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"Achilles tendon force"

Thijs Maria Anne Ackermans, Gaspar Epro, Christopher McCrum, Kai Daniel Oberländer, Frank Suhr, Maarten Robert Drost, Kenneth Meijer, Kiros Karamanidis
PURPOSE: We aimed to determine whether there are different changes in Achilles tendon (AT) mechanical properties in middle-aged, compared to younger runners that might indicate that tendon fatigue, induced by long-distance running, is age-dependent. METHODS: 27 middle-aged (50-67 years) and 22 younger (21-29 years) participants ran a 21 km route at their own pace (mean and SD: old: 3.1 ± 0.3 m s(-1); young: 3.6 ± 0.5 m s(-1)). We tested for changes in the AT force-elongation relationship using dynamometry and ultrasonography during isometric voluntary ankle plantarflexion ramp contractions, conducted 20-28 h pre-run, immediately pre-run, immediately post-run and 20-28 h post-run...
December 2016: European Journal of Applied Physiology
Nathan Patrick, Gregory S Lewis, Evan P Roush, Allen R Kunselman, Jarrett D Cain
Medial displacement calcaneal osteotomies have been shown to be successful in the surgical management of adult acquired flatfoot, in particular, stage 2 deformity. Classically, the medial displacement calcaneal osteotomy technique has been performed. However, a calcaneal Z osteotomy has been more recently described and applied in the surgical management of flatfoot deformity. Although the potential advantages of the calcaneal Z technique have been reported, data on its effect on the subtalar joint are lacking...
November 2016: Journal of Foot and Ankle Surgery: Official Publication of the American College of Foot and Ankle Surgeons
Taylor J M Dick, Allison S Arnold, James M Wakeling
This study evaluated a procedure for estimating in vivo Achilles tendon (AT) force from ultrasound images. Two aspects of the procedure were tested: (i) accounting for subject-specific AT stiffness and (ii) accounting for changes in the relative electromyographic (EMG) intensities of the three triceps surae muscles. Ten cyclists pedaled at 80rpm while a comprehensive set of kinematic, kinetic, EMG, and ultrasound data were collected. Subjects were tested at four crank loads, ranging from 14 to 44Nm (115 to 370W)...
October 3, 2016: Journal of Biomechanics
Umur Aydogan, Evan P Roush, Blake E Moore, Seth H Andrews, Gregory S Lewis
Destruction of the normal metatarsal arch by a long metatarsal is often a cause for metatarsalgia. When surgery is warranted, distal oblique or proximal dorsiflexion osteotomies of the long metatarsal bones are commonly used. The plantar fascia has anatomical connection to all metatarsal heads. There is controversial scientific evidence on the effect of plantar fascia release on forefoot biomechanics. In this cadaveric biomechanical study, we hypothesized that plantar fascia release would augment the plantar metatarsal pressure decreasing effects of two common second metatarsal osteotomy techniques...
June 9, 2016: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
Richard W Willy, Lisa Halsey, Andrew Hayek, Holly Johnson, John D Willson
Study Design Level 4, controlled laboratory study. Background Little is known regarding how the potential differences between treadmill and overground running may affect patellofemoral joint and Achilles tendon loading characteristics. Objectives To compare measures of loading of the patellofemoral joint and Achilles tendon across treadmill and overground running in healthy, uninjured runners. Methods Eighteen healthy runners ran at their self-selected speed on an instrumented treadmill and overground, while 3-D running mechanics were sampled...
August 2016: Journal of Orthopaedic and Sports Physical Therapy
Robert A Weinert-Aplin, Anthony M J Bull, Alison H McGregor
Conservative treatments such as in-shoe orthotic heel wedges to treat musculoskeletal injuries are not new. However, weak evidence supporting their use in the management of Achilles tendonitis suggests the mechanism by which these heel wedges works remains poorly understood. It was the aim of this study to test the underlying hypothesis that heel wedges can reduce Achilles tendon load. A musculoskeletal modeling approach was used to quantify changes in lower limb mechanics when walking due to the introduction of 12-mm orthotic heel wedges...
April 2016: Journal of Applied Biomechanics
J Sinclair, S J Hobbs, J Selfe
Plyometric training is used by athletes to promote strength and explosive power. However plyometric activities such as depth jumping are associated with a high incidence of injuries. This study examined the influence of minimalist and conventional footwear on the loads experienced by the patellofemoral joint and Achilles tendon. Patellofemoral and Achilles tendon forces were obtained from ten male participants using an eight-camera 3D motion capture system and force platform data as they completed depth jumps in both footwear conditions...
2015: Research in Sports Medicine
Robert A Weinert-Aplin, Anthony M J Bull, Alison H McGregor
This study aimed to characterise the biomechanics of the widely practiced eccentric heel-drop exercises used in the management of Achilles tendinosis. Specifically, the aim was to quantify changes in lower limb kinematics, muscle lengths and Achilles tendon force, when performing the exercise with a flexed knee instead of an extended knee. A musculoskeletal modelling approach was used to quantify any differences between these versions of the eccentric heel drop exercises used to treat Achilles tendinosis. 19 healthy volunteers provided a group from which optical motion, forceplate and plantar pressure data were recorded while performing both the extended and flexed knee eccentric heel-drop exercises over a wooden step when barefoot or wearing running shoes...
June 2015: Journal of Sports Science & Medicine
Jeam Marcel Geremia, Maarten Frank Bobbert, Mayra Casa Nova, Rafael Duvelius Ott, Fernando de Aguiar Lemos, Raquel de Oliveira Lupion, Viviane Bortoluzzi Frasson, Marco Aurélio Vaz
BACKGROUND: Acute ruptures of the Achilles tendon affect the tendon's structural and mechanical properties. The long-term effects of surgical repair on these properties remain unclear. PURPOSE: To evaluate effects of early mobilization versus traditional immobilization rehabilitation programs 2 years after surgical Achilles tendon repair, by comparing force-elongation and stress-strain relationships of the injured tendon to those of the uninjured tendon. METHODS: A group of males with previous Achilles tendon rupture (n=18) and a group of healthy male controls (n=9) participated...
June 2015: Clinical Biomechanics
Jonathan Sinclair, P J Taylor, S Atkins
Military recruits are known to be susceptible to Achilles tendon pathology. The British Army have introduced footwear models, the PT-03 (cross-trainer) and PT1000 (running shoes), in an attempt to reduce the incidence of injuries. The aim of the current investigation was to examine the Achilles tendon forces of the cross-trainer and running shoe in relation to conventional army boots. Ten male participants ran at 4.0 m/s in each footwear condition. Achilles tendon forces were obtained throughout the stance phase of running and compared using repeated-measures ANOVAs...
June 2015: Journal of the Royal Army Medical Corps
Saira Chaudhry, Dylan Morrissey, Roger C Woledge, Dan L Bader, Hazel R C Screen
Triceps surae eccentric exercise is more effective than concentric exercise for treating Achilles tendinopathy, however the mechanisms underpinning these effects are unclear. This study compared the biomechanical characteristics of eccentric and concentric exercises to identify differences in the tendon load response. Eleven healthy volunteers performed eccentric and concentric exercises on a force plate, with ultrasonography, motion tracking, and EMG applied to measure Achilles tendon force, lower limb movement, and leg muscle activation...
April 2015: Journal of Applied Biomechanics
Yen-Nien Chen, Chih-Wei Chang, Chun-Ting Li, Chih-Han Chang, Cheng-Feng Lin
BACKGROUND: The plantar fascia is a primary arch supporting structure of the foot and is often stressed with high tension during ambulation. When the loading on the plantar fascia exceeds its capacity, the inflammatory reaction known as plantar fasciitis may occur. Mechanical overload has been identified as the primary causative factor of plantar fasciitis. However, a knowledge gap exists between how the internal mechanical responses of the plantar fascia react to simple daily activities...
January 2015: Foot & Ankle International
Satoru Hashizume, Soichiro Iwanuma, Ryota Akagi, Hiroaki Kanehisa, Yasuo Kawakami, Toshimasa Yanai
The present study aimed to re-examine the influence of the isometric plantarflexors contraction on the Achilles tendon moment arm (ATMA) and the factors influencing the ATMA in three-dimensions. A series of coronal magnetic resonance images of the right ankle were recorded at foot positions of 10° of dorsiflexion, neutral position, and 10° of plantarflexion for the rest condition and the plantarflexors contraction condition at 30% maximal voluntary effort. The shortest distance between the talocrural joint axis and the line of action of the Achilles tendon force projected to the orthogonal plane of the talocrural joint axis was determined as the ATMA...
September 22, 2014: Journal of Biomechanics
J Sinclair, J Isherwood, P J Taylor
BACKGROUND: Achilles tendon pathology is a frequently occurring musculoskeletal disorder in runners. Foot orthoses have been shown to reduce the symptoms of pain in runners but their mechanical effects are still not well understood. METHODS: This study aimed to examine differences in Achilles tendon load when running with and without orthotic intervention. Twelve male runners ran at 4.0 m·s(-1). Ankle joint moments and Achilles tendon forces were compared when running with and without orthotics...
September 2014: Clinical Biomechanics
Jonathan Sinclair
BACKGROUND: Recreational runners frequently suffer from chronic pathologies. The knee and ankle have been highlighted as common injury sites. Barefoot and barefoot inspired footwear have been cited as treatment modalities for running injuries as opposed to more conventional running shoes. This investigation examined knee and ankle loading in barefoot and barefoot inspired footwear in relation to conventional running shoes. METHOD: Thirty recreational male runners underwent 3D running analysis at 4...
April 2014: Clinical Biomechanics
Paulo Roriz, Lídia Carvalho, Orlando Frazão, José Luís Santos, José António Simões
In vivo measurement, not only in animals but also in humans, is a demanding task and is the ultimate goal in experimental biomechanics. For that purpose, measurements in vivo must be performed, under physiological conditions, to obtain a database and contribute for the development of analytical models, used to describe human biomechanics. The knowledge and control of the mechanisms involved in biomechanics will allow the optimization of the performance in different topics like in clinical procedures and rehabilitation, medical devices and sports, among others...
April 11, 2014: Journal of Biomechanics
S Fukashiro, P V Komi, M Järvinen, M Miyashita
UNLABELLED: The purpose of this study was to compare the relationship between the achilles tendon force and the tendon force estimated from the ankle joint moment (EATF) during vertical jump. A healthy male subject performed the following jumps on the force platform: (a) maximal vertical jump from a squat position without counter-movement; (b) maximal vertical jump from an erect standing position with a preliminary counter-movement; (c) repetitive submaximal hopping on the spot with preferred frequency...
January 1993: Clinical Biomechanics
Juha-Pekka Kulmala, Janne Avela, Kati Pasanen, Jari Parkkari
PURPOSE: Knee pain and Achilles tendinopathies are the most common complaints among runners. The differences in the running mechanics may play an important role in the pathogenesis of lower limb overuse injuries. However, the effect of a runner's foot strike pattern on the ankle and especially on the knee loading is poorly understood. The purpose of this study was to examine whether runners using a forefoot strike pattern exhibit a different lower limb loading profile than runners who use rearfoot strike pattern...
December 2013: Medicine and Science in Sports and Exercise
Thomas Almonroeder, John D Willson, Thomas W Kernozek
In this study we compared Achilles tendon loading parameters during barefoot running among females with different foot strike patterns using open-source computer muscle modeling software to provide dynamic simulations of running. Muscle forces of the gastrocnemius and soleus were estimated from experimental data collected in a motion capture laboratory during barefoot running for 11 runners utilizing a rearfoot strike (RFS) and 8 runners utilizing a non-RFS (NRFS) pattern. Our results show that peak Achilles tendon force occurred earlier in stance phase (p = 0...
August 2013: Annals of Biomedical Engineering
Kurt Manal, Karin Gravare-Silbernagel, Thomas S Buchanan
The real-time estimation of muscle forces could be a very valuable tool for rehabilitation. By seeing how much muscle force is being produced during rehabilitation, therapists know whether they are working within safe limits in their therapies and patients know if they are producing enough force to expect improvement. This is especially true for rehabilitation of Achilles tendon ruptures where, out of fear of overloading and causing a re-rupture, minimal therapy is typically done for eight weeks post-surgery despite animal studies that show that low-level loading is beneficial...
August 2012: Multibody System Dynamics
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