Tug-of-war (TOW) is an internationally played activity including professional and amateur athletes and defined as early (4000 years ago as a rope less version) in the artwork on Egyptian tomb engravings and is played as per the rules laid out by TWIF, which has 73 member countries and administrative headquarters in the USA. Typically, two teams of “pullers” participate and apply enormous contra directional forces on the pulling rope. Originally, two types of competition are used: knockout and points. This narrative review describes the scientific state of the art about of TOW. For the best of the author’s knowledge no previous information has been published. Anthropometric parameters are near 83.6, lean body mass 69.4, and body fat 16. The VO2MAX is 55.8 ml/kg/min. Relative strength, the dynamic leg power was 4659.8 N. Endurance TOW elicits minimal muscle damage. The injured strains and sprains comprised over half of all injuries: back (42%), shoulder–upper limb (23%) and knee (17%). Pulling movement in TOW contests can be divided into three phases: namely "Drop", "Hold" and "Drive" phase. The maximal pulling forces was 1041.6 ± 123.9 N. The percentage of dynamic pulling force in static maximal pulling force was 75.5 ± 14.4% and the dynamic ranged from 106.4 to 182.5%. There are two gripping styles, indoor and outdoor. The friction characteristics between surface and shoe in TOW is important to determine a suitable shoe for indoor TOW. Waist Belt might be a useful piece of equipment for TOW sport. The EMG technique in Tow described a high activity of dorsal muscle during the pulling. The factor of force vanishing was the coordination among athletes. The force vanishing percentage goes from 8.82±5.59 for 2 contenders to 19.74±2.22 for 8 athletes, 6.4 % in the sum of 2 pullers. However, in the drop phase, for female elite TOW team, only the 0.5 % of them pulling force was wasted. Future studies are need in order to understand better this historical sport activity.

We discuss slip bonds, catch bonds and the tug-of-war mechanism using mathematical arguments. We propose simple 2-dimensional surface models to demonstrate how the potential energy surface of a molecule under an external force behaves. Examples are selectines. Catch bonds in particular are explained in more detail. We demonstrate that Newton trajectories are a powerful tool to describe these phenomena. Newton trajectories form the theoretical background of Mechanochemistry.

The progress in markerless technologies is bringing clinicians tools to rapidly evaluate tests such as Timed Up and Go (TUG) without compromising the time of the assessment, yet it raises questions about the potential trade-off in accuracy compared to traditional marker-based systems, suggesting that the precision of these evaluations is not yet conclusively established. The OpenCap system is an easy tool to process 3D kinematics with two iPhone cameras placed in front of the subject. Previous research has primarily focused on walking and movement towards the cameras with the subject facing the cameras (WF) and thus has been unable to disentangle the differences in the movement directions. We have compared the OpenCap system with a standard marker-based system for both walking directions. In OpenCap, we found significantly worse results capturing walking facing away from the cameras (RW). Compared to the marker-based system, our findings indicate troubles measuring kinematic parameters but provide good accuracy in measuring spatial-temporal parameters. These insights pave the way for refining markerless assessment technologies, potentially enhancing their utility in clinical settings.

The paper presents a method for estimating the inertia tensor components of a spacecraft that has expired its active life using measurement data of the Earth's magnetic field induction vector components. The implementation of this estimation method is supposed to be carried out when cleaning up space debris in the form of a clapped-out spacecraft with the help of a space tug. It is assumed that a three-component magnetometer and a transmitting device are attached on space debris. With the help of this measuring system, the parameters for the rotational motion of space debris are estimated. Then the known controlled action from the space tug is transferred to the space debris. Next, measurements for the rotational motion parameters are carried out once again. Based on the available measurement data and parameters of the controlled action, the space debris inertia tensor components are estimated. It is assumed that the measurements of the Earth's magnetic field induction vector components are made in a coordinate system which axes are parallel to the corresponding axes of the main body axis system. Such an estimation makes it possible to effectively solve the problem of cleaning up space debris, to calculate the costs of the space tug working body and the parameters of the space debris removal orbit. Examples of numerical simulation using the measurement data of the Earth's magnetic field induction vector components on the Aist-2D small spacecraft are given. The results of the work can be used in the development and implementation of missions to clean up space debris in the form of clapped-out spacecraft.

The paper introduces and describes the recent and still ongoing development activities performed in Luxembourg for In-Orbit Attach Mechanisms for (Drag) Sails Modules to be operated from Space Tugs. After some preparatory work aiming at understanding the possible operational aspects, three designs have been completed for their 3D (Metal and Plastic) Printing. The Plastic-printed prototype underwent a series of automated tests where a robotic arm, equipped with an advanced force sensor, replicated four docking scenarii in ideal and degraded modes. The observation of the forces and torques behaviors at and after impact allowed to characterize the typical patterns for the various contacts but also, to identify a type of impact potentially dramatic for the safety of the docking and its equipment: in case of off-axis approach, “point” contacts shall be avoided as they instantaneously transfer the total kinetic energy in a small area that could break.