scholarly journals Shorter heels are linked with greater elastic energy storage in the Achilles tendon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. D. Foster ◽  
B. Block ◽  
F. Capobianco ◽  
J. T. Peabody ◽  
N. A. Puleo ◽  
...  
Keyword(s):  
Energy Storage ◽  
Achilles Tendon ◽  
Elastic Energy ◽  
Mechanical Energy ◽  
Running Economy ◽  
Triceps Surae ◽  
Morphological Data ◽  
Energetic Cost ◽  
Moment Arm ◽  
Moment Arms

AbstractPrevious research suggests that the moment arm of the m. triceps surae tendon (i.e., Achilles tendon), is positively correlated with the energetic cost of running. This relationship is derived from a model which predicts that shorter ankle moment arms place larger loads on the Achilles tendon, which should result in a greater amount of elastic energy storage and return. However, previous research has not empirically tested this assumed relationship. We test this hypothesis using an inverse dynamics approach in human subjects (n = 24) at speeds ranging from walking to sprinting. The spring function of the Achilles tendon was evaluated using specific net work, a metric of mechanical energy production versus absorption at a limb joint. We also combined kinematic and morphological data to directly estimate tendon stress and elastic energy storage. We find that moment arm length significantly determines the spring-like behavior of the Achilles tendon, as well as estimates of mass-specific tendon stress and elastic energy storage at running and sprinting speeds. Our results provide support for the relationship between short Achilles tendon moment arms and increased elastic energy storage, providing an empirical mechanical rationale for previous studies demonstrating a relationship between calcaneal length and running economy. We also demonstrate that speed and kinematics moderate tendon performance, suggesting a complex relationship between lower limb geometry and foot strike pattern.

scholarly journals Achilles tendon moment arm in humans is not affected by inversion/eversion of the foot: a short report

2018 ◽  
Vol 5 (1) ◽  
pp. 171358 ◽  
Author(s):  
Susann Wolfram ◽  
Christopher I. Morse ◽  
Keith L. Winwood ◽  
Emma Hodson-Tole ◽  
Islay M. McEwan
Keyword(s):  
Achilles Tendon ◽  
Magnetic Resonance Images ◽  
Triceps Surae ◽  
Short Report ◽  
Moment Arm ◽  
Moment Arms ◽  
Musculoskeletal Models ◽  
Rotation Method ◽  
Centre Of Rotation ◽  
Foot Position

The triceps surae primarily acts as plantarflexor of the ankle joint. However, the group also causes inversion and eversion at the subtalar joint. Despite this, the Achilles tendon moment arm is generally measured without considering the potential influence of inversion/eversion of the foot during plantarflexion. This study investigated the effect of foot inversion and eversion on the plantarflexion Achilles tendon moment arm. Achilles tendon moment arms were determined using the centre-of-rotation method in magnetic resonance images of the left ankle of 11 participants. The foot was positioned at 15° dorsiflexion, 0° or 15° plantarflexion using a Styrofoam wedge. In each of these positions, the foot was either 10° inverted, neutral or 10° everted using an additional Styrofoam wedge. Achilles tendon moment arm in neutral foot position was 47.93 ± 4.54 mm and did not differ significantly when the foot was positioned in 10° inversion and 10° eversion. Hence, inversion/eversion position of the foot may not considerably affect the length of the Achilles tendon moment arm. This information could be useful in musculoskeletal models of the human lower leg and foot and when estimating Achilles tendon forces during plantarflexion with the foot positioned in inversion or eversion.

scholarly journals Elastic energy savings and active energy cost in a simple model of running

2021 ◽  
Vol 17 (11) ◽  
pp. e1009608
Author(s):  
Ryan T. Schroeder ◽  
Arthur D. Kuo
Keyword(s):  
Elastic Energy ◽  
Energy Cost ◽  
Energy Savings ◽  
Mechanical Energy ◽  
Metabolic Cost ◽  
The Body ◽  
Metabolic Energy ◽  
Energetic Cost ◽  
Mass Model ◽  
Human Running

The energetic economy of running benefits from tendon and other tissues that store and return elastic energy, thus saving muscles from costly mechanical work. The classic “Spring-mass” computational model successfully explains the forces, displacements and mechanical power of running, as the outcome of dynamical interactions between the body center of mass and a purely elastic spring for the leg. However, the Spring-mass model does not include active muscles and cannot explain the metabolic energy cost of running, whether on level ground or on a slope. Here we add explicit actuation and dissipation to the Spring-mass model, and show how they explain substantial active (and thus costly) work during human running, and much of the associated energetic cost. Dissipation is modeled as modest energy losses (5% of total mechanical energy for running at 3 m s-1) from hysteresis and foot-ground collisions, that must be restored by active work each step. Even with substantial elastic energy return (59% of positive work, comparable to empirical observations), the active work could account for most of the metabolic cost of human running (about 68%, assuming human-like muscle efficiency). We also introduce a previously unappreciated energetic cost for rapid production of force, that helps explain the relatively smooth ground reaction forces of running, and why muscles might also actively perform negative work. With both work and rapid force costs, the model reproduces the energetics of human running at a range of speeds on level ground and on slopes. Although elastic return is key to energy savings, there are still losses that require restorative muscle work, which can cost substantial energy during running.

scholarly journals Ankle morphology amplifies calcaneus movement relative to triceps surae muscle shortening

2013 ◽  
Vol 115 (4) ◽  
pp. 468-473 ◽  
Author(s):  
R. Csapo ◽  
J. Hodgson ◽  
R. Kinugasa ◽  
V. R. Edgerton ◽  
S. Sinha
Keyword(s):  
Magnetic Resonance ◽  
Achilles Tendon ◽  
Ankle Joint ◽  
Sagittal Plane ◽  
Triceps Surae ◽  
Myotendinous Junction ◽  
Joint Movement ◽  
Center Of Rotation ◽  
Moment Arms ◽  
Plantarflexor Muscles

The present study investigated the mechanical role of the dorsoventral curvature of the Achilles tendon in the conversion of the shortening of the plantarflexor muscles into ankle joint rotation. Dynamic, sagittal-plane magnetic resonance spin-tagged images of the ankle joint were acquired in six healthy subjects during both passive and active plantarflexion movements driven by a magnetic resonance compatible servomotor-controlled foot-pedal device. Several points on these images were tracked to determine the 1) path and deformation of the Achilles tendon, 2) ankle's center of rotation, and 3) tendon moment arms. The degree of mechanical amplification of joint movement was calculated as the ratio of the displacements of the calcaneus and myotendinous junction. In plantarflexion, significant deflection of the Achilles tendon was evident in both the passive (165.7 ± 7.4°; 180° representing a straight tendon) and active trials (166.9 ± 8.8°). This bend in the dorsoventral direction acts to move the Achilles tendon closer to the ankle's center of rotation, resulting in an ∼5% reduction of moment arm length. Over the entire range of movement, the overall displacement of the calcaneus exceeded the displacement of the myotendinous junction by ∼37%, with the mechanical gains being smaller in dorsi- and larger in plantarflexed joint positions. This is the first study to assess noninvasively and in vivo using MRI the curvature of the Achilles tendon during both passive and active plantarflexion movements. The dorsoventral tendon curvature amplifies the shortening of the plantarflexor muscles, resulting in a greater displacement of the tendon's insertion into the calcaneus compared with its origin.

scholarly journals The Cross-Bridge Spring: Can Cool Muscles Store Elastic Energy?

Science ◽  
2013 ◽  
Vol 340 (6137) ◽  
pp. 1217-1220 ◽  
Author(s):  
N. T. George ◽  
T. C. Irving ◽  
C. D. Williams ◽  
T. L. Daniel
Keyword(s):  
Energy Storage ◽  
Elastic Energy ◽  
Molecular Motors ◽  
High Speed ◽  
Mechanical Energy ◽  
Elastic Strain Energy ◽  
Time Resolved ◽  
X Ray ◽  
Cross Bridge ◽  
Cross Bridges

Muscles not only generate force. They may act as springs, providing energy storage to drive locomotion. Although extensible myofilaments are implicated as sites of energy storage, we show that intramuscular temperature gradients may enable molecular motors (cross-bridges) to store elastic strain energy. By using time-resolved small-angle x-ray diffraction paired with in situ measurements of mechanical energy exchange in flight muscles of Manduca sexta, we produced high-speed movies of x-ray equatorial reflections, indicating cross-bridge association with myofilaments. A temperature gradient within the flight muscle leads to lower cross-bridge cycling in the cooler regions. Those cross-bridges could elastically return energy at the extrema of muscle lengthening and shortening, helping drive cyclic wing motions. These results suggest that cross-bridges can perform functions other than contraction, acting as molecular links for elastic energy storage.

Achilles Tendon Moment Arms Computed Using Ultrasound and Motion Analysis: In Vivo Estimates for Male Subjects

2008 ◽  
Author(s):  
Justin D. Cowder ◽  
Thomas S. Buchanan ◽  
Kurt T. Manal
Keyword(s):  
Achilles Tendon ◽  
Motion Capture ◽  
Hybrid Method ◽  
Lower Limb ◽  
Muscle Force ◽  
Average Weight ◽  
Moment Arm ◽  
Moment Arms ◽  
Male Subjects

Accurate estimates for Achilles tendon moment arm (MA) are essential when computing gastroc-soleus force from the net plantarflexion moment. Errors in approximating the Achilles tendon MA will adversely affect the muscle force estimate. We have noted that Achilles tendon MAs reported by Maganaris [1] and others are significantly greater (> 1 cm) than values used by Delp et al. computed using SIMM [2]. It is important to note that the stature of Delp’s lower limb model was almost identical to the average weight and height of the subjects in a study by Maganaris. This led us to question which MA profiles were more anatomically meaningful. To address this, we calculated Achilles tendon MAs for 10 male subjects using a previously described method. The method combines ultrasound and video-based motion capture, and referred to as the hybrid method. Subjects in our study were chosen to ensure they were of a similar stature to those tested by Maganaris, thereby minimizing confounding effects of subject anthropometrics.

scholarly journals Considerations on the human Achilles tendon moment arm for in vivo triceps surae muscle–tendon unit force estimates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Denis Holzer ◽  
Florian Kurt Paternoster ◽  
Daniel Hahn ◽  
Tobias Siebert ◽  
Wolfgang Seiberl
Keyword(s):  
Achilles Tendon ◽  
Triceps Surae ◽  
Muscle Forces ◽  
Moment Arm ◽  
Unit Force ◽  
Plateau Region ◽  
Triceps Muscle ◽  
Triceps Surae Muscle ◽  
The Individual

Abstract Moment arm-angle functions (MA-a-functions) are commonly used to estimate in vivo muscle forces in humans. However, different MA-a-functions might not only influence the magnitude of the estimated muscle forces but also change the shape of the muscle’s estimated force-angle relationship (F-a-r). Therefore, we investigated the influence of different literature based Achilles tendon MA-a-functions on the triceps surae muscle–tendon unit F-a-r. The individual in vivo triceps torque–angle relationship was determined in 14 participants performing maximum voluntary fixed-end plantarflexion contractions from 18.3° ± 3.2° plantarflexion to 24.2° ± 5.1° dorsiflexion on a dynamometer. The resulting F-a-r were calculated using 15 literature-based in vivo Achilles tendon MA-a-functions. MA-a-functions affected the F-a-r shape and magnitude of estimated peak active triceps muscle–tendon unit force. Depending on the MA-a-function used, the triceps was solely operating on the ascending limb (n = 2), on the ascending limb and plateau region (n = 12), or on the ascending limb, plateau region and descending limb of the F-a-r (n = 1). According to our findings, the estimated triceps muscle–tendon unit forces and the shape of the F-a-r are highly dependent on the MA-a-function used. As these functions are affected by many variables, we recommend using individual Achilles tendon MA-a-functions, ideally accounting for contraction intensity-related changes in moment arm magnitude.

scholarly journals A Hybrid Method for Computing Achilles Tendon Moment Arm Using Ultrasound and Motion Analysis

2010 ◽  
Vol 26 (2) ◽  
pp. 224-228 ◽  
Author(s):  
Kurt Manal ◽  
Justin D. Cowder ◽  
Thomas S. Buchanan
Keyword(s):  
Achilles Tendon ◽  
Motion Capture ◽  
Hybrid Method ◽  
Moment Arm ◽  
Measurement Instruments ◽  
Moment Arms ◽  
Perpendicular Distance ◽  
The Moment ◽  
Joint Center

In this article, we outline a method for computing Achilles tendon moment arm. The moment arm is computed from data collected using two reliable measurement instruments: ultrasound and video-based motion capture. Ultrasound is used to measure the perpendicular distance from the surface of the skin to the midline of the tendon. Motion capture is used to determine the perpendicular distance from the bottom of the probe to the ankle joint center. The difference between these two measures is the Achilles tendon moment arm. Unlike other methods, which require an angular change in joint position to approximate the moment arm, the hybrid method can be used to compute the moment arm directly at a specific joint angle. As a result, the hybrid method involves fewer error-prone measurements and the moment arm can be computed at the limits of the joint range of motion. The method is easy to implement and uses modalities that are less costly and more accessible than MRI. Preliminary testing using a lamb shank as a surrogate for a human ankle revealed good accuracy (3.3% error). We believe the hybrid method outlined here can be used to measure subject-specific moment arms in vivo and thus will potentially benefit research projects investigating ankle mechanics.

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.

The role of elastic energy storage mechanisms in swimming: an analysis of mantle elasticity in escape jetting in the squid, Loligo opalescens

1983 ◽  
Vol 61 (6) ◽  
pp. 1421-1431 ◽  
Author(s):  
John M. Gosline ◽  
Robert E. Shadwick
Keyword(s):  
Energy Storage ◽  
Elastic Energy ◽  
Mechanical Energy ◽  
Storage System ◽  
Collagen Fibre ◽  
Energy Storage System ◽  
Mantle Cavity ◽  
Loligo Opalescens ◽  
Locomotory Performance

Elastic energy storage mechanisms have been shown to improve locomotory performance and efficiency in many animals. In this paper we consider the role of elastic energy storage in jet locomotion of the squid, Loligo opalescens. The jet is powered by the contraction of circular muscles in the mantle. In addition, the mantle contains a collagen fibre based energy storage system (the mantle "spring") which captures some of the mechanical energy produced by the circular muscles and then releases this energy to power the refilling of the mantle cavity. The mantle spring is constructed so that it stores energy from the circular muscles only at a time in the jet cycle when, by virtue of the cylindrical geometry of the mantle, the circular muscles are unable, to apply their full mechanical output to the generation of hydrodynamic thrust. Thus the mantle spring increases the utilization of the circular muscles, and our analysis indicates that these muscles are used at virtually 100% of their potential through the entire jet. Presumably this increase in muscle utilization improves the locomotory performance of the squid. Other swimming animals, such as fish, may obtain similar benefits if elastic energy storage systems are constructed to capture energy at a time in the swimming cycle when muscles can not apply their full output to the generation of useful hydrodynamic forces.

Sign in / Sign up

Export Citation Format

Share Document