Measuring Kinematic Response to Perturbed Locomotion in Young Adults

Daily life activities often require humans to perform locomotion in challenging scenarios. In this context, this study aimed at investigating the effects induced by anterior-posterior (AP) and medio-lateral (ML) perturbations on walking. Through this aim, the experimental protocol involved 12 participants who performed three tasks on a treadmill consisting of one unperturbed and two perturbed walking tests. Inertial measurement units were used to gather lower limb kinematics. Parameters related to joint angles, as the range of motion (ROM) and its variability (CoV), as well as the inter-joint coordination in terms of continuous relative phase (CRP) were computed. The AP perturbation seemed to be more challenging causing differences with respect to normal walking in both the variability of the ROM and the CRP amplitude and variability. As ML, only the ankle showed different behavior in terms of joint angle and CRP variability. In both tasks, a shortening of the stance was found. The findings should be considered when implementing perturbed rehabilitative protocols for falling reduction.

Supervised Exercise Training Improves 6 min Walking Distance and Modifies Gait Pattern during Pain-Free Walking Condition in Patients with Symptomatic Lower Extremity Peripheral Artery Disease

This study aimed to investigate the effects of supervised exercise training (SET) on spatiotemporal gait and foot kinematics parameters in patients with symptomatic lower extremity peripheral artery disease (PAD) during a 6 min walk test. Symptomatic patients with chronic PAD (Fontaine stage II) following a 3 month SET program were included. Prior to and following SET, a 6 min walk test was performed to assess the 6 min walking distance (6MWD) of each patient. During this test, spatiotemporal gait and foot kinematics parameters were assessed during pain-free and painful walking conditions. Twenty-nine patients with PAD (65.4 ± 9.9 years.) were included. The 6MWD was significantly increased following SET (+10%; p ≤ 0.001). The walking speed (+8%) and stride frequency (+5%) were significantly increased after SET (p ≤ 0.026). The stride length was only significantly increased during the pain-free walking condition (+4%, p = 0.001), whereas no significant differences were observed during the condition of painful walking. Similarly, following SET, the relative duration of the loading response increased (+12%), the relative duration of the foot-flat phase decreased (−3%), and the toe-off pitch angle significantly increased (+3%) during the pain-free walking condition alone (p ≤ 0.05). A significant positive correlation was found between changes in the stride length (r = 0.497, p = 0.007) and stride frequency (r = 0.786, p ≤ 0.001) during pain-free walking condition and changes in the 6MWD. A significant negative correlation was found between changes in the foot-flat phase during pain-free walking condition and changes in the 6MWD (r = −0.567, p = 0.002). SET was found to modify the gait pattern of patients with symptomatic PAD, and many of these changes were found to occur during pain-free walking. The improvement in individuals’ functional 6 min walk test was related to changes in their gait pattern.

Methodology of determining of the transfer function of engagement kinematics of accelerations of an aircraft and its elliptic coordinates in alternative representation

In this work, simplified expressions have been obtained that describe the kinematics parameters of the aircraft movement and its accelerations. These expressions are needed to obtain an optimal linear control law in order to provide movement of the aircraft using the hyperbola guidance method with a time difference of arrival navigation system. The key feature of the hyperbola navigation method is the ability to reduce the number of navigation positions by one when the on-board navigation equipment operates in a passive mode, carrying out only the reception of navigation information, like consumers of satellite navigation information.

Machining Performance of Robot-Type Machine Tool Consisted of Parallel and Serial Links Based on Calibration of Kinematics Parameters

This study aims to calibrate the posture of a robot-type machine tool comprising parallel and serial links using a kinematics error model and verify the machining performance based on the measurement results of a machined workpiece calibrated with kinematics parameters. A robot-type machine tool (XMINI, Exechon Enterprises LLC) is used in this study. Typically, the performance required of a robot-type machine tool is not only dimensional accuracy but also the contour accuracy of the machined workpiece. Therefore, in this study, we first construct a forward kinematics model of a robot-type machine tool and identify the kinematics parameters used in it via spatial positioning experiments using a coordinate measuring machine. Based on the parameter identification results, we calibrate this robot-type machine tool and evaluate its machining performance in terms of the dimensional accuracy and contour accuracy of the machined workpiece.

Mechanical Parameters and Trajectory of Two Chinese Cervical Manipulations Compared by a Motion Capture System

Objective: To compare the mechanical parameters and trajectory while operating the oblique pulling manipulation and the cervical rotation–traction manipulation.Methods: An experimental research measuring kinematics parameter and recording motion trajectories of two cervical manipulations were carried out. A total of 48 healthy volunteers participated in this study, who were randomly divided into two groups of 24 representing each of the two manipulations. A clinician performed two manipulations in two groups separately. A motion capture system was used to monitor and analyze kinematics parameters during the operation.Results: The two cervical manipulations have similar thrust time, displacement, mean velocity, max velocity, and max acceleration. There were no significant differences in active and passive amplitudes between the two cervical rotation manipulations. The thrust amplitudes of the oblique pulling manipulation and the cervical rotation–traction manipulation were 5.735 ± 3.041° and 2.142 ± 1.742°, respectively. The thrust amplitudes of the oblique pulling manipulation was significantly greater than that of the cervical rotation–traction manipulation (P < 0.001).Conclusion: Compared with the oblique pulling manipulation, the cervical rotation–traction manipulation has a less thrust amplitudes.

Numerical experiments of the action of power mechanisms and ways of determining the torque on the final actuators of mobile technological machines

A numerical experiment of angular displacement and angular velocity of power mechanisms is carried out on the example of potato harvesting machines. The ways of determining the torque on the final actuators such as hydraulic motors, propellers of machines and cardan gears of mobile technological machines using kinematics parameters are indicated.

Kinematic analysis as the basis for training strategy in gymnastics

The kinematic analysis of gymnastic skills performance is a widely used research method in sports science. This study presents the experience of applying the method of kinematic analysis in the managing the training process of junior gymnasts on the example of mastering three basic gymnastic skills. The test group included 10 junior male gymnasts of the age 9 to 12. The subject of kinematic analysis was based on comparing gymnasts’ joint angles, angular velocity and angular acceleration parameters. The kinematics parameters of gymnastic skills performance by a highly qualified gymnast became the target model for junior gymnasts. As a result of these targets application in the training of junior gymnasts, changes in the basic skills kinematic parameters were detected. At the end of the study, the kinematics parameters of junior gymnasts became much closer to the model parameters. Thus, the effectiveness of the kinematics analysis method in the training of junior gymnasts was demonstrated.