Minimal Kinematic Model for Inverse Dynamic Analysis of Gait

2014 ◽  
Author(s):  
D. S. Mohan Varma ◽  
S. Sujatha
Keyword(s):  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Center Of Mass ◽  
Reaction Force ◽  
Kinematic Model ◽  
Parameter Estimates ◽  
Dynamics Model ◽  
Kinematic Data ◽  
Segment Model ◽  
Internal Joint

The objective of this work is to develop an inverse dynamics model that uses minimal kinematic inputs to estimate the ground reaction force (GRF). The human body is modeled with 14 rigid segments and a circular ankle-foot-roll-over shape (AFROS) for the foot-ground interaction. The input kinematic data and body segment parameter estimates are obtained from literature. Optimization is used to ensure that the kinematic data satisfy the constraint that the swing leg clears the ground in the single support (SS) phase. For the SS phase, using the segment angles as the generalized degrees of freedom (DOF), the kinematic component of the GRF is expressed analytically as the summation of weighted kinematics of individual segments. The weighting functions are constants that are functions of the segment masses and center of mass distances. Using this form of the equation for GRF, it is seen that the kinematics of the upper body segments do not contribute to the vertical component GRFy in SS phase enabling the reduction of a 16-DOF 14-segment model to a 10-DOF 7-segment model. It is seen that the model can be further reduced to a 3-DOF model for GRFy estimation in the SS phase of gait. The horizontal component GRFx is computed assuming that the net GRF vector passes through the center of mass (CoM). The GRF in double support phase is assumed to change linearly from one foot to the other. The sagittal plane internal joint forces and moments acting at the ankle, knee and hip are computed using the 3-DOF model and the 10-DOF model and compared with the results from literature. An AFROS and measurements of the stance shank and thigh rotations in the sagittal plane, and of the lower trunk (or pelvis) in the frontal plane provide sufficient kinematics in an inverse dynamics model to estimate the GRF and joint reaction forces and moments. Such a model has the potential to simplify gait analysis.

scholarly journals Is Motorized Treadmill Running Biomechanically Comparable to Overground Running? A Systematic Review and Meta-Analysis of Cross-Over Studies

2019 ◽  
Vol 50 (4) ◽  
pp. 785-813 ◽  
Author(s):  
Bas Van Hooren ◽  
Joel T. Fuller ◽  
Jonathan D. Buckley ◽  
Jayme R. Miller ◽  
Kerry Sewell ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Knee Flexion ◽  
Sagittal Plane ◽  
Meta Analysis ◽  
Center Of Mass ◽  
Vertical Displacement ◽  
Treadmill Running ◽  
Low Grade ◽  
Healthy Humans ◽  
Internal Joint

Abstract Background Treadmills are often used in research, clinical practice, and training. Biomechanical investigations comparing treadmill and overground running report inconsistent findings. Objective This study aimed at comparing biomechanical outcomes between motorized treadmill and overground running. Methods Four databases were searched until June 2019. Crossover design studies comparing lower limb biomechanics during non-inclined, non-cushioned, quasi-constant-velocity motorized treadmill running with overground running in healthy humans (18–65 years) and written in English were included. Meta-analyses and meta-regressions were performed where possible. Results 33 studies (n = 494 participants) were included. Most outcomes did not differ between running conditions. However, during treadmill running, sagittal foot–ground angle at footstrike (mean difference (MD) − 9.8° [95% confidence interval: − 13.1 to − 6.6]; low GRADE evidence), knee flexion range of motion from footstrike to peak during stance (MD 6.3° [4.5 to 8.2]; low), vertical displacement center of mass/pelvis (MD − 1.5 cm [− 2.7 to − 0.8]; low), and peak propulsive force (MD − 0.04 body weights [− 0.06 to − 0.02]; very low) were lower, while contact time (MD 5.0 ms [0.5 to 9.5]; low), knee flexion at footstrike (MD − 2.3° [− 3.6 to − 1.1]; low), and ankle sagittal plane internal joint moment (MD − 0.4 Nm/kg [− 0.7 to − 0.2]; low) were longer/higher, when pooled across overground surfaces. Conflicting findings were reported for amplitude of muscle activity. Conclusions Spatiotemporal, kinematic, kinetic, muscle activity, and muscle–tendon outcome measures are largely comparable between motorized treadmill and overground running. Considerations should, however, particularly be given to sagittal plane kinematic differences at footstrike when extrapolating treadmill running biomechanics to overground running. Protocol registration CRD42018083906 (PROSPERO International Prospective Register of Systematic Reviews).

Regulation of Angular Impulse during Two Forward Translating Tasks

2007 ◽  
Vol 23 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Witaya Mathiyakom ◽  
Jill L. McNitt-Gray ◽  
Rand R. Wilcox
Keyword(s):  
Sagittal Plane ◽  
Center Of Mass ◽  
Reaction Force ◽  
Impulse Generation ◽  
Biarticular Muscles ◽  
Leg Coordination ◽  
Body Center ◽  
Total Body ◽  
Angular Impulse

Angular impulse generation is dependent on the position of the total body center of mass (CoM) relative to the ground reaction force (GRF) vector during contact with the environment. The purpose of this study was to determine how backward angular impulse was regulated during two forward translating tasks. Control of the relative angle between the CoM and the GRF was hypothesized to be mediated by altering trunk–leg coordination. Eight highly skilled athletes performed a series of standing reverse somersaults and reverse timers. Sagittal plane kinematics, GRF, and electromyograms of lower extremity muscles were acquired during the take-off phase of both tasks. The magnitude of the backward angular impulse generated during the push interval of both tasks was mediated by redirecting the GRF relative to the CoM. During the reverse timer, backward angular impulse generated during the early part of the take-off phase was negated by limiting backward trunk rotation and redirecting the GRF during the push interval. Biarticular muscles crossing the knee and hip coordinated the control of GRF direction and CoM trajectory via modulation of trunk–leg coordination.

Filtering Ground Reaction Force Data Affects the Calculation and Interpretation of Joint Kinetics and Energetics During Drop Landings

2013 ◽  
Vol 29 (6) ◽  
pp. 804-809 ◽  
Author(s):  
Steven T. McCaw ◽  
Jacob K. Gardner ◽  
Lindsay N. Stafford ◽  
Michael R. Torry
Keyword(s):  
Hip Joint ◽  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Joint Moment ◽  
Inverse Dynamic ◽  
Joint Kinetics ◽  
Marker Data ◽  
High Frequency Oscillations ◽  
Subsequent Calculation

An inverse dynamic analysis and subsequent calculation of joint kinetic and energetic measures is widely used to study the mechanics of the lower extremity. Filtering the kinematic and kinetic data input to the inverse dynamics equations affects the calculated joint moment of force (JMF). Our purpose was to compare selected integral values of sagittal plane ankle, knee, and hip joint kinetics and energetics when filtered and unfiltered GRF data are input to inverse dynamics calculations. Six healthy, active, injury-free university student (5 female, 1 male) volunteers performed 10 two-legged landings. JMFs were calculated after two methods of data filtering. Unfiltered: marker data were filtered at 10 Hz, GRF data unfiltered. Filtered: both GRF and marker data filtered at 10 Hz. The filtering of the GRF data affected the shape of the knee and hip joint moment-time curves, and the ankle, knee and hip joint mechanical power-time curves. We concluded that although the contributions of individual joints to the support moment and to total energy absorption were not affected, the attenuation of high-frequency oscillations in both JMF and JMP time curves will influence interpretation of CNS strategies during landing.

scholarly journals Segmental contributions to the ground reaction force in the single support phase of gait

2014 ◽  
Vol 5 (2) ◽  
pp. 37-52 ◽  
Author(s):  
D. S. Mohan Varma ◽  
S. Sujatha
Keyword(s):  
Ground Reaction Force ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Center Of Mass ◽  
Reaction Force ◽  
Experimental Studies ◽  
Vertical Component ◽  
Frontal Plane ◽  
Mathematical Form ◽  
Dynamics Models

Abstract. An inverse dynamics model for the single support (SS) phase of gait is developed to study segmental contributions to the ground reaction force (GRF). With segmental orientations as the generalized degrees of freedom (DOF), the acceleration of the body's center-of-mass is expressed analytically as the summation of the weighted kinematics of individual segments. The weighting functions are constants that are functions of the segment masses and center-of-mass distances. Using kinematic and anthropometric data from literature as inputs, and using the roll-over-shape (ROS) to model the foot-ground interaction, GRF obtained from the inverse model are compared with measured GRF data from literature. The choice of the generalized coordinates and mathematical form of the model provides a means to weigh individual segment contributions, simplify models and choose more kinetically accurate inverse dynamics models. For the kinematic data used, an anthropomorphic model that includes the frontal plane rotation of the pelvis in addition to the sagittal DOF of the thigh and shank most accurately captures the vertical component of the GRF in the SS phase of walking. Of the two ROS used, the ankle-foot roll-over shape provides a better approximation of the kinetics in the SS phase. The method presented here can be used with additional experimental studies to confirm these results.

Assessment of Internal Loads in the Joints of the Lower Extremities During the Snatch in Young Weightlifters

2019 ◽  
Vol 19 (05) ◽  
pp. 1941011
Author(s):  
Adam Czaplicki ◽  
Krzysztof Dziewiecki ◽  
Zenon Mazur ◽  
Wojciech Blajer
Keyword(s):  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Lower Extremities ◽  
Lower Limbs ◽  
Muscle Forces ◽  
Kinematic Data ◽  
Lower Trunk ◽  
Left And Right ◽  
Ground Reactions ◽  
Inverse Dynamics Problem

The aim of this paper is to present the results of an assessment of internal loads in the joints of the lower limbs during the snatch performed by young weightlifters. A planar model of a weightlifter composed of 7 rigid segments (the lower trunk, thighs, lower legs and feet) connected by six hinge joints was used in the computations. The dynamic equations of the motion of the model were obtained using a projective technique. Kinematic data were recorded by a Vicon system with a sampling frequency of 200 Hz. The ground reactions were measured independently for the left and right limbs on two force platforms. The inverse dynamics problem was solved to assess the internal loads (the muscle forces and joint reactions) in the lower limbs. Relatively high differences in the reactions in the joints and muscle forces in the left and right lower extremities were identified. The obtained results also reveal that the snatch, a lift which tends to be geometrically symmetrical in the sagittal plane, is not necessarily characterized by symmetry of internal loads. Thus, this study has shown that a kinematics analysis of the lifter’s movement, which is commonly used to assess the technique of the snatch, is insufficient and should be supplemented with a dynamics analysis.

POSTURE CONTROL AND BALANCE DURING TAI CHI CHUAN PUSH HANDS MOVEMENTS IN A FIXED STANCE

2012 ◽  
Vol 12 (05) ◽  
pp. 1250030 ◽  
Author(s):  
LIN-HWA WANG ◽  
KUO-CHENG LO ◽  
FONG-CHIN SU
Keyword(s):  
Tai Chi ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Reaction Force ◽  
Whole Body ◽  
Expert Group ◽  
Tai Chi Chuan ◽  
Kinematic Data ◽  
Analysis System ◽  
Force Data

The present study investigated the adequacy of the interaction between the center of mass (COM) and the center of pressure (COP) for maintaining dynamic stability during Tai Chi Chuan (TCC) Push Hands movements in a fixed stance. The COM of the whole body and COP were calculated. Four TCC experts, with 10.3 ± 1.7 years' experience in the Push Hands technique, and 4 TCC beginners, with 2.5 ± 1.3 years' Push Hands experience, were recruited. An Expert Vision Eagle motion analysis system collected kinematic data and 4 Kistler force plates collected the ground reaction force data. The expert group of TCC practitioners showed a significantly more vertical (P = 0.001) direction in the neutralizing circle, and significantly larger values for anterior–posterior (A–P) (P = 0.006) and vertical (P = 0.0004) displacement in the enticing circle, than the beginner group. Compared with the beginner group, the expert group demonstrated significantly greater velocity A–P (P = 0.001) and vertical (P = 0.001) COM displacements in the enticing circle. A significant extent main effect (P = 0.0028) was observed for the COPA–P excursion between the expert and beginner groups during Push Hands movements. The greater A–P force generated by both groups during the initiation of the Push Hands cycle probably reflects the more rapid and forward-oriented nature of this movement. The TCC beginners might have difficulties with movement transfers because of disruptions in the temporal sequencing of the forces. Overall, results indicated that the initial experience-related differences in COM transfers are reflected in the Push Hands movement cycle.

A Biomechanical Study of Side Steps at Different Distances

2013 ◽  
Vol 29 (3) ◽  
pp. 336-345 ◽  
Author(s):  
Yuki Inaba ◽  
Shinsuke Yoshioka ◽  
Yoshiaki Iida ◽  
Dean C. Hay ◽  
Senshi Fukashiro
Keyword(s):  
Inverse Dynamics ◽  
Center Of Mass ◽  
Reaction Force ◽  
Biomechanical Study ◽  
Joint Torque ◽  
Large Power ◽  
Lower Extremity Muscle ◽  
Ankle Joints ◽  
Hip Abduction ◽  
Muscle Groups

Lateral quickness is a crucial component of many sports. However, biomechanical factors that contribute to quickness in lateral movements have not been understood well. Thus, the purpose of this study was to quantify 3-dimensional kinetics of hip, knee, and ankle joints in side steps to understand the function of lower extremity muscle groups. Side steps at nine different distances were performed by nine male subjects. Kinematic and ground reaction force data were recorded, and net joint torque and work were calculated by a standard inverse-dynamics method. Extension torques and work done at hip, knee, and ankle joints contributed substantially to the changes in side step distances. On the other hand, hip abduction work was not as sensitive to the changes in the side step distances. The main roles of hip abduction torque and work were to accelerate the center of mass laterally in the earlier phase of the movement and to keep the trunk upright, but not to generate large power for propulsion.

scholarly journals Sagittal and Frontal Plane Gait Initiation Kinetics in Healthy, Young Subjects

2019 ◽  
Vol 67 (1) ◽  
pp. 85-100
Author(s):  
Andrew W. Smith ◽  
Del P. Wong
Keyword(s):  
Steady State ◽  
Sagittal Plane ◽  
Center Of Mass ◽  
Reaction Force ◽  
Frontal Plane ◽  
Step Test ◽  
Gait Initiation ◽  
Joint Moments ◽  
Plane Component ◽  
Young Subjects

AbstractThe study purposes were to record the lower extremity sagittal and frontal joint moments and powers during gait initiation (GI); evaluate GI support moments in both planes; and analyze planar energy patterns in a group of 15 healthy, young adults. 3D motion and ground reaction force data were used to calculate support moments (SM) and joint moments and powers as well as center of mass (COM) kinematics. STEP1 had no visible SM. It appeared in STEP2 and, by STEP3, resembled that seen in steady-state gait. Joint moments demonstrated a similar development towards typical patterns over the three steps. Correlations of moment data between planes indicate that the frontal plane component of the SM acts to keep the COM centered. It is suggested that Winter’s 1980 SM definition be extended to include both a support (sagittal) component and a centering (frontal) component. Energy was calculated for individual bursts of joint powers in both planes and each step had characteristic patterns in each plane, with patterns resembling steady-state gait appearing in the third step. Test-retest reliability (ICC range: 0.796 – 0.945) was high with CV values in the sagittal plane (36.6 – 37.5%) being less variable than in the frontal plane (39.0 – 82.0%). COM kinematics revealed that acceleration peaked in STEP2 (ICC range: 0.950 – 0.980, CV < 20.0%). Data supported hypotheses regarding the dominance of the frontal plane power in STEP1, with substantial power coming from hip flexors. As well, powers in the sagittal plane were generally of larger magnitude than in the frontal plane.

Human Knee Inverse Dynamics Model of Vertical Jump Exercise

2019 ◽  
Vol 14 (10) ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Ricardo Moreno
Keyword(s):  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Vertical Jump ◽  
Contact Forces ◽  
Collateral Ligaments ◽  
Dynamics Model ◽  
Human Knee ◽  
Jump Exercise ◽  
Joint Forces ◽  
Patella Ligament

Abstract This work deals with the dynamics of the human knee during vertical jump exercise. The focus is on the joint forces necessary to produce the jump and to dissipate energy during landing. A two-dimensional (2D) sagittal plane, inverse dynamics human leg model is developed. This model uses data from a motion capture system and force plates in order to predict knee and hip joint forces during the vertical jump exercise. The model consists of three bony structures femur, tibia, and patella, ligament structures to include both cruciate and collateral ligaments, and knee joint muscles. The inverse dynamics model is solved using optimization in order to predict joint forces during this exercise. matlab software package is used for the optimization computations. Results are compared with data available in the literature. This work provides insight regarding contact forces and ligaments forces, muscle forces, and knee and hip contact forces in the vertical jump exercise.

scholarly journals Changes in human walking dynamics induced by uneven terrain are reduced with ongoing exposure, but a higher variability persists

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jenny A. Kent ◽  
Joel H. Sommerfeld ◽  
Nicholas Stergiou
Keyword(s):  
Flat Surface ◽  
Sagittal Plane ◽  
Center Of Mass ◽  
Reaction Force ◽  
Movement Pattern ◽  
Transverse Plane ◽  
The Body ◽  
Whole Body ◽  
Uneven Terrain ◽  
Walking Dynamics

AbstractDuring walking, uneven terrain alters the action of the ground reaction force from stride to stride. The extent to which such environmental inconsistencies are withstood may be revealed by the regulation of whole-body angular momentum (L) during walking. L quantifies the balance of momenta of the body segments (thigh, trunk, etc.) about their combined center of mass, and remains close to zero during level walking. A failure to constrain L has been linked to falls. The aim of this study was to explore the ability of young adults to orchestrate their movement on uneven terrain, illustrated by the range of L (LR) and its variability (vLR). In eleven male adults, we observed significant increases in sagittal plane LR, and vLR in all three planes of motion during walking on an uneven in comparison to a flat surface. No reductions in these measures were observed within a 12-minute familiarisation period, suggesting that unimpaired adults either are unable to, or do not need to eliminate the effects of uneven terrain. Transverse plane LR, in contrast, was lower on immediate exposure, and then increased, pointing to the development of a less restrictive movement pattern, and would support the latter hypothesis.

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