Search results for "KINEMATICS"
showing 10 items of 481 documents
Grasp with hand and mouth: a kinematic study on healthy subjects
2001
Neurons involved in grasp preparation with hand and mouth were previously recorded in the premotor cortex of monkey. The aim of the present kinematic study was to determine whether a unique planning underlies the act of grasping with hand and mouth in humans as well. In a set of four experiments, healthy subjects reached and grasped with the hand an object of different size while opening the mouth ( experiments 1 and 3), or extending the other forearm ( experiment 4), or the fingers of the other hand ( experiment 5). In a subsequent set of three experiments, subjects grasped an object of different size with the mouth, while opening the fingers of the right hand ( experiments 6–8). The init…
3D characterisation of the dynamics of foot joints of adults during walking. Gait pattern identification
2017
A detailed description of the kinematics and kinetics of the ankle, midtarsal and metatarsophalangeal joints of the feet of a healthy adult male population during barefoot walking is provided. Plots of the angles and moments in each plane during the stance phase are reported, along with the mean and standard deviation values of 87 different parameters that characterise the 3D dynamics of the foot joints. These parameters were used to check for similarities between subjects through a hierarchical analysis that allowed three different gait patterns to be identified, most of the differences corresponding to the frontal and transverse planes.
Daily changes of individual gait patterns identified by means of support vector machines.
2016
Despite the common knowledge about the individual character of human gait patterns and about their non-repeatability, little is known about their stability, their interactions and their changes over time. Variations of gait patterns are typically described as random deviations around a stable mean curve derived from groups, which appear due to noise or experimental insufficiencies. The purpose of this study is to examine the nature of intrinsic inter-session variability in more detail by proving separable characteristics of gait patterns between individuals as well as within individuals in repeated measurement sessions. Eight healthy subjects performed 15 gait trials at a self-selected spee…
FUNCTIONAL EFFECT OF SHORT-TERM IMMOBILIZATION: KINEMATIC CHANGES AND RECOVERY ON REACHING-TO-GRASP
2012
Abstract Although previous investigations agree in showing significant cortical modifications related to short-term limb immobilization, little is known about the functional changes induced by non-use. To address this issue, we studied the kinematic effect of 10 h of hand immobilization. In order to prevent any movement, right handed healthy participants wore on their dominant hand a soft bandage. They were requested to perform the same reaching-to-grasping task immediately after immobilization, 1 day before (baseline 1) and in other two following days without non-use (baseline 2 and baseline 3). While no differences were found among baseline conditions, an increase of the total duration of…
Kinematics and electromyographic activity of horse riders during various cross-country jumps in equestrian
2019
International audience; The objective of this study was to identify the key biomechanical patterns (functional muscles and kinematics) of amateur horse riders during various cross-country jumps in equestrian. Eleven riders first performed a control condition that corresponded to jumps over three different obstacles (log wall, brush and tree trunk) before jumping over the same three obstacles in a cross-country course. 3D Kinematics and electromyographic (EMG) activity was synchronously collected which included seven muscles of the riders back, lower and upper limbs. Maximum voluntary isometric strength of knee extensors was also measured before and immediately after the race to investigate …
The effect of visual focus on spatio-temporal and kinematic parameters of treadmill running
2017
The characteristics of a treadmill and the environment where it is based could influence the user’s gaze and have an effect on their running kinematics and lower limb impacts. The aim of this study was to identify the effect of visual focus on spatio-temporal parameters and lower limb kinematics during treadmill running. Twenty six experienced runners ran at 3.33 m s−1 on a treadmill under two visual conditions, either looking ahead at a wall or looking down at the treadmill visual display. Spatio-temporal parameters, impact accelerations of the head and tibia, and knee and ankle kinematics were measured for the final 15 s of a 90 s bout of running under each condition. At the end of the te…
Effects of barbell back squat stance width on sagittal and frontal hip and knee kinetics
2018
Different stance widths are commonly utilized when completing the barbell back squat during athletic general preparedness training. Width manipulation is thought to influence sagittal plane stimuli to the hip and knee extensors, the primary extensor musculature in the squat. However, how width manipulation affects frontal plane stimuli is less understood. Knowledge of hip and knee net joint moments (NJM) could improve exercise selection when aiming to improve sport-specific performance and prevent injuries. Fourteen adult amateur rugby athletes were recruited for this study. After a familiarization period, participants performed wide- (WIDE, 1.5× greater trochanter width) and narrow-stance …
Kinematics reduction applied to the comparison of highly-pronated, normal and highly-supinated feet during walking
2019
Abstract Background Kinematic analysis could help to study how variations in the static foot posture affect lower limb biomechanical function. The analysis of foot kinematics is complex because it involves managing the time-dependent joint angles in different joints and in all three planes of motion. But it could be simplified if joint angles are coordinated. Methods The kinematics of the ankle, midtarsal and metatarsophalangeal joints were registered in 20 highly-pronated, 30 normal and 20 highly-supinated subjects (assessed by the Foot Posture Index – FPI) as they walked barefoot. Coordination for each sample was analysed through principal component analysis applied to the dorsiflexion, a…
Mechanical and neural function of triceps surae in elite racewalking
2016
Racewalking is a unique event combining mechanical elements of walking with speeds associated with running. It is currently unclear how racewalking technique impacts upon lower limb muscle-tendon function, despite the relevance of this to muscle economy and overall performance. The present study examined triceps surae neuromechanics in 11 internationally competitive racewalkers (age 25±11 years) walking and running on a treadmill at speeds between 4.5 - 13.8 km/h whilst triceps surae fascicle lengths, electromyography and kinematic data were recorded. Cumulative muscle activity required to traverse a unit distance (CMAPD) was calculated for each muscle. Medial gastrocnemius (MG) and soleus …
On orienting the hand to reach and grasp an object.
1996
Subjects were required to reach and grasp a parallelepiped, the position, orientation and size of which were varied. The kinematics of reaching and grasping movements was studied in full vision and in no vision conditions. Both direction and movement amplitude of reaching were affected by object orientation. Conversely, both the time course of finger axis orientation and the angular displacement of the hand at wrist were influenced by object position. These results were not modified by the absence of visual control. Finger aperture during grasping was affected by both object size and orientation. This latter result was not due to a distorted size perception, as shown by a control matching e…