scholarly journals Orthotic Heel Wedges Do Not Alter Hindfoot Kinematics and Achilles Tendon Force During Level and Inclined Walking in Healthy Individuals

2016 ◽  
Vol 32 (2) ◽  
pp. 160-170 ◽  
Author(s):  
Robert A. Weinert-Aplin ◽  
Anthony M.J. Bull ◽  
Alison H. McGregor
Keyword(s):  
Achilles Tendon ◽  
Plantar Flexion ◽  
Force Plate ◽  
The Body ◽  
Triceps Surae ◽  
Tibialis Posterior ◽  
Muscle Forces ◽  
Flexor Muscle ◽  
Optical Motion ◽  
Tendon Force

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. Nineteen healthy volunteers walked on an inclinable walkway while optical motion, force plate, and plantar pressure data were recorded. Walking with heel wedges increased ankle dorsiflexion moments and reduced plantar flexion moments; this resulted in increased peak ankle dorsiflexor muscle forces during early stance and reduced tibialis posterior and toe flexor muscle forces during late stance. Heel wedges did not reduce overall Achilles tendon force during any walking condition, but did redistribute load from the medial to lateral triceps surae during inclined walking. These results add to the body of clinical evidence confirming that heel wedges do not reduce Achilles tendon load and our findings provide an explanation as to why this may be the case.

Does Foot Anthropometry Predict Metabolic Cost During Running?

2017 ◽  
Vol 33 (5) ◽  
pp. 317-322 ◽  
Author(s):  
Herman van Werkhoven ◽  
Stephen J. Piazza
Keyword(s):  
Oxygen Consumption ◽  
Achilles Tendon ◽  
Body Height ◽  
Force Plate ◽  
Metabolic Cost ◽  
Running Economy ◽  
Metabolic Energy ◽  
Flexor Muscle ◽  
Reaction Forces ◽  
Tendon Force

Several recent investigations have linked running economy to heel length, with shorter heels being associated with less metabolic energy consumption. It has been hypothesized that shorter heels require larger plantar flexor muscle forces, thus increasing tendon energy storage and reducing metabolic cost. The goal of this study was to investigate this possible mechanism for metabolic cost reduction. Fifteen male subjects ran at 16 km⋅h−1 on a treadmill and subsequently on a force-plate instrumented runway. Measurements of oxygen consumption, kinematics, and ground reaction forces were collected. Correlational analyses were performed between oxygen consumption and anthropometric and kinetic variables associated with the ankle and foot. Correlations were also computed between kinetic variables (peak joint moment and peak tendon force) and heel length. Estimated peak Achilles tendon force normalized to body weight was found to be strongly correlated with heel length normalized to body height (r = −.751, p = .003). Neither heel length nor any other measured or calculated variable were correlated with oxygen consumption, however. Subjects with shorter heels experienced larger Achilles tendon forces, but these forces were not associated with reduced metabolic cost. No other anthropometric and kinetic variables considered explained the variance in metabolic cost across individuals.

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.

Experimental Animal Model to Study Muscle and Tendon Adaptations to Chronic Loading

1998 ◽  
Vol 02 (04) ◽  
pp. 283-288 ◽  
Author(s):  
J. M. Archambault ◽  
T. J. Koh ◽  
W. Herzog ◽  
D. A. Hart
Keyword(s):  
Animal Model ◽  
Achilles Tendon ◽  
Short Communication ◽  
Angular Position ◽  
Force Transducer ◽  
Triceps Surae ◽  
Experimental Setup ◽  
Cyclic Loads ◽  
Transverse Axis ◽  
Tendon Force

The purpose of this short communication is to present an animal model that: (1) allows for controlled, quantifiable loading of muscle and tendon; and (2) can be used to evaluate the response of musculo-skeletal tissues to chronic loading. A loading apparatus was used to move the rabbit foot through any desired angular position and velocity, while continuously measuring moments about the transverse axis of the ankle. A stimulator was triggered at a pre-set location in the range of motion to produce a contraction of the triceps surae and plantaris muscles. Muscle forces measured with an Achilles tendon force transducer were found to correlate well with externally measured ankle extensor moments. The experimental setup was used to provide cyclic loads to the triceps surae and plantaris muscles and Achilles tendon of 16 rabbits for three loading sessions per week over the period of one to eleven weeks. The experimental model described here is appropriate for the systematic study of the adaptation of muscle and tendon to chronic loading because of the repeatability of the setup and the quantification of tissue loads.

scholarly journals Considerations on the human Achilles tendon moment arm for in vivo triceps surae muscle–tendon unit force estimates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Denis Holzer ◽  
Florian Kurt Paternoster ◽  
Daniel Hahn ◽  
Tobias Siebert ◽  
Wolfgang Seiberl
Keyword(s):  
Achilles Tendon ◽  
Triceps Surae ◽  
Muscle Forces ◽  
Moment Arm ◽  
Unit Force ◽  
Plateau Region ◽  
Triceps Muscle ◽  
Triceps Surae Muscle ◽  
The Individual

Abstract Moment arm-angle functions (MA-a-functions) are commonly used to estimate in vivo muscle forces in humans. However, different MA-a-functions might not only influence the magnitude of the estimated muscle forces but also change the shape of the muscle’s estimated force-angle relationship (F-a-r). Therefore, we investigated the influence of different literature based Achilles tendon MA-a-functions on the triceps surae muscle–tendon unit F-a-r. The individual in vivo triceps torque–angle relationship was determined in 14 participants performing maximum voluntary fixed-end plantarflexion contractions from 18.3° ± 3.2° plantarflexion to 24.2° ± 5.1° dorsiflexion on a dynamometer. The resulting F-a-r were calculated using 15 literature-based in vivo Achilles tendon MA-a-functions. MA-a-functions affected the F-a-r shape and magnitude of estimated peak active triceps muscle–tendon unit force. Depending on the MA-a-function used, the triceps was solely operating on the ascending limb (n = 2), on the ascending limb and plateau region (n = 12), or on the ascending limb, plateau region and descending limb of the F-a-r (n = 1). According to our findings, the estimated triceps muscle–tendon unit forces and the shape of the F-a-r are highly dependent on the MA-a-function used. As these functions are affected by many variables, we recommend using individual Achilles tendon MA-a-functions, ideally accounting for contraction intensity-related changes in moment arm magnitude.

The Effects of Orthotic Heel Lifts on Achilles Tendon Force and Strain During Running

2012 ◽  
Vol 28 (5) ◽  
pp. 511-519 ◽  
Author(s):  
Dominic James Farris ◽  
Erica Buckeridge ◽  
Grant Trewartha ◽  
Miranda Polly McGuigan
Keyword(s):  
Achilles Tendon ◽  
Lower Limb ◽  
Inverse Dynamics ◽  
Force Plate ◽  
Medial Gastrocnemius ◽  
Ultrasound Images ◽  
Moment Arm ◽  
Flexion Extension ◽  
Tendon Force ◽  
The Right

This study assessed the effects of orthotic heel lifts on Achilles tendon (AT) force and strain during running. Ten females ran barefoot over a force plate in three conditions: no heel lifts (NHL), with 12 mm heel lifts (12HL) and with 18 mm heel lifts (18HL). Kinematics for the right lower limb were collected (200 Hz). AT force was calculated from inverse dynamics. AT strain was determined from kinematics and ultrasound images of medial gastrocnemius (50 Hz). Peak AT strain was less for 18HL (5.5 ± 4.4%) than for NHL (7.4 ± 4.2%) (p = .029, effect size [ES] = 0.44) but not for 12HL (5.8 ± 4.8%) versus NHL (ES = 0.35). Peak AT force was significantly (p = .024, ES = 0.42) less for 18HL (2382 ± 717 N) than for NHL (2710 ± 830 N) but not for 12HL (2538 ± 823 N, ES = 0.21). The 18HL reduced ankle dorsiflexion but not flexion-extension ankle moments and increased the AT moment arm compared with NHL. Thus, 18HL reduced force and strain on the AT during running via a reduction in dorsiflexion, which lengthened the AT moment arm. Therefore, heel lifts could be used to reduce AT loading and strain during the rehabilitation of AT injuries.

Achilles Tendon Mechanical Properties After Both Prolonged Continuous Running and Prolonged Intermittent Shuttle Running in Cricket Batting

2013 ◽  
Vol 29 (4) ◽  
pp. 453-462 ◽  
Author(s):  
Laurence Houghton ◽  
Brian Dawson ◽  
Jonas Rubenson
Keyword(s):  
Achilles Tendon ◽  
Elastic Energy ◽  
Plantar Flexion ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Force Transmission ◽  
Before And After ◽  
Tendon Force ◽  
Force Displacement ◽  
Tendon Properties

Effects of prolonged running on Achilles tendon properties were assessed after a 60 min treadmill run and 140 min intermittent shuttle running (simulated cricket batting innings). Before and after exercise, 11 participants performed ramp-up plantar flexions to maximum-voluntary-contraction before gradual relaxation. Muscle-tendon-junction displacement was measured with ultrasonography. Tendon force was estimated using dynamometry and a musculoskeletal model. Gradients of the ramp-up force-displacement curves fitted between 0–40% and 50–90% of the preexercise maximal force determined stiffness in the low- and high-force-range, respectively. Hysteresis was determined using the ramp-up and relaxation force-displacement curves and elastic energy storage from the area under the ramp-up curve. In simulated batting, correlations between tendon properties and shuttle times were also assessed. After both protocols, Achilles tendon force decreased (4% to 5%,P< .050), but there were no changes in stiffness, hysteresis, or elastic energy. In simulated batting, Achilles tendon force and stiffness were both correlated to mean turn and mean sprint times (r= −0.719 to −0.830,P< .050). Neither protocol resulted in fatigue-related changes in tendon properties, but higher tendon stiffness and plantar flexion force were related to faster turn and sprint times, possibly by improving force transmission and control of movement when decelerating and accelerating.

scholarly journals High Resolution Determination of Body Segment Inertial Parameters and Their Variation Due to Soft Tissue Motion

2001 ◽  
Vol 17 (4) ◽  
pp. 326-334 ◽  
Author(s):  
Matthew T.G. Pain ◽  
John H. Challis
Keyword(s):  
Soft Tissue ◽  
Plantar Flexion ◽  
Accurate Method ◽  
Muscular Contraction ◽  
Lower Leg ◽  
The Body ◽  
Triceps Surae ◽  
Body Segment ◽  
Inertial Parameters

This study had two purposes: to evaluate a new method for measuring segmental dimensions for determining body segment inertial parameters (BSIP), and to evaluate the changes in mass distribution within a limb as a consequence of muscular contraction. BSIP were calculated by obtaining surface data points of the body under investigation using a sonic digitizer, interpolating them into a regular grid, and then using Green’s theorem which relates surface to volume integrals. Four skilled operators measured a test object; the error was approximately 2.5% and repeatability was 1.4% (coefficient of variation) in the determination of BSIP. Six operators took repeat measures on human lower legs; coefficients of variation were typically around 5%, and 3% for the more skilled operators. Location of the center of mass of the lower leg was found to move up 1.7 cm proximally when the triceps surae muscles went from a relaxed state to causing plantar flexion. The force during an impact associated with such motion of the soft tissue of the lower leg was estimated to be up to 300 N. In summary, a new repeatable and accurate method for determining BSIP has been developed, and has been used to evaluate body segment mass redistribution due to muscular contraction.

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.

The functional and dynamometer-tested results of transtendinous flexor hallucis longus transfer for neglected ruptures of the Achilles tendon at six years’ follow-up

2018 ◽  
Vol 100-B (5) ◽  
pp. 584-589 ◽  
Author(s):  
C. J. Lever ◽  
H. A. Bosman ◽  
A. H. N. Robinson
Keyword(s):  
Achilles Tendon ◽  
Plantar Flexion ◽  
Contralateral Side ◽  
Triceps Surae ◽  
Wound Complications ◽  
Flexor Hallucis Longus ◽  
Flexor Hallucis Longus Transfer ◽  
The Mean ◽  
American Orthopaedic

Aims Flexor hallucis longus (FHL) tendon transfer is a well-recognized technique in the treatment of the neglected tendo Achillis (TA) rupture. Patients and Methods We report a retrospective review of 20/32 patients who had undergone transtendinous FHL transfer between 2003 and 2011 for chronic TA rupture. Their mean age at the time of surgery was 53 years (22 to 83). The mean time from rupture to surgery was seven months (1 to 36). The mean postoperative follow-up was 73 months (29 to 120). Six patients experienced postoperative wound complications. Results The mean postoperative Achilles tendon Total Rupture Score (ATRS) was 83 (40 to 100) and the mean American Orthopaedic Foot & Ankle Society (AOFAS) score was 94.3 (82 to 100). Tegner scoring showed a mean reduction of one level from the pre-injury level of activity. There was a mean reduction of 24% (4 to 54) in dynamometer-measured strength of ankle plantarflexion, in comparison with the non-operated side. The hallux had a mean of only 40% (2 to 90) strength of plantarflexion in comparison with the contralateral side. Conclusion We conclude that transtendinous FHL transfer for neglected TA ruptures, with a long harvest to allow reattachment of the triceps surae, provides reliable long-term function and good ankle plantarflexion strength. Despite the loss of strength in hallux plantar flexion, there is little comorbidity from the FHL harvest. Cite this article: Bone Joint J 2018;100-B:584–9.

Effects of 12-wk eccentric calf muscle training on muscle-tendon glucose uptake and SEMG in patients with chronic Achilles tendon pain

2014 ◽  
Vol 117 (2) ◽  
pp. 105-111 ◽  
Author(s):  
Tahir Masood ◽  
Kari Kalliokoski ◽  
S. Peter Magnusson ◽  
Jens Bojsen-Møller ◽  
Taija Finni
Keyword(s):  
Achilles Tendon ◽  
Glucose Uptake ◽  
Plantar Flexion ◽  
Achilles Tendinopathy ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Flexor Hallucis Longus ◽  
Myoelectric Activity ◽  
Plantar Flexors ◽  
Lateral Gastrocnemius

High-load eccentric exercises have been a key component in the conservative management of chronic Achilles tendinopathy. This study investigated the effects of a 12-wk progressive, home-based eccentric rehabilitation program on ankle plantar flexors' glucose uptake (GU) and myoelectric activity and Achilles tendon GU. A longitudinal study design with control ( n = 10) and patient ( n = 10) groups was used. Surface electromyography (SEMG) from four ankle plantar flexors and GU from the same muscles and the Achilles tendon were measured during submaximal intermittent isometric plantar flexion task. The results indicated that the symptomatic leg was weaker ( P < 0.05) than the asymptomatic leg at baseline, but improved ( P < 0.001) with eccentric rehabilitation. Additionally, the rehabilitation resulted in greater GU in both soleus ( P < 0.01) and lateral gastrocnemius ( P < 0.001) in the symptomatic leg, while the asymptomatic leg displayed higher uptake for medial gastrocnemius and flexor hallucis longus ( P < 0.05). While both patient legs had higher tendon GU than the controls ( P < 0.05), there was no rehabilitation effect on the tendon GU. Concerning SEMG, at baseline, soleus showed more relative activity in the symptomatic leg compared with both the asymptomatic and control legs ( P < 0.05), probably reflecting an effort to compensate for the decreased force potential. The rehabilitation resulted in greater SEMG activity in the lateral gastrocnemius ( P < 0.01) of the symptomatic leg with no other within- or between-group differences. Eccentric rehabilitation was effective in decreasing subjective severity of Achilles tendinopathy. It also resulted in redistribution of relative electrical activity, but not metabolic activity, within the triceps surae muscle.

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