Search results for "Achilles Tendon"
showing 10 items of 101 documents
Treatment of acute Achilles tendon ruptures with Achillon device: Clinical outcomes and kinetic gait analysis
2009
Abstract Background We reviewed the outcomes of the Achillon minimally invasive suture system and an early semi-functional rehabilitation program for the treatment of acute Achilles tendon ruptures. Methods From December 2006 to April 2008, 18 consecutive patients with acute Achilles tendon ruptures were retrospectively reviewed with an average follow-up of 22 months. Clinical data were assessed with the patient satisfaction and the AOFAS hindfoot score. Biomechanical gait parameters were obtained using the NedAMH/IBV dynamometric platform. Results At last follow-up the AOFAS score was 98 (range, 89–100) and correlated well with kinetic gait analysis. All patients regained normal range of m…
Biomechanical Loading of Achilles Tendon During Normal Locomotion
1992
Direct in vivo Achilles tendon force measurements open up new possibilities for understanding the loading of the Achilles tendon during natural locomotion. This article describes how these human experiments can be performed. The results of these experiments imply that Achilles tendon forces are unexpectedly high in certain activities (e.g., hopping) and that the rates of loading rather than the absolute magnitudes of the recorded forces may be more relevant for clinical purposes as well as for the construction of artificial tendon materials.
Age-related differences in Achilles tendon properties and triceps surae muscle architecture in vivo
2012
This study examined the concurrent age-related differences in muscle and tendon structure and properties. Achilles tendon morphology and mechanical properties and triceps surae muscle architecture were measured from 100 subjects [33 young (24 ± 2 yr) and 67 old (75 ± 3 yr)]. Motion analysis-assisted ultrasonography was used to determine tendon stiffness, Young's modulus, and hysteresis during isometric ramp contractions. Ultrasonography was used to measure muscle architectural features and size and tendon cross-sectional area. Older participants had 17% lower ( P < 0.01) Achilles tendon stiffness and 32% lower ( P < 0.001) Young's modulus than young participants. Tendon cross-section…
In vivo muscle mechanics during locomotion depend on movement amplitude and contraction intensity
2001
The effects of movement amplitude and contraction intensity on triceps surae and quadriceps femoris muscle function were studied during repetitive hopping. In vivo forces from Achilles and patellar tendons were recorded with the optic fibre technique from eight volunteers. The performances were filmed (200 Hz) to determine changes in muscle-tendon unit length and velocity. When hopping with a small amplitude (23 degrees knee flexion during the ground contact phase), the Achilles tendon was primarily loaded whereas patellar tendon forces were greater in large-amplitude hopping (56 degrees knee flexion). In spite of the different magnitudes of stretch in the quadriceps femoris muscle, the str…
In vivo achilles tendon loading' during jumping in humans
1995
Elastic behaviour of the human tendomuscular system during jumping was investigated by determination of the in vivo Achilles tendon force. A buckle-type transducer was implanted under local anaesthesia around the right Achilles tendon of an adult subject. After calibration, the Achilles tendon force was recorded together with the triceps surae muscle electromyogram activity and high speed filming and ground reaction force during: a maximal vertical jump from a squat position, a maximal vertical jump from an erect standing position with a preliminary counter-movement, and repetitive submaximal hopping on the spot. Jumping heights were 33, 40 and 7 cm in the squat, the counter movement, and t…
Force in the Achilles Tendon During Walking With Ankle Foot Orthosis
2009
Background Ankle foot orthoses are used for postoperative treatment of Achilles tendon ruptures and decrease calf muscle electromyography activity during walking. Hypothesis Achilles tendon load decreases with increased restriction of dorsiflexion and is associated with decreased triceps surae activity. Study Design Controlled laboratory study. Methods In 8 subjects, the maximum force and rate of force development in the Achilles tendon were measured with an optic fiber technique, and the activity of the gastrocnemius, soleus, and tibialis anterior muscles was recorded using electromyography. Trial conditions were walking barefoot and wearing an ankle-foot orthoses set in 3 different positi…
Some biomechanical aspects of the foot and ankle in athletes with and without shin splints
1983
Thirteen adult male athletes (long-distance runners and orienteerers without foot problems) and 35 male ath letes with shin splints were compared with respect to: 1) the position of the lower leg and the heel while standing, 2) the passive range of mobility in the subtalar joint, and 3) the angular displacement between the calcaneus and the midline of the lower leg (Achilles tendon angle) while running with bare feet on a tread mill. In standing, the two groups differed statistically significantly in the Achilles tendon angle, which values were greater in the shin splint group. With respect to passive mobility, the athletes with shin splints had significantly greater (P < 0.05-0.01) ang…
In vivo mechanical response of human Achilles tendon to a single bout of hopping exercise
2010
SUMMARY Stiffness of the human Achilles tendon (AT) was determined in vivo before and after a single bout of hopping exercise. It was hypothesized, based on published data using in vitro specimens, that a reduction in AT stiffness may occur after just 1000 loading cycles at physiological stress levels. Ten healthy subjects performed two-legged hopping exercise consisting of 1150–2600 high impacts. Tendon stiffness was determined in several isometric ramp contractions [20%, 40%, 60%, 80% and 100% maximum voluntary contraction (MVC)] during which tendon elongation was measured using ultrasonography and two cameras. Tendon force was calculated by dividing measured ankle torque by magnetic reso…
Conditioning hops increase triceps surae muscle force and Achilles tendon strain energy in the stretch-shortening cycle
2018
Postactivation potentiation can improve athletic performance, but the underlying mechanisms are poorly understood. This study investigated the effect of conditioning hops on triceps surae muscle force and tendon strain and its contribution to potentiated stretch-shortening cycle (SSC) performance. Thirty-two subjects participated in two experiments. In both experiments, subjects performed three drop jumps (DJs) after prior conditioning with 10 maximal hops, three unconditioned DJs served as control. Ground reaction forces, kinematics, and triceps surae electromyographic activity were recorded. Ultrasound imaging was used to determine fascicle lengths (FASC) of the gastrocnemius (GM) and sol…
Mechanical and neural function of triceps surae in elite racewalking
2016
Racewalking is a unique event combining mechanical elements of walking with speeds associated with running. It is currently unclear how racewalking technique impacts upon lower limb muscle-tendon function, despite the relevance of this to muscle economy and overall performance. The present study examined triceps surae neuromechanics in 11 internationally competitive racewalkers (age 25±11 years) walking and running on a treadmill at speeds between 4.5 - 13.8 km/h whilst triceps surae fascicle lengths, electromyography and kinematic data were recorded. Cumulative muscle activity required to traverse a unit distance (CMAPD) was calculated for each muscle. Medial gastrocnemius (MG) and soleus …