scholarly journals In-series compliance of gastrocnemius muscle in cat step cycle: do spindles signal origin-to-insertion length?

1990 ◽  
Vol 429 (1) ◽  
pp. 237-258 ◽  
Author(s):  
J Elek ◽  
A Prochazka ◽  
M Hulliger ◽  
S Vincent
Keyword(s):  
Gastrocnemius Muscle ◽  
Step Cycle ◽  
In Series ◽  
Series Compliance ◽  
Insertion Length

scholarly journals Additional in-series compliance reduces muscle force summation and alters the time course of force relaxation during fixed-end contractions

2016 ◽  
Vol 219 (22) ◽  
pp. 3587-3596 ◽  
Author(s):  
Dean L. Mayfield ◽  
Bradley S. Launikonis ◽  
Andrew G. Cresswell ◽  
Glen A. Lichtwark
Keyword(s):  
Time Course ◽  
Muscle Force ◽  
Force Relaxation ◽  
In Series ◽  
Series Compliance ◽  
Fixed End

scholarly journals Additional in‐series compliance does not affect the length dependence of activation in rat medial gastrocnemius

2020 ◽  
Vol 105 (11) ◽  
pp. 1907-1917 ◽  
Author(s):  
Keenan B. MacDougall ◽  
Anders M. Kristensen ◽  
Brian R. MacIntosh
Keyword(s):  
Medial Gastrocnemius ◽  
Length Dependence ◽  
In Series ◽  
Series Compliance

Active muscle stiffness in the human medial gastrocnemius muscle in vivo

2014 ◽  
Vol 117 (9) ◽  
pp. 1020-1026 ◽  
Author(s):  
Keitaro Kubo
Keyword(s):  
Gastrocnemius Muscle ◽  
Muscle Stiffness ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Active Muscle ◽  
Tendon Stiffness ◽  
Series Elastic Component ◽  
In Series ◽  
Medial Gastrocnemius Muscle

The aims of this study were to 1) directly assess active muscle stiffness according to actual length changes in muscle fibers (fascicles) during short range stretching; and 2) compare actual measured active muscle and tendon stiffness using ultrasonography with the stiffness of active (i.e., muscle) and passive (i.e., tendon) parts in series elastic component of plantar flexors using the alpha method. Twenty-four healthy men volunteered for this study. Active muscle stiffness in the medial gastrocnemius muscle was calculated according to changes in estimated muscle force and fascicle length during fast stretching after submaximal isometric contractions [10, 30, 50, 70, and 90% maximal voluntary contractions (MVC)]. Using the variables measured during this fast stretch experiment, the stiffness of active (i.e., muscle) and passive (i.e., tendon) parts in plantar flexors was assessed using alpha method. Tendon stiffness was determined during isometric plantar flexion by ultrasonography. Active muscle stiffness increased with the exerted torque levels. At 30, 50, 70, and 90% MVC, there were no significant correlations between muscle stiffness using ultrasonography and stiffness of active part (i.e., muscle) by alpha method, although this relationship at 10% MVC was significant ( r = 0.552, P = 0.005). In addition, no correlation was noted in tendon stiffness between the two different methods ( r = 0.226, P = 0.209). The present study demonstrated that ultrasonography could quantified active muscle stiffness in vivo. Furthermore, active muscle stiffness and tendon stiffness using ultrasonography were not related to active (i.e., muscle) or passive (i.e., tendon) stiffness in series elastic component of plantar flexors by alpha method.

scholarly journals Stiffening the human foot with a biomimetic exotendon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryan C. Riddick ◽  
Dominic J. Farris ◽  
Nicholas A. T. Brown ◽  
Luke A. Kelly
Keyword(s):  
Energy Savings ◽  
Metabolic Energy ◽  
Medial Gastrocnemius ◽  
The Novel ◽  
Abductor Hallucis ◽  
Human Foot ◽  
Alternative Approach ◽  
In Series ◽  
Series Compliance ◽  
Footwear Design

AbstractShoes are generally designed protect the feet against repetitive collisions with the ground, often using thick viscoelastic midsoles to add in-series compliance under the human. Recent footwear design developments have shown that this approach may also produce metabolic energy savings. Here we test an alternative approach to modify the foot–ground interface by adding additional stiffness in parallel to the plantar aponeurosis, targeting the windlass mechanism. Stiffening the windlass mechanism by about 9% led to decreases in peak activation of the ankle plantarflexors soleus (~ 5%, p < 0.001) and medial gastrocnemius (~ 4%, p < 0.001), as well as a ~ 6% decrease in positive ankle work (p < 0.001) during fixed-frequency bilateral hopping (2.33 Hz). These results suggest that stiffening the foot may reduce cost in dynamic tasks primarily by reducing the effort required to plantarflex the ankle, since peak activation of the intrinsic foot muscle abductor hallucis was unchanged (p = 0.31). Because the novel exotendon design does not operate via the compression or bending of a bulky midsole, the device is light (55 g) and its profile is low enough that it can be worn within an existing shoe.

Gastrocnemius Muscle Fascicle Behavior Explored With a 3D Muscle Model

2009 ◽  
Author(s):  
Silvia S. Blemker ◽  
Elisa S. Schrank
Keyword(s):  
Neurological Disorders ◽  
Fiber Length ◽  
Gastrocnemius Muscle ◽  
Joint Angle ◽  
Human Movement ◽  
Muscle Fascicle ◽  
Lumped Parameter ◽  
In Series ◽  
Length Changes ◽  
Gastrocnemius Muscles

The gastrocnemius muscles are important for support and forward progression of movement [1], and they are commonly impaired in neurological disorders, such as stroke and cerebral palsy [2]. Currently, lumped-parameter representations [3] are used to model the gastrocnemius muscles in simulations of human movement. These representations simplify muscle architecture by assuming that all fibers are the same length, that aponeuroses behave as if they are in series with muscle fibers, and that fibers have a simple geometric arrangement. Previous studies have suggested that these simplifications may result in an overestimation of fiber length changes during movement and therefore predict that too much variation in force with joint angle (e.g., [4]).

Effect of Parallel Compliance on Stability of Robotic Hands With Series Elastic Actuators

2015 ◽  
Author(s):  
Prashant Rao ◽  
Taylor D. Niehues ◽  
Ashish D. Deshpande
Keyword(s):  
Joint Stiffness ◽  
Combined Effects ◽  
Robotic Hands ◽  
Subsequent Increase ◽  
Grasping And Manipulation ◽  
In Series ◽  
Series Compliance ◽  
Robotic Joints ◽  
And Performance ◽  
The Stability

Compliance is a key requirement for safe interactions with the environment for any robot. It has been well established that the human body exploits various arrangements of compliance such as series compliance (musculo-tendon units) and parallel compliance (joint capsules and ligament complex) to achieve robust and graceful interaction with the environment. Mechanical compliance can be similarly arranged in robotic joints in series or parallel to actuators. The effects of such arrangements on the closed loop properties of robotic joints such as stability, disturbance rejection and tracking performance have been analyzed separately, but their combined effects have not been studied. We present a detailed analysis on the combined effects of series and parallel arrangements of compliance on low inertia robotic joints. Our analysis shows the stability limitations of achievable joint stiffness due to series compliance and the subsequent increase in the stable upper limit of achievable joint stiffness by addition of parallel compliance. We provide guidelines towards designing compliance to improve the stability and performance of low-inertia robotic joints, which can be applied to the improvement of robotic hands performing grasping and manipulation tasks. We validate our analysis by means of an experimental platform and discuss the various characteristics and the effects of both arrangements of compliance on robotic hands.

Techniques For The Preparation of Tissue Samples Containing Injectable Polymer Microcapsules

1985 ◽  
Vol 43 ◽  
pp. 710-711
Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Gastrocnemius Muscle ◽  
Degradation Process ◽  
Delivery Systems ◽  
Tissue Reaction ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Injectable Polymer ◽  
Microscopic Techniques

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.

The Shikani HME: A New Tracheostomy Heat and Moisture Exchanger

2020 ◽  
Vol 63 (9) ◽  
pp. 2921-2929
Author(s):  
Alan H. Shikani ◽  
Elamin M. Elamin ◽  
Andrew C. Miller
Keyword(s):  
Ex Vivo ◽  
Moisture Loss ◽  
Speaking Valve ◽  
Time Zero ◽  
In Series ◽  
Turbulent Airflow ◽  
The Difference ◽  
Loss Efficiency ◽  
Heat And Moisture ◽  
Lung Simulation

Purpose Tracheostomy patients face many adversities including loss of phonation and essential airway functions including air filtering, warming, and humidification. Heat and moisture exchangers (HMEs) facilitate humidification and filtering of inspired air. The Shikani HME (S-HME) is a novel turbulent airflow HME that may be used in-line with the Shikani Speaking Valve (SSV), allowing for uniquely preserved phonation during humidification. The aims of this study were to (a) compare the airflow resistance ( R airflow ) and humidification efficiency of the S-HME and the Mallinckrodt Tracheolife II tracheostomy HME (M-HME) when dry (time zero) and wet (after 24 hr) and (b) determine if in-line application of the S-HME with a tracheostomy speaking valve significantly increases R airflow over a tracheostomy speaking valve alone (whether SSV or Passy Muir Valve [PMV]). Method A prospective observational ex vivo study was conducted using a pneumotachometer lung simulation unit to measure airflow ( Q ) amplitude and R airflow , as indicated by a pressure drop ( P Drop ) across the device (S-HME, M-HME, SSV + S-HME, and PMV). Additionally, P Drop was studied for the S-HME and M-HME when dry at time zero (T 0 ) and after 24 hr of moisture testing (T 24 ) at Q of 0.5, 1, and 1.5 L/s. Results R airflow was significantly less for the S-HME than M-HME (T 0 and T 24 ). R airflow of the SSV + S-HME in series did not significant increase R airflow over the SSV or PMV alone. Moisture loss efficiency trended toward greater efficiency for the S-HME; however, the difference was not statistically significant. Conclusions The turbulent flow S-HME provides heat and moisture exchange with similar or greater efficacy than the widely used laminar airflow M-HME, but with significantly lower resistance. The S-HME also allows the innovative advantage of in-line use with the SSV, hence allowing concurrent humidification and phonation during application, without having to manipulate either device.

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