From twitch to tetanus: performance of excitation dynamics optimized for a twitch in predicting tetanic muscle forces

Abstract Various simulation type tools and conventional algorithms are being used to determine knee muscle forces of human during dynamic movement. These all may be good for clinical uses, but have some drawbacks, such as higher computational times, muscle redundancy and less cost-effective solution. Recently, there has been an interest to develop supervised learning-based prediction model for the computationally demanding process. The present research work is used to develop a cost-effective and efficient machine learning (ML) based models to predict knee muscle force for clinical interventions for the given input parameter like height, mass and angle. A dataset of 500 human musculoskeletal, have been trained and tested using four different ML models to predict knee muscle force. This dataset has obtained from anybody modeling software using AnyPyTools, where human musculoskeletal has been utilized to perform squatting movement during inverse dynamic analysis. The result based on the datasets predicts that the random forest ML model outperforms than the other selected models: neural network, generalized linear model, decision tree in terms of mean square error (MSE), coefficient of determination (R2), and Correlation (r). The MSE of predicted vs actual muscle forces obtained from the random forest model for Biceps Femoris, Rectus Femoris, Vastus Medialis, Vastus Lateralis are 19.92, 9.06, 5.97, 5.46, Correlation are 0.94, 0.92, 0.92, 0.94 and R2 are 0.88, 0.84, 0.84 and 0.89 for the test dataset, respectively.

Download Full-text

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

Applied Sciences ◽

10.3390/app11052356 ◽

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.

Download Full-text

Screwdriver torque strength and physiological cost of muscles dependent on hand preference and direction of rotation

Occupational Ergonomics ◽

10.3233/oer-1998-1103 ◽

1998 ◽

Vol 1 (1) ◽

pp. 13-22

Author(s):

Helmut Strasser ◽

Baoquiu Wang

Keyword(s):

Hand Preference ◽

Dominant Hand ◽

Muscle Forces ◽

Maximum Torque ◽

Physiological Cost ◽

Nondominant Hand ◽

Physiological Differences ◽

Torque Values ◽

The Right

The focus of this research was to investigate how maximum torque and muscle forces were affected by pronation and supination, i.e., inward and outward rotation of the forearm in a series of screwdriver tests with 6 varied handles. Consecutively, maximum torque for pronation and supination was determined, submaximum isometric levels of torque were demanded, and, finally, an equal dynamic screwing work for all subjects was simulated. Physiological cost of performance was simultaneously measured by registrations of electromyographic activities (EA) from 4 muscles, which were expected to be involved intensively in screwing tasks. Significant and essential differences between maximum torque values produced by pronation and supination of the right and the left arm of the mainly right-handed subjects were found. For clockwise work, as it is necessary e.g., for driving in screws, inward rotations (pronations) of the nondominant hand are at least as strong as outward rotations of the dominant hand. Differences of about 8% favour of pronations were found. Yet, for counter clockwise work involved e.g., in removing a tightened screw, inward rotations of the dominant hand yielded a much more stronger torque strength than outward rotations of the nondominant hand. Differences of more than 50% right-handed subjects were measured. Also, EA values of the 4 muscles monitored on the right arm differed significantly. Systematically operational and physiological differences due to the varied screwdriver grips, as results of investigations which were not the main objective of the study, corresponded well with the findings of prior studies.

Download Full-text

Real-Time Musculoskeletal Kinematics and Dynamics Analysis Using Marker- and IMU-Based Solutions in Rehabilitation

Sensors ◽

10.3390/s21051804 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1804

Author(s):

Dimitar Stanev ◽

Konstantinos Filip ◽

Dimitrios Bitzas ◽

Sokratis Zouras ◽

Georgios Giarmatzis ◽

...

Keyword(s):

Real Time ◽

Small Error ◽

Grand Challenge ◽

Muscle Forces ◽

Time Estimates ◽

Musculoskeletal Models ◽

Open Source Framework ◽

Measurement Units ◽

Technical Details ◽

Significant Milestone

This study aims to explore the possibility of estimating a multitude of kinematic and dynamic quantities using subject-specific musculoskeletal models in real-time. The framework was designed to operate with marker-based and inertial measurement units enabling extensions far beyond dedicated motion capture laboratories. We present the technical details for calculating the kinematics, generalized forces, muscle forces, joint reaction loads, and predicting ground reaction wrenches during walking. Emphasis was given to reduce computational latency while maintaining accuracy as compared to the offline counterpart. Notably, we highlight the influence of adequate filtering and differentiation under noisy conditions and its importance for consequent dynamic calculations. Real-time estimates of the joint moments, muscle forces, and reaction loads closely resemble OpenSim’s offline analyses. Model-based estimation of ground reaction wrenches demonstrates that even a small error can negatively affect other estimated quantities. An application of the developed system is demonstrated in the context of rehabilitation and gait retraining. We expect that such a system will find numerous applications in laboratory settings and outdoor conditions with the advent of predicting or sensing environment interactions. Therefore, we hope that this open-source framework will be a significant milestone for solving this grand challenge.

Download Full-text

Extrinsic foot muscle forces when running in varus, valgus and neutral shoes

Footwear Science ◽

10.1080/19424280902977301 ◽

2009 ◽

Vol 1 (sup1) ◽

pp. 61-62

Author(s):

Joseph Hamill ◽

Elizabeth Russell ◽

Allison Gruber ◽

Ross Miller ◽

Kristian O’Connor

Keyword(s):

Muscle Forces

Download Full-text

Influence of patellar thickness on patellofemoral contact forces and quadriceps muscle forces

Journal of Biomechanics ◽

10.1016/s0021-9290(06)85012-8 ◽

2006 ◽

Vol 39 ◽

pp. S492 ◽

Cited By ~ 1

Author(s):

L.F. Silveira ◽

C. Bernardes ◽

G. Portella ◽

F. Araujo ◽

J. Loss

Keyword(s):

Quadriceps Muscle ◽

Contact Forces ◽

Muscle Forces ◽

Patellar Thickness

Download Full-text

Theoretical studies of excitation dynamics in a peridinin-chlorophyll-protein coupled to a metallic nanoparticle

Open Physics ◽

10.2478/s11534-011-0003-x ◽

2011 ◽

Vol 9 (2) ◽

Cited By ~ 5

Author(s):

Mikolaj Schmidt ◽

Sebastian Mackowski

Keyword(s):

Energy Transfer ◽

Metallic Surface ◽

Energy Transfer Rate ◽

Metallic Nanoparticle ◽

Light Harvesting Complex ◽

Radiative Processes ◽

Förster Energy Transfer ◽

Chlorophyll Protein ◽

Induced Changes ◽

Excitation Dynamics

AbstractIn this work we study the influence of plasmon excitations on the excitation dynamics within a protein complex embedding two chlorophyll molecules coupled to a gold nanosphere. Small separation between the chlorophylls and metallic nanoparticle allows us to simplify the calculations of the Förster energy transfer rate and non-radiative processes by replacing a spherical nanoparticle with a metallic surface. Our results show modifications of all relevant processes and the energy transfer pathways within the system as well as the radiative processes. Plasmon induced changes result in strong qualitative effects of the fluorescence of the studied light-harvesting complex.

Download Full-text