A 3D Biomechanical Model of the Hand for Power Grip

2003 ◽  
Vol 125 (1) ◽  
pp. 78-83 ◽  
Author(s):  
Joaquı´n L. Sancho-Bru ◽  
A. Pe´rez-Gonza´lez ◽  
M. Vergara ◽  
D. J. Giurintano
Keyword(s):  
Three Dimensional ◽  
Biomechanical Model ◽  
Muscle Forces ◽  
Power Grip ◽  
Grasping Force ◽  
Different Diameters ◽  
Power Grasp

A three-dimensional scalable biomechanical model of the four fingers of the hand to evaluate power grip is proposed. The model has been validated by means of reproducing an experiment in which the subjects exerted the maximal voluntary grasping force over cylinders of different diameters. The model is used to simulate the cylinder grip for two hand sizes and for five different handle diameters. The reduction of the muscle forces using different handle diameters has been studied. The model can be applied to the design and evaluation of handles for power grip and to the study of power grasp for normal and abnormal hands.

scholarly journals Optimization-Based Biomechanical Evaluation of Isometric Exertions on a Brake Wheel

1993 ◽  
Vol 37 (10) ◽  
pp. 693-696 ◽  
Author(s):  
Christian A. Johnson ◽  
Jeffrey C. Woldstad
Keyword(s):  
Repeated Measures ◽  
Three Dimensional ◽  
Compressive Force ◽  
Biomechanical Model ◽  
The Body ◽  
Body Posture ◽  
Muscle Forces ◽  
Left Hand ◽  
Lumbar Muscle ◽  
External Forces

A static three-dimensional low-back biomechanical model was developed to estimate the levels of compressive force on the L3/L4 spinal joint during an experiment that simulated wheel turning. We recorded three-dimensional body posture and the resultant forces at the hands for analysis by the model. The model employed a standard link analysis procedure to resolve the external forces acting on the body to a resultant moment about L3/L4. The model then implemented an optimization algorithm to estimate the internal lumbar muscle forces generated to resist the external forces. The muscle forces and external forces were added to arrive at a prediction of compressive force at L3/L4. The experiment investigated the effects of general body posture, left hand grip, gender, and hand brake torque level upon predicted compressive force at L3/L4. A repeated measures analysis of variance (ANOVA) revealed all but one main effect and some interaction effects to be significant at p<0.05. Average predicted L3/L4 compressive forces at maximum wheel torque levels ranged from 1644N for females to 6926N for large males.

Comparison of Biomechanical Human Neck Models: Muscle Forces and Spinal Loads at C4/5 Level

1999 ◽  
Vol 15 (2) ◽  
pp. 120-138 ◽  
Author(s):  
Hyeonki Choi ◽  
Ray Vanderby
Keyword(s):  
Cervical Spine ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Distribution Patterns ◽  
Muscle Forces ◽  
Spinal Loads ◽  
Joint Loads ◽  
Electromyographic Signals ◽  
Male Subjects ◽  
Maximum Exertion

This study developed a three-dimensional biomechanical model to investigate the internal loads on the human neck that result from isometrically generated loads resisted by a force on the head. The first goal was to apply the double-optimization (DOPT) method, the EMG-based method, and the EMG assisted optimization (EMGAO) method to the neck model, calculating muscle forces and C4/5 cervical joint loads for each method. The second goal was to compare the results of the different methods, and the third was to determine maximum exertion forces in the cervical spine for isometric contractions. To formulate the EMG-based model, electromyographic signals were collected from 10 male subjects. EMG signals were obtained from 8 sites around the C4/5 level of the neck by surface electrodes, while the subject performed near maximum, isometric exertions. The mean maximum values (±SD) calculated for C4/5 joint compressive forces during peak exertions were 1654 (±308) N in flexion by the EMG method, 1674 (±319) N in flexion by the EMGAO method, and 1208 (±123) N in extension by the DOPT method. In contrast to the DOPT method, the EMG and EMGAO methods showed activation of all the muscles, including the antagonists, and accommodated various load distribution patterns among the agonist muscles during generation of the same magnitude of moments, especially in lateral bending. The EMG and EMGAO methods predicted higher cervical spinal loads than previously published results by the DOPT method. These results may be helpful to engineers and surgeons who are designing and using cervical spine implants and instrumentation.

The Effect of Lifting vs. Lowering on Spinal Loading

1996 ◽  
Vol 40 (13) ◽  
pp. 599-603 ◽  
Author(s):  
Kermit G. Davis
Keyword(s):  
Muscle Activity ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Muscle Forces ◽  
Shear Forces ◽  
Spinal Loading ◽  
Spinal Loads ◽  
Trunk Strength ◽  
Anterior Posterior ◽  
Three Dimensional Space

In industry, workers perform tasks requiring both lifting and lowering. During concentric lifting, the muscles are shortening as the force is being generated. Conversely, the muscle lengthens while generating force during eccentric lowering. While research on various lifting tasks is extensive, there has been limited research performed to evaluate the lowering tasks. Most of the research that does exist on lowering has investigated muscle activity and trunk strength. None of these studies have investigated spinal loading. The current study estimated the effects of lifting and lowering on spinal loads and predicted moments imposed on the spine. Ten subjects performed both eccentric and concentric lifts under sagittally symmetric conditions. The tasks were performed under isokinetic trunk velocities of 5, 10, 20, 40, and 80 deg/s while holding a box with weights of 9.1, 18.2, and 27.3 kg. Spinal loads and predicted moments in three dimensional space were estimated by an EMG-assisted model which has been adjusted to incorporate the artifacts of eccentric lifting. Eccentric strength was found to be 56 percent greater than during concentric lifting. The lowering tasks produced significantly higher compression forces but lower anterior-posterior shear forces than the concentric lifting tasks. The differences in the spinal loads between the two lifting tasks were attributed to the internal muscle forces and unequal moments resulting from differences in the lifting path of the box. Thus, the differences between the lifting tasks resulted from different lifting styles associated with eccentric and concentric movements

Mechanical Evaluation of the Pronator Teres Rerouting Tendon Transfer

2004 ◽  
Vol 29 (3) ◽  
pp. 257-262 ◽  
Author(s):  
H. E. J. VEEGER ◽  
M. KREULEN ◽  
M. J. C. SMEULDERS
Keyword(s):  
Biceps Brachii ◽  
External Rotation ◽  
Three Dimensional ◽  
Muscle Length ◽  
Biomechanical Model ◽  
Elbow Flexion ◽  
Axial Rotation ◽  
Original Position ◽  
Pronator Quadratus ◽  
Pronator Teres

We simulated pronator teres rerouting using a three-dimensional biomechanical model of the arm. Simulations comprised the evaluation of changes in muscle length and the moment arm of pronator teres with changes in forearm axial rotation and elbow flexion. The rerouting of Pronator Teres was simulated by defining a path for it through the interosseous membrane with re-attachment to its original insertion. However the effect of moving the insertion to new positions, 2 cm below and above, the original position was also assessed. The effect on total internal rotation and external rotation capacity was determined by calculating the potential moments for pronator teres, supinator, pronator quadratus, biceps brachii and brachioradialis. Pronator teres was found to be a weak internal rotator in extreme pronation, but a strong internal rotator in neutral rotation and in supination. After rerouting pronator teres was only a strong external rotator in full pronation and not at other forearm positions, where the effect of rerouting was comparable to a release procedure.

An Investigation of the Variability in Human Performance during Manual Material Handling Activities

1994 ◽  
Vol 38 (10) ◽  
pp. 578-582
Author(s):  
Gary A. Mirka ◽  
Ann Baker
Keyword(s):  
Material Handling ◽  
Human Performance ◽  
Sagittal Plane ◽  
Coupling Effect ◽  
Peak Velocity ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Manual Material Handling ◽  
Symmetric Lifting ◽  
Dependent Position

The goal of this study was to quantify the variability of the three-dimensional kinematic and kinetic parameters describing the motion of the torso during the performance of sagittally symmetric lifting tasks. Subjects performed eight repetitions of simple lifting tasks described by three levels of coupling (poor, fair and good) and seven levels of load (4.5, 9, 13.5, 18, 22.5, 27 and 31.5 kg). The three-dimensional, time dependent position, velocity and acceleration of the lumbar spine were monitored using the Lumbar Motion Monitor. These measures were then input into a dynamic biomechanical model which calculated torque about the L5/S1 joint in the sagittal plane. The results of the kinematic analysis showed significant variability in the magnitude of the peak velocity and acceleration in the sagittal plane and also showed significant motion in the transverse and coronal planes. The kinetic analysis showed an increase in the variability of the peak dynamic torque with greater levels of load but no coupling effect.

Temporally resolved measurements of heavy, rigid fibre translation and rotation in nearly homogeneous isotropic turbulence

2017 ◽  
Vol 814 ◽  
pp. 42-68 ◽  
Author(s):  
L. Sabban ◽  
A. Cohen ◽  
R. van Hout
Keyword(s):  
Isotropic Turbulence ◽  
Three Dimensional ◽  
Fibre Length ◽  
Flow Characteristics ◽  
Rotation Rates ◽  
Kolmogorov Length Scale ◽  
Air Turbulence ◽  
Different Diameters ◽  
Neutrally Buoyant ◽  
Fibre Rotation

A two orthogonal view, holographic cinematography system (volume of$17\times 17\times 17~\text{mm}^{3}$) was used to measure three-dimensional fibre translational velocities, orientations and rotation rates in near homogeneous isotropic air turbulence (HIT). Flow characteristics were determined from temporally resolved particle image velocimetry measurements. Two sets of rigid, nylon fibres having the same nominal length (0.5 mm) but different diameters (13.7 and$19.1~\unicode[STIX]{x03BC}\text{m}$), were released in near HIT at a Taylor microscale Reynolds number of$Re_{\unicode[STIX]{x1D706}}\approx 130$and tracked at more than five times the Kolmogorov frequency. The ratio of fibre length to the Kolmogorov length scale was 2.8 and the two sets were characterized by Stokes numbers of 1.35 and 2.44, respectively. As a result of increased inertia, the probability density functions (PDFs) of the fluctuating fibre translational velocities were narrower than the ones of the air and the fibre velocity autocorrelations decreased at a decreasing rate. While fibre orientations in the cameras’ frame of reference were random as a result of the strong turbulence, it was shown that fibres align with the flow to minimize drag. PDFs of the fibre rotation rates indicated the occurrence of extreme rotation rate events. Furthermore, increasing inertia lowered the normalized, mean squared fibre rotation rates in comparison to results obtained for neutrally buoyant fibres having the same aspect ratio and including the effect of preferential alignment. The present results compare well to direct numerical simulations including the effect of fibre inertia.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

Three-dimensional mechanical modeling of the barbell bench press exercise: Unveiling the biomechanical function of the triceps brachii

2020 ◽  
Vol 234 (3) ◽  
pp. 245-256
Author(s):  
Andrea Biscarini ◽  
Andrea Calandra ◽  
Samuele Contemori
Keyword(s):  
Internal Rotation ◽  
Bench Press ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Considerable Change ◽  
Shoulder Abduction ◽  
Triceps Brachii ◽  
Muscle Torque ◽  
A Value ◽  
Closed Chain

A three-dimensional biomechanical model has been developed to understand and quantify the effect of the triceps brachii force during bench press exercises executed with different external loads, grip widths, and positions of the barbell relative to the shoulders at the beginning of the lift. The upper limbs, chest, and barbell were modeled as a closed three-dimensional articulated system. The elbow extension torque [Formula: see text] developed by the triceps brachii is transferred through the links of the closed chain, yielding a shoulder transverse-flexion torque [Formula: see text], shoulder adduction torque [Formula: see text], and shoulder internal-rotation torque [Formula: see text] proportional to [Formula: see text]. The proportionality factors [Formula: see text], [Formula: see text], and [Formula: see text] are independent of the load and displayed a considerable change during the lift: [Formula: see text] increased from 0.5 to 2, while [Formula: see text] and [Formula: see text] decreased progressively to zero, with a value at the beginning of the lift between 0.5 and 1 depending on the starting barbell position and grip width. Overall, [Formula: see text] considerably decreased the demand for shoulder transverse-flexion and adduction muscle-torque, slightly increased the demand for shoulder abduction muscle-torque in the final phase of the lift, and induced a shoulder internal-rotation torque that should be equilibrated by an opposite torque developed by the shoulder external rotators. With the results of this study, sport practitioners can manage the variants and kinematics of the bench press exercise to modulate the effect of the triceps brachii force on the mechanical output during different phases of the lift and planes of movement.

Estimation of Muscle Forces About the Ankle During Gait in Healthy and Neurologically Impaired Subjects

2011 ◽  
pp. 320-347
Author(s):  
Daniel N. Bassett ◽  
Joseph D. Gardinier ◽  
Kurt T. Manal ◽  
Thomas S. Buchanan
Keyword(s):  
Muscle Activation ◽  
Inverse Dynamics ◽  
Biomechanical Model ◽  
Forward Dynamics ◽  
Muscle Forces ◽  
Dynamics Model ◽  
Joint Moments ◽  
Neurologically Impaired ◽  
Model Predictions ◽  
Contraction Dynamics

This chapter describes a biomechanical model of the forces about the ankle joint applicable to both unimpaired and neurologically impaired subjects. EMGs and joint kinematics are used as inputs and muscle forces are the outputs. A hybrid modeling approach that uses both forward and inverse dynamics is employed and physiological parameters for the model are tuned for each subject using optimization procedures. The forward dynamics part of the model takes muscle activation and uses Hill-type models of muscle contraction dynamics to estimate muscle forces and the corresponding joint moments. Inverse dynamics is used to calibrate the forward dynamics model predictions of joint moments. In this chapter we will describe how to implement an EMG-driven hybrid forward and inverse dynamics model of the ankle that can be used in healthy and neurologically impaired people.

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