Papers by Keyword: Kinematics

Abstract: The neurological rehabilitation focuses on enhancing functional recovery and improving the quality of life for people who have experienced injuries or diseases affecting the central or peripheral nervous system. This functional recovery includes a follow up of the kinematics of the patients limbs. The use of a open source software such as OpenSim, has been previously proposed as a tool for kinematic analysis, this software allows for highly specialized 3D musculoskeletal modeling, facilitates kinematic analysis and the assessment of force and angles in the lower and upper limbs of the human body. In this context, the propose of this research was to test the reliability of OpenSim for kinematic analysis during neurological rehabilitation. For this goal, the Motricity Index test was done by a group of three healthy participants, this values were used for comparison to the stroke patient who is currently undergoing neurological rehabilitation process. The results demonstrates all the limitations in the range of motion of the patient in comparison to the healthy group due his motor issues, such as muscle spasticity and weakness. This research shows the advantages and limitations of this software and its application in neurological rehabilitation. The goal is to contribute to the development of effective and personalized therapeutic strategies to improve the recovery process for these patients.

Abstract: The purpose of this study was to examine the recoil effect in jumping on a Korean teeterboard, a circus equipment resembling a seesaw. To our knowledge, our study is the first to include detailed measurements of bending movement of the teeterboard per section. Two elite acrobats performed 120 jumps while a motion capture system collected kinematic data from both acrobats and the teeterboard. Board bending angles and timing were analyzed with a Boosted Regression Tree (BRT) model to identify the most important teeterboard variables associated to jump height. The BRT model showed that both the board recoil effect and the landing of the opposite acrobat influenced 46% and 37% of the jump height, respectively. The recoil timing was found to be synchronized with the last contact at take-off. Coaches should encourage acrobats to take advantage of the recoil effect to increase jump height in Korean teeterboard.

Abstract: Running is one of the most accessible physical activities and long-distance running has attracted extensive attention in the past several years. While the incidence of running injuries, especially to the lower extremities, has increased. The objective of this study was to investigate the differences in ground reaction forces (GRF) and kinematic param between long-distance runners before and after long-distance running on treadmill (TM), asphalt road (AR), and plastic track (PT). Eight-camera Vicon motion analysis system was used to measure the hip, knee and ankle motion param of 10 healthy male subjects at a speed of 2.8 ± 0.2m/s. The hip, knee and ankle kinematics and the relationship of joint angles of lower limbs in the sagittal plane, coronal plane and transversal plane were analyzed. Ground reaction force (GRF) was collected using an AMTI force platform. The results showed that there were no significant differences in GRF and average loading rate (VALR). There was no significant difference in the range of motion (ROM) of ankle and hip after long-distance running on three surfaces compared to pre-test. Compared with stance-period of pre-test, the stance-period of AR and PT were significantly longer. Post hoc analyses exhibited the stance-period of AR and PT were longer than TM. In conclusion, runners can adjust different joints angles to maintain a similar GRF during long-distance running on different sports surfaces.

Abstract: The purpose of this work is to investigate the effect of anteriorly-added mass to simulate pregnancy on lower extremities kinematic and lumbar and thoracic angles during stair ascending and descending. 18 healthy females ascended and descended, with and without a pseudo-pregnancy sac of 12 kg (experimental and control groups, respectively), a costume-made wooden staircase while instrumented with 20 reflective markers placed on the lower extremities and the spine. The movements were captured by 12 infrared cameras surrounding the staircase. Tracked position data were exported to MATLAB to calculate the required joints angles. SPSS was used to compare the ascent and descent phases of control group, and to find if there are any significant differences between control and experimental groups in the ascent phase as well as in the descent phase. When comparing the ascent and descent phases of control group, data revealed a higher hip flexion during ascending and greater ankle planter-flexion and dorsiflexion, lumbar, and thoracic angles during descending; however, no significant difference was shown in the knee flexion angle between ascending and descending. Non-pregnant data showed greater maximum hip flexion and ankle dorsiflexion during stair ascending compared to simulated-pregnant group; while ankle planter-flexion, knee flexion, and lumbar angle were greater for simulated-pregnant status. During stair descending, non-pregnant group had greater minimum hip flexion and ankle dorsiflexion compared to simulated pregnant group; while ankle planter-flexion, knee flexion, and maximum hip flexion were greater for simulated-pregnant group. However, the lumbar and thoracic angles were found to be similar for simulated-pregnant and non-pregnant groups during stair descending. In conclusion, the current study revealed important kinematic modifications pregnant women adopt while ascending and descending stairs at their final stage of pregnancy to increase their stability.

Abstract: The growing popularity of endurance sports activities is associated with a growing number of running injuries among recreational runners. The aim of this study was to assess the kinematic and kinetic variation on biomechanical parameters before and after 5km of treadmill running in female runners. Fourteen habitually shod female runners were assessed during treadmill running at their self-selected 5km running speed. A VICON motion analysis system and a Novel Pedar insole plantar pressure measurement system were used to record kinematic and plantar pressure data. Key findings from the study were that the internal and external rotation angle of the ankle, hip and knee while pre-5k running showed significant differences to those evaluated post-5k. The peak values of ground reaction forces (GRF) recorded pre-5k running were larger than the forces measured post-5k running. Combining the inversion and eversion of the ankle in the coronal plane during the pushing off phase, post-5k running showed a bigger eversion angle than pre-5k running. These subtle differences may reflect adaptation of motor control in female runners during long distance running of 5km.

Abstract: In this paper an experimental research was performed in case of a human complex motion. The research aim was to evaluate the joint trajectories and angular variations of a human upper limb. Thus an experimental motion analysis was performed, by using a modern equipment called VICON Equipment and the interest joints are: shoulder, elbow and wrist. The experimental activity was developed on a human subject when perform a complex motion from baseball sport. The obtained results will be useful for the temporal recovery of the athletes’ complex motions after a severe injury or to reshape the upper arm behavior when strikes the ball in case of baseball athletes.

Abstract: In legged robot movement planning, the leg must be carefully design before trajectory analysis can be done. The objective of this paper is to develop a 3 DOF leg which will be used in quadruped robot. In addition, forward kinematic and comparison between real and simulation of the leg is presented. To achieve the objective, SolidWorks 2013 x64 Edition is used to develop the 3D modeling of the leg while SimMechanics with First Generation Format was applied to export the models to Simulink. For the comparison purposes, real model of 3 DOF leg with Arduino Pro Mini 328 - 5V/16MHz as a microcontroller to control the rotation of three servomotors was constructed. With MIT AI2 Companion software, android apps is developed to send signal to rotate each servomotor wirelessly. The zero position of the leg robot has been determined and the maximum rotation range of each servomotor. This is very important in determination of D-H Parameters which allow the resolving of kinematics problems. It is found that specific rotations of each servomotor provide the trajectory pattern of the leg which is compared through Simulink and real model. Nevertheless, there are errors between simulation and real position of the robot leg due to the open loop system.

Abstract: Based on upper limb’s biomechanisms, in this paper, a robotic rehabilitation system is presented. It is designed as a 4 DOFs wearable exoskeleton applicable for repetitive practice of passive or active movements of the arm in shoulder joint and forearm in elbow joint. The kinematic analysis of the proposed system is followed by the 3D model and a description of the developed prototype.

Abstract: The article aims to make the description of the process for obtaining a mathematician, kinematic and dynamic model of a six-wheeled robot, in order to obtain a representation that allows simulations of drivers in the following items addressed in different ways the development of differential kinematics robots mostly with castor wheel as a fulcrum.

Abstract: In this paper an experimental research was performed in case of a human complex motion. The research aim was to evaluate the joint trajectories and angular variations of the main human locomotion system. Thus an experimental motion analysis was performed, by using two modern equipments in parallel, one called VICON Equipment and the other called CONTEMPLAS. The experimental activity was developed on a human subject when perform a complex motion for hitting a ball. The obtained results will be useful for the improvement of the athletes’ complex motions on sports such as football in the way of conserving the energy or to reshape the foot behavior when strikes the ball.