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Robert U. Newton - One of the best experts on this subject based on the ideXlab platform.
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changes in Muscle Architecture and performance during a competitive season in female softball players
Journal of Strength and Conditioning Research, 2012Co-Authors: Sophia Nimphius, Michael R. Mcguigan, Robert U. NewtonAbstract:The purpose of this research was (a) to examine the performance changes that occur in elite female softball players during 20 weeks of softball training (that included 14 weeks of periodized resistance training [RT]) and (b) to examine the relationship between percent change (%change) in Muscle Architecture variables and %change in strength, speed, and change of direction performance. Ten female softball players (age = 18.1 ± 1.6 years, height = 166.5 ± 8.9 cm, weight = 72.4 ± 10.8 kg) from a state Australian Institute of Sport softball team were tested for maximal lower-body strength using a 3 repetition maximum for a predicted 1 repetition maximum (1RM) and peak force, peak velocity (PV), and peak power (PP) were measured during jump squats (JS) unloaded and loaded. In addition, the first base (1B) and the second base (2B) sprint performance, change of direction (505) on dominant (D) and nondominant (ND) sides, aerobic capacity, and Muscle Architecture characteristics of vastus lateralis (VL) including Muscle thickness (MT), fascicle length (FL), and pennation angle (θp) were examined. The testing sessions occurred pre, mid, and post training (total 20 week pre- and in-season training period). Changes over time were analyzed by repeated-measures analysis of variance. The relationship between %change in Muscle Architecture variables and strength, speed, and change of direction variables from pre to post were assessed by Pearson product-moment correlation coefficient. Significant improvements in PV and PP occurred at all JS loads pre- to mid-testing and pre- to post-testing. Significant increases occurred pre-post in absolute 1RM, relative 1RM, 505 ND, and 2B sprint. The strongest relationships were found between %change in VL MT and 1B sprint (r = -0.80, p = 0.06), %change in VL FL and 2B sprint (r = -0.835, p = 0.02), and %change in relative 1RM and 505 D (r = -0.70, p = 0.04). In conclusion, gains in strength, power, and performance can occur during the season in elite softball players who are also engaged in a periodized RT program. Furthermore, changes in performance measures are associated with changes in Muscle Architecture.
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Changes in Muscle Architecture and Performance During a Competitive Season in Female Softball Players
Journal of strength and conditioning research, 2012Co-Authors: Sophia Nimphius, Michael R. Mcguigan, Robert U. NewtonAbstract:The purpose of this research was (a) to examine the performance changes that occur in elite female softball players during 20 weeks of softball training (that included 14 weeks of periodized resistance training [RT]) and (b) to examine the relationship between percent change (%change) in Muscle Architecture variables and %change in strength, speed, and change of direction performance. Ten female softball players (age = 18.1 ± 1.6 years, height = 166.5 ± 8.9 cm, weight = 72.4 ± 10.8 kg) from a state Australian Institute of Sport softball team were tested for maximal lower-body strength using a 3 repetition maximum for a predicted 1 repetition maximum (1RM) and peak force, peak velocity (PV), and peak power (PP) were measured during jump squats (JS) unloaded and loaded. In addition, the first base (1B) and the second base (2B) sprint performance, change of direction (505) on dominant (D) and nondominant (ND) sides, aerobic capacity, and Muscle Architecture characteristics of vastus lateralis (VL) including Muscle thickness (MT), fascicle length (FL), and pennation angle ([theta]p) were examined. The testing sessions occurred pre, mid, and post training (total 20 week pre- and in-season training period). Changes over time were analyzed by repeated-measures analysis of variance. The relationship between %change in Muscle Architecture variables and strength, speed, and change of direction variables from pre to post were assessed by Pearson product-moment correlation coefficient. Significant improvements in PV and PP occurred at all JS loads pre- to mid-testing and pre- to post-testing. Significant increases occurred pre-post in absolute 1RM, relative 1RM, 505 ND, and 2B sprint. The strongest relationships were found between %change in VL MT and 1B sprint (r = -0.80, p = 0.06), %change in VL FL and 2B sprint (r = -0.835, p = 0.02), and %change in relative 1RM and 505 D (r = -0.70, p = 0.04). In conclusion, gains in strength, power, and performance can occur during the season in elite softball players who are also engaged in a periodized RT program. Furthermore, changes in performance measures are associated with changes in Muscle Architecture.
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Training-specific Muscle Architecture adaptation after 5-wk training in athletes.
Medicine and science in sports and exercise, 2003Co-Authors: Anthony J. Blazevich, Nicholas D. Gill, Roger Bronks, Robert U. NewtonAbstract:ABSTRACTBLAZEVICH, A. J., N. D. GILL, R. BRONKS, and R. U. NEWTON. Training-Specific Muscle Architecture Adaptation after 5-wk Training in Athletes. Med. Sci. Sports Exerc., Vol. 35, No. 12, pp. 2013–2022, 2003.PurposeThis study examined changes in the Muscle size, Muscle Architecture, strength, and
Richard L. Lieber - One of the best experts on this subject based on the ideXlab platform.
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Comparison of rotator cuff Muscle Architecture between humans and other selected vertebrate species
Journal of Experimental Biology, 2013Co-Authors: Margie A. Mathewson, Carolyn M. Eng, Richard L. Lieber, Alan Kwan, Samuel R. WardAbstract:In this study, we compare rotator cuff Muscle Architecture of typically used animal models with that of humans and quantify the scaling relationships of these Muscles across mammals. The four Muscles that correspond to the human rotator cuff – supraspinatus, infraspinatus, subscapularis and teres minor – of 10 commonly studied animals were excised and subjected to a series of comparative measurements. When body mass among animals was regressed against physiological cross-sectional area, Muscle mass and normalized fiber length, the confidence intervals suggested geometric scaling but did not exclude other scaling relationships. Based on the architectural difference index (ADI), a combined measure of fiber length-to-moment arm ratio, fiber length-to-Muscle length ratio and the fraction of the total rotator cuff physiological cross-sectional area contributed by each Muscle, chimpanzees were found to be the most similar to humans (ADI=2.15), followed closely by capuchins (ADI=2.16). Interestingly, of the eight non-primates studied, smaller mammals such as mice, rats and dogs were more similar to humans in architectural parameters compared with larger mammals such as sheep, pigs or cows. The force production versus velocity trade-off (indicated by fiber length-to-moment arm ratio) and the excursion ability (indicated by fiber length-to-Muscle length ratio) of humans were also most similar to those of primates, followed by the small mammals. Overall, primates provide the best architectural representation of human Muscle Architecture. However, based on the Muscle architectural parameters of non-primates, smaller rather than larger mammals may be better models for studying Muscles related to the human rotator cuff.
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Sample size considerations in human Muscle Architecture studies
Muscle & nerve, 2012Co-Authors: Lori J. Tuttle, Samuel R. Ward, Richard L. LieberAbstract:INTRODUCTION—This report is a meta-analysis of the human Muscle Architecture literature that analyzes the number of Muscles, number of subjects, and Muscle fiber length coefficient of variation (CV) by body region. METHODS—Muscle fiber length data are used to make recommendations for dissection-based architectural study sample sizes. RESULTS—An average of 9 ± 10 (mean ± SD) Muscles and an average of 9 ± 5 subjects were reported in the 26 studies considered. Across all studies, average fiber length CV was highly variable (18% ± 5%). This shows that sample sizes required to achieve adequate power varies by anatomical region. DISCUSSION—Studies involving Muscle Architecture should consider regional variability and effect size and determine sample size accordingly.
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Are Current Measurements of Lower Extremity Muscle Architecture Accurate
Clinical orthopaedics and related research, 2008Co-Authors: Samuel R. Ward, Carolyn M. Eng, Laura H. Smallwood, Richard L. LieberAbstract:Skeletal Muscle Architecture is defined as the arrangement of fibers in a Muscle and functionally defines performance capacity. Architectural values are used to model Muscle-joint behavior and to make surgical decisions. The two most extensively used human lower extremity data sets consist of five total specimens of unknown size, gender, and age. Therefore, it is critically important to generate a high-fidelity human lower extremity Muscle Architecture data set. We disassembled 27 Muscles from 21 human lower extremities to characterize Muscle fiber length and physiologic cross-sectional area, which define the excursion and force-generating capacities of a Muscle. Based on their architectural features, the soleus, gluteus medius, and vastus lateralis are the strongest Muscles, whereas the sartorius, gracilis, and semitendinosus have the largest excursion. The plantarflexors, knee extensors, and hip adductors are the strongest Muscle groups acting at each joint, whereas the hip adductors and hip extensors have the largest excursion. Contrary to previous assertions, two-joint Muscles do not necessarily have longer fibers than single-joint Muscles as seen by the similarity of knee flexor and extensor fiber lengths. These high-resolution data will facilitate the development of more accurate musculoskeletal models and challenge existing theories of Muscle design; we believe they will aid in surgical decision making.
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Scaling of Muscle Architecture and fiber types in the rat hindlimb
Journal of Experimental Biology, 2008Co-Authors: Carolyn M. Eng, Samuel R. Ward, Laura H. Smallwood, Maria Pia Rainiero, Michele Lahey, Richard L. LieberAbstract:The functional capacity of a Muscle is determined by its Architecture and metabolic properties. Although extensive analyses of Muscle Architecture and fiber type have been completed in a large number of Muscles in numerous species, there have been few studies that have looked at the interrelationship of these functional parameters among Muscles of a single species. Nor have the architectural properties of individual Muscles been compared across species to understand scaling. This study examined Muscle Architecture and fiber type in the rat (Rattus norvegicus) hindlimb to examine each Muscle's functional specialization. Discriminant analysis demonstrated that architectural properties are a greater predictor of Muscle function (as defined by primary joint action and anti-gravity or non anti-gravity role) than fiber type. Architectural properties were not strictly aligned with fiber type, but when Muscles were grouped according to anti-gravity versus non-anti-gravity function there was evidence of functional specialization. Specifically, anti-gravity Muscles had a larger percentage of slow fiber type and increased Muscle physiological cross-sectional area. Incongruities between a Muscle's Architecture and fiber type may reflect the variability of functional requirements on single Muscles, especially those that cross multiple joints. Additionally, discriminant analysis and scaling of architectural variables in the hindlimb across several mammalian species was used to explore whether any functional patterns could be elucidated within single Muscles or across Muscle groups. Several Muscles deviated from previously described Muscle Architecture scaling rules and there was large variability within functional groups in how Muscles should be scaled with body size. This implies that functional demands placed on Muscles across species should be examined on the single Muscle level.
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rotator cuff Muscle Architecture implications for glenohumeral stability
Clinical Orthopaedics and Related Research, 2006Co-Authors: Samuel R. Ward, Jan Fridén, Laura H. Smallwood, Eric R Hentzen, Robert K Eastlack, Katherine A Burns, Donald C Fithian, Richard L. LieberAbstract:We examined the architectural properties of the rotator cuff Muscles in 10 cadaveric specimens to understand their functional design. Based on our data and previously published joint angle-Muscle excursion data, sarcomere length operating ranges were modeled through all permutations in 75 masculine medial and lateral rotation and 75 masculine abduction at the glenohumeral joint. Based on physiologic cross-sectional area, the subscapularis would have the greatest force-producing capacity, followed by the infraspinatus, supraspinatus, and teres minor. Based on fiber length, the supraspinatus would operate over the widest range of sarcomere lengths. The supraspinatus and infraspinatus had relatively long sarcomere lengths in the anatomic position, and were under relatively high passive tensions at rest, indicating they are responsible for glenohumeral resting stability. However, the subscapularis contributed passive tension at maximum abduction and lateral rotation, indicating it plays a critical role in glenohumeral stability in the position of apprehension. These data illustrate the exquisite coupling of Muscle Architecture and joint mechanics, which allows the rotator cuff to produce near maximal active tensions in the midrange and produce passive tensions in the various end-range positions. During surgery relatively small changes to rotator cuff Muscle length may result in relatively large changes in shoulder function.
Anthony S. Kulas - One of the best experts on this subject based on the ideXlab platform.
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The effect of Nordic hamstring strength training on Muscle Architecture, stiffness, and strength
European Journal of Applied Physiology, 2017Co-Authors: Kayla D Seymore, Zachary J. Domire, Patrick M. Rider, Paul Devita, Anthony S. KulasAbstract:PurposeHamstring strain injury is a frequent and serious injury in competitive and recreational sports. While Nordic hamstring (NH) eccentric strength training is an effective hamstring injury-prevention method, the protective mechanism of this exercise is not understood. Strength training increases Muscle strength, but also alters Muscle Architecture and stiffness; all three factors may be associated with reducing Muscle injuries. The purpose of this study was to examine the effects of NH eccentric strength training on hamstring Muscle Architecture, stiffness, and strength.MethodsTwenty healthy participants were randomly assigned to an eccentric training group or control group. Control participants performed static stretching, while experimental participants performed static stretching and NH training for 6 weeks. Pre- and post-intervention measurements included: hamstring Muscle Architecture and stiffness using ultrasound imaging and elastography, and maximal hamstring strength measured on a dynamometer.ResultsThe experimental group, but not the control group, increased volume (131.5 vs. 145.2 cm3, p
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The effect of Nordic hamstring strength training on Muscle Architecture, stiffness, and strength.
European journal of applied physiology, 2017Co-Authors: Kayla D Seymore, Zachary J. Domire, Paul Devita, Patrick Rider, Anthony S. KulasAbstract:Hamstring strain injury is a frequent and serious injury in competitive and recreational sports. While Nordic hamstring (NH) eccentric strength training is an effective hamstring injury-prevention method, the protective mechanism of this exercise is not understood. Strength training increases Muscle strength, but also alters Muscle Architecture and stiffness; all three factors may be associated with reducing Muscle injuries. The purpose of this study was to examine the effects of NH eccentric strength training on hamstring Muscle Architecture, stiffness, and strength. Twenty healthy participants were randomly assigned to an eccentric training group or control group. Control participants performed static stretching, while experimental participants performed static stretching and NH training for 6 weeks. Pre- and post-intervention measurements included: hamstring Muscle Architecture and stiffness using ultrasound imaging and elastography, and maximal hamstring strength measured on a dynamometer. The experimental group, but not the control group, increased volume (131.5 vs. 145.2 cm3, p
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the effect of nordic hamstring strength training on Muscle Architecture stiffness and strength
European Journal of Applied Physiology, 2017Co-Authors: Zachary J. Domire, Kayla D Seymore, Paul Devita, Patrick Rider, Anthony S. KulasAbstract:Hamstring strain injury is a frequent and serious injury in competitive and recreational sports. While Nordic hamstring (NH) eccentric strength training is an effective hamstring injury-prevention method, the protective mechanism of this exercise is not understood. Strength training increases Muscle strength, but also alters Muscle Architecture and stiffness; all three factors may be associated with reducing Muscle injuries. The purpose of this study was to examine the effects of NH eccentric strength training on hamstring Muscle Architecture, stiffness, and strength. Twenty healthy participants were randomly assigned to an eccentric training group or control group. Control participants performed static stretching, while experimental participants performed static stretching and NH training for 6 weeks. Pre- and post-intervention measurements included: hamstring Muscle Architecture and stiffness using ultrasound imaging and elastography, and maximal hamstring strength measured on a dynamometer. The experimental group, but not the control group, increased volume (131.5 vs. 145.2 cm3, p < 0.001) and physiological cross-sectional area (16.1 vs. 18.1 cm2, p = 0.032). There were no significant changes to Muscle fascicle length, stiffness, or eccentric hamstring strength. The NH intervention was an effective training method for Muscle hypertrophy, but, contrary to common literature findings for other modes of eccentric training, did not increase fascicle length. The data suggest that the mechanism behind NH eccentric strength training mitigating hamstring injury risk could be increasing volume rather than increasing Muscle length. Future research is, therefore, warranted to determine if Muscle hypertrophy induced by NH training lowers future hamstring strain injury risk.
Kayla D Seymore - One of the best experts on this subject based on the ideXlab platform.
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The effect of Nordic hamstring strength training on Muscle Architecture, stiffness, and strength
European Journal of Applied Physiology, 2017Co-Authors: Kayla D Seymore, Zachary J. Domire, Patrick M. Rider, Paul Devita, Anthony S. KulasAbstract:PurposeHamstring strain injury is a frequent and serious injury in competitive and recreational sports. While Nordic hamstring (NH) eccentric strength training is an effective hamstring injury-prevention method, the protective mechanism of this exercise is not understood. Strength training increases Muscle strength, but also alters Muscle Architecture and stiffness; all three factors may be associated with reducing Muscle injuries. The purpose of this study was to examine the effects of NH eccentric strength training on hamstring Muscle Architecture, stiffness, and strength.MethodsTwenty healthy participants were randomly assigned to an eccentric training group or control group. Control participants performed static stretching, while experimental participants performed static stretching and NH training for 6 weeks. Pre- and post-intervention measurements included: hamstring Muscle Architecture and stiffness using ultrasound imaging and elastography, and maximal hamstring strength measured on a dynamometer.ResultsThe experimental group, but not the control group, increased volume (131.5 vs. 145.2 cm3, p
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The effect of Nordic hamstring strength training on Muscle Architecture, stiffness, and strength.
European journal of applied physiology, 2017Co-Authors: Kayla D Seymore, Zachary J. Domire, Paul Devita, Patrick Rider, Anthony S. KulasAbstract:Hamstring strain injury is a frequent and serious injury in competitive and recreational sports. While Nordic hamstring (NH) eccentric strength training is an effective hamstring injury-prevention method, the protective mechanism of this exercise is not understood. Strength training increases Muscle strength, but also alters Muscle Architecture and stiffness; all three factors may be associated with reducing Muscle injuries. The purpose of this study was to examine the effects of NH eccentric strength training on hamstring Muscle Architecture, stiffness, and strength. Twenty healthy participants were randomly assigned to an eccentric training group or control group. Control participants performed static stretching, while experimental participants performed static stretching and NH training for 6 weeks. Pre- and post-intervention measurements included: hamstring Muscle Architecture and stiffness using ultrasound imaging and elastography, and maximal hamstring strength measured on a dynamometer. The experimental group, but not the control group, increased volume (131.5 vs. 145.2 cm3, p
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the effect of nordic hamstring strength training on Muscle Architecture stiffness and strength
European Journal of Applied Physiology, 2017Co-Authors: Zachary J. Domire, Kayla D Seymore, Paul Devita, Patrick Rider, Anthony S. KulasAbstract:Hamstring strain injury is a frequent and serious injury in competitive and recreational sports. While Nordic hamstring (NH) eccentric strength training is an effective hamstring injury-prevention method, the protective mechanism of this exercise is not understood. Strength training increases Muscle strength, but also alters Muscle Architecture and stiffness; all three factors may be associated with reducing Muscle injuries. The purpose of this study was to examine the effects of NH eccentric strength training on hamstring Muscle Architecture, stiffness, and strength. Twenty healthy participants were randomly assigned to an eccentric training group or control group. Control participants performed static stretching, while experimental participants performed static stretching and NH training for 6 weeks. Pre- and post-intervention measurements included: hamstring Muscle Architecture and stiffness using ultrasound imaging and elastography, and maximal hamstring strength measured on a dynamometer. The experimental group, but not the control group, increased volume (131.5 vs. 145.2 cm3, p < 0.001) and physiological cross-sectional area (16.1 vs. 18.1 cm2, p = 0.032). There were no significant changes to Muscle fascicle length, stiffness, or eccentric hamstring strength. The NH intervention was an effective training method for Muscle hypertrophy, but, contrary to common literature findings for other modes of eccentric training, did not increase fascicle length. The data suggest that the mechanism behind NH eccentric strength training mitigating hamstring injury risk could be increasing volume rather than increasing Muscle length. Future research is, therefore, warranted to determine if Muscle hypertrophy induced by NH training lowers future hamstring strain injury risk.
Adamantios Arampatzis - One of the best experts on this subject based on the ideXlab platform.
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Reliability of a semi-automated algorithm for the vastus lateralis Muscle Architecture measurement based on ultrasound images
European Journal of Applied Physiology, 2017Co-Authors: Robert Marzilger, Kirsten Legerlotz, Chrystalla Panteli, Stephan Böhm, Adamantios ArampatzisAbstract:PurposeThe assessment of Muscle Architecture with B-mode ultrasound is an established method in Muscle physiology and mechanics. There are several manual, semi-automated and automated approaches available for Muscle Architecture analysis from ultrasound images or videos. However, most approaches have limitations such as workload, subjectivity, drift or they are applicable to short Muscle fascicles only. Addressing these issues, an algorithm was developed to analyse architectural parameters of the vastus lateralis Muscle (VL).MethodsIn 17 healthy young men and women, ultrasound images were taken five times on two different days during passive knee joint flexion. From the images, fascicle length (FL), pennation angle (PAN) and Muscle thickness (MTH) were calculated for both test days using the algorithm. Interday differences were determined using a two-way ANOVA. Interday and intraday reliability were assessed using intraclass correlation coefficients (ICC) and root mean square (RMS) differences.ResultsFL, MTH and PAN did not differ between day one and two. The within day ICCs were above 0.94 for all tested parameters. The average interday ICCs were 0.86 for the FL, 0.96 for MTH and 0.60 for PAN. The average RMS differences between both days were 5.0%, 8.5% and 12.0% for MTH, FL and PAN, respectively.ConclusionThe proposed algorithm provides high measurement reliability. However, the interday reliability might be influenced by small differences in probe position between days.
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Reliability of a semi-automated algorithm for the vastus lateralis Muscle Architecture measurement based on ultrasound images.
European journal of applied physiology, 2017Co-Authors: Robert Marzilger, Kirsten Legerlotz, Chrystalla Panteli, Sebastian Bohm, Adamantios ArampatzisAbstract:Purpose The assessment of Muscle Architecture with B-mode ultrasound is an established method in Muscle physiology and mechanics. There are several manual, semi-automated and automated approaches available for Muscle Architecture analysis from ultrasound images or videos. However, most approaches have limitations such as workload, subjectivity, drift or they are applicable to short Muscle fascicles only. Addressing these issues, an algorithm was developed to analyse architectural parameters of the vastus lateralis Muscle (VL).
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Muscle Architecture and torque production in stroke survivors an observational study
Topics in Stroke Rehabilitation, 2017Co-Authors: Caroline Pieta Dias, Adamantios Arampatzis, Bruno Freire, Natalia Batista Albuquerque Goulart, Eduardo Dos Santos Onzi, Jefferson Becker, Irenio Gomes, Marco Aurélio VazAbstract:Objective: Spasticity poststroke leads to Muscle weakness and soft tissue contracture, however, it is not clear how Muscle properties change due this motor neural disorder. The purpose was to compare medial gastrocnemius Muscle Architecture and mechanical properties of the plantarflexor Muscles between stroke survivors with spasticity and healthy subjects.Methods: The study included 15 stroke survivors with ankle spasticity and 15 healthy subjects. An isokinetic dynamometer was used for the evaluation of maximal isometric plantarflexor torque and images of the medial gastrocnemius Muscle were obtained using ultrasonography. Images were collected at rest and during a maximum voluntary contraction.Results: The affected limb showed reduced fascicle excursion (0.9 ± 0.7 cm), shorter fascicle length, and reduced Muscle thickness (0.095 ± 0.010% of leg length and 1.18 ± 0.20 cm, at rest) compared to contralateral (1.6 ± 0.4 cm, 0.106 ± 0.015% of leg length and 1.29 ± 0.24 cm, respectively) and to healthy partic...
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Inevitable joint angular rotation affects Muscle Architecture during isometric contraction.
Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology, 2005Co-Authors: Kiros Karamanidis, Savvas Stafilidis, Gianpiero Demonte, Gaspar Morey-klapsing, Gert-peter Brüggemann, Adamantios ArampatzisAbstract:Abstract The purpose of this study was to quantify the influence of inevitable ankle joint motion during an isometric contraction on the measured change of the gastrocnemius medialis Muscle (GM) Architecture in vivo during the loading and the unloading phase. Sitting on a dynamometer subjects performed isometric maximal voluntary contractions as well as contractions induced by electrostimulation. Synchronous joint angular motion, plantarflexion moment, foot's centre of pressure and real-time ultrasonography of Muscle Architecture changes of the GM were obtained. During the contraction the ankle joint position altered and significantly affected the change in Muscle Architecture. At maximal tendon force (1094±323N), the measured fascicle length overestimated the change in fascicle length due to the tendon force by 1.53cm, while the measured pennation angle overestimated the change in pennation angle due to the tendon force by 5.5°. At the same tendon force the measured fascicle length and pennation angle were significantly different between loading and unloading conditions. After correcting the values for the change in ankle joint angle no differences between the loading and the unloading phase at the same tendon force were found. Concerning the estimation of GM fascicle length–force and pennation angle–force curves during the loading and unloading phase of an isometric contraction, these findings indicate that not accounting for ankle joint motion will produce unreliable results.
