Dynamic Effects of Muscle Moment Arm Variation and Heavy External Loads on Hinge Joints

2003 ◽  
Vol 19 (3) ◽  
pp. 223-238 ◽  
Author(s):  
Andrea Biscarini
Keyword(s):  
Angular Velocity ◽  
Range Of Motion ◽  
External Load ◽  
Joint Angle ◽  
Joint Modeling ◽  
Moment Arm ◽  
Moment Arms ◽  
Flexion Extension ◽  
External Loads ◽  
Load Weight

A two-dimensional model has been developed to predict and explain the effects of the variation of muscle moment arms during dynamic exercises involving heavy external loads. The analytical dependence of the muscle moment arm on the joint angle and on the origin and insertion position was derived for an ideal uniaxial hinge joint, modeling the muscle as a cable following an idealized minimum distance path from the origin to insertion that wraps around the bony geometry. Analytical expressions for the ratios of muscular force and the joint restraining reaction components to the external load weight were deduced, for isokinetic and static exercises, as a function of joint angle, joint angular velocity, and the other geometric parameters defining the model. Therefore, external load weight, joint angular velocity, and constraints to joint range of motion may be adjusted reciprocally in order to control in advance the peak value of the components of the joint load during isokinetic exercises. A dynamic formulation of forearm flexion/extension was solved numerically under the condition of constant biceps force in order to highlight the key role played by the variation in muscle moment arm in preventing injury during lifting of external loads against gravity. For example, our analysis indicates that the mean and peak resultant joint loads decrease by 5% and 14%, respectively, as a result of the change in muscle moment arm that occurs over the range of motion.

Analysis of the mero-carpopodite joint of the American lobster and snow crab. II. Kinematics, morphometrics and moment arms

2003 ◽  
Vol 83 (6) ◽  
pp. 1249-1259 ◽  
Author(s):  
S.C. Mitchell ◽  
M.E. DeMont
Keyword(s):  
Joint Angle ◽  
Snow Crab ◽  
Moment Arm ◽  
Scaling Effects ◽  
Joint Angles ◽  
Positive Allometry ◽  
Moment Arms ◽  
Arm Reaching ◽  
Flexion Extension ◽  
The Moment

This research reports on the kinematics of lobster and snow crab walking, documents changes in the moment arms of the mero-carpopodite joint during rotation, and examines scaling effects of morphological and mechanical variables in these crustacean species. Forward walking lobsters and lateral walking crabs were recorded and images analysed to describe the kinematics of these animals, and subsequently morphometric and moment arm measurements made. During forward walking the lobster maintains fixed mero-carpopodite joint angles during both the power and recovery strokes, though each of the walking legs maintains different joint angles. Legs 3 and 5 are maintained at angles which appear to equalize the flexor and extensor moment arms, and leg 4 joint angle appears to maximize the extensor moment arm. The snow crab has a joint excursion angle of between approximately 50° to 150° and, during flat bed walking, the leading and trailing legs move through similar excursion angles. The length of the meropodite for both species are longer for the anterior two leg pairs relative to the posterior two pairs and the rate of growth of the meropodite is largely isometric for the lobster while consistently increases with positive allometry in the crab. The flexor and extensor moment arms generated as the joint undergoes flexion/extension show two distinct patterns with the extensor moment arm being maximized at relatively low joint angles (55°–115°) and the flexor moment arm reaching a plateau at joint extension with angles between 95° and 155°. The flexor apodeme possesses the largest moment arms in all legs for both species, suggesting the flexors are able to generate greater torques. It appears that, mechanically, these laterally moving animals may be ‘pulling’ with the leading legs to a greater extent than ‘pushing’ with the trailing legs.

FUNCTIONAL AND KINEMATIC ANALYSIS OF A WRIST RADIAL HEMIARTHROPLASTY DESIGN

2018 ◽  
Vol 21 (01) ◽  
pp. 1850005
Author(s):  
Alexander W. Hooke ◽  
Eric Wagner ◽  
Kurt Pettersson ◽  
Per Fischer ◽  
Marco Rizzo
Keyword(s):  
Range Of Motion ◽  
Moment Arm ◽  
Ulnar Deviation ◽  
Functional Changes ◽  
Flexor Carpi Radialis ◽  
Moment Arms ◽  
Flexion Extension ◽  
Flexion Moment ◽  
The Mean ◽  
Extensor Carpi Radialis

Purpose: A biomechanical functional assessment was performed on a newly designed wrist hemiarthroplasty implant with aimed to identifying differences between the native wrist and wrist following the hemiarthroplasty procedure with [Formula: see text] and without a proximal row carpectomy (Hemi). Methods: Six cadaveric wrists were mounted on a custom testing fixture and underwent a series of functional tests to investigate differences in range of motion, muscles moment arms, and axis of rotation between the intact and post-operative wrists. The tested movements included manually-driven flexion-extension, radial-ulnar deviation, dart throwers motion, and circumduction. Results: The only significant change in range of motion was a decrease in flexion between the intact [Formula: see text] and both the Hemi [Formula: see text] and [Formula: see text] [Formula: see text] conditions. Minor differences in the mean position and variability of the axis of rotation’s piercing point were identified. A statistically significant decrease in the flexion moment arm of the flexor carpi radialis was identified between the intact ([Formula: see text][Formula: see text]mm) and [Formula: see text] ([Formula: see text][Formula: see text]mm) conditions. Statistically significant decreases were also identified in the radial deviation moment arms of the extensor carpi radialis brevis’ between the intact ([Formula: see text][Formula: see text]mm) and [Formula: see text] ([Formula: see text][Formula: see text]mm) conditions and the flexor carpi radialis’ between the intact ([Formula: see text][Formula: see text]mm) and Hemi ([Formula: see text][Formula: see text]mm) conditions as well as in the ulnar deviation moment arm of the extensor carpi ulnaris between the intact ([Formula: see text][Formula: see text]mm) and Hemi ([Formula: see text][Formula: see text]mm) conditions. Conclusions: While some statistically significant functional changes were identified between the native and hemiarthroplasty wrist, the findings suggest that post-operative function is equally acceptable in hemiarthroplasty with and without resection of the proximal carpal row.

scholarly journals Functional and Structural Moment Arm Validation for Musculoskeletal Models: A Study of the Human Forearm and Hand

2020 ◽  
Author(s):  
Matthew T Boots ◽  
Russell Hardesty ◽  
Anton Sobinov ◽  
Valeriya Gritsenko ◽  
Jennifer L. Collinger ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Force Generation ◽  
High Dimensional ◽  
Artificial Limbs ◽  
Moment Arm ◽  
Joint Torques ◽  
Moment Arms ◽  
Physiological Range ◽  
Musculoskeletal Models ◽  
Flexion Extension

AbstractThe development of realistic musculoskeletal models is a fundamental goal for the theoretical progress in sensorimotor control and its engineering applications, e.g., in the biomimetic control of artificial limbs. Yet, accurate models require extensive experimental measures to validate structural and functional parameters describing muscle state over the full physiological range of motion. However, available experimental measurements of, for example, muscle moment arms are sparse and often disparate. Validation of these models is not trivial because of the highly complex anatomy and behavior of human limbs. In this study, we developed a method to validate and scale kinematic muscle parameters using posture-dependent moment arm profiles, isometric force measurements, and a computational detection of assembly errors. We used a previously published model with 18 degrees of freedom (DOFs) and 32 musculotendon actuators with force generated from a Hill-type muscle model. The muscle path from origin to insertion with wrapping geometry was used to model the muscle lengths and moment arms. We simulated moment arm profiles across the full physiological range of motion and compared them to an assembled dataset of published and merged experimental profiles. The muscle paths were adjusted using custom metrics based on root-mean-square and correlation coefficient of the difference between simulated and experimental values. Since the available measurements were sparse and the examination of high-dimensional muscles is challenging, we developed analyses to identify common failures, i.e., moment arm functional flipping due to the sign reversal in simulated moments and the imbalance of force generation between antagonistic groups in postural extremes. The validated model was used to evaluate the expected errors in torque generation with the assumption of constant instead of the posture-dependent moment arms at the wrist flexion-extension DOF, which is the critical joint in our model with the largest number of crossing muscles. We found that there was a reduction of joint torques by about 35% in the extreme quartiles of the wrist DOF. The use of realistic musculoskeletal models is essential for the reconstruction of hand dynamics. These models may improve the understanding of muscle actions and help in the design and control of artificial limbs in future applications.New & NoteworthyRealistic models of human limbs are a development goal required for the understanding of motor control and its applications in biomedical fields. However, developing accurate models is restrained by the lack of accurate and reliable musculoskeletal measurements in humans. Here, we have overcome this challenge by using multi-stage validation of simulated structures using both experimental data and the identification of structural failures in the high-dimensional muscle paths. We demonstrate that the rigorous structural and functional validation method is essential for the understanding of force generation at the wrist.

scholarly journals Validation of a Feedback-Controlled Elbow Simulator Design: Elbow Muscle Moment Arm Measurement

2009 ◽  
Vol 3 (3) ◽  
Author(s):  
Laurel Kuxhaus ◽  
Patrick J. Schimoler ◽  
Jeffrey S. Vipperman ◽  
Mark Carl Miller
Keyword(s):  
Closed Loop ◽  
Joint Angle ◽  
Ulnar Collateral Ligament ◽  
Moment Arms ◽  
Pronator Teres ◽  
Flexion Extension ◽  
Simulator Design ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
Allegheny General Hospital

The Allegheny General Hospital (AGH) elbow simulator was designed to be a closed-loop physiologic simulator actuating movement in cadaveric elbow specimens via servoelectric motors that attach to the tendons of the biceps, brachialis, triceps, and pronator teres muscles. A physiologic elbow simulator should recreate the appropriate moment arms throughout the elbow’s range of motion. To validate this design goal, muscle moment arms were measured in three cadaver elbow specimens using the simulator. Flexion-extension moment arms of four muscles were measured at three different pronation/supination angles: fully pronated, fully supinated, and neutral; pronation-supination moment arms were measured at three different flexion-extension angles: 30 deg, 60 deg, and 90 deg. The tendon-displacement method was used in these measurements, in which the ratio of the change in musculotendon length to the change in joint angle was computed. The numeric results compared well with those previously reported; the biceps and pronator teres flexion-extension moment arms varied with pronation-supination position, and vice versa. This is one of the few reports of both flexion-extension and pronation-supination moment arms in the same specimens, and represents the first use of closed-loop feedback control in the AGH elbow simulator. The simulator is now ready for use in clinical studies such as in analyses of radial head replacement and medial ulnar collateral ligament repair.

scholarly journals Mechanistic insights into the modulatory role of the mechanoreflex on central hemodynamics using passive leg movement in humans

2018 ◽  
Vol 125 (2) ◽  
pp. 545-552 ◽  
Author(s):  
Nicholas T. Kruse ◽  
William E. Hughes ◽  
Darren P. Casey
Keyword(s):  
Cardiac Output ◽  
Angular Velocity ◽  
Range Of Motion ◽  
Joint Angle ◽  
Feedback Mechanism ◽  
Fascicle Length ◽  
Percent Change ◽  
Muscle Fascicle ◽  
Angular Velocities ◽  
Leg Movement

The aim of this study was to examine the independent contributions of joint range of motion (ROM), muscle fascicle length (MFL), and joint angular velocity on mechanoreceptor-mediated central cardiovascular dynamics using passive leg movement (PLM) in humans. Twelve healthy men (age: 23 ± 2 yr, body mass index: 23.7 kg/m2) performed continuous PLM at various randomized joint angle ROMs (0°–50° vs. 50°–100° vs. 0°–100°) and joint angular velocities (“fast”: 200°/s vs. “slow”: 100°/s). Measures of heart rate (HR), cardiac output (CO), and mean arterial pressure (MAP) were recorded during baseline and during 60 s of PLM. MFL was calculated from muscle architectural measurements of fascicle pennation angle and tissue thickness (Doppler ultrasound). Percent change in MFL increased across the transition of PLM from 0° to 50° (15 ± 3%; P < 0.05) and from 0° to 100° knee flexion (27 ± 4%; P < 0.05). The average peak percent change in HR (increased, approx. +5 ± 2%; P < 0.05), CO (increased, approx. +5 ± 3%; P < 0.05), and MAP (decreased, approx. −2 ± 2%; P < 0.05) were similar between fast versus slow angular velocities when compared against shorter absolute joint ROMs (i.e., 0°–50° and 50°–100°). However, the condition that exhibited the greatest angular velocity in combination with ROM (0°–100° at 200°/s) elicited the greatest increases in HR (+13 ± 2%; P < 0.05) and CO (+12 ± 2%; P < 0.05) compared with all conditions. Additionally, there was a significant relationship between MFL and HR within 0°–100° at 200°/s condition ( r2 = 0.59; P < 0.05). These findings suggest that increasing MFL and joint ROM in combination with increased angular velocity via PLM are important components that activate mechanoreflex-mediated cardioacceleration and increased CO. NEW & NOTEWORTHY The mechanoreflex is an important autonomic feedback mechanism that serves to optimize skeletal muscle perfusion during exercise. The present study sought to explore the mechanistic contributions that initiate the mechanoreflex using passive leg movement (PLM). The novel findings show that progressively increasing joint angle range of motion and muscle fascicle length via PLM, in combination with increased angular velocity, are important components that activate mechanoreflex-mediated cardioacceleration and increase cardiac output in humans.

scholarly journals Interactive Effects of Joint Angle, Contraction State and Method on Estimates of Achilles Tendon Moment Arms

2013 ◽  
Vol 29 (2) ◽  
pp. 241-244 ◽  
Author(s):  
Florian Fath ◽  
Anthony J. Blazevich ◽  
Charlie M. Waugh ◽  
Stuart C. Miller ◽  
Thomas Korff
Keyword(s):  
Achilles Tendon ◽  
Joint Angle ◽  
Input Parameter ◽  
Maximum Voluntary Contraction ◽  
Muscular Contraction ◽  
Voluntary Contraction ◽  
Interactive Effects ◽  
Moment Arm ◽  
Moment Arms ◽  
Musculoskeletal Models

The muscle-tendon moment arm is an important input parameter for musculoskeletal models. Moment arms change as a function of joint angle and contraction state and depend on the method being employed. The overall purpose was to gain insights into the interactive effects of joint angle, contraction state and method on the Achilles tendon moment arm using the center of rotation (COR) and the tendon excursion method (TE). Achilles tendon moment arms were obtained at rest (TErest, CORrest) and during a maximum voluntary contraction (CORMVC) at four angles. We found strong correlations between TErest and CORMVC for all angles (.72 ≤ r ≤ .93) with Achilles tendon moment arms using CORMVC being 33–36% greater than those obtained from TErest. The relationship between Achilles tendon moment arms and angle was similar across both methods and both levels of muscular contraction. Finally, Achilles tendon moment arms for CORMVC were 1–8% greater than for CORrest.

scholarly journals Pilot Study of a Powered Exoskeleton for Upper Limb Rehabilitation Based on the Wheelchair

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Qiaoling Meng ◽  
Qiaolian Xie ◽  
Haicun Shao ◽  
Wujing Cao ◽  
Feng Wang ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Upper Limb ◽  
Joint Angle ◽  
Maximum Error ◽  
Upper Limb Rehabilitation ◽  
Rehabilitation Training ◽  
Flexion Extension ◽  
Powered Exoskeleton ◽  
Limb Rehabilitation ◽  
Flexion And Extension

To help hemiplegic patients with stroke to restore impaired or lost upper extremity functionalities efficiently, the design of upper limb rehabilitation robotics which can substitute human practice becomes more important. The aim of this work is to propose a powered exoskeleton for upper limb rehabilitation based on a wheelchair in order to increase the frequency of training and reduce the preparing time per training. This paper firstly analyzes the range of motion (ROM) of the flexion/extension, adduction/abduction, and internal/external of the shoulder joint, the flexion/extension of the elbow joint, the pronation/supination of the forearm, the flexion/extension and ulnar/radial of the wrist joint by measuring the normal people who are sitting on a wheelchair. Then, a six-degree-of-freedom exoskeleton based on a wheelchair is designed according to the defined range of motion. The kinematics model and workspace are analyzed to understand the position of the exoskeleton. In the end, the test of ROM of each joint has been done. The maximum error of measured and desired shoulder flexion and extension joint angle is 14.98%. The maximum error of measured and desired elbow flexion and extension joint angle is 14.56%. It is acceptable for rehabilitation training. Meanwhile, the movement of drinking water can be realized in accordance with the range of motion. It demonstrates that the proposed upper limb exoskeleton can also assist people with upper limb disorder to deal with activities of daily living. The feasibility of the proposed powered exoskeleton for upper limb rehabilitation training and function compensating based on a wheelchair is proved.

Effect of Curvature on Sagittal Plane Moment Arms of Human Neck Muscles

2013 ◽  
Author(s):  
Bethany L. Suderman ◽  
Anita N. Vasavada
Keyword(s):  
Soft Tissues ◽  
Sagittal Plane ◽  
Neck Muscle ◽  
Moment Arm ◽  
Moment Arms ◽  
Musculoskeletal Models ◽  
Flexion Extension ◽  
Neck Rotation ◽  
Curved Paths

In musculoskeletal models of the cervical spine, muscles are often modeled as straight paths from origin to insertion [ e.g., 1]. However, muscle paths in the neck are constrained by bone and other soft tissues, and some studies have found that applying curvature to muscle paths improves anatomical accuracy [2; 3] and affects muscle parameters such as moment arm [3] and moment [4]. Currently, data available in the literature for neck muscle moment arms (MA) are sparse. In this study we estimated in-vivo moment arms using MRI-derived neck muscle paths modeled with curvature and those modeled as straight paths, for head and neck rotation in the sagittal plane (flexion-extension motion). We hypothesize that moment arm estimates for curved paths will be significantly different from estimates for straight paths.

scholarly journals Kinematic Analysis of 360° Turning in Stroke Survivors Using Wearable Motion Sensors

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 385
Author(s):  
Masoud Abdollahi ◽  
Pranav Madhav Kuber ◽  
Michael Shiraishi ◽  
Rahul Soangra ◽  
Ehsan Rashedi
Keyword(s):  
Angular Velocity ◽  
Range Of Motion ◽  
Stance Phase ◽  
Core Stability ◽  
P Value ◽  
Stroke Survivors ◽  
Lateral Bending ◽  
Body Segments ◽  
Increased Risk ◽  
Flexion Extension

Background: A stroke often bequeaths surviving patients with impaired neuromusculoskeletal systems subjecting them to increased risk of injury (e.g., due to falls) even during activities of daily living. The risk of injuries to such individuals can be related to alterations in their movement. Using inertial sensors to record the digital biomarkers during turning could reveal the relevant turning alterations. Objectives: In this study, movement alterations in stroke survivors (SS) were studied and compared to healthy individuals (HI) in the entire turning task due to its requirement of synergistic application of multiple bodily systems. Methods: The motion of 28 participants (14 SS, 14 HI) during turning was captured using a set of four Inertial Measurement Units, placed on their sternum, sacrum, and both shanks. The motion signals were segmented using the temporal and spatial segmentation of the data from the leading and trailing shanks. Several kinematic parameters, including the range of motion and angular velocity of the four body segments, turning time, the number of cycles involved in the turning task, and portion of the stance phase while turning, were extracted for each participant. Results: The results of temporal processing of the data and comparison between the SS and HI showed that SS had more cycles involved in turning, turn duration, stance phase, range of motion in flexion–extension, and lateral bending for sternum and sacrum (p-value < 0.035). However, HI exhibited larger angular velocity in flexion–extension for all four segments. The results of the spatial processing, in agreement with the prior method, showed no difference between the range of motion in flexion–extension of both shanks (p-value > 0.08). However, it revealed that the angular velocity of the shanks of leading and trailing legs in the direction of turn was more extensive in the HI (p-value < 0.01). Conclusions: The changes in upper/lower body segments of SS could be adequately identified and quantified by IMU sensors. The identified kinematic changes in SS, such as the lower flexion–extension angular velocity of the four body segments and larger lateral bending range of motion in sternum and sacrum compared to HI in turning, could be due to the lack of proper core stability and effect of turning on vestibular system of the participants. This research could facilitate the development of a targeted and efficient rehabilitation program focusing on the affected aspects of turning movement for the stroke community.

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