VELOCITY BASED STRENGTH TRAINING: VALIDITY OF THE APPLE WATCH 7 TO MEASURE MOVEMENT VELOCITY IN THE BACK SQUAT

Velocity-Based resistance Training (VBT) measurement methods based on commercially-available electronics in smartphones and other wearables are not yet accessible to the broad public. Building on this gap, the motivation for this study was to assess the validity of the Apple Watch 7 for broad application to VBT. In particular, the velocity predictions of a barbell mounted Apple Watch 7 were compared against data from 3D optical motion capture (Vicon) as gold standard in 22 subjects for the free weight back squat. The subjects reported to the lab for one testing session and performed the free weight back squat at intensities between 45 and 100 percent of their one-repetition-maximum. A total of 574 repetitions (total), 285 repetitions (slow), 289 repetitions (fast) were successfully recorded, with only 30 repetitions missing because of connection issues between the Apple Watch and the server infrastructure. The peak and mean velocity predictions of the concentric movement phase were with a high precision compared to Vicon (Vmean: SEE=0.049m/s, r=0.976, Vpeak: 0.092m/s, r=0.959), with the error being similar or smaller compared to other validation studies. The insight gained in this work plays a crucial part toward advancing VBT monitoring technologies for broader use by demonstrating the validity of commercially-available and highly popular consumer electronics

PILOT STUDY: OPTICAL TRACKING OF BARBELL KINEMATICS FOR LOW-COST STRENGTH TRAINING PERFORMANCE MONITORING

Velocity based training (VBT) is a promising method to quantify and direct resistance training. Recent advances in computer science have opened the way for low-cost methods to measure VBT using video data from a smartphone. This work introduces and analyses the feasibility of a computer vision-based Python application in tracking barbell kinematics during VBT, compared against Vicon data during the back squat in one subject. As input into the algorithm, sagittal-plane video data is needed with the barbell plate in focus. Time of the concentric part of the squat and vertical barbell displacement are then automatically tracked using OpenCV libraries. The time parameter was accurately assessed using two different OpenCv Tracker, the KCF (r=0.83, SEE=0.02s) and the MOSSE (r=0.81, SEE=0.02s) tracker, respectively. For the vertical displacement, a lower accuracy was obtained using KCF (r=0.36, SEE=0.02m) and MOSSE (r=0.62, SEE=0.01m). Tracking errors could be explained by the camera set-up, as well as differences in frame rates between the video and the Vicon data. It might be possible to correct these errors in future work using machine learning techniques. This pilot study shows the feasibility of a computer vision-based Python application to measure barbell kinematics in a low-cost manner and might play a part towards advancing VBT monitoring technologies for widespread use

Cooperative Human Rights Obligations: Operationalising Cooperation for the Effective Protection of Civil and Political Rights in Transnational Constellations

This thesis examines how complex interdependence among states can be reflected and the consequent imperative of cooperation to effectively ensure civil and political rights operationalised in international human rights law. It has long been recognised that in light of states’ economic (inter-)dependence, international assistance and cooperation are necessary to enable states to fully realise economic, social, and cultural rights. In contrast, in the context of civil and political rights the concept of interdependence and its consequences have barely been explored. Seeking to fill this gap, the thesis initially outlines how transnational phenomena such as climate change or pandemics intensify states’ interdependence and extend it beyond the purely economic realm. It shows that this undermines states’ capacity to effectively ensure the civil and political rights of individuals within their territories and subject to their jurisdictions. On the basis thereof, the thesis proposes that states should and in fact do incur obligations to act jointly and cooperate if required to effectively protect civil and political rights in transnational constellations. The thesis uses the limited but growing case law on cooperative human rights obligations as a starting point for thinking about how the traditional co-existence paradigm could be replaced and obligations to act jointly and cooperate operationalised within existing frameworks for the protection of civil and political rights. It begins by exploring the collective enforcement character of human rights treaties and how it ought to affect the conceptualisation of the relationship of states parties thereto as a foundation for cooperative human rights obligations. The thesis subsequently reflects on which states should incur cooperative human rights obligations. It argues that a capacity-based re-conceptualisation of (extraterritorial) jurisdiction would contribute to an effective allocation and thus operationalisation of obligations to act jointly and cooperate. The thesis continues to examine the nature, contextual emergence and determination of the scope and content of cooperative human rights obligations. In particular, it proposes to situate cooperative human rights obligations along a spectrum. At its minimal end, cooperative human rights obligations are conceptualised as obliging states not to undermine other states’ capacity to ensure civil and political rights. In contrast, a maximalist interpretation could conceivably require states to cooperatively achieve a specific outcome. The thesis finally critically reflects on states’ responsibility for breaching cooperative human rights obligations. It focuses particularly on the allocation of the content of responsibility among multiple contributing states, advocating for their joint and several responsibility

Völkerrechtliche Grundlagen und Hürden für eine Einziehung russischer Gelder und wirtschaftlicher Ressourcen

Nach dem völkerrechtswidrigen Angriff Russlands auf die Ukraine fordern Politiker die Einziehung eingefrorener russischer Gelder und wirtschaftlicher Ressourcen zwecks Vollstreckung der Wiedergutmachungsforderung der Ukraine gegen Russland. Dieser Beitrag situiert diese politische Forderung im Völkerrecht. Zunächst thematisiert er kurz die völkerrechtliche Verantwortlichkeit Russlands und die Wiedergutmachungsforderung der Ukraine als deren Rechtsfolge. Danach werden potenzielle völkerrechtliche Rechtsgrundlagen für eine solche Einziehung eruiert. Da diese wenig erfolgsversprechend scheinen, geht der Beitrag schliesslich auf völkerrechtliche Hürden beim Erlass einer entsprechenden Rechtsgrundlage zur Einziehung russischer Gelder und wirtschaftlicher Ressourcen auf nationaler Ebene ein. Neben Fragen der Immunität wären dabei insbesondere menschenrechtliche und investitionsschutzrechtliche Schranken zu beachten. -- Suite à l'invasion de l'Ukraine en violation du droit international, certains politiciens demandent la confiscation des fonds et des ressources économiques russes gelés afin d'exécuter la demande de réparation de l'Ukraine contre la Russie. Cet article situe cette demande politique dans le cadre du droit international. Il aborde tout d'abord brièvement la responsabilité de la Russie en droit international et la demande de réparation de l'Ukraine comme conséquence juridique. Il identifie ensuite les fondements qui pourraient permettre une telle confiscation. Comme ceux-ci semblent peu prometteurs, l'article aborde finalement les obstacles du droit international public à l'adoption d'une base juridique permettant la confiscation des fonds et des ressources économiques russes au niveau national. Outre les questions d'immunité, il convient notamment de tenir compte des limites imposées par les droits de l'homme et la protection des investissements

Introducing a time-efficient workflow for processing IMU data to identify sport-specific movement patterns

Introduction The use of inertial measurement unit (IMU) has become popular in sports assessment. New IMU devices may make the monitoring process easier; however, their validity and reliability should be established prior to widespread use. IMU devices use a combination of gyroscopic and accelerometer data which allow the derivation of velocity and position vectors by integrating the data over time. Because the process of time integration suffers from time varying biases and noise, the resulting velocity and position vectors are prone to drift after a few seconds. This must be accounted for when processing data from IMUs. Aim Motivated by the variety of approaches to IMU-based human motion tracking, the aim of this paper is to deliver a report of the author’s experience in processing and handling acceleration data from a wearable IMU sensor recorded during resistance training and present a workflow to identify specific movement patterns across different sports. Methods Given acceleration data from a wearable sensor during sports practice, the workflow to derive velocity and position measures of specific movement patterns is divided into the following seven steps: 1) Rough cropping of region of interest (ROI). 2) Application of low pass filter to remove jittering upon visual inspection. Depending on ROI length, a detrend filter should be applied on the integrated position and maybe on the velocity data to correct for drift. 3) Visual analysis of characteristics of at least one movement pattern (more if the pattern shows a high inter-repetition variability) to identify key events (e.g. maximal velocity). 4) Automatically find and count key events along ROI. 5) Reassess characteristics of movement pattern to determine other relevant events. 6) Next, segmentation of ROI based on selected events and integration of individual sections to avoid drift. The aim is to integrate the smallest pieces possible. 7) Finally, check to make sure that segmentation worked correctly (e.g. correct number of repetitions, resulting values in a possible range). Results Acceleration data was captured with an Apple Watch 7 (Apple Inc. California) using the SensorLog app streaming to a customized node.js server application. For the processing and visualization of the data, the programming language Python with usage of the Pandas and SciPy libraries were utilized. The velocity and position data were determined by finding the integral of the acceleration and velocity respectively. Using the previous mentioned workflow 306 repetitions of the back squat executed by 11 recreational athletes (w: 5/m: 6, age: 22-37, weight:58-90kg) were successful segmented. Discussion The technology underlying commercial IMU sensors are often not communicated transparently. Thus, it is important to properly study the task of calibration the IMU and calculating the vertical component before using it for sport science measurements. Furthermore, it is rarely the case that the movement pattern remains the same over each training session. Therefore, characteristics of the movement pattern must be studied thoroughly to create a robust identification criterium. By applying the presented workflow researcher have a structured, easy to apply and time efficient approach to analyze recorded acceleration data on different sport-specific movement patterns

Is there a connection between individual thigh muscle volume and squat lifting velocity

Background Identifying key musculoskeletal and biomechanical criteria that are associated with Resistance Training (RT) is essential to avoid injury and optimise training outcome. Biomechanically, so-called velocity-based RT is an objective approach to directly quantify training intensity and effect. From a musculoskeletal perspective, RT enhances muscle force, which is correlated to the muscle’s physiological cross-sectional area, and thus muscle volume. Goal The goal of this study is to find out whether there exists a correlation between the change in lifting velocity during a squat set-to-exhaustion and the Hamstring to Quadriceps Muscle Volume Ratio (H/Q Ratio) as indicator of muscle strength. Methodology Ethical approval for this study was given by the Kantonale Ethikkommission Bern. Recreationally trained RT athletes (age 20-40years) were recruited through the investigator’s network. The methodology is divided into three parts. Firstly, the hamstring and quadriceps muscle volumes are determined using Magnetic Resonance Imaging (MRI) as gold standard. Thereby, the open-source software SASHIMI with an automatic tracking function is utilised to segment the MRI data. The segmented data is further processed with the Python programming language to derive the H/Q ratios. Secondly, lifting velocity during the squat is determined using data from optical motion capture (Vicon Nexus System with 10 infrared cameras) as gold standard. Thereby, a set-to-exhaustion is performed at 80% of each individual one repetition maximum (1RM), whereby the subjects are asked to complete the concentric phase at maximum speed to comply with velocity-based RT recommendations. Lifting velocity is derived from the tracked position of two reflective markers on the bar using the Python programming language. Thirdly, a statistical correlation analysis is conducted between the musculoskeletal and the biomechanical parameters. Statistical analysis is performed with the statistical analysis software R, with the level of significance set at p = 0.05. Results To date, MRI data have been acquired in five athletes and the corresponding muscle volumes have been determined (Quadriceps: 0.00525 +/-0.00185 m3 and Hamstrings: 0.0019 +/-0.007 m3). In addition, the load-velocity profiles have been derived in the same group of subjects. The MRI-based muscle volumes are in a similar range to previously published data (Maeo et al., 2021). Furthermore, the results of the load-velocity profiles show the anticipated decrease according to velocity-based RT guidelines (Rodriguez-Rosell et al., 2020). Discussion In a next step further data will be acquired in more subjects for subsequent statistical analysis. The outcome of the present study is expected to provide new scientific insights into the relationship between musculoskeletal and biomechanical criteria that affect squat performance. The insight may help to optimize velocity-based RT recommendations for individual athletes to maximise performance and reduce injury risks. References Rodríguez-Rosell, D., Yáñez-García, J. M., Sánchez-Medina, L., Mora-Custodio, R., & González-Badillo, J. J. (2020). Relationship between velocity loss and repetitions in Reserve in the bench press and back squat exercises. Journal of Strength and Conditioning Research, 34(9), 2537–2547. https://doi.org/10.1519/JSC.0000000000002881 Maeo, S., Huang, M., Wu, Y., Sakurai, H., Kusagawa, Y., Sugiyama, T., Kanehisa, H., & Isaka, T. (2021). Greater hamstrings muscle hypertrophy but similar damage protection after training at long versus short muscle lengths. Medicine & Science in Sports & Exercise, 53(4), 825–837. https://doi.org/10.1249/MSS.000000000000252

First Insights in the Relationship between Lower Limb Anatomy and Back Squat Performance in Resistance-Trained Males and Females

Identifying key criteria of squat performance is essential to avoiding injuries and optimizing strength training outcomes. To work towards this goal, this study aimed to assess the correlation between lower limb anatomy and back squat performance during a set-to-exhaustion in resistance-trained males and females. Optical motion captures of squat performance and data from magnetic resonance imaging (MRI) of the lower limbs were acquired in eight healthy participants (average: 28.4 years, four men, four women). It was hypothesized that there is a correlation between subject-specific musculoskeletal and squat-specific parameters. The results of our study indicate a high correlation between the summed volume of the hamstrings and quadriceps and squat depth normalized to thigh length (r = −0.86), and a high correlation between leg size and one-repetition maximum load (r = 0.81), respectively. Thereby, a marked difference was found in muscle volume and one-repetition maximum load between males and females, with a trend of females squatting deeper. The present study offers new insights for trainers and athletes for targeted musculoskeletal conditioning using the squat exercise. It can be inferred that greater muscle volume is essential to achieving enhanced power potential, and, consequently, a higher 1RM value, especially for female athletes that tend to squat deeper than their male counterparts.ISSN:2306-535

Velocity-Based Strength Training: The Validity and Personal Monitoring of Barbell Velocity with the Apple Watch

Velocity-based training (VBT) is a method to monitor resistance training based on measured kinematics. Often, measurement devices are too expensive for non-professional use. The purpose of this study was to determine the accuracy and precision of the Apple Watch 7 and the Enode Pro device for measuring mean, peak, and propulsive velocity during the free-weighted back squat (in comparison to Vicon as the criterion). Velocity parameters from Vicon optical motion capture and the Apple Watch were derived by processing the motion data in an automated Python workflow. For the mean velocity, the barbell-mounted Apple Watch (r = 0.971–0.979, SEE = 0.049), wrist-worn Apple Watch (r = 0.952–0.965, SEE = 0.064) and barbell-mounted Enode Pro (r = 0.959–0.971, SEE = 0.059) showed an equal level of validity. The barbell-mounted Apple Watch (Vpeak: r = 0.952–0.965, SEE = 0.092; Vprop: r = 0.973–0.981, SEE = 0.05) was found to be the most valid for assessing propulsive and peak lifting velocity. The present results on the validity of the Apple Watch are very promising, and may pave the way for the inclusion of VBT applications in mainstream consumer wearables.ISSN:2075-466

Gender-specific issues of strength training loads planning for elite female athletes

Introduction Strength training is a fairly popular topic, both among sports product users and among scientists in Switzerland and other countries around the world. Nevertheless, the analysis of the literature is indicating that there is not enough scientifically based research on gender-specific issues of strength training loads planning for female athletes in sports of higher achievements. Purpose The goal of this study was to identify gender-specific issues in the planning of strength training loads for elite female athletes based on the psychophysiological and biomechanical methods of controlling. Methods To determine the model characteristics of the optimal psychophysiological state (indicators of the efficiency of attention, volume of voluntary attention, productivity, coefficients of motivational, volitional and typological components, stress resistance) and balance function of elite male and female athletes during practising competitions, we compared two independent groups (women, n = 17 and men, n = 24). All participants were aware of the objectives of the study and agreed to participate. Mathematical and statistical processing and data analysis were carried out using the computing and graphic capabilities of the computer programs “Statistica” (Statsoft, version 7.0) and Microsoft Excel 2010. Results The analysed factors and their component indicators to determine the state of psychophysiological functions for women and men. The analysis of the obtained indicators indicates that the manifestation of the characteristics of psychophysiological functions for men and women has its own gender characteristics. For men, it is a predominance of attention, and for women, mobility and strength of nervous processes. As for the quality of the balance function, significantly higher indicators (p < 0,05) are observed for women precisely when performing an attempt with closed eyes. Conclusions The sexual peculiarities of the formation of psychophysiological functions of elite athletes, the functional peculiarities of psychomotor and mental activity, as well as the peculiarities of the psychophysiological organization of information processing were revealed. The nuances regarding the indicators of quality of the balance function among elite athletes, depending on gender, are revealed, which is primarily related to the location of the centres of gravity: in women, it is located in the hips, and in men, it is much higher. This will, for example, directly affect the difference in the recommended angle in the knee area for female and male athletes during the strength exercise “squat with a barbell”. In addition, we would like to note that the data of the studied literature sources and our previous studies allow us to formulate a hypothesis regarding the change in the speed of basic training in elite female athletes under the influence of hormonal changes in different phases of their menstrual cycle. This hypothesis will be further investigated in forthcoming research