Search results for "Tendon"
showing 10 items of 240 documents
Non‐uniform displacement within ruptured Achilles tendon during isometric contraction
2021
The purpose of this study was investigate tendon displacement patterns in non‐surgically treated patients 14 months after acute Achilles tendon rupture (ATR) and to classify patients into groups based on their Achilles tendon (AT) displacement patterns. Twenty patients were tested. Sagittal images of AT were acquired using B‐mode ultrasonography during ramp contractions at a torque level corresponding to 30% of the maximal isometric plantarflexion torque of the uninjured limb. A speckle tracking algorithm was used to track proximal‐distal movement of the tendon tissue at 6 antero‐posterior locations. Two‐way repeated measures ANOVA for peak tendon displacement was performed. K‐means cluster…
Approximation of pre-twisted Achilles sub-tendons with continuum beam elements
2022
Achilles sub-tendons are materially and geometrically challenging structures that can nearly undergo around 15% elongation from their pre-twisted initial states during physical activities. Sub-tendons' cross-sectional shapes are subject-specific, varying from simple to complicated. Therefore, the Achilles sub-tendons are often described by three-dimensional elements that lead to a remarkable number of degrees of freedom. On the other hand, the continuum-based beam elements in the framework of the absolute nodal coordinate formulation have already been shown to be a reliable and efficient replacement for the three-dimensional continuum elements in some special problems. So far, that element …
Medial gastrocnemius muscle fascicle function during heel-rise after non-operative repair of Achilles tendon rupture
2023
Background To better understand muscle remodelling in dynamic conditions after an Achilles tendon rupture, this study examined the length of medial gastrocnemius muscle fascicles during a heel-rise at 6- and 12-months after non-operative ATR treatment. Methods Participants (15 M, 3F) were diagnosed with acute Achilles tendon rupture. Medial gastrocnemius subtendon length, fascicle length and pennation angle were assessed in resting conditions, and fascicle shortening during bi- and unilateral heel-rises. Findings Fascicle shortening was smaller on the injured side (mean difference [95% CI]: −9. 7 mm [−14.7 to −4.7 mm]; −11.1 mm [−16.5 to −5.8 mm]) and increased from 6- to 12 months (4.5 mm …
Association of Arthroscopically-Assisted Latissimus Dorsi Tendon Transfer with Implantation of a Subacromial Balloon Spacer for Patients with Irrepar…
2022
Purpose. Massive irreparable posterosuperior rotator cuff tears in an active population, resulting in a pseudo-paralytic shoulder, pose a challenge for the orthopaedic surgeon. In an effort to avoid or delay arthroplasty surgery, other surgical strategies such as arthroscopically-assisted latissimus dorsi transfer (aLDT) or the implantation of a subacromial spacer (SAS) can be considered. The aim of the present study is to associate, for the first time, these two surgical procedures in order to demonstrate the surgical feasibility and the effectiveness of their synergistic biomechanical effect. Methods. The study group consisted of patients who underwent aLDT for a massive irreparable poste…
Distinct muscle-tendon interaction during running at different speeds and in different loading conditions
2019
The interaction between the Achilles tendon and the triceps surae muscles seems to be modulated differently with various task configurations. Here we tested the hypothesis that the increased forces and ankle joint work during running under contrasting conditions (altered speed or load) would be met by different, time-dependent adjustments at the muscle-tendon level. Ultrasonography, electromyography, kinematics, and ground reaction force measurements were used to examine Achilles tendon, gastrocnemius, and soleus muscle mechanics in 16 runners in four different running conditions, consisting of a combination of two different speeds (preferred and +20% of preferred speed) and two loading con…
Contribution of In‐Vivo Human Tendon Force Measurements for Understanding Tendomuscular Loading during SSC
2010
Effect of Physical Training on Enzyme Activities of Bones, Tendons and Skeletal Muscles in Mice
1975
According to several recent papers the activity of some enzymes of energy yielding metabolic pathways increases by endurance training in muscles, but it is not yet known whether similar changes occur also in connective tissues. Some structural, chemical, physical and metabolic changes, however, appear in connective tissues during adaptation to physical exercise. Physical training produces hypertrophy of e.g. tendon and articular cartilage in young rabbits [6] and increases the tensile strength of tendons and breaking strength of bones in growing mice [7]. The level of physical activity affects the turnover of collagen in long bones and Achilles tendons of mice [4] and also affects the miner…
99 Muscle-tendon Properties During Recovery From Complete Achilles Tendon Rupture – A Case Study
2014
Introduction Achilles tendon is the most common tendon to suffer for complete rupture. Physically active young adults are often treated with surgery. Most of the patients do not suffer from activity limitations after injury 3 but performance level is often significantly decreased. 1,2 The purpose of this study was to follow recovery of Achilles tendon and triceps surae muscles after complete Achilles tendon rupture and subsequent surgery. This study served as a pilot phase for future research project. Methods Three subjects were recruited to this pilot phase of the study. Subjects were first time measured 2 to 8 months after injury and followed 6 to 8 months. Plantarflexion strength was mea…
Zur Achillessehnenbelastung im alpinen Skisport
1987
In an attempt to gain more systematic knowledge of the biomechanical mechanism involved in the genesis of injuries caused by a fall during skiing, we undertook a comprehensive analysis of more than 100 experimental ski falls simulated under controlled conditions. The well-known relation between speed, release time of the ski binding and injury risk of the lower extremity was confirmed by our experimental results. The EMG investigations revealed the central importance of the musculus triceps surae, and hence of the Achilles tendon, during a fall. The results of our biomechanical model indicate that the present method of setting the ski binding according to the tibial strength, is rather ques…
Okkulte Fraktur einer Achillessehnenossifikation ohne begleitende Sehnenruptur
2000
Ossification of the Achilles tendon is the result of a traumatic, hypoxic injury of the tendon. The usually asymptomatic ossification has a clinical importance only in case of a new trauma. We report about a patient with an isolated fracture of the ossification without an accompanying rupture of the Achilles tendon. Because of the radiologically "occult" fracture the diagnosis could only be verified by MRI. With a conservative treatment without resection of the ossification we could reach painless recovery.