scholarly journals Effects of long-term athletic training on muscle morphology and tendon stiffness in preadolescence: association with jump performance

2020 ◽  
Vol 120 (12) ◽  
pp. 2715-2727
Author(s):  
Nikolaos Pentidis ◽  
Falk Mersmann ◽  
Sebastian Bohm ◽  
Erasmia Giannakou ◽  
Nickos Aggelousis ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Achilles Tendon ◽  
Muscle Hypertrophy ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Triceps Surae ◽  
Plantar Flexors ◽  
Tendon Stiffness ◽  
Jumping Performance

Abstract Purpose Evidence on training-induced muscle hypertrophy during preadolescence is limited and inconsistent. Possible associations of muscle strength and tendon stiffness with jumping performance are also not investigated. We investigated the thickness and pennation angle of the gastrocnemius medialis muscle (GM), as indicators for potential muscle hypertrophy in preadolescent athletes. Further, we examined the association of triceps surae muscle–tendon properties with jumping performance. Methods Eleven untrained children (9 years) and 21 similar-aged artistic gymnastic athletes participated in the study. Muscle thickness and pennation angle of the GM were measured at rest and muscle strength of the plantar flexors and Achilles tendon stiffness during maximum isometric contractions. Jumping height in squat (SJ) and countermovement jumps (CMJ) was examined using a force plate. We evaluated the influence of normalised muscle strength and tendon stiffness on jumping performance with a linear regression model. Results Muscle thickness and pennation angle did not differ significantly between athletes and non-athletes. In athletes, muscle strength was greater by 25% and jumping heights by 36% (SJ) and 43% (CMJ), but Achilles tendon stiffness did not differ between the two groups. The significant predictor for both jump heights was tendon stiffness in athletes and normalised muscle strength for the CMJ height in non-athletes. Conclusion Long-term artistic gymnastics training during preadolescence seems to be associated with increased muscle strength and jumping performance but not with training-induced muscle hypertrophy or altered tendon stiffness in the plantar flexors. Athletes benefit more from tendon stiffness and non-athletes more from muscle strength for increased jumping performance.

scholarly journals Correlation between age, muscle architecture, and muscle strength in children with Erb’s palsy

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Ahmed Saad Awad ◽  
Mostafa Soliman Ali ◽  
Mohamed Ismail Elassal
Keyword(s):  
Muscle Strength ◽  
Muscle Weakness ◽  
Muscle Thickness ◽  
Study Groups ◽  
Pennation Angle ◽  
Muscle Architecture ◽  
Active Movement ◽  
Significant Relation ◽  
Erb’S Palsy ◽  
Significant Difference

Abstract Background Muscle weakness is a widespread problem in children with Erb’s palsy as it can cause changes in muscle architecture parameters, which can be detected by ultrasonography. This study was conducted to determine the relation between age, muscle architecture, and muscle strength in children with Erb’s palsy. A total of 40 children with Erb’s palsy from both sexes aged 1–2.5 years were included in this study. Muscle thickness and pennation angle were measured by ultrasonography, and muscle strength was measured using the active movement scale. Results A significant relation was found between age, muscle thickness, pennation angle, and muscle strength (P < 0.05). Moreover, a significant difference was found in muscle architecture parameters during relaxation and contraction in both study groups and in each study group (P < 0.05). Conclusion Muscle weakness in children with Erb’s palsy has an effect on muscle architecture parameters, and these parameters also increase with age.

Moderate-duration static stretch reduces active and passive plantar flexor moment but not Achilles tendon stiffness or active muscle length

2009 ◽  
Vol 106 (4) ◽  
pp. 1249-1256 ◽  
Author(s):  
Anthony D. Kay ◽  
Anthony J. Blazevich
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Muscle Stiffness ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Static Stretch ◽  
Tendon Stiffness ◽  
Neuromuscular Activity ◽  
Time Motion ◽  
The Impact

The effects of static stretch on muscle and tendon mechanical properties and muscle activation were studied in fifteen healthy human volunteers. Peak active and passive moment data were recorded during plantar flexion trials on an isokinetic dynamometer. Electromyography (EMG) monitoring of the triceps surae muscles, real-time motion analysis of the lower leg, and ultrasound imaging of the Achilles-medial gastrocnemius muscle-tendon junction were simultaneously conducted. Subjects performed three 60-s static stretches before being retested 2 min and 30 min poststretch. There were three main findings in the present study. First, peak concentric moment was significantly reduced after stretch; 60% of the deficit recovered 30 min poststretch. This was accompanied by, and correlated with ( r = 0.81 ; P < 0.01) reductions in peak triceps surae EMG amplitude, which was fully recovered at 30 min poststretch. Second, Achilles tendon length was significantly shorter during the concentric contraction after stretch and at 30 min poststretch; however, no change in tendon stiffness was detected. Third, passive joint moment was significantly reduced after stretch, and this was accompanied by significant reductions in medial gastrocnemius passive muscle stiffness; both measures fully recovered by 30 min poststretch. These data indicate that the stretching protocol used in this study induced losses in concentric moment that were accompanied by, and related to, reductions in neuromuscular activity, but they were not associated with alterations in tendon stiffness or shorter muscle operating length. Reductions in passive moment were associated with reductions in muscle stiffness, whereas tendon mechanics were unaffected by the stretch. Importantly, the impact on mechanical properties and neuromuscular activity was minimal at 30 min poststretch.

scholarly journals DEFICITS OF CALF MUSCLES STRENGTH AND RATE OF FORCE DEVELOPMENT AFTER ACHILLES TENDON RUPTURE

2019 ◽  
Vol 2 (8) ◽  
pp. 118
Author(s):  
Vaida Aleknavičiūtė - Ablonskė ◽  
Agnė Savenkovienė ◽  
Albertas Skurvydas
Keyword(s):  
Achilles Tendon ◽  
Achilles Tendon Rupture ◽  
Biomechanical Properties ◽  
Calf Muscle ◽  
Plantar Flexors ◽  
Adaptive Changes ◽  
Motor Strategy ◽  
Neural Factors ◽  
Muscle Changes

<p>The Achilles tendon is the thickest and the strongest tendon in the human body. Many studies, investigating biomechanical properties of plantar flexors muscle-tendon unit after ATR surgery, reported an incomplete calf muscle contractile functional recovery. However, these studies only investigated the plantar flexors muscle function failing to provide information about the adaptive changes in motor strategy. In fact, the development of adaptive changes in motor strategies, due to both mechanical and neural factors, may result in pathological musculoskeletal conditions over the long term. Understanding physiological calf muscle changes due to long-term immobilization may help prevent Achilles tendon re-rupture cases.</p>

scholarly journals Measurement of Muscle Thickness as Quantitative Muscle Evaluation for Adults With Severe Cerebral Palsy

2006 ◽  
Vol 86 (9) ◽  
pp. 1231-1239 ◽  
Author(s):  
Koji Ohata ◽  
Tadao Tsuboyama ◽  
Noriaki Ichihashi ◽  
Satosi Minami
Keyword(s):  
Cerebral Palsy ◽  
Muscle Strength ◽  
Functional Status ◽  
Motor Function ◽  
Ultrasound Imaging ◽  
Daily Activity ◽  
Muscle Thickness ◽  
Triceps Surae ◽  
Convenience Sample ◽  
Muscle Spasticity

Abstract Background and Purpose. The muscle strength of people with severe cerebral palsy (CP) is difficult to quantify because of cognitive and selective motor control problems. However, if muscle strength is related to muscle atrophy caused by activity limitation, quantitative morphological analysis such as analysis of muscle thickness (MTH), measured by ultrasound imaging, may be used to examine the muscle condition in daily use. The primary purpose of this investigation was to clarify the difference in MTH of several muscles by the motor functions used in daily activity in adults with CP with different levels of severity of involvement. The secondary purpose was to examine whether MTH is associated with age, body characteristics, and muscle spasticity. Subjects. Data were collected from a convenience sample of 25 adults with severe CP. Methods. The MTH of the biceps brachii (BB), quadriceps femoris (QF), triceps surae (TS), and longissimus (LO) muscles was measured with an ultrasound imaging device. The severity of the condition was classified with the Gross Motor Function Classification System (GMFCS), and functional status in sitting and standing was evaluated with a questionnaire administered to the staff assisting in the care of the subjects. Muscle spasticity was assessed with the Modified Ashworth Scale (MAS). Results. The MTH of the QF, LO, and TS showed significant differences according to the GMFCS level, and the MTH of the QF and LO differed significantly depending on functional status during activities of daily living. Age and body mass index showed no significant correlation with the MTH of any muscle. Body weight was correlated with the MTH of the BB and LO. The girth of the extremity was correlated only with the MTH of the BB. There was no relationship between MTH and MAS scores. Discussion and Conclusion. These results suggest that the MTH of the QF and LO differed significantly depending on the subjects' motor function during daily activity. The measurement of MTH may be an alternative method of quantitative muscle evaluation for people with severe CP for whom direct measurement of muscle strength is difficult. [Ohata K, Tsuboyama T, Ichihashi N, Minami S. Measurement of muscle thickness as quantitative muscle evaluation for adults with severe cerebral palsy. Phys Ther. 2006;86:1231–1239.]

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

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

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

Effects of eccentric training on mechanical properties of the plantar flexor muscle-tendon complex

2013 ◽  
Vol 114 (5) ◽  
pp. 523-537 ◽  
Author(s):  
Alexandre Fouré ◽  
Antoine Nordez ◽  
Christophe Cornu
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Plantar Flexion ◽  
Triceps Surae ◽  
Elastic Component ◽  
Plantar Flexor ◽  
Eccentric Training ◽  
Tendon Stiffness ◽  
Series Elastic Component ◽  
Series Elastic

Eccentric training is a mechanical loading classically used in clinical environment to rehabilitate patients with tendinopathies. In this context, eccentric training is supposed to alter tendon mechanical properties but interaction with the other components of the muscle-tendon complex remains unclear. The aim of this study was to determine the specific effects of 14 wk of eccentric training on muscle and tendon mechanical properties assessed in active and passive conditions in vivo. Twenty-four subjects were randomly divided into a trained group ( n = 11) and a control group ( n = 13). Stiffness of the active and passive parts of the series elastic component of plantar flexors were determined using a fast stretch during submaximal isometric contraction, Achilles tendon stiffness and dissipative properties were assessed during isometric plantar flexion, and passive stiffness of gastrocnemii muscles and Achilles tendon were determined using ultrasonography while ankle joint was passively moved. A significant decrease in the active part of the series elastic component stiffness was found ( P < 0.05). In contrast, a significant increase in Achilles tendon stiffness determined under passive conditions was observed ( P < 0.05). No significant change in triceps surae muscles and Achilles tendon geometrical parameters was shown ( P > 0.05). Specific changes in muscle and tendon involved in plantar flexion are mainly due to changes in intrinsic mechanical properties of muscle and tendon tissues. Specific assessment of both Achilles tendon and plantar flexor muscles allowed a better understanding of the functional behavior of the muscle-tendon complex and its adaptation to eccentric training.

Back Squat vs. Hip Thrust Resistance-training Programs in Well-trained Women

2020 ◽  
Vol 41 (05) ◽  
pp. 306-310 ◽  
Author(s):  
Matheus Barbalho ◽  
Victor Coswig ◽  
Daniel Souza ◽  
Julio Cerca Serrão ◽  
Mário Hebling Campos ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Muscle Hypertrophy ◽  
Training Programs ◽  
Gluteus Maximus ◽  
Muscle Thickness ◽  
Quadriceps Femoris ◽  
Repetition Maximum ◽  
Back Squat ◽  
Before And After ◽  
Gluteus Maximus Muscle

AbstractThe study compared the effects of back squat (BS) and hip thrust (HT) exercises on muscle strength and hypertrophy in well-trained women. Twenty-two participants were divided in two groups: BS group (n=12, 26.4±1.32 years, 171.8±3.79 cm, and 69.5±4.9 kg) performed the BS exercise and HT group (n=10, 27.5±1.42 years, 170.8±4.4 cm, 67.5±4.7 kg) performed the HT exercise. Training was performed for 12 weeks. Before and after the training period, participants were assessed for quadriceps femoris and gluteus maximus muscle thickness (MT) and 1 repetition maximum (1RM) test on the BS and HT. Both groups significantly increased hip extensors MT and HT 1RM; however, the improvements in BS group were higher than in HT group on quadriceps femoris (12.2% for BS and 2% for HT, P<0.001) and gluteus maximus MT (9.4% for BS and 3.7% for HT, P=0.001) and BS 1 RM (35.9% for BS and 4.3% for HT, P<0.001). BS was more efficient than HT, since it resulted in greater muscle hypertrophy of the quadriceps femoris and gluteus maximus, increases in BS 1RM and similar increases in HT.

scholarly journals Monitoring Muscle-Tendon Adaptation Over Several Years of Athletic Training and Competition in Elite Track and Field Jumpers

2020 ◽  
Vol 11 ◽  
Author(s):  
Kiros Karamanidis ◽  
Gaspar Epro
Keyword(s):  
Muscle Strength ◽  
Athletic Training ◽  
Track And Field ◽  
Triceps Surae ◽  
Overuse Injuries ◽  
Cross Sectional ◽  
Tendon Stiffness ◽  
Adaptive Changes ◽  
Tendon Strain ◽  
Over Time

Differences in muscle and tendon responsiveness to mechanical stimuli and time courses of adaptive changes may disrupt the interaction of the musculotendinous unit (MTU), increasing the risk for overuse injuries. We monitored training-induced alterations in muscle and tendon biomechanical properties in elite jumpers over 4 years of athletic training to detect potential non-synchronized adaptations within the triceps surae MTU. A combined cross-sectional and longitudinal investigation over 4 years was conducted by analyzing triceps surae MTU mechanical properties in both legs via dynamometry and ultrasonography in 67 elite track and field jumpers and 24 age-matched controls. Fluctuations in muscle and tendon adaptive changes over time were quantified by calculating individual residuals. The cosine similarity of the relative changes of muscle strength and tendon stiffness between sessions served as a measure of uniformity of adaptive changes. Our cross-sectional study was unable to detect clear non-concurrent differences in muscle strength and tendon stiffness in elite jumpers. However, when considering the longitudinal data over several years of training most of the jumpers demonstrated greater fluctuations in muscle strength and tendon stiffness and hence tendon strain compared to controls, irrespective of training period (preparation vs. competition). Moreover, two monitored athletes with chronic Achilles tendinopathy showed in their affected limb lower uniformity in MTU adaptation as well as higher fluctuations in tendon strain over time. Habitual mechanical loading can affect the MTU uniformity in elite jumpers, leading to increased mechanical demand on the tendon over an athletic season and potentially increased risk for overuse injuries.

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