3 making secondary prevention vital.3,4 High amounts of sedentary time have been found to increase the risk of cardiovascular disease,5–11 particularly when the sedentary time is accumulated in prolonged bouts.12–15 Sedentary behavior, is defined as “any waking behavior characterized by an energy expenditure ≤1.5 Metabolic Equivalent of Task (METs) while in a sitting, reclining or lying posture”.16,17 Studies in healthy people, as well as people with diabetes and obesity, have shown that reducing the total amount of sedentary time and/or breaking up long periods of uninterrupted sedentary time, reduces metabolic risk factors associated with cardiovascular disease.6,9,10,12–15 Recent studies have shown that people living in the community after stroke spend more time each day sedentary, and more time in uninterrupted bouts of sedentary time compared to age-matched healthy peers.18–20 Reducing sedentary time and breaking up long sedentary bouts with short bursts of activity may be a promising intervention to reduce the risk of recurrent stroke and other cardiovascular diseases in people with stroke. To develop effective interventions, it is important to understand the factors associated with sedentary time in people with stroke. Previous studies have found associations between self-reported physical function after stroke and total sedentary time, but inconsistent results with regards to the relationship of age, stroke severity, and walking speed with sedentary time.20,21 These results are from secondary analyses of single-site observational studies, not powered to address associations, and inconsistent in the methods used to determine waking hours; thus making direct comparisons between studies difficult.20,21 Individual participant data pooling, with consistent processing of wake time data, allows novel exploratory analyses of larger datasets with greater power. By pooling all available individual participant data internationally, this study aimed to comprehensively explore the factors associated with sedentary time in community-dwelling people with stroke. Specifically, our research questions were: (1) What factors are associated with total sedentary time during waking hours after stroke? (2) What factors are associated with time spent in prolonged sedentary bouts during waking hours?
DOCUMENT
Purpose: A more dynamic school day that includes less sitting and more physical activity throughout the day may support health in primary school children. In this mixed methodologies study, we assessed which physical activity possibilities are incorporated in the school policies of Dutch primary schools and if this translates into more physical activity in pupils.Methods: Seven primary schools were included in the study. The head teachers completed a questionnaire on the incorporation of physical activity in the school policy. Physical activity policy was assessed for physical education, physical activity during breaks, scheduling of physical activity during lessons, after school physical activity and active transport to school. In each school, actual physical activity was objectively measured using accelerometers in pupils in two classes and planning and logging of PA by teachers.Results: We will assess the impact of the school policy on physical activity in pupils using logistic regression. We will assess the impact of the several school policies on total physical activity in pupils, and on the three (light, moderate and high) modalities of physical activity.Conclusion: The results of this study will give us more insight in the current role of physical activity in Dutch primary schools. The potential impact of the school policy on physical activity levels in pupils can be used as a starting point for a more integral dynamic school day approach.Support/Funding Source: This study was partially funded by “Stichting Westelijke Tuinsteden’
DOCUMENT
Purpose: Law enforcement may require police officers to inhibit intuitive responses to high threat and thereby affect their emotional reaction and operational effectiveness. Upon this premise, the current study reports two experiments which compare the impact of two relevant shot execution strategies on police officers’ shooting performance under high threat, including (1) fire at an armed assailant and then step away from the assailant's line of fire (‘fire-step’) or (2) step away from the assailant's line of fire and then fire (‘step-fire’). Method: In Experiment 1, 15 experienced police officers performed both shot execution strategies against a stationary assailant who occasionally shot back with coloured soap cartridges (high threat), while we measured their state anxiety, movement times and shot accuracy. In Experiment 2, the same 15 officers remained stationary and fired at the assailant who now performed both shot execution strategies in random order, thereby providing an indication of the risk (i.e., chance to get hit) associated with performing either strategy. Results: Experiment 1 showed that officers preferred using the step-fire strategy and that using this strategy resulted in lower levels of anxiety, increased time for aiming and more accurate shooting than the fire-step strategy. Experiment 2, however, indicated that the step-fire strategy also increases one's chance of getting hit. Conclusions: Findings suggest that inhibition of preferred responses under high threat (as in the fire-step strategy) may increase state anxiety and negatively affect shooting performance in police officers. Future work is needed to reveal underlying mechanisms and explore implications for practice.
DOCUMENT
Abstract—Pressure ulcers (PUs) are highly prevalent in people with spinal cord injury (SCI). Electrical stimulation (ES) activates muscles and might reduce risk factors. Our objectives were to study and compare the effects of two duty cycles during 3 h of ES-induced gluteal and hamstring activation on interface pressure distribution in sitting individuals with SCI and study the usability of a newly developed electrode garment (ES shorts). Ten individuals with SCI participated in this study, in which two ES protocols with different duty cycles (1:1 s vs 1:4 s on-off) were applied in counterbalanced order using a custom-made garment with built-in electrodes. Outcome variables included interface pressure of the ischial tuberosities (ITs) and pressure gradient. A questionnaire was used to determine usability of the ES shorts. In both protocols, ES caused a significant decrease in average IT pressure compared with rest (no ES); on average, 35% for protocol 1:4 and 13% for protocol 1:1. The ES on-off duty cycle of protocol 1:4 showed less muscle fatigue. In general, participants scored the usability of the ES shorts as satisfactory. In this study, the application of ES resulted in a significant decrease in IT pressure. The ES on-off duty cycle of 1:4 s is recommended because of the less fatiguing effect. ES of the hamstrings and gluteal muscles might be a promising method in preventing PUs, but further study is needed.
DOCUMENT
OBJECTIVE: To investigate the level of agreement of the behavioural mapping method with an accelerometer to measure physical activity of hospitalized patients. DESIGN: A prospective single-centre observational study. SETTING: A university medical centre in the Netherlands. SUBJECTS: Patients admitted to the hospital. MAIN MEASURES: Physical activity of participants was measured for one day from 9 AM to 4 PM with the behavioural mapping method and an accelerometer simultaneously. The level of agreement between the percentages spent lying, sitting and moving from both measures was evaluated using the Bland-Altman method and by calculating Intraclass Correlation Coefficients. RESULTS: In total, 30 patients were included. Mean (±SD) age was 63.0 (16.8) years and the majority of patients were men (n = 18). The mean percentage of time (SD) spent lying was 47.2 (23.3) and 49.7 (29.8); sitting 42.6 (20.5) and 40.0 (26.2); and active 10.2 (6.1) and 10.3 (8.3) according to the accelerometer and observations, respectively. The Intraclass Correlation Coefficient and mean difference (SD) between the two measures were 0.852 and -2.56 (19.33) for lying; 0.836 and 2.60 (17.72) for sitting; and 0.782 and -0.065 (6.23) for moving. The mean difference between the two measures is small (⩽2.6%) for all three physical activity levels. On patient level, the variation between both measures is large with differences above and below the mean of ⩾20% being common. CONCLUSION: The overall level of agreement between the behavioural mapping method and an accelerometer to identify the physical activity levels 'lying', 'sitting' and 'moving' of hospitalized patients is reasonable.
DOCUMENT
Prolonged sitting time in adults has become a major societal issue with far-reaching health, economic, and social consequences. The objective of this study is to reduce sedentary behaviour in office workers by integrating physical activity with work. In this case study, we present Workwalk, a concept to encourage and facilitate office workers to have a walking meeting. This idea arose by merging a traditional health research approach with an iterative design process. With this method, it was possible to integrate behaviour change techniques effectively into an interaction design process.
DOCUMENT
