274 results match your criteria Medial Gastrocnemius Strain


Magnetic resonance imaging based muscle strain rate mapping during eccentric contraction to study effects of unloading induced by unilateral limb suspension.

Eur J Transl Myol 2020 Apr 1;30(1):8935. Epub 2020 Apr 1.

Department of Radiology, University of California San Diego, San Diego, CA, USA.

Age- and disuse- related loss of muscle force is disproportionately larger than the loss of muscle mass. Earlier studies reported that comparing concentric and eccentric contractions, there is a significant age-related decrease in force only in concentric contractions. Magnetic Resonance Imaging enables mapping of muscle deformation and has been used to study isometric but not eccentric contractions. Read More

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http://dx.doi.org/10.4081/ejtm.2019.8935DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7254429PMC

Skeletal Muscle Shape Change in Relation to Varying Force Requirements Across Locomotor Conditions.

Front Physiol 2020 20;11:143. Epub 2020 Mar 20.

Concord Field Station, Department of Organismic and Evolutionary Biology, Harvard University, Bedford, MA, United States.

Contractions of skeletal muscles to generate movement involve dynamic changes in contractile and elastic tissue strains that likely interact to influence the force and work of a muscle. However, studies of the dynamics of skeletal muscle and tendon strains remain largely limited to bipedal animals, and rarely cover the broad spectra of movement requirements met by muscles that operate as motors, struts, or brakes across the various gaits that animals commonly use and conditions they encounter. Using high-speed bi-planar fluoromicrometry, we analyze strains within the rat medial gastrocnemius (MG) across a range of gait and slope conditions. Read More

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http://dx.doi.org/10.3389/fphys.2020.00143DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7100385PMC

A multiple fascicle muscle force model of the human triceps surae.

J Theor Biol 2020 Jun 19;495:110251. Epub 2020 Mar 19.

Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, T6G 1H9 AB, Canada.

Muscle is typically modelled using a lump sum idealization, scaling a single fascicle to represent the entire muscle. However, fascicles within a muscle have unique orientations, which could result in forces exerted not only in the axis running along the tendon, but also the two perpendicular axes, describing the muscle's width and depth. The purpose of this research was to develop a geometric-based model of the soleus, medial gastrocnemius, and lateral gastrocnemius as distributed force systems which can predict three-dimensional forces. Read More

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http://dx.doi.org/10.1016/j.jtbi.2020.110251DOI Listing

Flip-flops do not alter the neuromuscular function of the gastrocnemius muscle and tendon during walking in children.

Gait Posture 2020 03 7;77:83-88. Epub 2020 Jan 7.

Queensland Children's Motion Analysis Service, Children's Health Queensland Hospital and Health Service, Brisbane, Australia; Gold Coast Orthopaedic Research and Education Alliance, Menzies Health Institute Queensland, Gold Coast, Australia.

Introduction/aim: Flip-flops are a popular choice of footwear for children. However, their inherent design provides minimal support to the foot and ankle and has been suggested to increase the work performed by muscle and tendon structures, potentially predisposing them to injury. Therefore, the aim of this study was to compare the length change behaviour of the medial gastrocnemius (MG) muscle fascicles and muscle tendon unit (MTU) and their mechanical function at the ankle and subtalar joints in children during walking with and without flip-flop. Read More

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http://dx.doi.org/10.1016/j.gaitpost.2019.12.032DOI Listing

Compressed sensing velocity encoded phase contrast imaging: Monitoring skeletal muscle kinematics.

Magn Reson Med 2020 Jul 11;84(1):142-156. Epub 2019 Dec 11.

Muscle Imaging and Modeling Lab, Department of Radiology, UC San Diego, San Diego, California.

Purpose: This study implements a compressed sensing (CS) 3-directional velocity encoded phase contrast (VE-PC) imaging for studying skeletal muscle kinematics within 40 s.

Methods: Independent variable density random sampling in the phase encoding direction for each temporal frame was implemented for various combinations of CS-factors and views per segment. CS reconstruction was performed for the combined multicoil, temporal datasets using temporal Fourier transform followed by temporal principal component analysis sparsifying transformations. Read More

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http://dx.doi.org/10.1002/mrm.28100DOI Listing

Effects of hyperbaric oxygen therapy on recovery acceleration in Japanese professional or semi-professional rugby players with grade 2 medial collateral ligament injury of the knee: A comparative non-randomized study.

Undersea Hyperb Med 2019 Sep - Dec - Fourth Quarter;46(5):647-654

Department of Orthopaedic Surgery, Tokyo Medical and Dental University.

Introduction: The effects of hyperbaric oxygen (HBO2) therapy on sprains, ligament injuries, and muscle strains have been reported in several animal studies. In a dog model of compartment syndrome and in a rat contused skeletal muscle injury model, the significant effects of HBO2 therapy on the reduction of edema and muscle necrosis have been reported. In basic research HBO2 therapy stimulated fibroblast activity to improve the healing process. Read More

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November 2019
2 Reads

Non-commutative, nonlinear, and non-analytic aspects of the ocular motor plant.

Authors:
Joseph L Demer

Prog Brain Res 2019 20;248:93-102. Epub 2019 May 20.

Stein Eye Institute and Departments of Ophthalmology and Neurology, University of California, Los Angeles, CA, United States. Electronic address:

The ocular motor plant, consisting of the globe, extraocular muscles (EOMs), and connective tissue suspension, constitutes an intricate and non-linear actuator of eye movements. The pulley system of the rectus EOMs constitutes a non-linear inner gimbal actuated by the orbital layers of these EOMs that renders the sequence of ocular rotations effectively commutative to the central controller, and can be rotated by the outer gimbal driven by the oblique EOMs. Optic nerve (ON) length is insufficient to permit large angle adduction without tethering by the ON and sheath, creating at and beyond this threshold a large additional load on the medial rectus muscle. Read More

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http://dx.doi.org/10.1016/bs.pbr.2019.04.015DOI Listing
April 2020
2 Reads

Effects of the strain rate on mechanical properties of tendon structures in knee extensors and plantar flexors .

Sports Biomech 2019 Jun 24:1-14. Epub 2019 Jun 24.

a Department of Life Science , University of Tokyo , Tokyo , Japan.

The purpose of present study was to investigate site differences in the effects of strain rate on tendon properties between knee extensors and plantar flexors. Elongation of tendon structures (L) in vastus lateralis and medial gastrocnemius muscles was measured by ultrasonography while participants performed ramp and ballistic contractions to their voluntary maximum, followed by ramp and sudden relaxation. The relationship between muscle force (Fm) and L was fit to linear regression, the slope of which was defined as stiffness of tendon structures. Read More

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http://dx.doi.org/10.1080/14763141.2019.1615541DOI Listing
June 2019
16 Reads

Running status and history: A self-report study.

Phys Ther Sport 2019 Sep 5;39:8-15. Epub 2019 Jun 5.

University of Nevada, Las Vegas, United States. Electronic address:

Objectives: The purpose of the current study was to compare injury and running history among current and former runners who consider themselves either injured or uninjured.

Design: Cross-sectional survey.

Setting: Online survey, available to any individuals over the age of 18 who currently run (runners) or who once ran regularly but are no longer running (former runners). Read More

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http://dx.doi.org/10.1016/j.ptsp.2019.06.003DOI Listing
September 2019
9 Reads

Ulnar Nerve Compression due to Anconeus Epitrochlearis: A Case Report and Review of the Literature.

JBJS Case Connect 2019 Apr-Jun;9(2):e0189

Hansjörg Wyss Department of Plastic Surgery, New York University Langone Health, New York, New York.

Case: A 32-year-old right-handed surgeon presented with a history of intermittent pain at the right medial epicondyle, a mild Tinel's sign, and dysesthesia in the ulnar nerve distribution. Dynamic ultrasound demonstrated a hypertrophic anconeus epitrochlearis bilaterally, and chronic irritation of the ulnar nerve. Anterior release with myectomy of the accessory muscle was performed. Read More

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http://dx.doi.org/10.2106/JBJS.CC.18.00189DOI Listing
June 2020
1 Read

Impaired mechanical properties of Achilles tendon in spastic stroke survivors: an observational study.

Top Stroke Rehabil 2019 05 19;26(4):261-266. Epub 2019 Mar 19.

a School of Physical Education, Physiotherapy and Dance , Federal University of Rio Grande do Sul , Porto Alegre , Brazil.

Background: The spasticity could lead to decreased functional capacity and changes in musculoskeletal tissue.

Objective: To compare the Achilles tendon properties between the affected and contralateral limbs of participants with spasticity due to stroke and the healthy subjects.

Methods: Fifteen individuals with ankle spasticity due to stroke and 15 healthy subjects were recruited. Read More

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http://dx.doi.org/10.1080/10749357.2019.1591688DOI Listing
May 2019
11 Reads

Passive and dynamic muscle architecture during transverse loading for gastrocnemius medialis in man.

J Biomech 2019 03 12;86:160-166. Epub 2019 Feb 12.

Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada.

External forces from our environment impose transverse loads on our muscles. Studies in rats have shown that transverse loads result in a decrease in the longitudinal muscle force. Changes in muscle architecture during contraction may contribute to the observed force decrease. Read More

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http://dx.doi.org/10.1016/j.jbiomech.2019.01.054DOI Listing
March 2019
11 Reads

Differences in the strain applied to Achilles tendon fibers when the subtalar joint is overpronated: a simulation study.

Surg Radiol Anat 2019 May 8;41(5):595-599. Epub 2019 Jan 8.

Department of Anatomy, School of Life Dentistry at Niigata, Nippon Dental University, Niigata, Japan.

Purpose: The purpose of this study was to investigate the strain applied to each of the tendon fiber bundles of the medial head of the gastrocnemius (MG), the lateral head of the gastrocnemius (LG), and the soleus muscle (Sol) that compose the Achilles tendon (AT) when the subtalar joint is pronated and supinated.

Methods: Three AT twist types (least, moderate, extreme) were investigated. Using the MicroScribe system, the AT and the talocrural and subtalar joints were digitized to reconstruct three-dimensional models. Read More

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http://dx.doi.org/10.1007/s00276-019-02181-3DOI Listing
May 2019
11 Reads

Dynamic stretching is not detrimental to neuromechanical and sensorimotor performance of ankle plantarflexors.

Scand J Med Sci Sports 2019 Feb 8;29(2):200-212. Epub 2018 Nov 8.

Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, UK.

The acute effects of two dynamic stretching (DS) protocols on changes in the ankle range of motion (RoM), neuromechanical, and sensorimotor properties of the plantarflexor muscle group were examined. Eighteen participants received slow (SDS) or fast dynamic stretching (FDS) on two separate days. Outcome measures were assessed pre- and 2 minutes post-interventions, and included maximum dorsiflexion angle, maximum isometric torque at neutral ankle position, maximum concentric and eccentric torques, force matching capacity, joint position sense and medial gastrocnemius muscle and tendon strain. Read More

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http://dx.doi.org/10.1111/sms.13321DOI Listing
February 2019
9 Reads

Evaluation of the activities of the medial and lateral heads of quadratus plantae in flexion movements of the lateral four toes using ultrasound real-time tissue elastography.

Foot (Edinb) 2018 Sep 5;36:25-29. Epub 2018 Mar 5.

Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagai, Yamagata-city, Yamagata 990-2212, Japan.

Quadratus plantae (QP), one of the plantar intrinsic foot muscles, assist plantarflexion of the lesser toes. QP has medial and lateral muscle heads with different anatomical structures. The two heads of this muscle may have different roles in foot function. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S09582592173017
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http://dx.doi.org/10.1016/j.foot.2018.02.005DOI Listing
September 2018
30 Reads

Innervation of the anconeus epitrochlearis muscle: MRI and cadaveric studies.

Clin Anat 2019 Mar 14;32(2):218-223. Epub 2018 Oct 14.

Seattle Science Foundation, Seattle, Washington.

Ulnar neuropathy at the cubital tunnel is common. However, a rare form of ulnar neuropathy here is due to compression from an accessory muscle, the anconeus epitrochlearis. Reports in the literature regarding the details of this muscle's innervation are vague, so the aim of the present study was to characterize this anatomy more clearly. Read More

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https://onlinelibrary.wiley.com/doi/abs/10.1002/ca.23285
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http://dx.doi.org/10.1002/ca.23285DOI Listing
March 2019
37 Reads

A rare variation of intrinsic and extrinsic hand muscles represented by a bi-ventered first lumbrical extending into the carpal tunnel combined with bilateral fifth superficial flexor digitorum tendon regression.

Morphologie 2018 Dec 25;102(339):294-301. Epub 2018 Sep 25.

Institute of Anatomy, Paracelsus Medical University, Nuremberg and Salzburg, General Hospital Nuremberg, Prof. Ernst Nathan street. 1, 90419 Nuremberg, Germany. Electronic address:

A rare unilateral variation of the first left lumbrical muscle was discovered in a female Caucasian cadaver dissected during a first year anatomy course at the Paracelsus Medical University - Nuremberg, Germany. The muscle possessed two venters with the first originating near the medial epicondyle of the humerus together with the intramuscular tendon of the superficial flexor digitorum tendon, and the second presenting as a regular first lumbrical muscle with radial palmar origin from first tendon of the deep flexor digitorum muscle. Both muscle bellies were connected by a 1. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S12860115183018
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http://dx.doi.org/10.1016/j.morpho.2018.09.001DOI Listing
December 2018
16 Reads

Leg blood flow and skeletal muscle microvascular perfusion responses to submaximal exercise in peripheral arterial disease.

Am J Physiol Heart Circ Physiol 2018 11 10;315(5):H1425-H1433. Epub 2018 Aug 10.

VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, Queensland, Australia.

Peripheral arterial disease (PAD) is characterized by stenosis and occlusion of the lower limb arteries. Although leg blood flow is limited in PAD, it remains unclear whether skeletal muscle microvascular perfusion is affected. We compared whole leg blood flow and calf muscle microvascular perfusion after cuff occlusion and submaximal leg exercise between patients with PAD ( n = 12, 69 ± 9 yr) and healthy age-matched control participants ( n = 12, 68 ± 7 yr). Read More

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http://dx.doi.org/10.1152/ajpheart.00232.2018DOI Listing
November 2018
16 Reads

Elasticity of the pronator teres muscle in youth baseball players with elbow injuries: evaluation using ultrasound strain elastography.

J Shoulder Elbow Surg 2018 Sep 22;27(9):1642-1649. Epub 2018 Jun 22.

Department of Physical Therapy, Akita University Graduate School of Health Sciences, Akita, Japan.

Background: Although the pronator teres muscle, a major dynamic stabilizer of elbow valgus stress during throwing, frequently presents stiffness, its relationship with elbow injuries in youth baseball players is unknown. This study investigated the relationship between the elasticity of the pronator teres muscle and elbow injuries in youth baseball players.

Methods: The strain ratio (SR) of 15 individuals with osteochondritis dissecans of the humeral capitellum (OCD group), 67 individuals with medial epicondylar fragmentation (medial injury group), and 115 healthy individuals (control group) was measured as the index of the elasticity of the pronator teres muscle using ultrasound strain elastography. Read More

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http://dx.doi.org/10.1016/j.jse.2018.05.021DOI Listing
September 2018
8 Reads

Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force-Length Relationships.

Integr Comp Biol 2018 08;58(2):219-231

Concord Field Station, MCZ, Harvard University, 100 Old Causeway Road, Bedford, MA 01730, USA.

To relate in vivo behavior of fascicle segments within a muscle to their in vitro force-length relationships, we examined the strain behavior of paired segments within each of three vertebrate muscles. After determining in vivo muscle activity patterns and length changes of in-series segments within the semimembranosus muscle (SM) in the American Toad (Bufo americanus) during hopping and within the sternohyoid (SH) muscle in the rat (Rattus rattus) during swallowing, and of spatially separated fascicles within the medial gastrocnemius (MG) muscle in the rat during trotting, we measured their corresponding in vitro (toad) or in situ (rat) force-length relationships (FLRs). For all three muscles, in vivo strain heterogeneity lasted for about 36-57% of the behavior cycle, during which one segment or fascicle shortened while the other segment or fascicle simultaneously lengthened. Read More

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http://dx.doi.org/10.1093/icb/icy040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6104704PMC
August 2018
7 Reads

Patellar tendon properties distinguish elite from non-elite soccer players and are related to peak horizontal but not vertical power.

Eur J Appl Physiol 2018 Aug 2;118(8):1737-1749. Epub 2018 Jun 2.

School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK.

Purpose: To investigate potential differences in patellar tendon properties between elite and non-elite soccer players, and to establish whether tendon properties were related to power assessed during unilateral jumps performed in different directions.

Methods: Elite (n = 16; age 18.1 ± 1. Read More

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http://dx.doi.org/10.1007/s00421-018-3905-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6060780PMC
August 2018
54 Reads

The repeated bout effect can occur without mechanical and neuromuscular changes after a bout of eccentric exercise.

Scand J Med Sci Sports 2018 Oct 7;28(10):2123-2134. Epub 2018 Jun 7.

School of Human Movement and Nutrition Sciences, Centre for Sensorimotor Performance, The University of Queensland, Brisbane, Queensland, Australia.

Changes in muscle fascicle mechanics have been postulated to underpin the repeated bout effect (RBE) observed following exercise-induced muscle damage (EIMD). However, in the medial gastrocnemius (MG), mixed evidence exists on whether fascicle stretch amplitude influences the level of EIMD, thus questioning whether changes in fascicle mechanics underpin the RBE. An alternative hypothesis is that neural adaptations contribute to the RBE in this muscle. Read More

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http://dx.doi.org/10.1111/sms.13222DOI Listing
October 2018
9 Reads

Static Postural Stability in Chronic Ankle Instability, an Ankle Sprain and Healthy Ankles.

Authors:
Yong Ung Kwon

Int J Sports Med 2018 Jul 18;39(8):625-629. Epub 2018 May 18.

Youngstown State University Bitonte College of Health and Human Services, Kinesiology and Sport Science, Youngstown, United States.

To identify the single leg balance (SLB) test that discriminates among healthy, coper, and chronic ankle instability (CAI) groups and to determine effects of ankle muscles on the balance error scoring system (BESS) among the three populations. 60 subjects (20 per group) performed the SLB test with eyes open (EO) and eyes closed (EC). Normalized mean amplitude (NMA) of the tibia anterior (TA), fibularis longus (FL), and medial gastrocnemius (MG) muscles and BESS were measured while performing the SLB test. Read More

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http://dx.doi.org/10.1055/a-0608-4552DOI Listing
July 2018
13 Reads

Effects of an acute bout of dynamic stretching on biomechanical properties of the gastrocnemius muscle determined by shear wave elastography.

PLoS One 2018 3;13(5):e0196724. Epub 2018 May 3.

Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom.

Aims: The aim of this study was to examine the acute effects of dynamic stretching (DS) exercise on passive ankle range of motion (RoM), resting localized muscle stiffness, as measured by shear wave speed (SWS) of medial gastrocnemius muscle, fascicle strain, and thickness.

Methods/results: Twenty-three participants performed a DS protocol. Before and after stretching, SWS was measured in the belly of the resting medial gastrocnemius muscle (MGM) using shear wave elastography. Read More

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0196724PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5933711PMC
August 2018
9 Reads

Measurement of large strain properties in calf muscles in vivo using magnetic resonance elastography and spatial modulation of magnetization.

NMR Biomed 2018 10 19;31(10):e3925. Epub 2018 Apr 19.

Neuroscience Research Australia, Randwick, NSW, Australia.

It is important to measure the large deformation properties of skeletal muscle in vivo in order to understand and model movement and the force-producing capabilities of muscle. As muscle properties are non-linear, an understanding of how the deformation state affects the measured shear moduli is also useful for clinical applications of magnetic resonance elastography (MRE) to muscle disorders. MRE has so far only been used to measure the linear viscoelastic (small strain) properties of muscles. Read More

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http://dx.doi.org/10.1002/nbm.3925DOI Listing
October 2018
13 Reads

Shear strain rate from phase contrast velocity encoded MRI: Application to study effects of aging in the medial gastrocnemius muscle.

J Magn Reson Imaging 2018 11 1;48(5):1351-1357. Epub 2018 Apr 1.

Muscle Imaging and Modeling Lab, Department of Radiology, UC San Diego, San Diego, California, USA.

Background: Strain rate (SR) is a measure of the rate of regional deformation that can be computed by analyzing velocity-encoded phase-contrast 2D images. Recent studies have explored the changes in normal components of the strain tensor in aging muscle, while shear strain may also provide valuable information.

Purpose: To compute the shear SR from velocity-encoded MRI of the lower leg and to study the correlation of SR parameters measured in the medial gastrocnemius (MG) to muscle force in a cohort of young and senior subjects. Read More

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http://dx.doi.org/10.1002/jmri.26030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6167202PMC
November 2018
9 Reads

Differences in in vivo muscle fascicle and tendinous tissue behavior between the ankle plantarflexors during running.

Scand J Med Sci Sports 2018 Jul 23;28(7):1828-1836. Epub 2018 Apr 23.

Department of Mechanical Engineering, University of Melbourne, Parkville, VIC, Australia.

The primary human ankle plantarflexors, soleus (SO), medial gastrocnemius (MG), and lateral gastrocnemius (LG) are typically regarded as synergists and play a critical role in running. However, due to differences in muscle-tendon architecture and joint articulation, the muscle fascicles and tendinous tissue of the plantarflexors may exhibit differences in their behavior and interactions during running. We combined in vivo dynamic ultrasound measurements with inverse dynamics analyses to identify and explain differences in muscle fascicle, muscle-tendon unit, and tendinous tissue behavior of the primary ankle plantarflexors across a range of steady-state running speeds. Read More

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http://dx.doi.org/10.1111/sms.13089DOI Listing
July 2018
8 Reads

Effects of cochlear synaptopathy on middle-ear muscle reflexes in unanesthetized mice.

Hear Res 2018 06 13;363:109-118. Epub 2018 Mar 13.

Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA 02114, USA; Department of Otolaryngology, Harvard Medical School, Boston, MA 02115, USA.

Cochlear synaptopathy, i.e. the loss of auditory-nerve connections with cochlear hair cells, is seen in aging, noise damage, and other types of acquired sensorineural hearing loss. Read More

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http://dx.doi.org/10.1016/j.heares.2018.03.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6359722PMC
June 2018
7 Reads

Change in skeletal muscle stiffness after running competition is dependent on both running distance and recovery time: a pilot study.

PeerJ 2018 12;6:e4469. Epub 2018 Mar 12.

Department of Mechanical and Nuclear Engineering, Pennsylvania State University, State College, PA, United States of America.

Long-distance running competitions impose a large amount of mechanical loading and strain leading to muscle edema and delayed onset muscle soreness (DOMS). Damage to various muscle fibers, metabolic impairments and fatigue have been linked to explain how DOMS impairs muscle function. Disruptions of muscle fiber during DOMS exacerbated by exercise have been shown to change muscle mechanical properties. Read More

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http://dx.doi.org/10.7717/peerj.4469DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5853607PMC
March 2018
8 Reads

Tracking of Time-Dependent Changes in Muscle Hardness After a Full Marathon.

J Strength Cond Res 2019 Dec;33(12):3431-3437

Department of Physical Therapy, Health Science University, Minamitsuru, Japan.

Inami, T, Nakagawa, K, Yonezu, T, Fukano, M, Higashihara, A, Iizuka, S, Abe, T, and Narita, T. Tracking of time-dependent changes in muscle hardness after a full marathon. J Strength Cond Res 33(12): 3431-3437, 2019-We sought to identify changes in individual muscle hardness after a full marathon and to track time-dependent changes using ultrasound strain elastography (SE). Read More

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http://dx.doi.org/10.1519/JSC.0000000000002495DOI Listing
December 2019
7 Reads

Non-uniform displacement and strain between the soleus and gastrocnemius subtendons of rat Achilles tendon.

Scand J Med Sci Sports 2018 Mar 23;28(3):1009-1017. Epub 2017 Nov 23.

Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands.

Achilles tendon (AT) comprises of 3 subtendons arising from the soleus (SOL) and the lateral (LG) and medial (MG) heads of the gastrocnemius muscle. While recent human studies show differential displacement within AT, these displacements have not been attributed to specific subtendons. We tested the hypothesis that the SOL and LG subtendons show differential displacement and strain during various combinations of SOL, LG, and MG excitations. Read More

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http://dx.doi.org/10.1111/sms.13001DOI Listing
March 2018
6 Reads

The use of platelet-rich plasma (PRP) in the treatment of gastrocnemius strains: a retrospective observational study.

Platelets 2018 Sep 12;29(6):596-601. Epub 2017 Sep 12.

a Department of Movement, Human and Health Sciences , University of Rome "Foro Italico" , Rome , Italy.

The aim of the present retrospective observational study was to evaluate the time of functional recovery following a specific combined therapeutic approach characterized by an active exercise therapy carried out immediately after Platelet-rich plasma (PRP) injections for the treatment of the muscular lesion of the distal musculotendinous junction of the gastrocnemius medial head.Medical records of 31 subjects treated with three PRP intra-lesional ultrasound guided injections and 30 patients treated with the standard therapeutic approach (control group) were analyzed. Both groups followed the same rehabilitation therapy. Read More

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http://dx.doi.org/10.1080/09537104.2017.1349307DOI Listing
September 2018
19 Reads

Are extramedian symptoms associated with peripheral causes in patient with carpal tunnel syndrome? Electrodiagnostic and ultrasonographic study.

J Electromyogr Kinesiol 2018 Feb 10;38:203-207. Epub 2017 Aug 10.

Marmara University School of Medicine, Department of Physical Medicine and Rehabilitation, Istanbul, Turkey.

Objective: To evaluate the relationship between extramedian spreading of sensorial symptoms and median and ulnar nerve cross-sectional area (CSA) and to compare the ultrasonographic and electrophysiological findings in patients with carpal tunnel syndrome (CTS) with or without extramedian sensory symptoms.

Design: Cross-sectional study.

Materials And Methods: Patients with CTS were divided into two groups as with or without extramedian symptoms and were assessed clinically, electrophysiologically and ultrasonographically by three blind investigators. Read More

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http://dx.doi.org/10.1016/j.jelekin.2017.08.003DOI Listing
February 2018
13 Reads

Ultrasound Diagnosis of Calf Injuries.

Sports Health 2017 Jul/Aug;9(4):352-355. Epub 2017 Mar 10.

Cone Health Sports Medicine Fellowship Program, Cone Health Hospital System, Greensboro, North Carolina.

Context: The medial head of the gastrocnemius is the third most commonly strained muscle in elite athletes after the biceps femoris and rectus femoris. The differential diagnosis of posterior calf injury includes musculoskeletal and nonmusculoskeletal causes. Classically, delineation of these injuries from one another relied primarily on historical features and physical examination findings. Read More

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http://dx.doi.org/10.1177/1941738117696019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5496702PMC
August 2017
71 Reads

Relationship of changes in strain rate indices estimated from velocity-encoded MR imaging to loss of muscle force following disuse atrophy.

Magn Reson Med 2018 02 30;79(2):912-922. Epub 2017 May 30.

Muscle Imaging and Modeling Lab, Department of Radiology, University of California, San Diego, California, USA.

Purpose: This study explores changes in strain rate (SR) (rate of regional deformation) parameters extracted from velocity-encoded MRI and their relationship to muscle force loss following 4-week unilateral lower limb suspension in healthy humans.

Methods: Two-dimensional SR maps were derived from three directional velocity-encoded MR phase-contrast images of the medial gastrocnemius in seven subjects. Atrophy-related and regional differences in the SR eigenvalues, angle between the SR and muscle fiber (SR-fiber angle), and strain rates in the fiber basis were statistically analyzed using analysis of variance and linear regression. Read More

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http://doi.wiley.com/10.1002/mrm.26759
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http://dx.doi.org/10.1002/mrm.26759DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5709278PMC
February 2018
11 Reads

Pronator Teres Myotendinous Tear.

Am J Orthop (Belle Mead NJ) 2017 Mar/Apr;46(2):E105-E107

Department of Orthopaedic Surgery, New York Presbyterian/Columbia University Medical Center, New York, NY.

Pronator teres muscle strain is a rare sporting injury reported thus far only in cricket and golf players. The injury appears to occur when the sporting club or racket strikes the ground during a forceful swing and causes the elbow to experience an eccentric force during resisted elbow flexion and pronation. On initial presentation, this injury can be mistaken for injury to the medial ulnar collateral ligament, or exacerbation of medial epicondylitis. Read More

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January 2018
69 Reads

Magnetic resonance and diffusion tensor imaging analyses indicate heterogeneous strains along human medial gastrocnemius fascicles caused by submaximal plantar-flexion activity.

J Biomech 2017 05 9;57:69-78. Epub 2017 Apr 9.

Biomedical Engineering Institute, Boğaziçi University, Istanbul, Turkey. Electronic address:

Sarcomere length changes are central to force production and excursion of skeletal muscle. Previous modeling indicates non-uniformity of that if mechanical interaction of muscle with its surrounding muscular and connective tissues is taken into account. Hence, quantifying length changes along the fascicles of activated human muscle in vivo is crucial, but this is lacking due to technical complexities. Read More

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http://dx.doi.org/10.1016/j.jbiomech.2017.03.028DOI Listing
May 2017
55 Reads

Neuromuscular Alterations After Ankle Sprains: An Animal Model to Establish Causal Links After Injury.

J Athl Train 2016 Oct 10;51(10):797-805. Epub 2016 Nov 10.

Department of Rehabilitation Sciences, University of Kentucky, Lexington.

Context: The mechanisms that contribute to the development of chronic ankle instability are not understood. Investigators have developed a hypothetical model in which neuromuscular alterations that stem from damaged ankle ligaments are thought to affect periarticular and proximal muscle activity. However, the retrospective nature of these studies does not allow a causal link to be established. Read More

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http://dx.doi.org/10.4085/1062-6050-51.11.13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5189233PMC
October 2016
12 Reads

Application of shear wave elastography for the gastrocnemius medial head to tennis leg.

Clin Anat 2017 Jan 28;30(1):114-119. Epub 2016 Oct 28.

Department of Sports Medicine, Japan Institute of Sports Science, Tokyo, Japan.

Muscle strain of the gastrocnemius medial head mainly occurs at the musculotendinous junction (MTJ), and stiffness is a risk factor. Shear wave elastography (SWE) measures elasticity by determining the propagation velocity. The aim of this study was to measure the elasticity of the normal muscle and aponeurosis in the MTJ of the gastrocnemius medial head using SWE, thus obtaining information relevant to muscle strain at this point. Read More

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http://dx.doi.org/10.1002/ca.22788DOI Listing
January 2017
16 Reads

Characterization of three dimensional volumetric strain distribution during passive tension of the human tibialis anterior using Cine Phase Contrast MRI.

J Biomech 2016 10 15;49(14):3430-3436. Epub 2016 Sep 15.

Motion Analysis Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA. Electronic address:

Intramuscular pressure correlates strongly with muscle tension and is a promising tool for quantifying individual muscle force. However, clinical application is impeded by measurement variability that is not fully understood. Previous studies point to regional differences in IMP, specifically increasing pressure with muscle depth. Read More

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5074901PMC
http://dx.doi.org/10.1016/j.jbiomech.2016.09.002DOI Listing
October 2016
17 Reads

Hip abductor strength and lower extremity running related injury in distance runners: A systematic review.

J Sci Med Sport 2017 Apr 20;20(4):349-355. Epub 2016 Sep 20.

Walsh University, Doctorate of Physical Therapy Program, United States. Electronic address:

Objectives: Determine the association between hip abduction strength and lower extremity running related injury in distance runners.

Design: Systematic review.

Methods: Prospective longitudinal and cross sectional studies that quantified hip abduction strength and provided diagnosis of running related injury in distance runners were included and assessed for quality. Read More

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http://dx.doi.org/10.1016/j.jsams.2016.09.002DOI Listing
April 2017
48 Reads

Lack of Effect of Ankle Position During the Nordic Curl on Muscle Activity of the Biceps Femoris and Medial Gastrocnemius.

J Sport Rehabil 2017 May 24;26(3):202-207. Epub 2016 Aug 24.

Context: Regular performance (~2×/wk) of Nordic curls has been shown to increase hamstring strength and reduce the risk of hamstring strain injury, although no consensus on ankle position has been provided.

Objective: To compare the effects of performing Nordic curls, with the ankle in a dorsiflexed (DF) or plantar-flexed (PF) position, on muscle activity of the biceps femoris (BF) and medial gastrocnemius (MG).

Participants: 15 male college athletes (age 22. Read More

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http://dx.doi.org/10.1123/jsr.2015-0130DOI Listing
May 2017
31 Reads

Muscular Calf Injuries in Runners.

Curr Sports Med Rep 2016 Sep-Oct;15(5):320-4

Sports Medicine Fellowship Division of Sports Medicine Department of Family Medicine Cone Health Sports Medicine Center, Greenboro North Carolina, Greensboro, NC.

Calf pain is a common complaint among runners of all ages but is most frequent in masters athletes. This article focuses on injuries to the triceps surae or true 'calf muscles.' The most common calf injury is a tear of the medial gastrocnemius muscle (Tennis Leg) but other structures including the lateral gastrocnemius, plantaris and soleus also may be the cause of muscular pain. Read More

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http://dx.doi.org/10.1249/JSR.0000000000000292DOI Listing
February 2017
10 Reads

Human ankle plantar flexor muscle-tendon mechanics and energetics during maximum acceleration sprinting.

J R Soc Interface 2016 08;13(121)

Department of Mechanical Engineering, University of Melbourne, Victoria 3010, Australia.

Tendon elastic strain energy is the dominant contributor to muscle-tendon work during steady-state running. Does this behaviour also occur for sprint accelerations? We used experimental data and computational modelling to quantify muscle fascicle work and tendon elastic strain energy for the human ankle plantar flexors (specifically soleus and medial gastrocnemius) for multiple foot contacts of a maximal sprint as well as for running at a steady-state speed. Positive work done by the soleus and medial gastrocnemius muscle fascicles decreased incrementally throughout the maximal sprint and both muscles performed more work for the first foot contact of the maximal sprint (FC1) compared with steady-state running at 5 m s(-1) (SS5). Read More

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http://dx.doi.org/10.1098/rsif.2016.0391DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5014066PMC
August 2016
16 Reads

An Integrated Musculoskeletal-Finite-Element Model to Evaluate Effects of Load Carriage on the Tibia During Walking.

J Biomech Eng 2016 10;138(10)

Prior studies have assessed the effects of load carriage on the tibia. Here, we expand on these studies and investigate the effects of load carriage on joint reaction forces (JRFs) and the resulting spatiotemporal stress/strain distributions in the tibia. Using full-body motion and ground reaction forces from a female subject, we computed joint and muscle forces during walking for four load carriage conditions. Read More

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http://dx.doi.org/10.1115/1.4034216DOI Listing
October 2016
47 Reads

Protection from Muscle Damage in the Absence of Changes in Muscle Mechanical Behavior.

Med Sci Sports Exerc 2016 08;48(8):1495-505

Centre for Sensorimotor Performance, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland, AUSTRALIA.

Introduction: The repeated bout effect characterizes the protective adaptation after a single bout of unaccustomed eccentric exercise that induces muscle damage. Sarcomerogenesis and increased tendon compliance have been suggested as potential mechanisms for the repeated bout effect by preventing muscle fascicles from being stretched onto the descending limb of the length-tension curve (the region where sarcomere damage is thought to occur). In this study, evidence was sought for three possible mechanical changes that would support either the sarcomerogenesis or the increased tendon compliance hypotheses: a sustained rightward shift in the fascicle length-tension relationship, reduced fascicle strain amplitude, and reduced starting fascicle length. Read More

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http://dx.doi.org/10.1249/MSS.0000000000000920DOI Listing
August 2016
9 Reads

Combined magnetic resonance and diffusion tensor imaging analyses provide a powerful tool for in vivo assessment of deformation along human muscle fibers.

J Mech Behav Biomed Mater 2016 10 5;63:207-219. Epub 2016 Jul 5.

Institute of Biomedical Engineering, Boğaziçi University, 34684 Çengelköy, Istanbul, Turkey. Electronic address:

Muscle fiber direction strain provides invaluable information for characterizing muscle function. However, methods to study this for human muscles in vivo are lacking. Using magnetic resonance (MR) imaging based deformation analyses and diffusion tensor (DT) imaging based tractography combined, we aimed to assess muscle fiber direction local tissue deformations within the human medial gastrocnemius (GM) muscle. Read More

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http://dx.doi.org/10.1016/j.jmbbm.2016.06.031DOI Listing
October 2016
29 Reads

Anconeus Epitrochlearis Muscle Causing Ulnar Neuropathy at the Elbow: Clinical and Neurophysiological Differential Diagnosis.

Orthopedics 2016 Sep 12;39(5):e988-91. Epub 2016 Jul 12.

Ulnar neuropathy at the elbow is the second most frequent entrapment neuropathy and is considered idiopathic in most patients. However, several anatomic variations, including the anconeus epitrochlearis muscle, have been reported to cause ulnar nerve compression. The anconeus epitrochlearis muscle is a common anatomic variation, with a prevalence of up to 34%, but the clinical diagnosis of ulnar neuropathy of the elbow as a result of this variation is rare, with an unknown prevalence. Read More

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http://dx.doi.org/10.3928/01477447-20160623-11DOI Listing
September 2016
27 Reads

Intermuscular aponeuroses between the flexor muscles of the forearm and their relationships with the ulnar nerve.

Surg Radiol Anat 2016 Dec 12;38(10):1183-1189. Epub 2016 May 12.

Department of Anatomy, Catholic Institute for Applied Anatomy, College of Medicine, The Catholic University of Korea, Seoul, 06591, Korea.

Introduction: The aim of this study was to clarify the morphological characteristics of the intermuscular aponeurosis between the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS; IMAS), and that between the FCU and flexor digitorum profundus (FDP; IMAP), and their topographic relationships with the ulnar nerve.

Materials And Methods: Fifty limbs of 38 adult cadavers were studied.

Results: The IMAS extended along the deep surface of the FCU adjoining the FDS, having the appearance of a ladder, giving off "steps" that decreased in width from superficial to deep around the middle of the forearm. Read More

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http://dx.doi.org/10.1007/s00276-016-1695-9DOI Listing
December 2016
7 Reads