Gait asymmetry during 400- to 1000-m high-intensity track running in relation to injury history

Purpose: To quantify gait asymmetry in well-trained runners with and without previous injuries during interval training sessions incorporating different distances.Methods: Twelve well-trained runners participated in 8 high-intensity interval-training sessions on a synthetic track over a 4-wk period. The training consisted of 10 × 400, 8 × 600, 7 × 800, and 6 × 1000-m running. Using an inertial measurement unit, the ground- contact time (GCT) of every step was recorded. To determine gait asymmetry, the GCTs between the left and right foot were compared.Results: Overall, gait asymmetry was 3.3% ± 1.4%, and over the course of a training session, the gait asymmetry did not change (F1,33 = 1.673, P = .205). The gait asymmetry of the athletes with a previous history of injury was significantly greater than that of the athletes without a previous injury. However, this injury-related enlarged asymmetry was detectable only at short (400 m), but not at longer, distances (600–1000 m).Conclusion: The gait asymmetry of well-trained athletes differed, depending on their history of injury and the running distance. To detect gait asymmetries, high-intensity runs over relatively short distances are recommended

Detecting Soldiers' Fatigue Using Eye-Tracking Glasses: Practical Field Applications and Research Opportunities.

Objectively determining soldiers' fatigue levels could help prevent injuries or accidents resulting from inattention or decreased alertness. Eye-tracking technologies, such as optical eye tracking (OET) and electrooculography (EOG), are often used to monitor fatigue. Eyeblinks-especially blink frequency and blink duration-are known as easily observable and valid biomarkers of fatigue. Currently, various eye trackers (i.e., eye-tracking glasses) are available on the market using either OET or EOG technologies. These wearable eye trackers offer several advantages, including unobtrusive functionality, practicality, and low costs. However, several challenges and limitations must be considered when implementing these technologies in the field to monitor fatigue levels. This review investigates the feasibility of eye tracking in the field focusing on the practical applications in military operational environments.; This paper summarizes the existing literature about eyeblink dynamics and available wearable eye-tracking technologies, exposing challenges and limitations, as well as discussing practical recommendations on how to improve the feasibility of eye tracking in the field.; So far, no eye-tracking glasses can be recommended for use in a demanding work environment. First, eyeblink dynamics are influenced by multiple factors; therefore, environments, situations, and individual behavior must be taken into account. Second, the glasses' placement, sunlight, facial or body movements, vibrations, and sweat can drastically decrease measurement accuracy. The placement of the eye cameras for the OET and the placement of the electrodes for the EOG must be chosen consciously, the sampling rate must be minimal 200 Hz, and software and hardware must be robust to resist any factors influencing eye tracking.; Monitoring physiological and psychological readiness of soldiers, as well as other civil professionals that face higher risks when their attention is impaired or reduced, is necessary. However, improvements to eye-tracking devices' hardware, calibration method, sampling rate, and algorithm are needed in order to accurately monitor fatigue levels in the field

Eyeblink Detection in the Field: A Proof of Concept Study of Two Mobile Optical Eye-Trackers.

High physical and cognitive strain, high pressure, and sleep deficit are part of daily life for military professionals and civilians working in physiologically demanding environments. As a result, cognitive and physical capacities decline and the risk of illness, injury, or accidents increases. Such unfortunate outcomes could be prevented by tracking real-time physiological information, revealing individuals' objective fatigue levels. Oculometrics, and especially eyeblinks, have been shown to be promising biomarkers that reflect fatigue development. Head-mounted optical eye-trackers are a common method to monitor these oculometrics. However, studies measuring eyeblink detection in real-life settings have been lacking in the literature. Therefore, this study aims to validate two current mobile optical eye-trackers in an unrestrained military training environment.; Three male participants (age 20.0 ± 1.0) of the Swiss Armed Forces participated in this study by wearing three optical eye-trackers, two VPS16s (Viewpointsystem GmbH, Vienna, Austria) and one Pupil Core (Pupil Labs GmbH, Berlin, Germany), during four military training events: Healthcare education, orienteering, shooting, and military marching. Software outputs were analyzed against a visual inspection (VI) of the video recordings of participants' eyes via the respective software. Absolute and relative blink numbers were provided. Each blink detected by the software was classified as a "true blink" (TB) when it occurred in the software output and the VI at the same time, as a "false blink" (FB) when it occurred in the software but not in the VI, and as a "missed blink" (MB) when the software failed to detect a blink that occurred in the VI. The FBs were further examined for causes of the incorrect recordings, and they were divided into four categories: "sunlight," "movements," "lost pupil," and "double-counted". Blink frequency (i.e., blinks per minute) was also analyzed.; Overall, 49.3% and 72.5% of registered eyeblinks were classified as TBs for the VPS16 and Pupil Core, respectively. The VPS16 recorded 50.7% of FBs and accounted for 8.5% of MBs, while the Pupil Core recorded 27.5% of FBs and accounted for 55.5% of MBs. The majority of FBs-45.5% and 73.9% for the VPS16 and Pupil Core, respectively-were erroneously recorded due to participants' eye movements while looking up, down, or to one side. For blink frequency analysis, systematic biases (±limits of agreement) stood at 23.3 (±43.5) and -4.87 (±14.1) blinks per minute for the VPS16 and Pupil Core, respectively. Significant differences in systematic bias between devices and the respective VIs were found for nearly all activities (P < .05).; An objective physiological monitoring of fatigue is necessary for soldiers as well as civil professionals who are exposed to higher risks when their cognitive or physical capacities weaken. However, optical eye-trackers' accuracy has not been specified under field conditions-especially not in monitoring fatigue. The significant overestimation and underestimation of the VPS16 and Pupil Core, respectively, demonstrate the general difficulty of blink detection in the field

Accuracy of elevation recording using sport watches while walking and running on hilly and flat terrain

Elevation gain (EG) is a significant contributor to the total workload in many endurance sports. Hence, the aim of this study was to evaluate the accuracy of elevation recording as assessed by popular sport watches. Eighteen participants walked and ran at different speeds in various weather conditions in two terrain types: on a hilly 2490 m course with a total EG of 90 m and on a flat 1200 m outdoor track with 0 m EG. In total, 180 recordings from each sport watch were analyzed and compared according to two processing types: filtered and unfiltered EG data. Compared to the reference values, regarding default settings, on hilly terrain, EG was underestimated by −3.3 to −9.8 %, and on flat terrain, EG was overestimated by 0.0– 4.8 m per 1200 m. These errors could be reduced to −3.3 to +0.4 %, when filtering conditions were adjusted according to the terrain. Gait speed (ranging from 1.47 to 4.89 m s−1) or fluctuations in weather conditions between- or within-trials did not influence EG accuracy. A straightforward comparison between manufacturers is hampered as the filter conditions set by default differ. In conclusion, all devices measure EG adequately; however, the displayed default feedback on EG data is not always the most accurate measurement. Consequently, accuracy in elevation recordings could be increased if users appropriately post-process EG data

The influence of the gait-related arm swing on elevation gain measured by sport watches

The elevation gain is an important contributor to the total workload in endurance sports. The purpose of this study was to evaluate the influence of the arm swing on elevation gain in three sport watches (Garmin® Forerunner 910XT, Polar® RS800CX and Suunto® Ambit2) on a flat 400 m outdoor track. Altogether, a total of 120 repetitions of 1,200 m were performed at self-selected speeds corresponding to strolling, walking, jogging and running. During the assessment two devices of each sport watch, one secured on the hip and one on the wrist, were worn by the participants. A small but significant (effect size = .39; p < .001) influence of the arm swing on elevation was revealed in all sport watches. Elevation indication errors recorded on the wrist were significantly larger than the ones recorded on the hip (4.0- 7.4 vs. 1.2-5.7 m per 1,200 m; p < .05). Furthermore, when wearing the devices on the wrist, errors in elevation indication increased when gait speed increased. Users should be aware that wearing the devices on the hip can significantly decrease measurement errors. This might be especially relevant for activities with high dynamics, such as jogging and running

Influence of Soldiers' Cardiorespiratory Fitness on Physiological Responses and Dropouts During a Loaded Long-distance March.

Introduction: In military service, marching is an important, common, and physically demanding task. Minimizing dropouts, maintaining operational readiness during the march, and achieving a fast recovery are desirable because the soldiers have to be ready for duty, sometimes shortly after an exhausting task. The present field study investigated the influence of the soldiers' cardiorespiratory fitness on physiological responses during a long-lasting and challenging 34 km march. Materials and methods: Heart rate (HR), body core temperature (BCT), total energy expenditure (TEE), energy intake, motivation, and pain sensation were investigated in 44 soldiers (20.3 ± 1.3 years, 178.5 ± 7.0 cm, 74.8 ± 9.8 kg, body mass index: 23.4 ± 2.7 kg × m-2, peak oxygen uptake ($\dot{\rm{V}}$O2peak): 54.2 ± 7.9 mL × kg-1 × min-1) during almost 8 hours of marching. All soldiers were equipped with a portable electrocardiogram to record HR and an accelerometer on the hip, all swallowed a telemetry pill to record BCT, and all filled out a pre- and post-march questionnaire. The influence of aerobic capacity on the physiological responses during the march was examined by dividing the soldiers into three fitness groups according to their $\dot{\rm{V}}$O2peak. Results: The group with the lowest aerobic capacity ($\dot{\rm{V}}$O2peak: 44.9 ± 4.8 mL × kg-1 × min-1) compared to the group with the highest aerobic capacity ($\dot{\rm{V}}$O2peak: 61.7 ± 2.2 mL × kg-1 × min-1) showed a significantly higher (P < .05) mean HR (133 ± 9 bpm and 125 ± 8 bpm, respectively) as well as peak BCT (38.6 ± 0.3 and 38.4 ± 0.2 °C, respectively) during the march. In terms of recovery ability during the break, no significant differences could be identified between the three groups in either HR or BCT. The energy deficit during the march was remarkably high, as the soldiers could only replace 22%, 26%, and 36% of the total energy expenditure in the lower, middle, and higher fitness group, respectively. The cardiorespiratory fittest soldiers showed a significantly higher motivation to perform when compared to the least cardiorespiratory fit soldiers (P = .002; scale from 1 [not at all] to 10 [extremely]; scale difference of 2.3). A total of nine soldiers (16%) had to end marching early: four soldiers (21%) in the group with the lowest aerobic capacity, five (28%) in the middle group, and none in the highest group. Conclusion: Soldiers with a high $\dot{\rm{V}}$O2peak showed a lower mean HR and peak BCT throughout the long-distance march, as well as higher performance motivation, no dropouts, and lower energy deficit. All soldiers showed an enormous energy deficit; therefore, corresponding nutritional strategies are recommended

Individualised PPI prescription in patients on combination antiplatelet therapy and upper gastrointestinal events after percutaneous coronary intervention: a cohort study

Zusammenfassung: GRUNDLAGEN: In einer Patientenkohorte, welche nach perkutaner koronarer Intervention (PCI) kombinierte Thrombozytenaggregationshemmung (Aspirin und Clopidogrel) erhielt, wurde die Wirksamkeit einer individualisierten PPI-Gabe zur Reduktion unerwünschter gastrointestinaler Ereignisse untersucht. METHODIK: Das gastrointestinale Risikofaktorprofil und andere Parameter wurden aus einer speziell angelegten elektronischen Datenbank extrahiert. Die Patienten wurden via standardisierten Fragebogen kontaktiert und bei Patienten mit unerwünschten gastrointestinalen Ereignissen wurde zusätzlich ein strukturiertes Telefoninterview durchgeführt. ERGEBNISSE: In einer Kohorte von 718 Patienten erhielten 87 (12,1 %) eine prophylaktische PPI-Therapie. Bei insgesamt 12 % wurden unerwünschte gastrointestinale Ereignisse gefunden, wobei 18,4 % eine PPI-Prophylaxe und 11,1 % kein PPI hatten (OR 1,80, P = 0,054). Eine Komedikation mit Steroiden war der hauptsächliche Risikofaktor für unerwünschte gastrointestinale Ereignissen (adjusted OR 5,45, P = 0,014). SCHLUSSFOLGERUNGEN: Die individualisierte PPI-Therapie basierend auf einer Risikoabschätzung für gastrointestinale Blutungsereignisse scheint ein effizientes Instrument zu sein, um gastrointestinale Ereignisse nach PCI zu minimiere

Rekonstruktive Forschungsmethoden in der Lehre: Eine Beforschung der Fallwerkstätten durch die involvierten Lehrpersonen nach der Idee von Scholarship of Teaching and Learning (SoTL)

Das vorliegende Forschungsprojekt hat das Ziel, das Potential des rekonstruktiven Ansatzes für die Kompetenzentwicklung im Rahmen der praxisbegleitenden Module (Fallwerkstätte) von Studierenden der Sozialen Arbeit zu untersuchen. Das Forschungsprojekt untersuchte die Fallwerkstätten über drei Semester. Dabei wurde der Fokus auf den Einsatz von Methoden der rekonstruktiven Sozialforschung (Kapitel 3) gelegt und dabei insbesondere auf deren Nutzen und Leistungsfähigkeit für die Kompetenzentwicklung der Studierenden und die Praxis der Sozialen Arbeit. Das Forschungsteam bestand im Sinne von Scholarship of Teaching and Learning (Kapitel 3.1) aus den Lehrpersonen der beforschten Fallwerkstätten

Evaluation of pulse rate measurement with a wrist worn device during different tasks and physical activity

The purpose of this study was to evaluate the wrist-worn device Mio FUSE, which estimates heart rate (HR) based on photo-plethysmography, 1) in a large study group during a standardised activity, 2) in a small group during a variety of activities and 3) to investigate factors affecting HR accuracy in a real-world setting. First, 53 male participants (20 ±1 years; 1.79 ±0.07 m; 76.1 ±10.5 kg) completed a 35-km march wearing the Equivital EQ-02 as a criterion measure. Second, 5 participants (whereof 3 female; 29 ±5 years; 1.74 ±0.07 m; 67.8 ±11.1 kg) independently performed 25 activities, categorised as sitting passive, sitting active, standing, cyclic and anti-cyclic activities with the Polar H7 as a criterion device. Equivalence testing and Bland-and-Altman analyses were undertaken to assess the accuracy to the criterion devices. Third, confounders affecting HR accuracy were investigated using multiple backwards regression analyses. The Mio FUSE was equivalent to the respective criterion measures with only small systematic biases of -3.5 bpm (-2.6%) and -1.7 bpm (-1.3%) with limits of agreements of ±10.1 bpm and ±10.8 bpm during the 35-km march and during different activities, respectively. Confounding factors negatively affecting the accuracy of the Mio FUSE were found to include larger wrist size and intensified arm and/or wrist movement. The wrist-worn Mio FUSE can be recommended to estimate overall HR accurately for different types of activities in healthy adults. However, during sporting activities involving intensified arm and/or wrist movement or for detailed continuous analysis, a chest strap is preferred to the Mio FUSE to optimise HR estimation accuracy

Validation of ambulatory monitoring devices to measure energy expenditure and heart rate in a military setting

Objectives.; To investigate the validity of different devices and algorithms used in military organizations worldwide to assess physical activity energy expenditure (PAEE) and heart rate (HR) among soldiers.; Design.; Device validation study.; Methods; . Twenty-three male participants serving their mandatory military service accomplished, firstly, nine different military specific activities indoors, and secondly, a normal military routine outdoors. Participants wore simultaneously an ActiHeart, Everion, MetaMax 3B, Garmin Fenix 3, Hidalgo EQ02, and PADIS 2.0 system. The PAEE and HR data of each system were compared to the criterion measures MetaMax 3B and Hidalgo EQ02, respectively.; Results; . Overall, the recorded systematic errors in PAEE estimation ranged from 0.1 (±1.8) kcal.min; -1; to -1.7 (±1.8) kcal.min; -1; for the systems PADIS 2.0 and Hidalgo EQ02 running the Royal Dutch Army algorithm, respectively, and in the HR assessment ranged from -0.1 (±2.1) b.min; -1; to 0.8 (±3.0) b.min; -1; for the PADIS 2.0 and ActiHeart systems, respectively. The mean absolute percentage error (MAPE) in PAEE estimation ranged from 29.9% to 75.1%, with only the Everion system showing an overall MAP