Rasmus Kildedal

Mr. Rasmus Kildedal

Department of Musculoskeletal Disorders and Physical Workload, National Research Centre for the Working Environment
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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ALAnders Lerche
Anders Lerche
MVMaja Vilhelmsen
Maja Vilhelmsen
KSkathrine Schmidt
kathrine Schmidt
RKRasmus Kildedal
Rasmus Kildedal
NLNatja Launbo
Natja Launbo
AHAndreas Holtermann
Andreas Holtermann
Childcare workers are reported to have high variation in physical activity during work hours, but also to sit for about half of the workday and have almost no high intensity physical activity (HIPA). No study has investigated if their work can be re-designed to introduce HIPA, thus promoting fitness and health according to the Goldilocks principle. This study investigated the feasibility of designing pedagogical games (‘Goldilocks-games’) intended to lead to more HIPA. Heart rate was measured in nineteen childcare workers during Goldilocks-games, and compared to measurements during a regular workday. Worker perceptions of feasibility, and researcher observations of contextual factors were also collected. The Goldilocks-games (33 min) elicited significantly more HIPA (18/33 min) compared to the most active period of equal length on a regular workday (0.5/33 min). Seventy-four-percent of the childcare workers reported that it was feasible to integrate the Goldilocks-games pedagogically, and seventy-two-percent could see themselves using them. Thus, we found it possible to re-design a work task in childcare according to the Goldilocks principle so that it leads to substantial time with HIPA. The sustainability of Goldilocks-games in childcare, and their effectiveness in improving fitness and health among childcare workers, needs to be tested in further studies.

6 June 2022 in JMIR Research Protocols
Verified
Journal Article
Open access
PCPatrick Crowley
Patrick Crowley
EIErika Ikeda
Erika Ikeda
Sheikh Mohammed Shariful IslamSheikh Mohammed Shariful Islam
Sheikh Mohammed Shariful Islam
RKRasmus Kildedal
Rasmus Kildedal
SJSandra Schade Jacobsen
Sandra Schade Jacobsen
NGNidhi Gupta
Nidhi Gupta
Background: There is increasing recognition of the need for more comprehensive surveillance data, including information on physical activity of all intensities, sedentary behavior, and sleep. However, meeting this need poses significant challenges for current surveillance systems, which are mainly reliant on self-report. Objective: The primary objective of this project is to develop and evaluate the feasibility of a sensor-based system for use in the surveillance of physical activity, sedentary behavior, and sleep (SurPASS) at a national level in Denmark. Methods: The SurPASS project involves an international, multidisciplinary team of researchers collaborating with an industrial partner. The SurPASS system consists of (1) a thigh-worn accelerometer with Bluetooth connectivity, (2) a smartphone app, (3) an integrated back end, facilitating the automated upload, analysis, storage, and provision of individualized feedback in a manner compliant with European Union regulations on data privacy, and (4) an administrator web interface (web application) to monitor progress. The system development and evaluation will be performed in 3 phases. These phases will include gathering user input and specifications (phase 1), the iterative development, evaluation, and refinement of the system (phase 2), and the feasibility evaluation (phase 3). Results: The project started in September 2020 and completed phase 2 in February 2022. Phase 3 began in March 2022 and results will be made available in 2023. Conclusions: If feasible, the SurPASS system could be a catalyst toward large-scale, sensor-based surveillance of physical activity, sedentary behavior, and sleep. It could also be adapted for cohort and interventional research, thus contributing to the generation of evidence for both interventions and public health policies and recommendations. International Registered Report Identifier (IRRID): DERR1-10.2196/35697

17 November 2023 in JMIR Formative Research
Verified
Journal Article
Open access
PCPatrick Crowley
Patrick Crowley
RKRasmus Kildedal
Rasmus Kildedal
SVSimon Overvad Vindelev
Simon Overvad Vindelev
SJSandra Schade Jacobsen
Sandra Schade Jacobsen
JLJon Roslyng Larsen
Jon Roslyng Larsen
NGNidhi Gupta
Nidhi Gupta
Background: Device-based measurements of physical behavior, using the current methods, place a large burden on participants. The Motus system could reduce this burden by removing the necessity for in-person meetings, replacing diaries written on paper with digital diaries, and increasing the automation of feedback generation. Objective: This study aims to describe the development of the Motus system and evaluate its potential to reduce participant burden in a two-phase usability evaluation. Methods: Motus was developed around (1) a thigh-worn accelerometer with Bluetooth data transfer; (2) a smartphone app containing an attachment guide, a digital diary, and facilitating automated data transfer; (3) a cloud infrastructure for data storage; (4) an analysis software to generate feedback for participants; and (5) a web-based app for administrators. We recruited 19 adults with a mean age of 45 (SD 11; range 27-63) years, of which 11 were female, to assist in the two-phase evaluation of Motus. A total of 7 participants evaluated the usability of mockups for a smartphone app in phase 1. Participants interacted with the app while thinking aloud, and any issues raised were classified as critical, serious, or minor by observers. This information was used to create an improved and functional smartphone app for evaluation in phase 2. A total of 12 participants completed a 7-day free-living measurement with Motus in phase 2. On day 1, participants attempted 20 system-related tasks under observation, including registration on the study web page, reading the information letter, downloading and navigating the smartphone app, attaching an accelerometer on the thigh, and completing a diary entry for both work and sleep hours. Task completion success and any issues encountered were noted by the observer. On completion of the 7-day measurement, participants provided a rating from 0 to 100 on the System Usability Scale and participated in a semistructured interview aimed at understanding their experience in more detail. Results: The task completion rate for the 20 tasks was 100% for 13 tasks, >80% for 4 tasks, and <50% for 3 tasks. The average rating of system usability was 86 on a 0-100 scale. Thematic analysis indicated that participants perceived the system as easy to use and remember, and subjectively pleasing overall. Participants with shift work reported difficulty with entering sleep hours, and 66% (8/12) of the participants experienced slow data transfer between the app and the cloud infrastructure. Finally, a few participants desired a greater degree of detail in the generated feedback. Conclusions: Our two-phase usability evaluation indicated that the overall usability of the Motus system is high in free-living. Issues around the system’s slow data transfer, participants with atypical work shifts, and the degree of automation and detail of generated feedback should be addressed in future iterations of the Motus system. International Registered Report Identifier (IRRID): RR2-10.2196/35697

1 October 2025 in Journal of Physical Activity and Health
Verified
Journal Article
Open access
PDF file
NGNidhi Gupta
Nidhi Gupta
MEMartin Eghøj
Martin Eghøj
TLTonje Pedersen Ludvigsen
Tonje Pedersen Ludvigsen
JLJon Roslyng Larsen
Jon Roslyng Larsen
CWChristian Tolstrup Wester
Christian Tolstrup Wester
AHAndreas Holtermann
Andreas Holtermann
Background: For detailed, large-scale data on 24-hour movement behaviors, we designed a system “Motus” using state-of-the-art wearable and cloud technology, and tested its feasibility on randomly chosen Danish adults in a 2-stage evaluation. Methods: Stage 1: We invited 7735 adults, responding to a national occupational health surveillance-2021. Consented participants received a wearable (SENSmotion Plus) and downloaded the Motus app, which provided instructions for wearable attachment on the thigh and for self-reporting work and sleep hours. Following the 7-day measurement, participants completed a feasibility questionnaire. Administrators recorded time spent on Motus-related tasks (eg, postal package preparation). Identified feasibility issues led to revisions of protocol and Motus elements. Stage 2: We invited 6993 adults from a national public health surveillance-2023. Participants used the revised Motus version. We evaluated Motus on the key issues identified from stage 1. Results: Stage 1: Feasibility ranged from 77% for social acceptability to 98% for adherence to the measurement protocol. Participants reported spending 73 minutes per week (eg, attaching the sensors) on Motus, while administrators reported 15 minutes per participant. We identified 3 issues: 6% consent rate, 20% lost wearables (but not the data), and 10% wearable patches becoming loose. We addressed these issues by sending reminders, using stronger return envelopes, and replacing patch adhesive with higher quality alternatives, respectively. At stage 2, we observed a higher consent rate (23%) and lower patch complaints (<3%) but higher wearables loss (25%). Conclusion: Motus displays promising feasibility for collecting large-scale 24-hour movement behavior data. However, the low participation rate and high sensor loss require improvement before broader implementation, especially in surveillance.

KSkathrine Schmidt
kathrine Schmidt
RKRasmus Kildedal
Rasmus Kildedal
ALAnders Lerche
Anders Lerche
MVMaja Vilhelmsen
Maja Vilhelmsen
CRCharlotte Lund Rasmussen
Charlotte Lund Rasmussen
AHAndreas Holtermann
Andreas Holtermann
Childcare workers are reported to have poor cardiorespiratory fitness and health. The Goldilocks Work Principle argues that productive work should be designed with the right composition, intensity and alternations of physical behaviors so that workers get fit and healthy. The purpose of this study was to investigate: (1) composition, (2) intensity and (3) alternations of physical behaviors during work and leisure among childcare workers. Data were collected using accelerometers and heart rate monitors over five workdays among 51 childcare workers at five Danish childcare institutions. Workers mainly spent their work time sedentary (43.0%), spent little time (0.7%) at sufficiently high cardiometabolic intensity to increase cardiorespiratory fitness and often alternated between physical behaviors (67.0% occurred in bouts of <5 min). These findings indicate that the workers have a composition of behaviors at work dominated by sedentary time, little time with high cardiometabolic intensity, and frequent alternations between behaviors. During leisure, workers spent more time sedentary (59.4%), more time at high cardiometabolic intensity (3.4%) and less time occurred in bouts <5 min (38.7%). We see a potential for promoting cardiorespiratory fitness and health of childcare workers by redesigning the way they play with the children, so that work time with high cardiometabolic intensity is increased.

15 April 2023 in JMIR Preprints
Verified
Preprint
Open access
PCPatrick Crowley
Patrick Crowley
RKRasmus Kildedal
Rasmus Kildedal
SVSimon Overvad Vindelev
Simon Overvad Vindelev
SJSandra Schade Jacobsen
Sandra Schade Jacobsen
JLJon Roslyng Larsen
Jon Roslyng Larsen
NGNidhi Gupta
Nidhi Gupta
BACKGROUND Device-based measurements of physical behavior, using the current methods, place a large burden on participants. The Motus system could reduce this burden by removing the necessity for in-person meetings, replacing diaries written on paper with digital diaries, and increasing the automation of feedback generation. OBJECTIVE This study aims to describe the development of the Motus system and evaluate its potential to reduce participant burden in a two-phase usability evaluation. METHODS Motus was developed around (1) a thigh-worn accelerometer with Bluetooth data transfer; (2) a smartphone app containing an attachment guide, a digital diary, and facilitating automated data transfer; (3) a cloud infrastructure for data storage; (4) an analysis software to generate feedback for participants; and (5) a web-based app for administrators. We recruited 19 adults with a mean age of 45 (SD 11; range 27-63) years, of which 11 were female, to assist in the two-phase evaluation of Motus. A total of 7 participants evaluated the usability of mockups for a smartphone app in phase 1. Participants interacted with the app while thinking aloud, and any issues raised were classified as critical, serious, or minor by observers. This information was used to create an improved and functional smartphone app for evaluation in phase 2. A total of 12 participants completed a 7-day free-living measurement with Motus in phase 2. On day 1, participants attempted 20 system-related tasks under observation, including registration on the study web page, reading the information letter, downloading and navigating the smartphone app, attaching an accelerometer on the thigh, and completing a diary entry for both work and sleep hours. Task completion success and any issues encountered were noted by the observer. On completion of the 7-day measurement, participants provided a rating from 0 to 100 on the System Usability Scale and participated in a semistructured interview aimed at understanding their experience in more detail. RESULTS The task completion rate for the 20 tasks was 100% for 13 tasks, >80% for 4 tasks, and <50% for 3 tasks. The average rating of system usability was 86 on a 0-100 scale. Thematic analysis indicated that participants perceived the system as easy to use and remember, and subjectively pleasing overall. Participants with shift work reported difficulty with entering sleep hours, and 66% (8/12) of the participants experienced slow data transfer between the app and the cloud infrastructure. Finally, a few participants desired a greater degree of detail in the generated feedback. CONCLUSIONS Our two-phase usability evaluation indicated that the overall usability of the Motus system is high in free-living. Issues around the system’s slow data transfer, participants with atypical work shifts, and the degree of automation and detail of generated feedback should be addressed in future iterations of the Motus system. INTERNATIONAL REGISTERED REPORT RR2-10.2196/35697