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 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.

Estimation of Achilles Tendon Moment Arms In Vivo: A Novel Hybrid Method Using Ultrasound and Motion Analysis

2008 ◽  
Author(s):  
Justin D. Cowder ◽  
Nicole J. Chimera ◽  
Thomas S. Buchanan ◽  
Kurt T. Manal
Keyword(s):  
Achilles Tendon ◽  
Motion Capture ◽  
Moment Arm ◽  
Measurement Instruments ◽  
Center Of Rotation ◽  
Moment Arms ◽  
Rotation Methods ◽  
Hybrid Methodology ◽  
Tendon Excursion

The musculotendon moment arm (MA) is the perpendicular distance from a muscle’s line of action to the rotational center of a joint. Moment arms are important in muscle modeling [1], and thus their accuracy is of great importance. Current in vivo techniques for computing MAs include the center of rotation and tendon excursion methods [1, 2]. The tendon excursion (TE) method relates the change in musculotendon length to an angular change in joint position [3]. This requires two measurements of musculotendon length for each MA computed. Similarly, the center of rotation method requires multiple image-based geometry measurements to compute the MA for a specific joint angle. The TE and center of rotation methods are both prone to measurement error, and thus it is difficult to ascertain the accuracy of the resulting MA. In this paper we present a novel hybrid methodology combining ultrasound (US) and video-based motion capture to compute the Achilles tendon moment arm. An advantage of this approach is that data used to derive the MA are acquired using highly accurate and reliable measurement instruments (i.e, US & motion capture), which may improve the accuracy of the MA estimate. The purpose of this paper is to present the hybrid methodology and validation results based on testing the method using an animal model.

Direct comparison of in vivo Achilles tendon moment arms obtained from ultrasound and MR scans

2010 ◽  
Vol 109 (6) ◽  
pp. 1644-1652 ◽  
Author(s):  
Florian Fath ◽  
Anthony J. Blazevich ◽  
Charlie M. Waugh ◽  
Stuart C. Miller ◽  
Thomas Korff
Keyword(s):  
Achilles Tendon ◽  
Strong Relationship ◽  
Coefficient Of Determination ◽  
Moment Arm ◽  
Mr Images ◽  
Moment Arms ◽  
Musculoskeletal Models ◽  
Tendon Excursion ◽  
Differentiation Technique

Accurate and reliable estimation of muscle moment arms is a prerequisite for the development of musculoskeletal models. Numerous techniques are available to estimate the Achilles tendon moment arm in vivo. The purposes of this study were 1) to compare in vivo Achilles tendon moment arms obtained using the center of rotation (COR) and tendon excursion (TE) methods and 2) to assess the reliability of each method. For the COR method, magnetic resonance (MR) images from nine participants were obtained at ankle angles of −15°, 0°, and +15° and analyzed using Reuleaux' method. For the TE method, the movement of the gastrocnemius medialis-Achilles tendon junction was recorded using ultrasonography as the ankle was passively rotated through its range of motion. The Achilles tendon moment arm was obtained by differentiation of tendon displacement with respect to ankle angular excursion using seven different differentiation techniques. Moment arms obtained using the COR method were significantly greater than those obtained using the TE method ( P < 0.01), but results from both methods were well correlated. The coefficient of determination between moment arms derived from the COR and TE methods was highest when tendon displacement was linearly differentiated over a ±10° interval ( R2 = 0.94). The between-measurement coefficient of variation was 3.9% for the COR method and 4.5–9.7% for the TE method, depending on the differentiation technique. The high reliabilities and strong relationship between methods demonstrate that both methods are robust against their limitations. The large absolute between-method differences (∼25–30%) in moment arms have significant implications for their use in musculoskeletal models.

scholarly journals Mechanical properties of tendon and aponeurosis of human gastrocnemius muscle in vivo

2001 ◽  
Vol 90 (5) ◽  
pp. 1671-1678 ◽  
Author(s):  
Tadashi Muramatsu ◽  
Tetsuro Muraoka ◽  
Daisuke Takeshita ◽  
Yasuo Kawakami ◽  
Yuichi Hirano ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Gastrocnemius Muscle ◽  
Plantar Flexion ◽  
Medial Gastrocnemius ◽  
Significant Difference ◽  
Functional Implications ◽  
Male Subjects ◽  
Maximal Strain

Load-strain characteristics of tendinous tissues (Achilles tendon and aponeurosis) were determined in vivo for human medial gastrocnemius (MG) muscle. Seven male subjects exerted isometric plantar flexion torque while the elongation of tendinous tissues of MG was determined from the tendinous movements by using ultrasonography. The maximal strain of the Achilles tendon and aponeurosis, estimated separately from the elongation data, was 5.1 ± 1.1 and 5.9 ± 1.6%, respectively. There was no significant difference in strain between the Achilles tendon and aponeurosis. In addition, no significant difference in strain was observed between the proximal and distal regions of the aponeurosis. The results indicate that tendinous tissues of the MG are homogenously stretched along their lengths by muscle contraction, which has functional implications for the operation of the human MG muscle-tendon unit in vivo.

scholarly journals Shear Wave Predictions of Achilles Tendon Loading during Human Walking

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Emily M. Keuler ◽  
Isaac F. Loegering ◽  
Jack A. Martin ◽  
Joshua D. Roth ◽  
Darryl G. Thelen
Keyword(s):  
Achilles Tendon ◽  
Shear Wave ◽  
Wave Speed ◽  
Inverse Dynamics ◽  
Human Walking ◽  
Cross Sectional ◽  
Moment Arms ◽  
Subject Specific ◽  
S Peak

Abstract The evaluation of in vivo muscle-tendon loads is fundamental to understanding the actuation of normal and pathological human walking. However, conventional techniques for measuring muscle-tendon loads in the human body are too invasive for use in gait analysis. Here, we demonstrate the use of noninvasive measures of shear wave propagation as a proxy for Achilles tendon loading during walking. Twelve healthy young adults performed isometric ankle plantarflexion on a dynamometer. Achilles tendon wave speed, tendon moment arms, tendon cross-sectional area and ankle torque were measured. We first showed that the linear relationship between tendon stress and wave speed squared can be calibrated from isometric tasks. There was no significant effect of knee angle, ankle angle or loading rate on the subject-specific calibrations. Calibrated shear wave tensiometers were used to estimate Achilles tendon loading when walking at speeds ranging from 1 to 2 m/s. Peak tendon stresses during pushoff increased from 41 to 48 MPa as walking speed was increased, and were comparable to estimates from inverse dynamics. The tensiometers also detected Achilles tendon loading of 4 to 7 MPa in late swing. Late swing tendon loading was not discernible in the inverse dynamics estimates, but did coincide with passive stretch of the gastrocnemius muscle-tendon units. This study demonstrates the capacity to use calibrated shear wave tensiometers to evaluate tendon loading in locomotor tasks. Such technology could prove beneficial for identifying the muscle actions that underlie subject-specific movement patterns.

In vivo physiological cross-sectional area and specific force are reduced in the gastrocnemius of elderly men

2005 ◽  
Vol 99 (3) ◽  
pp. 1050-1055 ◽  
Author(s):  
Christopher I. Morse ◽  
Jeanette M. Thom ◽  
Neil D. Reeves ◽  
Karen M. Birch ◽  
Marco V. Narici
Keyword(s):  
Achilles Tendon ◽  
Voluntary Contraction ◽  
Pennation Angle ◽  
Specific Force ◽  
Plantar Flexor ◽  
Moment Arm ◽  
Plantar Flexors ◽  
Elderly Men ◽  
Cross Sectional

Sarcopenia and muscle weakness are well-known consequences of aging. The aim of the present study was to ascertain whether a decrease in fascicle force (Ff) could be accounted for entirely by muscle atrophy. In vivo physiological cross-sectional area (PCSA) and specific force (Ff/PCSA) of the lateral head of the gastrocnemius (GL) muscle were assessed in a group of elderly men [EM, aged 73.8 yr (SD 3.5), height 173.4 cm (SD 4.4), weight 78.4 kg (SD 8.3); means (SD)] and for comparison in a group of young men [YM, aged 25.3 yr (SD 4.4), height 176.4 cm (SD 7.7), weight 79.1 kg (SD 11.9)]. GL muscle volume (Vol) and Achilles tendon moment arm length were evaluated using magnetic resonance imaging. Pennation angle and fiber fascicle length (Lf) were measured using B-mode ultrasonography during isometric maximum voluntary contraction of the plantar flexors. PCSA was estimated as Vol/Lf. GL Ff was calculated by dividing Achilles tendon force by the cosine of θ, during the interpolation of a supramaximal doublet, and accounting for antagonist activation level (assessed using EMG), Achilles tendon moment arm length, and the relative PCSA of the GL within the plantar flexor group. Voluntary activation of the plantar flexors was lower in the EM than in the YM (86 vs. 98%, respectively, P < 0.05). Compared with the YM, plantar flexor maximal voluntary contraction torque and Ff of the EM were lower by 47 and 40%, respectively ( P < 0.01). Both Vol and PCSA were smaller in the EM by 28% ( P < 0.01) and 16% ( P < 0.05), respectively. Also, pennation angle was 12% smaller in the EM, whereas there was no significant difference in Lf between the YM and EM. After accounting for differences in agonists and antagonists activation, the Ff/PCSA of the EM was 30% lower than that of the YM ( P < 0.01). These findings demonstrate that the loss of muscle strength with aging may be explained not only by a reduction in voluntary drive to the muscle, but mostly by a decrease in intrinsic muscle force. This phenomenon may possibly be due to a reduction in single-fiber specific tension.

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.

In vivo measurement-based estimations of the human Achilles tendon moment arm

2000 ◽  
Vol 83 (4-5) ◽  
pp. 363-369 ◽  
Author(s):  
Constantinos N. Maganaris ◽  
Vasilios Baltzopoulos ◽  
Anthony J. Sargeant
Keyword(s):  
Achilles Tendon ◽  
Moment Arm ◽  
In Vivo Measurement

Sources of Error When Measuring Achilles Tendon Mechanics During the Stance Phase of Running

2021 ◽  
Author(s):  
Giorgos Krikelis ◽  
Matthew T.G. Pain ◽  
Laura-Anne M. Furlong
Keyword(s):  
Achilles Tendon ◽  
Motion Capture ◽  
Stance Phase ◽  
Total Error ◽  
Motion Capture Data ◽  
Moment Arm ◽  
Sources Of Error ◽  
Combine Motion ◽  
Tendon Mechanics ◽  
Potential Sources

Abstract In recent years, the use of methods that combine motion capture with ultrasound (MoCapUs) has increased. Although several limitations and individual errors of these methods have been reported, the total error from all the potential sources together has not been estimated. The aim of this study was to establish the total error in the Achilles tendon (AT) measurements, specifically its length (ATL), strain (ATS) and moment arm (ATMA) acquired with MoCapUs during running. The total error from digitising, marker movement, ultrasound calibration and probe rotation errors caused mean ATL error of 4.2 ± 0.6 mm, mean ATMA error of 0.1 ± 0.1 mm, and could potentially alter measured ATS by a mean 2.9 ± 0.2 %. Correcting the calcaneus insertion position (CIP) and properly synchronising ultrasound and motion capture data combined caused ATL and ATMA changes up to 5.4 ± 1.7 mm and 11.6 ± 1.3 mm, respectively. Changes in ATL and ATS due to the CIP correction and synchronisation individually were similar. However, the ATMA change was almost exclusively due to the CIP correction. Finally, if all sources of error were combined, the total ATL error could reach 13.1 mm, the total ATMA error could reach 14.4 mm, and ATS differences could reach up to ± 6.7%. The magnitude such errors emphasises the fact that MoCapUS based AT measurements must be interpreted within the scope of their corresponding errors.

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