scholarly journals Complex couplings between joints, muscles and performance: the role of the wrist in grasping

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mathieu Caumes ◽  
Benjamin Goislard de Monsabert ◽  
Hugo Hauraix ◽  
Eric Berton ◽  
Laurent Vigouroux
Keyword(s):  
Muscle Activation ◽  
Grip Force ◽  
Muscle Force ◽  
Muscle Length ◽  
Musculoskeletal Model ◽  
Muscle Properties ◽  
Length Relationship ◽  
And Performance ◽  
The Relationship ◽  
Maximum Grip

AbstractThe relationship between posture, muscle length properties and performance remains unclear, because of a lack of quantitative data. Studies on grasping tasks suggested that wrist position could favour the extrinsic finger flexor in regards to their length to maximise grip force performance. The present study aimed at providing quantitative evidence of the links between wrist posture, muscle capacities and grip capabilities. It combines experimental measurements and a musculoskeletal model including the force-length relationship of the four prime muscles used in grasping. Participants exerted their maximum grip force on a cylindrical dynamometer in four different wrist postures, including one freely chosen by participants (spontaneous). A musculoskeletal model computed the muscle force level and length from motion capture and muscle activation. Results revealed that participants exerted maximum grip force spontaneously, with a loss of force when using other postures. At muscle force and length level, grip force variation seems to be associated with all the muscles under study. This observation led to a first quantitative link between power grip, posture and muscle properties, which could provide more insight into neuromechanical interaction involved when grasping. The design of ergonomic devices could also benefit from this quantification of the relationship between wrist angle and muscle length properties.

Dissecting muscle power output

1999 ◽  
Vol 202 (23) ◽  
pp. 3369-3375 ◽  
Author(s):  
R.K. Josephson
Keyword(s):  
Time Course ◽  
Muscle Activation ◽  
Muscle Force ◽  
Muscle Power ◽  
Muscle Length ◽  
Velocity Relationship ◽  
Shortening Deactivation ◽  
Force Velocity ◽  
Work Done ◽  
Kinetics Of

The primary determinants of muscle force throughout a shortening-lengthening cycle, and therefore of the net work done during the cycle, are (1) the shortening or lengthening velocity of the muscle and the force-velocity relationship for the muscle, (2) muscle length and the length-tension relationship for the muscle, and (3) the pattern of stimulation and the time course of muscle activation following stimulation. In addition to these primary factors, there are what are termed secondary determinants of force and work output, which arise from interactions between the primary determinants. The secondary determinants are length-dependent changes in the kinetics of muscle activation, and shortening deactivation, the extent of which depends on the work that has been done during the preceding shortening. The primary and secondary determinants of muscle force and work are illustrated with examples drawn from studies of crustacean muscles.

Fast Deformation of Skeletal Muscle Using Constraint Functions

2010 ◽  
Vol 139-141 ◽  
pp. 903-907
Author(s):  
Xiu Xia Liang
Keyword(s):  
Deformation Process ◽  
Skeletal Muscles ◽  
Muscle Force ◽  
Musculoskeletal Model ◽  
Passive Force ◽  
Fast Speed ◽  
Fast Approach ◽  
Length Relationship ◽  
Anatomical Properties ◽  
The Cost

In this paper, we propose a fast approach to simulate the dynamic behavior of skeletal muscles based on bio-mechanical and anatomical properties. In contrast to physically accurate deformation, this simulation achieves faster and better simulation of skeletal muscles, with the cost of unnoticeable visual accuracy. Internal constrains are generated to conserve linear and angular momentum which is essential for cloth self-collision. Deformation constraints are defined by using the muscle force-length relationship serve as Control Axial Curve, which constrainedly generates the active and passive force of the muscles to drive skeletal motion during the deformation process. This approach generates realistic visual effect, and manages the deformation of muscles on the basis of the bio-mechanical properties with fast speed. We have demonstrated the simulation by creating a musculoskeletal model of the upper limb.

Mechanical actions of heterogenic reflexes linking long toe flexors with ankle and knee extensors of the cat hindlimb

1994 ◽  
Vol 71 (3) ◽  
pp. 1096-1110 ◽  
Author(s):  
S. J. Bonasera ◽  
T. R. Nichols
Keyword(s):  
Muscle Activation ◽  
Muscle Force ◽  
Muscle Length ◽  
Knee Extensors ◽  
Flexor Hallucis Longus ◽  
Force Output ◽  
Small Magnitude ◽  
Dramatic Decline ◽  
Muscle Pair ◽  
Length Changes

1. To study the means whereby ankle biomechanics are represented in the interneuronal circuitry of the spinal cord we examined stretch-evoked reflex interactions between the physiological extensors flexor hallucis longus (FHL) and flexor digitorum longus (FDL) as well as their interactions with gastrocnemius (G), soleus (S), and the quadriceps group (Q) in 34 unanesthetized decerebrate cats. To evoke stretch, DC motors provided ramp-hold-release length changes to tendons detached from their bony insertions. Semiconductor myographs measured resultant muscle force response. Reflexes were examined under both quiescent (no active force generation) and activated conditions; muscle activation was achieved through either crossed-extension or flexion reflexes. 2. FHL and FDL share mutual excitatory stretch-evoked interactions under most conditions examined. These interactions depended on muscle length, were asymmetric (with FHL contributing a larger magnitude of reflex excitation onto FDL), and occurred at a latency of 16 ms. Mutual Ia synergism previously described for these two muscles provides a basis for all of the above findings. Our data demonstrate that for this muscle pair, reflex connectivities revealed at the intracellular level can be extrapolated to cover the entire motoneuron pool; further, our data directly demonstrate the net mechanical result of ensemble synaptic events. 3. FHL was found to share strong, mutually inhibitory stretch-evoked interactions with G, S, and Q. Stepwise regression statistical analyses determined that these interactions depended on recipient muscle force and donor muscle force. These reflex interactions all occurred at a latency of 28 +/- 4 (SE) ms. Further, the heterogenic inhibition between FHL/G and FHL/S was attenuated by strychnine infusion (intravenous) but unaffected by either mecamylamine, picrotoxin, or baclofen infusion (intravenous, intrathecal). Disynaptic Ib inhibition previously described among hindlimb extensors provides a basis for the above findings; our data demonstrate that under certain conditions the ensemble activity of this system can cause a dramatic decline in whole muscle force output. 4. By contrast, FDL was found to share mutually inhibitory, stretch-evoked reflex interactions with G, S, and Q that were much weaker than those observed between FHL and these same muscles. The small magnitude of inhibition observed in these interactions made it difficult to assess reflex latency or to determine the factor(s) that best predicted the heterogenic inhibition. 5. This study provides further evidence of intrinsic differences in interneuronal organization between muscles whose activity occurs in a periodic manner during locomotion ("stereotypical") and a muscle whose locomotor activity is characterized by both periodic and nonperiodic components ("facultative").(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Relationship between force and stiffness in muscle fibers after stretch

2005 ◽  
Vol 99 (5) ◽  
pp. 1769-1775 ◽  
Author(s):  
Dilson E. Rassier ◽  
Walter Herzog
Keyword(s):  
Fiber Length ◽  
Muscle Activation ◽  
Isometric Force ◽  
Ringer Solution ◽  
Isometric Contractions ◽  
Force Enhancement ◽  
Weakly Bound ◽  
Length Relationship ◽  
Cross Bridges ◽  
The Relationship

The purpose of this study was to evaluate the relationship between force and stiffness after stretch of activated fibers, while simultaneously changing contractility by interfering with the cross-bridge kinetics and muscle activation. Single fibers dissected from lumbrical muscles of frogs were placed at a length 20% longer than the plateau of the force-length relationship, activated, and stretched by 5 and 10% of fiber length (speed: 40% fiber length/s). Experiments were conducted with maximal and submaximal stimulation in Ringer solution and with the addition of 2 and 5 mM of the myosin inhibitor 2,3-butanedione monoxime (BDM) to the solution. The steady-state force after stretch of an activated fiber was higher than the isometric force produced at the corresponding length in all conditions investigated. Lowering the frequency of stimulation decreased the force and stiffness during isometric contractions, but it did not change force enhancement and stiffness enhancement after stretch. Administration of BDM decreased the force and stiffness during isometric contractions, but it increased the force enhancement and stiffness enhancement after stretch. The relationship between force enhancement and stiffness suggests that the increase in force after stretch may be caused by an increase in the proportion of cross bridges attached to actin. Because BDM places cross bridges in a weakly bound, pre-powerstroke state, our results further suggest that force enhancement is partially associated with a recruitment of weakly bound cross bridges into a strongly bound state.

scholarly journals Muscle short-range stiffness can be used to estimate the endpoint stiffness of the human arm

2011 ◽  
Vol 105 (4) ◽  
pp. 1633-1641 ◽  
Author(s):  
Xiao Hu ◽  
Wendy M. Murray ◽  
Eric J. Perreault
Keyword(s):  
Experimental Data ◽  
Short Range ◽  
Muscle Activation ◽  
Three Dimensional ◽  
Musculoskeletal Model ◽  
Muscle Stiffness ◽  
Muscle Properties ◽  
Human Arm ◽  
Wide Range ◽  
Endpoint Stiffness

The mechanical properties of the human arm are regulated to maintain stability across many tasks. The static mechanics of the arm can be characterized by estimates of endpoint stiffness, considered especially relevant for the maintenance of posture. At a fixed posture, endpoint stiffness can be regulated by changes in muscle activation, but which activation-dependent muscle properties contribute to this global measure of limb mechanics remains unclear. We evaluated the role of muscle properties in the regulation of endpoint stiffness by incorporating scalable models of muscle stiffness into a three-dimensional musculoskeletal model of the human arm. Two classes of muscle models were tested: one characterizing short-range stiffness and two estimating stiffness from the slope of the force-length curve. All models were compared with previously collected experimental data describing how endpoint stiffness varies with changes in voluntary force. Importantly, muscle properties were not fit to the experimental data but scaled only by the geometry of individual muscles in the model. We found that force-dependent variations in endpoint stiffness were accurately described by the short-range stiffness of active arm muscles. Over the wide range of evaluated arm postures and voluntary forces, the musculoskeletal model incorporating short-range stiffness accounted for 98 ± 2, 91 ± 4, and 82 ± 12% of the variance in stiffness orientation, shape, and area, respectively, across all simulated subjects. In contrast, estimates based on muscle force-length curves were less accurate in all measures, especially stiffness area. These results suggest that muscle short-range stiffness is a major contributor to endpoint stiffness of the human arm. Furthermore, the developed model provides an important tool for assessing how the nervous system may regulate endpoint stiffness via changes in muscle activation.

Effect of muscle length on electromyogram in a canine diaphragm strip preparation

1985 ◽  
Vol 58 (5) ◽  
pp. 1602-1607 ◽  
Author(s):  
M. J. Kim ◽  
W. S. Druz ◽  
J. T. Sharp
Keyword(s):  
Phrenic Nerve ◽  
Isometric Force ◽  
Muscle Length ◽  
Significant Variable ◽  
Light Pressure ◽  
Bipolar Electrodes ◽  
Length Relationship ◽  
Different Types ◽  
The Relationship ◽  
Phrenic Stimulation

The relationship between diaphragm electromyogram (EMG), isometric force, and length was studied in the canine diaphragm strip with intact blood supply and innervation under three conditions: supramaximal tetanic (100 Hz) phrenic nerve stimulation (STPS; n = 12), supramaximal phrenic stimulation at 25 Hz (n = 15), and submaximal phrenic stimulation at 25 Hz (n = 5). In the same preparation, the EMG-length relationship was also examined with direct muscle stimulation when the neuromuscular junction was blocked. EMG from three different sites and via two types of electrodes (direct or sewn-in and surface) were recorded during isometric contraction at different lengths. Direct EMGs were recorded from two bipolar electrodes sutured into the strip, one near its central end and the other near its costal end. A third EMG electrode configuration summed potentials from the whole strip by recording potentials between central and costal sites. Surface EMGs were recorded by a bipolar spring clip electrode that made contact with upper and lower surfaces of the muscle strip with light pressure. In all conditions of stimulation with different types of electrodes, all EMGs decreased significantly (P less than 0.05) when muscle length was changed from 50 to 120% of resting length (L0). Minimal and maximal force outputs were observed at 50 and 120% of L0, respectively, in all experiments. The results of this study indicated that the muscle length is a significant variable that affects the EMG recording and that the diaphragmatic EMG may not be an accurate reflection of phrenic nerve activity.

scholarly journals Joint and muscle-tendon coordination strategies during submaximal jumping

2020 ◽  
Vol 128 (3) ◽  
pp. 596-603
Author(s):  
Logan Wade ◽  
Glen A. Lichtwark ◽  
Dominic J. Farris
Keyword(s):  
Neural Control ◽  
Muscle Activation ◽  
Length Change ◽  
Task Demands ◽  
Joint Work ◽  
Fascicle Length ◽  
Muscle Properties ◽  
Joint Kinetics ◽  
Coordination Strategies ◽  
Length Relationship

Previous research has demonstrated that during submaximal jumping humans prioritize reducing energy consumption by minimizing countermovement depth. However, sometimes movement is constrained to a nonpreferred pattern, and this requires adaptation of neural control that accounts for complex interactions between muscle architecture, muscle properties, and task demands. This study compared submaximal jumping with either a preferred or a deep countermovement depth to examine how joint and muscle mechanics are integrated into the adaptation of coordination strategies in the deep condition. Three-dimensional motion capture, two force plates, electromyography, and ultrasonography were used to examine changes in joint kinetics and kinematics, muscle activation, and muscle kinematics for the lateral gastrocnemius and soleus. Results demonstrated that a decrease in ankle joint work during the deep countermovement depth was due to increased knee flexion, leading to unfavorably short biarticular muscle lengths and reduced active fascicle length change during ankle plantar flexion. Therefore, ankle joint work was likely decreased because of reduced active fascicle length change and operating position on the force-length relationship. Hip joint work was significantly increased as a result of altered muscle activation strategies, likely due to a substantially greater hip extensor muscle activation period compared with plantar flexor muscles during jumping. Therefore, coordination strategies at individual joints are likely influenced by time availability, where a short plantar flexor activation time results in dependence on muscle properties, instead of simply altering muscle activation, while the longer time for contraction of muscles at the hip allows for adjustments to voluntary neural control. NEW & NOTEWORTHY Using human jumping as a model, we show that adapting movement patterns to altered task demands is achieved differently by muscles across the leg. Because of proximal-to-distal sequencing, distal muscles (i.e., plantar flexors) have reduced activation periods and, as a result, rely on muscle contractile properties (force-length relationship) for adjusting joint kinetics. For proximal muscles that have greater time availability, voluntary activation is modulated to adjust muscle outputs.

Relação entre a força de preensão palmar máxima e destreza dos dedos em adultos saudáveis: Implicações para a avaliação da função manual

1969 ◽  
Vol 6 (3) ◽  
Author(s):  
Kauã C. de A. Lima ◽  
Roberto Q. Santos ◽  
Paulo Barbosa de Freitas
Keyword(s):  
Grip Strength ◽  
Grip Force ◽  
Hand Function ◽  
Strength Test ◽  
Dominant Hand ◽  
Hand Dexterity ◽  
Hand Dynamometer ◽  
Maximum Grip Strength ◽  
The Relationship ◽  
Maximum Grip

Abstract: Successful object manipulation is fundamental to maintaining an independent lifestyle and, as a result, several tests have been used to assess hand function. The maximum grip strength test is one of the most used, but its validity could be questioned because, among other aspects, we rarely use maximum grip strength (GSMax) during daily manipulation task. Thus, the main aim of this study was to examine the relationship between GSMax and the performance in a hand dexterity task. Twenty-four healthy adults (12 males) between 20 and 39 years of age performed the nine hole peg test (9-HPT) and the maximum grip strength test (Jamar® hydraulic hand dynamometer). The results revealed that males were stronger than females and dominant hand was stronger than non-dominant hand. Moreover, males and females had similar performance in the 9-HPT, but both groups had better performance when using their dominant hand compared to their non-dominant one. Finally, and most importantly, the results revealed that there was no significant relationship between GSMax and individuals’ performance in the 9-HPT. The lack of relationship between them indicates that digits dexterity assessed by 9-HPT is not dependent on maximum grip strength exerted by the hand, suggesting that the evaluation of hand function should not be only based upon the results of the maximum grip strength test. Consequently, other grip strength related measurements (e.g., rate of grip force development, grip force control) should be taken into consideration for hand function assessment.Key Words: Upper limb, evaluation, motor skill, force. 

scholarly journals Nonlinear summation of force in cat soleus muscle results primarily from stretch of the common-elastic elements

2000 ◽  
Vol 89 (6) ◽  
pp. 2206-2214 ◽  
Author(s):  
Thomas G. Sandercock
Keyword(s):  
Muscle Activation ◽  
Muscle Force ◽  
Muscle Length ◽  
Stimulus Train ◽  
The Common ◽  
Tension Peak ◽  
Whole Muscle ◽  
Tetanic Tension ◽  
Connective Tissue Structure ◽  
Elastic Elements

The complex connective tissue structure of muscle and tendon suggests that forces from two parts of a muscle may not summate linearly. This study measured the nonlinear summation of force (Fnl) in whole cat soleus during isometric and ramp movements. In six anesthetized cats, the soleus was attached to a servomechanism to control muscle length and record force. The ventral roots were divided into two bundles, each innervating about half the soleus; thus the two parts could be stimulated alone or together. In all experiments, Fnl was small (<6% of maximum tetanic tension). Peak Fnl occurred during changes in muscle force, either as a result of imposed muscle movement or the onset or offset of a stimulus train. The data were fit to a model in which both parts of the muscle were assumed to stretch to a common elasticity. The servomechanism was programmed to compensate for reduced stretch of the common elasticity during partial compared with whole muscle activation. These compensatory movements showed how the model could account for most, but not all, of Fnl.

scholarly journals Development and Evaluation of a Musculoskeletal Model of the Elbow Joint Complex

1996 ◽  
Vol 118 (1) ◽  
pp. 32-40 ◽  
Author(s):  
R. V. Gonzalez ◽  
E. L. Hutchins ◽  
R. E. Barr ◽  
L. D. Abraham
Keyword(s):  
Elbow Joint ◽  
Muscle Force ◽  
Elbow Flexion ◽  
Musculoskeletal Model ◽  
Joint Torque ◽  
Time Varying ◽  
Moment Arm ◽  
Flexion Extension ◽  
The Relationship ◽  
Ballistic Movements

This paper describes the development and evaluation of a musculoskeletal model that represents human elbow flexion-extension and forearm pronation-supination. The length, velocity, and moment arm for each of the eight musculotendon actuators were based on skeletal anatomy and joint position. Musculotendon parameters were determined for each actuator and verified by comparing analytical moment-angle curves with experimental joint torque data. The parameters and skeletal geometry were also utilized in the musculoskeletal model for the analysis of ballistic (rapid-directed) elbow joint complex movements. The key objective was to develop a computational model, guided by parameterized optimal control, to investigate the relationship among patterns of muscle excitation, individual muscle forces, and to determine the effects of forearm and elbow position on the recruitment of individual muscles during a variety of ballistic movements. The model was partially verified using experimental kinematic, torque, and electromyographic data from volunteer subjects performing both isometric and ballistic elbow joint complex movements. This verification lends credibility to the time-varying muscle force predictions and the recruitment of muscles that contribute to both elbow flexion-extension and forearm pronation-supination.

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