The Comparison of Muscle Forces Derived From Different Muscle Models

2005 ◽  
Author(s):  
Miloslav Vilimek
Keyword(s):  
Elbow Joint ◽  
Inverse Dynamics ◽  
Optimization Techniques ◽  
Muscle Forces ◽  
Bone Implant ◽  
Optimization Criteria ◽  
Functional Activities ◽  
Flexion Extension ◽  
Activation Dynamics ◽  
Muscle Models

This study, investigated the accuracy, practicality, and sensitivity of several different methods of calculating muscle forces during functional activities in humans. The upper extremity dynamic system was chosen, where the movement flexion / extension elbow joint was studied. The redundant mechanisms were solved using optimization criteria with and without models of individual muscles according to their active and passive properties. Exploration of the control problem for the redundant elbow system was performed using muscle models with and without tendon and activation dynamics. Comparisons with known movements solved by inverse dynamics approach and optimization techniques, provided similar results across to all optimization criteria. Moreover, if muscle models with active and passive properties are included in these analyses, it is relatively easy to calculate muscle forces of both agonists and antagonists. These approaches may be used to provide input data for dynamic FEM stress analysis of bones and bone-implant systems.

Prediction of Antagonistic Muscle Forces Using Inverse Dynamic Optimization During Flexion/Extension of the Knee

1999 ◽  
Vol 121 (3) ◽  
pp. 316-322 ◽  
Author(s):  
G. Li ◽  
K. R. Kaufman ◽  
E. Y. S. Chao ◽  
H. E. Rubash
Keyword(s):  
Dynamic Optimization ◽  
Optimization Procedure ◽  
Muscle Forces ◽  
Inverse Dynamic ◽  
Optimization Criteria ◽  
Flexion Extension ◽  
Antagonistic Muscle ◽  
Joint Reaction Forces ◽  
Reaction Forces ◽  
Joint Reaction

This paper examined the feasibility of using different optimization criteria in inverse dynamic optimization to predict antagonistic muscle forces and joint reaction forces during isokinetic flexion/extension and isometric extension exercises of the knee. Both quadriceps and hamstrings muscle groups were included in this study. The knee joint motion included flexion/extension, varus/valgus, and internal/external rotations. Four linear, nonlinear, and physiological optimization criteria were utilized in the optimization procedure. All optimization criteria adopted in this paper were shown to be able to predict antagonistic muscle contraction during flexion and extension of the knee. The predicted muscle forces were compared in temporal patterns with EMG activities (averaged data measured from five subjects). Joint reaction forces were predicted to be similar using all optimization criteria. In comparison with previous studies, these results suggested that the kinematic information involved in the inverse dynamic optimization plays an important role in prediction of the recruitment of antagonistic muscles rather than the selection of a particular optimization criterion. Therefore, it might be concluded that a properly formulated inverse dynamic optimization procedure should describe the knee joint rotation in three orthogonal planes.

Using Hill-Type Muscle Models and EMG Data in a Forward Dynamic Analysis of Joint Moment

2003 ◽  
Vol 03 (02) ◽  
pp. 169-186 ◽  
Author(s):  
Richard Heine ◽  
Kurt Manal ◽  
Thomas S. Buchanan
Keyword(s):  
Muscle Activation ◽  
Joint Moment ◽  
Model Parameters ◽  
Time Varying ◽  
Muscle Forces ◽  
Joint Moments ◽  
Delay Term ◽  
Activation Dynamics ◽  
Moment Models ◽  
Muscle Models

There has been considerable interest in estimating muscle forces and joint moments from EMG signals, but most approaches have not been very successful. This is largely because robust models of muscle activation dynamics, Hill-type muscle contraction dynamics, and musculoskeletal geometry are generally not included. Here we present a model which includes these sub-models and we determine which model parameters are most important. The models abilities to predict joint moments about the human elbow during time-varying isometric tasks were examined. Inputs to the models were EMGs from eight muscles. Joint moment was the output, which was compared with the measured moment. Models varied in complexity, having up to 59 adjustable parameters. It was found that a seven adjustable parameter model could adequately estimate time-varying joint moments without substantial sacrifice in performance. The key parameters that were fit for each subject were two global gain factors, a time delay term, a non-linear EMG-force term, two muscle activation terms, and a term for skewing the length-tension curve with muscle activation. This approach offers advantages over optimization-based methods for estimating individual muscle forces. Most importantly, it accounts for the way muscles are activated, which makes it potentially powerful to evaluate patients with pathologies.

scholarly journals Towards Subject-Specific Strength Training Design through Predictive Use of Musculoskeletal Models

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Michael Plüss ◽  
Florian Schellenberg ◽  
William R. Taylor ◽  
Silvio Lorenzetti
Keyword(s):  
Muscle Force ◽  
Inverse Dynamics ◽  
Gluteus Medius ◽  
The Body ◽  
External Loading ◽  
Detailed Knowledge ◽  
Muscle Forces ◽  
Specific Strength ◽  
Musculoskeletal Models ◽  
Flexion Extension

Lower extremity dysfunction is often associated with hip muscle strength deficiencies. Detailed knowledge of the muscle forces generated in the hip under specific external loading conditions enables specific structures to be trained. The aim of this study was to find the most effective movement type and loading direction to enable the training of specific parts of the hip muscles using a standing posture and a pulley system. In a novel approach to release the predictive power of musculoskeletal modelling techniques based on inverse dynamics, flexion/extension and ab-/adduction movements were virtually created. To demonstrate the effectiveness of this approach, three hip orientations and an external loading force that was systematically rotated around the body were simulated using a state-of-the art OpenSim model in order to establish ideal designs for training of the anterior and posterior parts of the M. gluteus medius (GM). The external force direction as well as the hip orientation greatly influenced the muscle forces in the different parts of the GM. No setting was found for simultaneous training of the anterior and posterior parts with a muscle force higher than 50% of the maximum. Importantly, this study has demonstrated the use of musculoskeletal models as an approach to predict muscle force variations for different strength and rehabilitation exercise variations.

scholarly journals A fair and EMG-validated comparison of recruitment criteria, musculotendon models and muscle coordination strategies, for the inverse-dynamics based optimization of muscle forces during gait

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Florian Michaud ◽  
Mario Lamas ◽  
Urbano Lugrís ◽  
Javier Cuadrado
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cost Function ◽  
Objective Function ◽  
Inverse Dynamics ◽  
Muscle Coordination ◽  
Muscle Forces ◽  
Actuator Dynamics ◽  
Activation Dynamics ◽  
The Central Nervous System

AbstractExperimental studies and EMG collections suggest that a specific strategy of muscle coordination is chosen by the central nervous system to perform a given motor task. A popular mathematical approach for solving the muscle recruitment problem is optimization. Optimization-based methods minimize or maximize some criterion (objective function or cost function) which reflects the mechanism used by the central nervous system to recruit muscles for the movement considered. The proper cost function is not known a priori, so the adequacy of the chosen function must be validated according to the obtained results. In addition of the many criteria proposed, several physiological representations of the musculotendon actuator dynamics (that prescribe constraints for the forces) along with different musculoskeletal models can be found in the literature, which hinders the selection of the best neuromusculotendon model for each application. Seeking to provide a fair base for comparison, this study measures the efficiency and accuracy of: (i) four different criteria within the static optimization approach (where the physiological character of the muscle, which affects the constraints of the forces, is not considered); (ii) three physiological representations of the musculotendon actuator dynamics: activation dynamics with elastic tendon, simplified activation dynamics with rigid tendon and rigid tendon without activation dynamics; (iii) a synergy-based method; all of them within the framework of inverse-dynamics based optimization. Motion/force/EMG gait analyses were performed on ten healthy subjects. A musculoskeletal model of the right leg actuated by 43 Hill-type muscles was scaled to each subject and used to calculate joint moments, musculotendon kinematics and moment arms. Muscle activations were then estimated using the different approaches, and these estimates were compared with EMG measurements. Although no significant differences were obtained with all the methods at statistical level, it must be pointed out that a higher complexity of the method does not guarantee better results, as the best correlations with experimental values were obtained with two simplified approaches: the static optimization and the physiological approach with simplified activation dynamics and rigid tendon, both using the sum of the squares of muscle forces as objective function.

scholarly journals The Effects of External Loads and Muscle Forces on the Knee Joint Ligaments during Walking: A Musculoskeletal Model Study

2021 ◽  
Vol 11 (5) ◽  
pp. 2356
Author(s):  
Carlo Albino Frigo ◽  
Lucia Donno
Keyword(s):  
Knee Joint ◽  
Cruciate Ligament ◽  
Musculoskeletal Model ◽  
Optimization Approach ◽  
Muscle Forces ◽  
Collateral Ligaments ◽  
Flexion Extension ◽  
Lateral Collateral Ligaments ◽  
Gastrocnemius Muscles ◽  
External Loads

A musculoskeletal model was developed to analyze the tensions of the knee joint ligaments during walking and to understand how they change with changes in the muscle forces. The model included the femur, tibia, patella and all components of cruciate and collateral ligaments, quadriceps, hamstrings and gastrocnemius muscles. Inputs to the model were the muscle forces, estimated by a static optimization approach, the external loads (ground reaction forces and moments) and the knee flexion/extension movement corresponding to natural walking. The remaining rotational and translational movements were obtained as a result of the dynamic equilibrium of forces. The validation of the model was done by comparing our results with literature data. Several simulations were carried out by sequentially removing the forces of the different muscle groups. Deactivation of the quadriceps produced a decrease of tension in the anterior cruciate ligament (ACL) and an increase in the posterior cruciate ligament (PCL). By removing the hamstrings, the tension of ACL increased at the late swing phase, while the PCL force dropped to zero. Specific effects were observed also at the medial and lateral collateral ligaments. The removal of gastrocnemius muscles produced an increase of tension only on PCL and lateral collateral ligaments. These results demonstrate how musculoskeletal models can contribute to knowledge about complex biomechanical systems as the knee joint.

AN ALGORITHM TO CALCULATE THE COMPONENTS OF ALL MUSCLE FORCES DURING EACH PHASES OF THE GAIT CYCLE, FOR THE PELVIC-FEMUR COMPLEX

2005 ◽  
Vol 05 (04) ◽  
pp. 539-548 ◽  
Author(s):  
SANTANU MAJUMDER ◽  
AMIT ROYCHOWDHURY ◽  
SUBRATA PAL
Keyword(s):  
Finite Element ◽  
Hip Joint ◽  
Computational Models ◽  
Gait Cycle ◽  
Muscle Force ◽  
Fe Analysis ◽  
Muscle Forces ◽  
Force Magnitude ◽  
Flexion Extension ◽  
Force Components

With the help of finite element (FE) computational models of femur, pelvis or hip joint to perform quasi-static stress analysis during the entire gait cycle, muscle force components (X, Y, Z) acting on the hip joint and pelvis are to be known. Most of the investigators have presented only the net muscle force magnitude during gait. However, for the FE software, either muscle force components (X, Y, Z) or three angles for the muscle line of action are required as input. No published algorithm (with flowchart) is readily available to calculate the required muscle force components for FE analysis. As the femur rotates about the hip center during gait, the lines of action for 27 muscle forces are also variable. To find out the variable lines of action and muscle force components (X, Y, Z) with directions, an algorithm was developed and presented here with detailed flowchart. We considered the varying angles of adduction/abduction, flexion/extension during gait. This computer program, obtainable from the first author, is able to calculate the muscle force components (X, Y, Z) as output, if the net magnitude of muscle force, hip joint orientations during gait and muscle origin and insertion coordinates are provided as input.

ANALYSIS OF THE EFFECTS OF SPINE STABILIZATION EXERCISES USING A WHOLE BODY TILT DEVICE ON MUSCLE FORCES IN THE SPINE

2014 ◽  
Vol 14 (06) ◽  
pp. 1440003
Author(s):  
KAP-SOO HAN ◽  
CHANG HO YU ◽  
MYOUNG-HWAN KO ◽  
TAE KYU KWON
Keyword(s):  
Inverse Dynamics ◽  
The Elderly ◽  
Body Tilt ◽  
Whole Body ◽  
Muscle Forces ◽  
Activation Patterns ◽  
Muscle Strengthening ◽  
Spine Stabilization ◽  
Inverse Dynamics Analysis ◽  
The Right

The objective of the study was to investigate the effects of 3D stabilization exercises using a whole body tilt device on forces in the trunk, such as individual muscle forces and activation patterns, maximum muscle activities and spine loads. For this sake, a musculoskeletal (MS) model of the whole body was developed, and an inverse dynamics analysis was performed to predict the forces on the spine. An EMG measurement experiment was conducted to validate the muscle forces and activation patterns. The MS model was rotated and tilted in eight different directions: anterior (A), posterior (P), anterior right (AR), posterior right (PR), anterior left (AL), posterior left (PL), right (R) and left (L), replicating the directions of the 3D spine balance exercise device, as performed in the experiment. The anterior directions of the tilt primarily induced the activation of long and superficial back muscles and the posterior directions activated the front muscles. However, deep muscles, such as short muscles and multifidi, were activated in all directions of the tilt. The resultant joint forces in the right and left directions of the tilt were the least among the directions, but higher muscle activations and more diverse muscle recruitments than other positions were observed. Therefore, these directions of tilt may be suitable for the elderly and rehabilitation patients who require muscle strengthening with less spinal loads. In the present investigation, it was shown that 3D stabilization exercises could provide considerable muscle exercise effects with a minimum perturbation of structure. The results of this study can be used to provide safety guidelines for muscle exercises using this type of tilting device. Therefore, the proposed direction of tilt can be used to strengthen targeted muscles, depending on the patients' muscular condition.

Kinematics and Laxity of Ulnohumeral Joint Under Valgus-Varus Stress

1998 ◽  
Vol 02 (01) ◽  
pp. 45-54 ◽  
Author(s):  
Shinji Tanaka ◽  
Kai-Nan An ◽  
Bernard F. Morrey
Keyword(s):  
Elbow Joint ◽  
Three Dimensional ◽  
Elbow Flexion ◽  
Axial Rotation ◽  
Joint Laxity ◽  
Treatment Modalities ◽  
Trochlear Groove ◽  
Flexion Extension ◽  
Varus Stress ◽  
Baseline Information

Three-dimensional kinematics of the ulnohumeral joint under simulated active elbow joint flexion-extension was obtained by using an electromagnetic tacking device. The joint motion was analyzed based on Eulerian angle description. In order to minimize the effect of "downstream cross-talk" on calculation of the three Eulerian angles, an optimal axis to best represent flexion-extension of the elbow joint was established. This axis, on average, is close to the line joining the centers of the capitellum and the trochlear groove. Furthermore, joint laxity under valgus-varus stress was also examined. With the weight of the forearm as the stress, maximums of 7.6° valgus-varus laxity and 5.3° axial rotation laxity were observed within a range of elbow flexion. The results of this study provide useful baseline information on joint laxity for the evaluation of elbow joints with implant replacements and other surgical treatment modalities.

Gradient Optimization of Inverse Dynamics for Robotic Manipulator Motion Planning Using Combined Optimal Control

2017 ◽  
Author(s):  
Shangdong Gong ◽  
Redwan Alqasemi ◽  
Rajiv Dubey
Keyword(s):  
Optimal Control ◽  
Motion Planning ◽  
Inverse Dynamics ◽  
Null Space ◽  
Optimal Solution ◽  
Human Motion ◽  
Optimization Techniques ◽  
Redundant Manipulators ◽  
Robot Arm ◽  
Gradient Optimization

Motion planning of redundant manipulators is an active and widely studied area of research. The inverse kinematics problem can be solved using various optimization methods within the null space to avoid joint limits, obstacle constraints, as well as minimize the velocity or maximize the manipulability measure. However, the relation between the torques of the joints and their respective positions can complicate inverse dynamics of redundant systems. It also makes it challenging to optimize cost functions, such as total torque or kinematic energy. In addition, the functional gradient optimization techniques do not achieve an optimal solution for the goal configuration. We present a study on motion planning using optimal control as a pre-process to find optimal pose at the goal position based on the external forces and gravity compensation, and generate a trajectory with optimized torques using the gradient information of the torque function. As a result, we reach an optimal trajectory that can minimize the torque and takes dynamics into consideration. We demonstrate the motion planning for a planar 3-DOF redundant robotic arm and show the results of the optimized trajectory motion. In the simulation, the torque generated by an external force on the end-effector as well as by the motion of every link is made into an integral over the squared torque norm. This technique is expected to take the torque of every joint into consideration and generate better motion that maintains the torques or kinematic energy of the arm in the safe zone. In future work, the trajectories of the redundant manipulators will be optimized to generate more natural motion as in humanoid arm motion. Similar to the human motion strategy, the robot arm is expected to be able to lift weights held by hands, the configuration of the arm is changed along from the initial configuration to a goal configuration. Furthermore, along with weighted least norm (WLN) solutions, the optimization framework will be more adaptive to the dynamic environment. In this paper, we present the development of our methodology, a simulated test and discussion of the results.

Sign in / Sign up

Export Citation Format

Share Document