scholarly journals Biomechanical properties of the plantar flexor muscle-tendon complex 6 months post-rupture of the achilles tendon

2013 ◽  
Vol 31 (9) ◽  
pp. 1469-1474 ◽  
Author(s):  
Peter McNair ◽  
Antoine Nordez ◽  
Margie Olds ◽  
Simon W. Young ◽  
Christophe Cornu
2017 ◽  
Vol 21 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Pollyana R.T. Borges ◽  
Thiago R.T. Santos ◽  
Paula R.S. Procópio ◽  
Jessica H.D. Chelidonopoulos ◽  
Roberto Zambelli ◽  
...  

2019 ◽  
Vol 31 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Annika Kruse ◽  
Christian Schranz ◽  
Martin Svehlik ◽  
Markus Tilp

Purpose: The purpose of this study was to investigate the effects of functional progressive resistance training (PRT) and high-intensity circuit training (HICT) on the mechano-morphological properties of the plantar flexor muscle-tendon unit in children with spastic cerebral palsy. Methods: Twenty-two children (12.8 [2.6] y old, Gross Motor Function Classification System levels I/II = 19/3) were randomly assigned to either a PRT group or an HICT group. The interventions consisted of functional lower limb exercises, which were performed at home 3 times per week for 8 weeks. Measurements at baseline, preintervention, postintervention, and follow-up were taken to assess ankle joint range of motion and the properties of the gastrocnemius medialis, vastus lateralis, rectus femoris, and Achilles tendon (eg, thickness, strength, stiffness). Results: Despite a nonsignificant increase in active torque in the HICT group, neither gastrocnemius medialis morphology nor Achilles tendon properties were significantly altered after the interventions. Vastus lateralis thickness increased following PRT only. Conclusions: Functional home-based strength training did not lead to significant changes at the muscular level in children with cerebral palsy. We therefore assume that a more specific stimulus of higher intensity combined with a longer training duration might be necessary to evoke changes in muscles and tendons in individuals with cerebral palsy.


2019 ◽  
Author(s):  
Jennifer R. Yong ◽  
Christopher L. Dembia ◽  
Amy Silder ◽  
Rachel W. Jackson ◽  
Michael Fredericson ◽  
...  

ABSTRACTRunning is thought to be an efficient gait due, in part, to the behavior of the plantar flexor muscles and the elastic energy storage in the Achilles tendon. Although plantar flexor muscle mechanics and Achilles tendon energy storage have been explored during rearfoot striking, they have not been fully characterized during forefoot striking. This study examines how plantar flexor muscle-tendon mechanics during running differ between rearfoot and forefoot striking. We used musculoskeletal simulations, driven by joint angles and electromyography recorded from runners using both rearfoot and forefoot striking running patterns, to characterize plantar flexor muscle-tendon mechanics. The simulations revealed that foot strike pattern affected the soleus and gastrocnemius differently. For the soleus, forefoot striking resulted in decreased tendon energy storage and decreased positive fiber work compared to rearfoot striking. For the gastrocnemius, forefoot striking resulted in greater activation and increased negative fiber work compared to rearfoot striking. The increased activation and negative fiber work in the gastrocnemius during forefoot striking suggest that runners planning to convert to forefoot striking would benefit from a progressive eccentric gastrocnemius strengthening program to avoid injury.


2014 ◽  
Vol 116 (8) ◽  
pp. 961-969 ◽  
Author(s):  
R. Csapo ◽  
V. Malis ◽  
J. Hodgson ◽  
S. Sinha

The aim of the present study was to test the hypothesis that the age-associated decrease of tendon stiffness would necessitate greater muscle fascicle strains to produce similar levels of force during isometric contraction. Greater fascicle strains could force sarcomeres to operate in less advantageous regions of their force-length and force-velocity relationships, thus impairing the capacity to generate strong and explosive contractions. To test this hypothesis, sagittal-plane dynamic velocity-encoded phase-contrast magnetic resonance images of the gastrocnemius medialis (GM) muscle and Achilles tendon (AT) were acquired in six young (YW; 26.1 ± 2.3 yr) and six senior (SW; 76.7 ± 8.3 yr) women during submaximal isometric contraction (35% maximum voluntary isometric contraction) of the plantar flexor muscles. Multiple GM fascicle lengths were continuously determined by automatically tracking regions of interest coinciding with the end points of muscle fascicles evenly distributed along the muscle's proximo-distal length. AT stiffness and Young's modulus were measured as the slopes of the tendon's force-elongation and stress-strain curves, respectively. Despite significantly lower AT stiffness at older age (YW: 120.2 ± 52.3 N/mm vs. SW: 53.9 ± 44.4 N/mm, P = 0.040), contraction-induced changes in GM fascicle lengths were similar in both age groups at equal levels of absolute muscular force (4–5% fascicle shortening in both groups), and even significantly larger in YW (YW: 11–12% vs. SW: 6–8% fascicle shortening) at equal percentage of maximum voluntary contraction. These results suggest that factors other than AT stiffness, such as age-associated changes in muscle composition or fascicle slack, might serve as compensatory adaptations, limiting the degree of fascicle strains upon contraction.


Author(s):  
Timothy S. Pulverenti ◽  
Gabriel S. Trajano ◽  
Benjamin J. C. Kirk ◽  
Vanesa Bochkezanian ◽  
Anthony J. Blazevich

VCOT Open ◽  
2021 ◽  
Vol 04 (01) ◽  
pp. e37-e40
Author(s):  
Hélène Dosseray ◽  
Claire Deroy-Bordenave

AbstractThe aim of this study was to report a posttraumatic partial Achilles tendon (AT) rupture associated with lateral luxation of the superficial digital flexor tendon (SDFT) in a Whippet. This article is a brief communication. A Whippet was presented with posttraumatic plantigrade stance and non-load-bearing lameness of the right pelvic limb. The objective findings consisted in partial AT rupture and SDFT lateral luxation. Surgical treatment ensued: tenorrhaphy of the torn tendons and calcaneo-tibial screw insertion for tarsal immobilization, followed by suturing of the SDFT retinaculum. A casting bandage was employed for additional immobilization. Nonetheless, a bandage complication prompted the premature removal of the fixation screw and casting wrap. Complete functional recovery was achieved by the 20th postoperative week. The simultaneous occurrence of SDFT luxation and partial AT tear has not been reported in the literature before. The long-term postoperative functional outcome was highly satisfactory.


2017 ◽  
Vol 50 ◽  
pp. 78-83 ◽  
Author(s):  
Carlos De la Fuente ◽  
Carlos Cruz-Montecinos ◽  
Helen L. Schimidt ◽  
Hugo Henríquez ◽  
Sebastián Ruidiaz ◽  
...  

2019 ◽  
Vol 2 (8) ◽  
pp. 118
Author(s):  
Vaida Aleknavičiūtė - Ablonskė ◽  
Agnė Savenkovienė ◽  
Albertas Skurvydas

<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>


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