scholarly journals In Vivo Human Gastrocnemius Architecture With Changing Joint Angle at Rest and During Graded Isometric Contraction of Normal and Weak Muscle

2020 ◽  
pp. 010-014
Author(s):  
Koryak Yuri
Keyword(s):  
Isometric Contraction ◽  
Plantar Flexion ◽  
Normal Subjects ◽  
Triceps Surae ◽  
Mean Values ◽  
Patient Groups ◽  
Triceps Surae Muscles ◽  
Muscle Changes ◽  
Ultrasonic Images

Architectural properties of the triceps surae muscles complex were determined In Vivo for thirty subjects. These subjects were assigned to two groups. The first group of subjects consisted of 8 healthy men and the second group of subjects was composed of 22 patients with motor disorders. The ankle was positioned at -15 ° (dorsiflexion), and 0 ° (neutral anatomical position), and 15 °, and 30 ° (plantarflexion), with the knee set at 120 °and with an angle in the ankle joint of 90 °. At each position, longitudinal ultrasonic images of the Medial (MG) and Lateral (LG) Gastrocnemius and Soleus (SOL) muscles were obtained while the subject was relaxed (passive) and performed 50 % maximal voluntary isometric plantar flexion (active), from which fascicle Lengths (L) and angles (Θ) with respect to the aponeuroses were determined. From the ultrasonic image, it was observed that and Θ changed during an isometric contraction of the triceps surae muscle. Changes in L and were expressed as a function of relative torque. The Θ change was not identical for the three muscles. The fascicle Θ of MG demonstrated the greatest variation in three muscles. The effects of activation and relaxation positions were significant in all three muscles. The differences in MG fascicle Θ because of changes in ankle positions were significant among control and patients both in the passive and active conditions. Fascicle Θ of LG and SOL not differed among control and patient in the relaxation condition but not in the activation condition. For LG, and SOL ol fascicle Θ were changes were larger in control with the patients. The mean values fascicle Θ of MG, LG, and SOL an isometric contraction (50 % MVC) in the control groups increased by 60 %, 41 %, and 41 %, respectively; in the patient groups were a smaller increase, by 28 %, 26 %, and 36 %, respectively. Different lengths and angles of fascicles, and their changes bу contraction by patients and normal subjects, might bе related to differences in force-producing capabilities of the muscles and elastic characteristics of tendons and aponeuroses.

Architectural and functional features of human triceps surae muscles during contraction

1998 ◽  
Vol 85 (2) ◽  
pp. 398-404 ◽  
Author(s):  
Yasuo Kawakami ◽  
Yoshiho Ichinose ◽  
Tetsuo Fukunaga
Keyword(s):  
Plantar Flexion ◽  
Triceps Surae ◽  
Passive Condition ◽  
Human Triceps Surae ◽  
Functional Features ◽  
The Subject ◽  
Triceps Surae Muscles ◽  
Ultrasonic Images ◽  
Elastic Characteristics

Architectural properties of the triceps surae muscles were determined in vivo for six men. The ankle was positioned at 15° dorsiflexion (−15°) and 0, 15, and 30° plantar flexion, with the knee set at 0, 45, and 90°. At each position, longitudinal ultrasonic images of the medial (MG) and lateral (LG) gastrocnemius and soleus (Sol) muscles were obtained while the subject was relaxed (passive) and performed maximal isometric plantar flexion (active), from which fascicle lengths and angles with respect to the aponeuroses were determined. In the passive condition, fascicle lengths changed from 59, 65, and 43 mm (knee, 0°; ankle, −15°) to 32, 41, and 30 mm (knee, 90° ankle, 30°) for MG, LG, and Sol, respectively. Fascicle shortening by contraction was more pronounced at longer fascicle lengths. MG had greatest fascicle angles, ranging from 22 to 67°, and was in a very disadvantageous condition when the knee was flexed at 90°, irrespective of ankle positions. Different lengths and angles of fascicles, and their changes by contraction, might be related to differences in force-producing capabilities of the muscles and elastic characteristics of tendons and aponeuroses.

Architecture of Contracting Human Muscles and Its Functional Significance

2000 ◽  
Vol 16 (1) ◽  
pp. 88-97 ◽  
Author(s):  
Yasuo Kawakami ◽  
Yoshiho Ichinose ◽  
Keitaro Kubo ◽  
Masamitsu Ito ◽  
Morihiro Imai ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Muscle Thickness ◽  
Normal Subjects ◽  
Human Muscle ◽  
Muscle Architecture ◽  
Triceps Brachii ◽  
Fascicle Length ◽  
Ultrasonic Images ◽  
Relationship Of

This paper reviews three of our recent studies on human muscle architecture in vivo. 1. Hypertrophic changes: From B-mode ultrasonograms, pennation angles and thickness of triceps brachii were determined for normal subjects and highly-trained bodybuilders. There was a significant correlation between muscle thickness and pennation angles. It was confirmed that hypertrophy was accompanied by an increase in pennation angles. 2. Variation of fascicle architecture: Fascicle lengths and pennation angles were obtained from different positions in the gastrocnemius muscle while the subjects relaxed and performed isometric plantar flexion. The fascicle length was uniform throughout the muscle and shortened by contraction (30-34% at 50% of the maximal force). On the other hand, pennation angles differed among positions and increased by contraction. The muscle thickness did not change by contraction. Pen-nation angles were significantly correlated with muscle thickness within muscle. 3. Joint position-fascicle length relationships: Ultrasonic images of the gastrocnemius and soleus muscles were obtained while the subject performed maximal isometric plantarflexion at various joint positions, from which fascicle lengths and angles were determined. The length-force relationship of each muscle was estimated. It was suggested that human muscle architecture has an ability to make substantial changes to adapt to environmental conditions.

scholarly journals Strain distribution within human triceps surae muscles during isometric contraction: in vivo study by Tagging MRI

2008 ◽  
Vol 22 (S1) ◽  
Author(s):  
Toshiaki Oda ◽  
Ryuta Kinugasa ◽  
Mayoran Rajendra ◽  
Ryutaro Himeno ◽  
Hiroyuki Kataoka ◽  
...  
Keyword(s):  
Isometric Contraction ◽  
Strain Distribution ◽  
Triceps Surae ◽  
In Vivo Study ◽  
Human Triceps Surae ◽  
Triceps Surae Muscles ◽  
Tagging Mri

Production of hydroxyl radicals in contracting skeletal muscle of cats

1996 ◽  
Vol 81 (3) ◽  
pp. 1197-1206 ◽  
Author(s):  
C. A. O'Neill ◽  
C. L. Stebbins ◽  
S. Bonigut ◽  
B. Halliwell ◽  
J. C. Longhurst
Keyword(s):  
Skeletal Muscle ◽  
Triceps Surae ◽  
Oxygen Species ◽  
Static Contraction ◽  
Maximal Tension ◽  
Cumulative Production ◽  
Triceps Surae Muscles ◽  
Specific Species

Reactive oxygen species increase during exhaustive contraction of skeletal muscle, but characterization of the specific species involved and their rates of production during nonexhaustive muscle contraction have not been investigated. We hypothesized that the production rate of hydroxyl radical (.OH) increases in contracting muscle and that this rate is attenuated by pretreatment with deferoxamine (Def) or dimethylthiourea (DMTU). We measured the rate of production of .OH before, during, and after 5 min of intermittent static contraction of the triceps surae muscles in cats (n = 6) using the formation of p-, m-, and o-tyrosines by hydroxylation of phenylalanine. L-Phenylalanine (30 mg/kg i.v.) was administered to each animal 3 min before contraction. Blood samples were collected from the popliteal vein 1 min before contraction; 1, 3, and 4.5 min during contraction; and 1 min after contraction. During and after contraction, the cumulative production rates of p-, m-, and o-tyrosines were elevated by 42.84 +/- 5.41, 0.25 +/- 0.04, and 0.21 +/- 0.03 nmol.min-1.g-1, respectively, compared with noncontracting triceps surae muscles. Pretreatment with Def (10 mg/kg i.v.; n = 5) or DMTU (10 mg/kg i.v.; n = 4) decreased the cumulative rates of production of p-, m-, and o-tyrosines during and after contraction. Additionally, the rate of tyrosine production increased in proportion to the percentage of maximal tension developed by the triceps surae muscles. These results directly demonstrate that .OH is produced in vivo in the skeletal muscle of cats during intermittent static contraction and that production can occur before the onset of fatigue.

Effect of Sodium-Transport Inhibitors on Bronchial Reactivity in Vivo

1990 ◽  
Vol 79 (4) ◽  
pp. 325-330 ◽  
Author(s):  
Alan J. Knox ◽  
John R. Britton ◽  
Anne E. Tattersfield
Keyword(s):  
Confidence Intervals ◽  
Sodium Transport ◽  
Geometric Mean ◽  
Normal Subjects ◽  
Bronchial Reactivity ◽  
Mean Values ◽  
Doubling Dose ◽  
The Difference

1. We have recently shown that ouabain, an inhibitor of Na+/K+-adenosine triphosphatase, causes contraction of bovine and human airways in vitro, and that amiloride causes relaxation and inhibits receptor-operated contraction in bovine trachealis. 2. To determine whether such drugs alter bronchial reactivity in vivo, we have studied the effect of oral digoxin (an inhibitor of Na+/K+-adenosine triphosphatase) and oral and inhaled amiloride on bronchial reactivity to histamine in three double-blind, placebo-controlled studies. 3. Histamine reactivity was measured as the provocative dose causing a 20% reduction in the forced expiratory volume in 1 s (PD20FEV1) or, when normal subjects were included, the provocative dose causing a 35% reduction in the specific airways conductance (PD35sGaw); the results are given as geometric mean values. 4. In study 1, 13 atopic asthmatic subjects were given 20 mg of oral amiloride or placebo on separate days. Two hours after the drug, the geometric mean PD20FEV1 for histamine was 0.43 μmol after amiloride and 0.54 μmol after placebo (95% confidence intervals for the difference: 0.9 to −0.2 doubling doses of histamine; P = 0.2). 5. In study 2, six normal and 24 atopic asthmatic men inhaled 10 ml of 10−2 mol/l amiloride or diluent control in a crossover study. The mean values of PD35sGaw for histamine immediately after inhalation of amiloride and placebo were 3.0 μmol and 4.3 μmol, respectively, in the normal subjects (95% confidence intervals for the difference: −0.53 to 1.52 doubling doses, P = 0.2), and 0.33 μmol and 0.29 μmol in the asthmatic subjects (95% confidence intervals for the difference: −0.95 to 0.57 doubling doses; P = 0.6). 6. In study 3, 24 atopic asthmatic men were treated for 7 days with placebo or oral digoxin (1.5 mg loading dose plus 0.25 mg twice daily for 6 days). The PD20FEV1 for histamine was measured before, 12 h after the loading dose and on day 7 of treatment. The change in PD20FEV1 did not differ significantly after digoxin and placebo, after either 1 day's treatment [mean (95% confidence intervals) difference: 0.56 doubling dose (−0.37 to 1.5 doubling dose)] or 7 day's treatment [mean (95% confidence intervals) difference: 0.3 doubling dose (−1.23 to 1.8 doubling doses)]. 7. Although our work in vitro has suggested that membrane sodium transport may play an important role in determining airway smooth muscle contractility, we have been unable to demonstrate any effect of the sodium-transport inhibitors amiloride and digoxin on histamine reactivity in these studies.

scholarly journals Architectural and functional specifics of the human triceps surae muscle in vivo and its adaptation to microgravity

2019 ◽  
Vol 126 (4) ◽  
pp. 880-893 ◽  
Author(s):  
Yuri A. Koryak
Keyword(s):  
Fiber Length ◽  
Plantar Flexion ◽  
Force Production ◽  
Voluntary Contraction ◽  
Triceps Surae ◽  
Functional Roles ◽  
Contraction Times ◽  
Main Determinants ◽  
General Physical

Long-term exposure to microgravity (μG) is known to reduce the strength of a skeletal muscle contraction and the level of general physical performance in humans, while little is known about its effect on muscle architecture. Architectural and contractile properties of the triceps surae (TS) muscle were determined in vivo for male cosmonauts in response ( n = 8) to a spaceflight (213.0 ± 30.5 days). The maximal voluntary contraction (MVC), tetanic tension ( Ро), and voluntary and electrically evoked contraction times and force deficiency (Pd) were determined. The ankle was positioned at 15° dorsiflexion (−15°) and 0, 15, and 30° plantar flexion, with the knee set at 90°. At each position, longitudinal ultrasonic images of the medial (MG) and lateral (LG) gastrocnemius and soleus (SOL) muscles were obtained while the subject was relaxed. After a spaceflight, MVC and Pо decreased by 42 and 26%, respectively, and Pd increased by 50%. The rate of tension of a voluntary contraction substantially reduced but evoked contractions remained unchanged. In the passive condition, fiber length ( Lf) changed from 43, 57, and 35 mm (knee, 0°; ankle, −15°) to 34, 38, and 25 mm (knee, 0°; ankle, 30°) for MG, LG, and SOL, respectively, and Θf changed from 27, 21, and 23° (knee, 0°; ankle, −15°) to 43, 29, and 34° (knee, 0°; ankle, 30°) for MG, LG, and SOL, respectively. Different Lf and Θf, and their changes after spaceflight, might be related to differences in force-producing capabilities of the muscles and elastic characteristics of tendons and aponeuroses. NEW & NOTEWORTHY The present work was the first to combine measuring the fiber length and pennation angle (ultrasound imaging) as main determinants of mechanical force production and evaluating the muscle function after a long-duration spaceflight. The results demonstrate that muscles with different functional roles may differently respond to unloading, and this circumstance is important to consider when planning rehabilitation after unloading of any kind, paying particular attention to postural muscles.

Effects of exercise on muscle transverse relaxation determined by MR imaging and in vivo relaxometry

2000 ◽  
Vol 88 (1) ◽  
pp. 226-233 ◽  
Author(s):  
George Saab ◽  
R. Terry Thompson ◽  
Greg D. Marsh
Keyword(s):  
Magnetic Resonance ◽  
Intense Exercise ◽  
Transverse Relaxation ◽  
Mean Values ◽  
Before And After ◽  
Echo Time ◽  
Magnetic Resonance Imaging Mri ◽  
Muscle Changes ◽  
Resting Muscle

The purpose of this study was to determine the effects of intense exercise on the proton transverse (T2) relaxation of human skeletal muscle. The flexor digitorium profundus muscles of 12 male subjects were studied by using magnetic resonance imaging (MRI; 6 echoes, 18-ms echo time) and in vivo magnetic resonance relaxometry (1,000 echoes, 1.2-ms echo time), before and after an intense handgrip exercise. MRI of resting muscle produced a single T2 value of 32 ms that increased by 19% ( P < 0.05) with exercise. In vivo relaxometry showed at least three T2 components (>5 ms) for all subjects with mean values of 21, 40, and 137 ms and respective magnitudes of 34, 49, and 14% of the total magnetic resonance signal. These component magnitudes changed with exercise by −44% ( P < 0.05), +52% ( P < 0.05), and +23% ( P < 0.05), respectively. These results demonstrate that intense exercise has a profound effect on the multicomponent T2 relaxation of muscle. Changes in the magnitudes of all the T2 components synergistically increase MRI T2, but changes in the two shortest T2components predominate.

The Influence of Fascicle Behavior on the Lack of Velocity Dependence in Eccentric Joint Torque in Humans: In Vivo Observation

2009 ◽  
Vol 25 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Kentaro Chino ◽  
Naotoshi Mitsukawa ◽  
Kai Kobayashi ◽  
Yusuke Miyoshi ◽  
Toshiaki Oda ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Triceps Surae ◽  
Joint Torque ◽  
Fascicle Length ◽  
Significant Difference ◽  
Isometric Torque ◽  
The Difference ◽  
The Relationship ◽  
Real Time Ultrasonography

To investigate the relationship between fascicle behavior and joint torque, the fascicle behavior of the triceps surae during isometric and eccentric (30 and 60 deg/s) plantar flexion by maximal voluntary and submaximal electrical activation (MVA and SEA) was measured by real-time ultrasonography. Eccentric torque at 30 and 60 deg/s was significantly higher than isometric torque under SEA, but not under MVA. However, fascicle length did not significantly differ between isometric and eccentric trials under either condition. Therefore, the difference in developed torque by MVA and SEA cannot be explained by fascicle behavior. Under both MVA and SEA conditions, eccentric torque at 30 and 60 deg/s was equivalent. Similarly, fascicle lengthening velocities at 30 and 60deg/s did not show any significant difference. Such fascicle behavior can be attributed to the influence of tendinous tissue and pennation angle, and lead to a lack of increase in eccentric torque with increasing angular velocity.

Effect of toe extension on EMG of triceps surae muscles during isometric dorsiflexion

2016 ◽  
Vol 61 (6) ◽  
Author(s):  
Ariba Siddiqi ◽  
Sridhar P. Arjunan ◽  
Dinesh Kumar
Keyword(s):  
Root Mean Square ◽  
Plantar Flexion ◽  
T Test ◽  
Triceps Surae ◽  
Mean Square ◽  
Force Of Contraction ◽  
Large Variability ◽  
Triceps Surae Muscles ◽  
Student’S T ◽  
Student’S T Test

AbstractThe protocol for estimating force of contraction by triceps surae (TS) muscles requires the immobilization of the ankle during dorsiflexion and plantar flexion. However, large variability in the results has been observed. To identify the cause of this variability, experiments were conducted where ankle dorsiflexion force and electromyogram (EMG) of the TS were recorded under two conditions: (i) toes were strapped and (ii) toes were unstrapped, with all other conditions such as immobilization of the ankle remaining unchanged. The root mean square (RMS) of the EMG and the force were analyzed and one-tail Student’s t-test was performed for significance between the two conditions. The RMS of the EMG from TS muscles was found to be significantly higher (~55%) during dorsiflexion with toes unstrapped compared with when the toes were strapped. The torque corresponding to dorsiflexion was also higher with toes unstrapped. Our study has shown that it is important to strap the toes when measuring the torque at the ankle and EMG of the TS muscles.

Differential displacement of the human soleus and medial gastrocnemius aponeuroses during isometric plantar flexor contractions in vivo

2004 ◽  
Vol 97 (5) ◽  
pp. 1908-1914 ◽  
Author(s):  
Jens Bojsen-Møller ◽  
Philip Hansen ◽  
Per Aagaard ◽  
Ulla Svantesson ◽  
Michael Kjaer ◽  
...  
Keyword(s):  
Knee Joint ◽  
Achilles Tendon ◽  
Plantar Flexion ◽  
Human Locomotion ◽  
Muscular Contraction ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Plantar Flexor ◽  
Flexion Moment

The human triceps surae muscle-tendon complex is a unique structure with three separate muscle compartments that merge via their aponeuroses into the Achilles tendon. The mechanical function and properties of these structures during muscular contraction are not well understood. The purpose of the study was to investigate the extent to which differential displacement occurs between the aponeuroses of the medial gastrocnemius (MG) and soleus (Sol) muscles during plantar flexion. Eight subjects (mean ± SD; age 30 ± 7 yr, body mass 76.8 ± 5.5 kg, height 1.83 ± 0.06 m) performed maximal isometric ramp contractions with the plantar flexor muscles. The experiment was performed in two positions: position 1, in which the knee joint was maximally extended, and position 2, in which the knee joint was maximally flexed (125°). Plantarflexion moment was assessed with a strain gauge load cell, and the corresponding displacement of the MG and Sol aponeuroses was measured by ultrasonography. Differential shear displacement of the aponeurosis was quantified by subtracting displacement of Sol from that of MG. Maximal plantar flexion moment was 36% greater in position 1 than in position 2 (132 ± 20 vs. 97 ± 11 N·m). In position 1, the displacement of the MG aponeurosis at maximal force exceeded that of the Sol (12.6 ± 1.7 vs. 8.9 ± 1.5 mm), whereas in position 2 displacement of the Sol was greater than displacement of the MG (9.6 ± 1.0 vs. 7.9 ± 1.2 mm). The amount and “direction” of shear between the aponeuroses differed significantly between the two positions across the entire range of contraction, indicating that the Achilles tendon may be exposed to intratendinous shear and stress gradients during human locomotion.

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