On the Use of Induced End Effector Force Analysis for Determining Muscle Roles During Movement

2007 ◽  
Author(s):  
Stephen J. Piazza ◽  
Vladimir M. Zatsiorsky
Keyword(s):  
Electrical Stimulation ◽  
Muscle Function ◽  
Muscle Force ◽  
Human Movement ◽  
The Body ◽  
Joint Torque ◽  
Force Analysis ◽  
End Effector ◽  
Joint Torques ◽  
Muscle Strengthening

It is often of interest in studies of human movement to quantify the function of a muscle force or muscular joint torque. Such information is useful for the identification of the causes of movement disorders and for predicting the effects of interventions including surgical procedures, targeted muscle strengthening, focal treatments for spasticity, and functional electrical stimulation. One useful way to characterize the actions of muscle forces or muscular joint torques is to create linked-segment models of the body and analyze these linkages to determine the joint angular accelerations or end effector forces that result solely from the application of the muscle force or torque in question. Such induced acceleration (IA) analyses or induced end effector force (IEF) analyses have been applied most often to quantify muscle function during normal and pathological walking [1,2].

scholarly journals Optimization of Coupling Ratio and Kinematics of an Underactuated Robot Leg for Passive Terrain Adaptability

2012 ◽  
Author(s):  
Oren Y. Kanner ◽  
Aaron M. Dollar
Keyword(s):  
Performance Metrics ◽  
Reaction Force ◽  
The Body ◽  
Joint Torque ◽  
Design Parameters ◽  
Leg Length ◽  
Coupling Ratio ◽  
Joint Torques ◽  
Robot Leg ◽  
Underactuated Robot

This paper investigates how the passive adaptability of an underactuated robot leg to uneven terrain is affected by variations in design parameters. In particular, the ratio between the joint torques, the ratio between the link lengths, and the initial joint rest angles are varied to determine configurations that allow for maximum terrain roughness adaptability while minimizing the transmission of disturbance forces to the body. The results show that a proximal/distal joint torque coupling ratio of 1.58, proximal/distal leg length ratio of 0.5, and an initial proximal joint angle of −49 degrees maximize the terrain variability over which the robot can remain stable by exerting a near-constant vertical reaction force while minimizing lateral force and moment disturbances. In addition, the spring stiffness ratio allows for a tradeoff to be made between the different performance metrics.

A Postural Model of Balance-Correcting Movement Strategies

1992 ◽  
Vol 2 (4) ◽  
pp. 323-347
Author(s):  
J.H.J. Allum ◽  
F. Honegger
Keyword(s):  
Normal Subjects ◽  
Opposite Polarity ◽  
The Body ◽  
Joint Torque ◽  
Support Surface ◽  
Joint Torques ◽  
Eyes Closed ◽  
Movement Strategies ◽  
Eyes Open ◽  
Balance Corrections

The patterns of joint torques and movement strategies underlying human balance corrections were examined using a postural model. Two types of support-surface perturbation, dorsiflexion rotation (ROT) and rearward translation (TRANS), were employed. These two perturbations were adjusted to produce similar profiles of ankle dorsiflexion in order to obtain information on the role of lower leg proprioceptive inputs on triggering balance corrections. In addition, the dependence of balance control on head angular and linear accelerations was investigated by comparing the responses of normal and vestibularly deficient subjects under eyes-closed and eyes-open conditions. Differences in ROT and TRANS movement strategies were examined in three ways First, the amplitude and polarity of active joint torques were analysed. These were obtained by altering joint torques applied to a postural model until movements of the model accurately duplicated those of measured responses. Second, the pattern of body-segment angular movements depicted by stick figures moving in response to the computed joint torques was investigated. Third, the peak amplitude and patterns of crosscorrelations between joint torques were measured. Active ankle, knee, and hip joint torques computed for normal subjects rotated the body forward for ROT. In the case of TRANS, computed active torques in normal were of opposite polarity to those of ROT and reversed the forward motion of the body. Subjects with vestibular deficits had lower amplitude torques for ROT and failed to counter the platform rotation. Hip torques for TRANS in vestibular deficient subjects were of opposite polarity to those of normal subjects and resulted in excessive forward trunk rotation. Normally, neck torques acted to stabilize the head in space when trunk angular velocity peaked. Vestibular deficient subjects displayed head movements in response to ROT similar to those generated when neck torques were absent. For TRANS, these same subjects exhibited overcompensatory neck torques. Stick figures of normal responses indicated a stiffening of the body into a leg and a trunk-head link for ROT and a flexible multilink motion for TRANS. Likewise, normal response strategies, defined by using crosscorrelations of joint torques, differed for ROT and TRANS. All joint torque crosscorrelations were significant for TRANS. Neck torques led those of all other joint torques by 40 ms or more, and hip joint led ankle torques by 30 ms. Joint torque correlations for ROT were organised around hip and ankle torques without a major correlation to neck torques. Fundamental changes in all torque crosscorrelations occurred for vestibularly deficient subjects under both eyes-open and eyes-closed conditions. These results support the hypothesis that the modulation of postural responses by vestibular signals occurs at all major joint links of the upright human body and that the strategy underlying balance corrections at the hip and neck is selected independent of local sensory input from the lower leg. Rearward translation and dorsiflexion rotation of a support-surface elicit different movement strategies when ankle angle, changes are matched for such disturbances to human upright balance.

Women Ankle Joint Torques Comparison between Bare Foot and High Heel

2013 ◽  
Vol 378 ◽  
pp. 382-386
Author(s):  
Hai Bin Liu ◽  
Zhi Qiang He ◽  
Wen Xue Yuan ◽  
Zhao Li Meng
Keyword(s):  
Ankle Joint ◽  
Muscle Force ◽  
Inverse Dynamics ◽  
Frontal Plane ◽  
Joint Torque ◽  
Force System ◽  
Joint Torques ◽  
High Heel ◽  
Internal Phase ◽  
The Stability

Objective: Research on ankle joint torques of healthy women with high heel compared with bare foot based on Inverse Dynamics. Methods: 12 women were recruited and tested by motion and force system. Kinematical, kinetic and personal segment parameter data were used to compute ankle joint torques and compare the differences between bare foot and high heel.Conclusion: compared with bare foot, It can infer that Soleus and Gastrocnemius access the contraction in advance and keep higher muscle force. Tibia Anterior and Posterior must have to make powerful contraction that could keep the ankle joint with higher torque. Compared with sagital and frontal plane, high heel doesnt change the joint torque in horizontal plane during the whole internal phase, but the fluctuations of torque value may influence the stability during normal level walking.

The relationship between controlled joint torque and end-effector force in underactuated robotic systems

Robotica ◽  
2010 ◽  
Vol 29 (4) ◽  
pp. 581-584 ◽  
Author(s):  
Jaeheung Park
Keyword(s):  
Jacobian Matrix ◽  
Joint Torque ◽  
Generalized Jacobian ◽  
End Effector ◽  
Joint Torques ◽  
Floating Base ◽  
Force Moment ◽  
Generalized Jacobian Matrix ◽  
The Relationship ◽  
Jacobian Inverse

SUMMARYThe generalized Jacobian matrix was introduced for dealing with end-effector control in space robots. One of the applications of this Jacobian is to be used in Jacobian transpose control to generate joint torques given end-effector position error. It would be misleading, however, to consider the transpose of this Jacobian as a mapping from end-effector force/moment to controlled joint torques for underactuated systems or floating base robots. This paper explains why it does not represent the mapping and provides a simple example. Later, the correct mapping is provided using the dynamically consistent Jacobian inverse and then a method to compute the actuated-joint torques is explained given the desired end-effector force. Finally, the effect of using the generalized Jacobian in the Jacobian transpose control is analyzed.

scholarly journals Are Torque-Driven Simulation Models of Human Movement Limited by an Assumption of Monoarticularity?

2021 ◽  
Vol 11 (9) ◽  
pp. 3852
Author(s):  
Martin G. C. Lewis ◽  
Maurice R. Yeadon ◽  
Mark A. King
Keyword(s):  
Lower Limb ◽  
Simulation Models ◽  
Human Movement ◽  
Joint Torque ◽  
Whole Body ◽  
Countermovement Jump ◽  
Joint Torques ◽  
Large Joint ◽  
Subject Specific ◽  
Similar Accuracy

Subject-specific torque-driven computer simulation models employing single-joint torque generators have successfully simulated various sports movements with a key assumption that the maximal torque exerted at a joint is a function of the kinematics of that joint alone. This study investigates the effect on model accuracy of single-joint or two-joint torque generator representations within whole-body simulations of squat jumping and countermovement jumping. Two eight-segment forward dynamics subject-specific rigid body models with torque generators at five joints are constructed—the first model includes lower limb torques, calculated solely from single-joint torque generators, and the second model includes two-joint torque generators. Both models are used to produce matched simulations to a squat jump and a countermovement jump by varying activation timings to the torque generators in each model. The two-joint torque generator model of squat and countermovement jumps matched measured jump performances more closely (6% and 10% different, respectively) than the single-joint simulation model (10% and 24% different, respectively). Our results show that the two-joint model performed better for squat jumping and the upward phase of the countermovement jump by more closely matching faster joint velocities and achieving comparable amounts of lower limb joint extension. The submaximal descent phase of the countermovement jump was matched with similar accuracy by the two models (9% difference). In conclusion, a two-joint torque generator representation is likely to be more appropriate for simulating dynamic tasks requiring large joint torques and near-maximal joint velocities.

scholarly journals On the Organizing Role of Nonmuscular Forces During Performance of a Giant Circle in Gymnastics

2012 ◽  
Vol 28 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Violaine Sevrez ◽  
Guillaume Rao ◽  
Eric Berton ◽  
Reinoud J. Bootsma
Keyword(s):  
Muscle Force ◽  
Inverse Dynamics ◽  
Joint Torque ◽  
Hip Joints ◽  
Joint Torques ◽  
Kinematic Pattern ◽  
Triple Pendulum ◽  
Inverse Dynamics Analysis ◽  
Induced Changes

Five elite gymnasts performed giant circles on the high bar under different conditions of loading (without and with 6-kg loads attached to the shoulders, waist or ankles). Comparing the gymnasts’ kinematic pattern of movement with that of a triple-pendulum moving under the sole influence of nonmuscular forces revealed qualitative similarities, including the adoption of an arched position during the downswing and a piked position during the upswing. The structuring role of nonmuscular forces in the organization of movement was further reinforced by the results of an inverse dynamics analysis, assessing the contributions of gravitational, inertial and muscular components to the net joint torques. Adding loads at the level of the shoulders, waist or ankles systematically influenced movement kinematics and net joint torques. However, with the loads attached at the level of the shoulders or waist, the load-induced changes in gravitational and inertial torques provided the required increase in net joint torque, thereby allowing the muscular torques to remain unchanged. With the loads attached at the level of the ankles, this was no longer the case and the gymnasts increased the muscular torques at the shoulder and hip joints. Together, these results demonstrate that expert gymnasts skillfully exploit the operative nonmuscular forces, employing muscle force only in the capacity of complementary forces needed to perform the task.

scholarly journals Effects of body movement on yaw motion in bipedal running lizard by dynamic simulation

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243798
Author(s):  
Jeongryul Kim ◽  
Hongmin Kim ◽  
Jaeheung Park ◽  
Hwa Soo Kim ◽  
TaeWon Seo
Keyword(s):  
Dynamic Simulation ◽  
Body Movement ◽  
The Body ◽  
Joint Torque ◽  
Stride Frequency ◽  
Body Movements ◽  
Joint Torques ◽  
Biomechanical Simulation ◽  
Bipedal Gait ◽  
The Relationship

Lizards run quickly and stably in a bipedal gait, with their bodies exhibiting a lateral S-shaped undulation. We investigate the relationship between a lizard’s bipedal running and its body movement with the help of a dynamic simulation. In this study, a dynamic theoretical model of lizard is assumed as a three-link consisting of an anterior and posterior bodies, and a tail, with morphometrics based on Callisaurus draconoides. When a lizard runs straight in a stable bipedal gait, its pelvic rotation is periodically synchronized with its gait. This study shows that the S-shaped body undulation with the yaw motion is generated by minimizing the square of joint torque. Furthermore, we performed the biomechanical simulation to figure out the relationship between the lizard’s lateral body undulation and the bipedal running locomotion. In the biomechanical simulation, all joint torques significantly vary by the waist and tail’ motions at the same locomotion. Besides, when the waist and tail joint angles increase, the stride length and duration of the model also increase, and the stride frequency decreases at the same running speed. It means that the lizard’s undulatory body movements increase its stride and help it run faster. In this study, we found the benefits of the lizard’s undulatory body movement and figured out the relationship between the body movement and the locomotion by analyzing the dynamics. In the future works, we will analyze body movements under different environments with various simulators.

Leg intramuscular pressures during locomotion in humans

1998 ◽  
Vol 84 (6) ◽  
pp. 1976-1981 ◽  
Author(s):  
Richard E. Ballard ◽  
Donald E. Watenpaugh ◽  
Gregory A. Breit ◽  
Gita Murthy ◽  
Daniel C. Holley ◽  
...  
Keyword(s):  
Muscle Function ◽  
Tibialis Anterior ◽  
Stance Phase ◽  
Muscle Force ◽  
Joint Torque ◽  
Heel Strike ◽  
Intramuscular Pressure ◽  
Biphasic Response ◽  
Linear Relationships ◽  
Tissue Deformations

To assess the usefulness of intramuscular pressure (IMP) measurement for studying muscle function during gait, IMP was recorded in the soleus and tibialis anterior muscles of 10 volunteers during treadmill walking and running by using transducer-tipped catheters. Soleus IMP exhibited single peaks during late-stance phase of walking [181 ± 69 (SE) mmHg] and running (269 ± 95 mmHg). Tibialis anterior IMP showed a biphasic response, with the largest peak (90 ± 15 mmHg during walking and 151 ± 25 mmHg during running) occurring shortly after heel strike. IMP magnitude increased with gait speed in both muscles. Linear regression of soleus IMP against ankle joint torque obtained by a dynamometer produced linear relationships ( n = 2, r = 0.97 for both). Application of these relationships to IMP data yielded estimated peak soleus moment contributions of 0.95–1.65 N ⋅ m/kg during walking, and 1.43–2.70 N ⋅ m/kg during running. Phasic elevations of IMP during exercise are probably generated by local muscle tissue deformations due to muscle force development. Thus profiles of IMP provide a direct, reproducible index of muscle function during locomotion in humans.

An EMG-Driven Forward Dynamics Model to Simulate Stance Phase of Gait

2009 ◽  
Author(s):  
Qi Shao ◽  
Kurt Manal ◽  
Thomas S. Buchanan
Keyword(s):  
Muscle Activation ◽  
Stance Phase ◽  
Control Strategies ◽  
Neuromuscular Control ◽  
Human Movement ◽  
Joint Torque ◽  
Forward Dynamics ◽  
Activation Patterns ◽  
Joint Torques ◽  
Muscle Activation Patterns

Simulations based on forward dynamics have been used to identify the biomechanical mechanisms how human movement is generated. They used either net joint torques [1] or muscle forces [2, 3, 4] as actuators to drive forward simulation. However, very few models used EMG-based patterns to define muscle excitations [4] or were actually driven by EMGs. Muscle activation patterns vary from subject to subject and from movement to movement, and the activations depend on the control task, sometimes quite different even for the same joint angle and joint torque [5]. Using EMG as input can account for subjects’ different muscle activation patterns and help revealing the neuromuscular control strategies.

Stiffness Design for a Spatial Three Degrees of Freedom Serial Compliant Manipulator Based on Impact Configuration Decomposition

2012 ◽  
Vol 5 (1) ◽  
Author(s):  
Dongming Gan ◽  
Nikos G. Tsagarakis ◽  
Jian S. Dai ◽  
Darwin G. Caldwell ◽  
Lakmal Seneviratne
Keyword(s):  
Degrees Of Freedom ◽  
General Procedure ◽  
Joint Torque ◽  
End Effector ◽  
Joint Torques ◽  
Serial Manipulators ◽  
Stiffness Design ◽  
Compliant Joint ◽  
The Impact ◽  
Three Degrees Of Freedom

This paper proposes a method of stiffness design for a spatial Three Degrees of Freedom (3DOF) serial compliant manipulator with the objective of protecting the compliant joint actuators when the manipulator comes up against impact. System dynamic equations of serial compliant manipulators integrated with an impact model are linearized to identify the maximum joint torques in the impact. Based on this, a general procedure is given in which maximum joint torques are calculated with different directions of end-effector velocity and impact normal in the manipulator workspace based on a given magnitude of end-effector velocity. By tuning the stiffness for each compliant joint to ensure the maximum joint torque does not exceed the maximum value of the actuator, candidate stiffness values are obtained to make the compliant actuators safe in all cases. The theory and procedure are then applied to the spatial 3DOF serial compliant manipulator of which the impact configuration is decomposed into a 2DOF planar serial manipulator and a 1DOF manipulator with a 2DOF link based on the linearized impact-dynamic model. Candidate stiffness of the 3DOF serial compliant manipulator is obtained by combining analysis of the 2DOF and 1DOF manipulators. The method introduced in this paper can be used for both planar and spatial compliant serial manipulators.

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