scholarly journals In vivo human gracilis whole muscle passive stress-sarcomere strain relationship

2021 ◽  
Author(s):  
Lomas S. Persad ◽  
Benjamin I. Binder-Markey ◽  
Alexander Y. Shin ◽  
Kenton R. Kaufman ◽  
Richard L. Lieber
Keyword(s):  
Mechanical Properties ◽  
Sarcomere Length ◽  
Mammalian Species ◽  
Muscle Length ◽  
Human Muscle ◽  
Gracilis Muscle ◽  
Rabbit Muscle ◽  
Cross Sectional ◽  
Whole Muscle

We measured the passive mechanical properties of intact, living human gracilis muscles (n=11 individuals, 1 female, age: 33±12years, mass: 89±23kg, height: 177±8cm). Measurements were performed in patients undergoing surgery for free functioning myocutaneous tissue transfer of the gracilis muscle to restore elbow flexion after brachial plexus injury. Whole muscle force of the gracilis tendon was measured in four joint configurations (JC1-JC4) with a buckle force transducer placed at the distal tendon. Sarcomere length was also measured by biopsy from the proximal gracilis muscle. After the muscle was removed a three-dimensional volumetric reconstruction of the muscle was created via photogrammetry. Muscle length from JC1 to JC4 increased by 3.3±1.0 cm, 7.7±1.2 cm, 10.5±1.3 cm and 13.4±1.2 cm respectively, corresponding to 15%, 34%, 46% and 59% muscle fiber strain respectively. Muscle volume and an average optimal fiber length of 23.1±0.7 cm yielded an average muscle physiological cross-sectional area of 6.8±0.7 cm2 which is approximately three times that measured previously from cadaveric specimens. Absolute passive tension increased from 0.90±0.21 N in JC1 to 16.50±2.64 N in JC4. As expected, sarcomere length also increased from 3.24±0.08 µm at JC1 to 3.63±0.07 µm at JC4, which are on the descending limb of the human sarcomere length-tension curve. Peak passive muscle stress was 27.8±5.5 kPa in JC4 and muscle modulus ranged from 44.8 MPa in JC1 to 125.7 MPa in JC4. Compared to other mammalian species, human muscle passive mechanical properties are more similar to rodent muscle than rabbit muscle. These data provide direct measurements of whole human muscle passive mechanical properties that can be used in modeling studies and for understanding comparative passive mechanical properties among mammalian muscles.

scholarly journals Three-dimensional geometrical changes of the human tibialis anterior muscle and its central aponeurosis measured with three-dimensional ultrasound during isometric contractions

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2260 ◽  
Author(s):  
Brent J. Raiteri ◽  
Andrew G. Cresswell ◽  
Glen A. Lichtwark
Keyword(s):  
Three Dimensional ◽  
Muscle Length ◽  
Pennation Angle ◽  
Human Muscle ◽  
Muscle Fibres ◽  
Isometric Contractions ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Shape Changes

Background.Muscles not only shorten during contraction to perform mechanical work, but they also bulge radially because of the isovolumetric constraint on muscle fibres. Muscle bulging may have important implications for muscle performance, however quantifying three-dimensional (3D) muscle shape changes in human muscle is problematic because of difficulties with sustaining contractions for the duration of anin vivoscan. Although two-dimensional ultrasound imaging is useful for measuring local muscle deformations, assumptions must be made about global muscle shape changes, which could lead to errors in fully understanding the mechanical behaviour of muscle and its surrounding connective tissues, such as aponeurosis. Therefore, the aims of this investigation were (a) to determine the intra-session reliability of a novel 3D ultrasound (3DUS) imaging method for measuringin vivohuman muscle and aponeurosis deformations and (b) to examine how contraction intensity influencesin vivohuman muscle and aponeurosis strains during isometric contractions.Methods.Participants (n= 12) were seated in a reclined position with their left knee extended and ankle at 90° and performed isometric dorsiflexion contractions up to 50% of maximal voluntary contraction. 3DUS scans of the tibialis anterior (TA) muscle belly were performed during the contractions and at rest to assess muscle volume, muscle length, muscle cross-sectional area, muscle thickness and width, fascicle length and pennation angle, and central aponeurosis width and length. The 3DUS scan involved synchronous B-mode ultrasound imaging and 3D motion capture of the position and orientation of the ultrasound transducer, while successive cross-sectional slices were captured by sweeping the transducer along the muscle.Results.3DUS was shown to be highly reliable across measures of muscle volume, muscle length, fascicle length and central aponeurosis length (ICC ≥ 0.98, CV < 1%). The TA remained isovolumetric across contraction conditions and progressively shortened along its line of action as contraction intensity increased. This caused the muscle to bulge centrally, predominantly in thickness, while muscle fascicles shortened and pennation angle increased as a function of contraction intensity. This resulted in central aponeurosis strains in both the transverse and longitudinal directions increasing with contraction intensity.Discussion.3DUS is a reliable and viable method for quantifying multidirectional muscle and aponeurosis strains during isometric contractions within the same session. Contracting muscle fibres do work in directions along and orthogonal to the muscle’s line of action and central aponeurosis length and width appear to be a function of muscle fascicle shortening and transverse expansion of the muscle fibres, which is dependent on contraction intensity. How factors other than muscle force change the elastic mechanical behaviour of the aponeurosis requires further investigation.

Bronchial smooth muscle mechanics of a canine model of allergic airway hyperresponsiveness

1992 ◽  
Vol 72 (1) ◽  
pp. 39-45 ◽  
Author(s):  
H. Jiang ◽  
K. Rao ◽  
A. J. Halayko ◽  
W. Kepron ◽  
N. L. Stephens
Keyword(s):  
Mechanical Properties ◽  
Smooth Muscle ◽  
Muscle Mechanics ◽  
Bronchial Hyperresponsiveness ◽  
Muscle Length ◽  
Canine Model ◽  
Control Group ◽  
Shortening Velocity ◽  
Bronchial Smooth Muscle ◽  
Cross Sectional

Although we have reported that tracheal smooth muscle from sensitized dogs shows altered mechanical properties, we did not know, because of technical difficulties with the preparation, whether similar changes occur in the properties of sensitized central bronchial smooth muscle (BSM), the site at which the acute asthmatic response is believed to develop. We have now succeeded in developing a cartilage-free BSM preparation that retains optimal mechanical properties. Such strips were obtained from mongrel dogs that had been sensitized to ragweed pollen. Controls were littermates injected with adjuvant alone. Length-tension relationships were obtained for both control and sensitized BSM strips (CBSM and SBSM, respectively). The maximal active stresses were the same (P greater than 0.05) when normalized to muscle fraction in total tissue cross-sectional area [6.2 +/- 0.6 x 10(4) and 5.9 +/- 0.6 x 10(4) (SE) for SBSM and CBSM, respectively]. This suggests that optimal tension is an insensitive indicator of bronchial hyperresponsiveness and that isotonic studies might be more revealing. The maximal shortening velocity (Vo) for SBSM at 2 s [0.35 +/- 0.017 (SE) lo/s, where lo signifies optimal muscle length], in the course of a 10-s contraction, was significantly greater (P less than 0.05) than Vo measured for CBSM (0.27 +/- 0.015 lo/s). However, Vo did not differ at the 8-s point of contraction. The sensitized group demonstrated a statistically significantly greater maximal shortening capacity (0.67 +/- 0.04 lo) than the control group (0.51 +/- 0.04 lo). At 2 s of contraction, 80% of maximal SBSM shortening had been completed and was significantly greater than for CBSM.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced myogenic activation in skeletal muscle arterioles from spontaneously hypertensive rats

1993 ◽  
Vol 265 (6) ◽  
pp. H1847-H1855 ◽  
Author(s):  
J. C. Falcone ◽  
H. J. Granger ◽  
G. A. Meininger
Keyword(s):  
Venous Pressure ◽  
Muscle Length ◽  
Vascular Wall ◽  
Intraluminal Pressure ◽  
Active Tension ◽  
Hypertensive Rats ◽  
Cross Sectional ◽  
Wall Area ◽  
Myogenic Responses

The purpose of this study was to determine whether the vascular myogenic response is enhanced in hypertension. Experiments were conducted in the intact cremaster muscle microcirculation as well as in isolated arterioles of hypertensive (SHR) and normotensive (WKY) rats. Increasing venous pressure in vivo by approximately 5 mmHg had no effect on normotensive first- (1A) or third-order arteriolar (3A) diameters; in contrast, hypertensive 1A diameter decreased 4% (89 +/- 2 to 85 +/- 3 microns) with an 8% decrease in 3A (24 +/- 2 to 22 +/- 2 microns). To further examine this enhanced constriction to elevated intravascular pressure in SHR, diameter was monitored in isolated 1A during step increases and decreases in intraluminal pressure. Normotensive arterioles displayed myogenic responses between pressures of 50 and 170 cmH2O; in contrast, hypertensive arterioles demonstrated myogenic responses over an extended pressure range (50–210 cmH2O). In addition, the change in diameter for each step change in pressure was greater in the arterioles from SHR, indicating an increased myogenic responsiveness. The myogenic reactions were unaffected by alpha-receptor blockade with phentolamine (10(-6) M), indicating that adrenergic hypersensitivity was not involved in the enhanced response to stretch. Morphometric analysis of the vascular wall revealed no differences in wall thickness, cross-sectional wall area, or wall-to-lumen ratio between normotensive and hypertensive rats. The length-tension relationships for normotensive and hypertensive rats demonstrated that peak active tension occurred at nearly the same vascular smooth muscle length. In addition, SHR arterioles were capable of maintaining higher levels of active tension that WKY arterioles, indicating an altered length-tension curve in chronic arterial hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals PRACTICAL CONSIDERATIONS FOR STANDARDIZED RECORDING OF MUSCLE MECHANICAL PROPERTIES USING A MYOMETRIC DEVICE: RECORDING SITE, MUSCLE LENGTH, STATE OF CONTRACTION AND PRIOR ACTIVITY

2018 ◽  
Vol 21 (02) ◽  
pp. 1850010 ◽  
Author(s):  
Sandra Agyapong-Badu ◽  
Martin Warner ◽  
Dinesh Samuel ◽  
Maria Stokes
Keyword(s):  
Mechanical Properties ◽  
Biceps Brachii ◽  
Muscle Length ◽  
Rectus Femoris ◽  
Healthy Adults ◽  
Muscle Stiffness ◽  
Minimal Detectable Change ◽  
Experimental Conditions ◽  
Cross Sectional ◽  
Resting Muscle

Purpose: This study aimed to systematically examine the influence of various muscle and experimental conditions on Myoton recordings. Methods: A cross-sectional, observational design was used to examine muscle conditions and experimental factors (different recording sites, muscle length, level of contraction and prior physical activity) that may influence reproducibility of Myoton recordings for biceps brachii (BB) and rectus femoris (RF). Fifty-three healthy adults (26 young, 27 older) aged 18–90 years were studied. Muscle stiffness, tone and elasticity were measured using the MyotonPRO device. Results: Statistically significant differences in Myoton parameters were found for aspects of all four muscle and experimental conditions compared with the control condition ([Formula: see text]). However, clinically relevant differences in tone, stiffness and elasticity were only found for contracted compared to resting muscle, with changes being greater than the minimal detectable change. Elasticity was not affected by prior activity. Conclusions: The conditions studied significantly altered Myoton parameters of BB and RF in healthy adults, but only changes in parameters during muscle contraction were clinically relevant. These findings provide evidence to support the need to consider muscle condition and experimental factors for improving the robustness of test protocols for assessing muscle mechanical properties using the MyotonPRO device.

scholarly journals Three-dimensional architecture of the whole human soleus muscle in vivo

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4610 ◽  
Author(s):  
Bart Bolsterlee ◽  
Taija Finni ◽  
Arkiev D’Souza ◽  
Junya Eguchi ◽  
Elizabeth C. Clarke ◽  
...  
Keyword(s):  
Soleus Muscle ◽  
Diffusion Tensor ◽  
Three Dimensional ◽  
Muscle Length ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Quantitative Measurements ◽  
Muscle Fascicle ◽  
Total Muscle

Background Most data on the architecture of the human soleus muscle have been obtained from cadaveric dissection or two-dimensional ultrasound imaging. We present the first comprehensive, quantitative study on the three-dimensional anatomy of the human soleus muscle in vivo using diffusion tensor imaging (DTI) techniques. Methods We report three-dimensional fascicle lengths, pennation angles, fascicle curvatures, physiological cross-sectional areas and volumes in four compartments of the soleus at ankle joint angles of 69 ± 12° (plantarflexion, short muscle length; average ± SD across subjects) and 108 ± 7° (dorsiflexion, long muscle length) of six healthy young adults. Microdissection and three-dimensional digitisation on two cadaveric muscles corroborated the compartmentalised structure of the soleus, and confirmed the validity of DTI-based muscle fascicle reconstructions. Results The posterior compartments of the soleus comprised 80 ± 5% of the total muscle volume (356 ± 58 cm3). At the short muscle length, the average fascicle length, pennation angle and curvature was 37 ± 8 mm, 31 ± 3° and 17 ± 4 /m, respectively. We did not find differences in fascicle lengths between compartments. However, pennation angles were on average 12° larger (p < 0.01) in the posterior compartments than in the anterior compartments. For every centimetre that the muscle-tendon unit lengthened, fascicle lengths increased by 3.7 ± 0.8 mm, pennation angles decreased by −3.2 ± 0.9° and curvatures decreased by −2.7 ± 0.8 /m. Fascicles in the posterior compartments rotated almost twice as much as in the anterior compartments during passive lengthening. Discussion The homogeneity in fascicle lengths and inhomogeneity in pennation angles of the soleus may indicate a functionally different role for the anterior and posterior compartments. The data and techniques presented here demonstrate how DTI can be used to obtain detailed, quantitative measurements of the anatomy of complex skeletal muscles in living humans.

scholarly journals Estimation of the force–velocity properties of individual muscles from measurement of the combined plantarflexor properties

2020 ◽  
Vol 223 (18) ◽  
pp. jeb219980
Author(s):  
Mehrdad Javidi ◽  
Craig P. McGowan ◽  
David C. Lin
Keyword(s):  
Muscle Length ◽  
Muscle Architecture ◽  
Muscle Group ◽  
Cross Sectional ◽  
Fiber Properties ◽  
Group Modeling ◽  
Force Velocity ◽  
The Individual

ABSTRACTThe force–velocity (F–V) properties of isolated muscles or muscle fibers have been well studied in humans and other animals. However, determining properties of individual muscles in vivo remains a challenge because muscles usually function within a synergistic group. Modeling has been used to estimate the properties of an individual muscle from the experimental measurement of the muscle group properties. While this approach can be valuable, the models and the associated predictions are difficult to validate. In this study, we measured the in situ F–V properties of the maximally activated kangaroo rat plantarflexor group and used two different assumptions and associated models to estimate the properties of the individual plantarflexors. The first model (Mdl1) assumed that the percent contributions of individual muscles to group force and power were based upon the muscles' cross-sectional area and were constant across the different isotonic loads applied to the muscle group. The second model (Mdl2) assumed that the F–V properties of the fibers within each muscle were identical, but because of differences in muscle architecture, the muscles' contributions to the group properties changed with isotonic load. We compared the two model predictions with independent estimates of the muscles' contributions based upon sonomicrometry measurements of muscle length. We found that predictions from Mdl2 were not significantly different from sonomicrometry-based estimates while those from Mdl1 were significantly different. The results of this study show that incorporating appropriate fiber properties and muscle architecture is necessary to parse the individual muscles' contributions to the group F–V properties.

Gastrocnemius muscle specific force in boys and men

2008 ◽  
Vol 104 (2) ◽  
pp. 469-474 ◽  
Author(s):  
Christopher I. Morse ◽  
Keith Tolfrey ◽  
Jeanette M. Thom ◽  
Vasilios Vassilopoulos ◽  
Constantinos N. Maganaris ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Muscle Length ◽  
Tanner Stage ◽  
Surface Emg ◽  
Specific Force ◽  
Moment Arm ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Adult Men

The aim of this study was to assess whether the in vivo specific force and architectural characteristics of the lateral gastrocnemius (GL) muscle of early pubescent boys ( n = 11, age = 10.9 ± 0.3 yr, Tanner stage 2) differed from those of adult men ( n = 12, age = 25.3 ± 4.4 yr). Plantarflexor torque was 55% lower in the boys (77.4 ± 21.4 N·m) compared with the adults (175.6 ± 31.7 N·m, P < 0.01). Physiological cross-sectional area (PCSA), determined in vivo using ultrasonography and MRI, was 52% smaller in the boys ( P < 0.01). No difference was found in pennation angle, or in the ratio of fascicle length ( Lf) to muscle length between the boys and men. Moment arm length was 25% smaller in the boys ( P < 0.01). Antagonist coactivation, assessed using surface EMG on the dorsiflexors, was not different between the boys and men (11.8 ± 6.7% and 13.5 ± 5.8%, respectively). Surprisingly, GL force normalized to PCSA (specific force) was significantly higher (21%) in the boys than in the men (13.1 ± 2.0 vs. 15.9 ± 2.7 N/cm2, P < 0.05). This finding could not be explained by differences in moment arm length, muscle activation, or architecture, and other factors, such as tendinous characteristics and/or changes in moment arm length with contraction, may be held responsible. These observations warrant further investigation.

Mechanical properties and collagen cross-linking of the patellar tendon in old and young men

2009 ◽  
Vol 107 (3) ◽  
pp. 880-886 ◽  
Author(s):  
C. Couppé ◽  
P. Hansen ◽  
M. Kongsgaard ◽  
V. Kovanen ◽  
C. Suetta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Patellar Tendon ◽  
Structural Integrity ◽  
Young Men ◽  
Activity Level ◽  
Cross Linking ◽  
Collagen Concentration ◽  
Cross Sectional ◽  
Age Related

Age-related loss in muscle mass and strength impairs daily life function in the elderly. However, it remains unknown whether tendon properties also deteriorate with age. Cross-linking of collagen molecules provides structural integrity to the tendon fibrils and has been shown to change with age in animals but has never been examined in humans in vivo. In this study, we examined the mechanical properties and pyridinoline and pentosidine cross-link and collagen concentrations of the patellar tendon in vivo in old (OM) and young men (YM). Seven OM (67 ± 3 years, 86 ± 10 kg) and 10 YM (27 ± 2 years, 81 ± 8 kg) with a similar physical activity level (OM 5 ± 6 h/wk, YM 5 ± 2 h/wk) were examined. MRI was used to assess whole tendon dimensions. Tendon mechanical properties were assessed with the use of simultaneous force and ultrasonographic measurements during ramped isometric contractions. Percutaneous tendon biopsies were taken and analyzed for hydroxylysyl pyridinoline (HP), lysyl pyridinoline (LP), pentosidine, and collagen concentrations. We found no significant differences in the dimensions or mechanical properties of the tendon between OM and YM. Collagen concentrations were lower in OM than in YM (0.49 ± 0.27 vs. 0.73 ± 0.14 mg/mg dry wt; P < 0.05). HP concentrations were higher in OM than in YM (898 ± 172 vs. 645 ± 183 mmol/mol; P < 0.05). LP concentrations were higher in OM than in YM (49 ± 38 vs. 16 ± 8 mmol/mol; P < 0.01), and pentosidine concentrations were higher in OM than in YM (73 ± 13 vs. 11 ± 2 mmol/mol; P < 0.01). These cross-sectional data raise the possibility that age may not appreciably influence the dimensions or mechanical properties of the human patellar tendon in vivo. Collagen concentration was reduced, whereas both enzymatic and nonenzymatic cross-linking of concentration was elevated in OM vs. in YM, which may be a mechanism to maintain the mechanical properties of tendon with aging.

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