Tendon disorders are frequent and are responsible for substantial morbidity both in sports and in the workplace. Tendinopathy, as opposed to tendinitis or tendinosis, is the best generic descriptive term for the clinical conditions in and around tendons arising from overuse. Tendinopathy is a difficult problem requiring lengthy management, and patients often respond poorly to treatment. Preexisting degeneration has been implicated as a risk factor for acute tendon rupture. Several physical modalities have been developed to treat tendinopathy. There is limited and mixed high-level evidence to support the, albeit common, clinical use of these modalities. Further research and scientific evaluation are required before biological solutions become realistic options.

http://health120years.com/cn/pdf/hd_tendonopathy_tendinosis_healing_repair.pdf

Tendon injury and tendinopathy: healing and repair.

http://billnordt.com/MUSCLEANDJOINTFUNCTION/stretchshorteningresearcharticle.pdf

Stretch-shortening cycle: a powerful model to study normal and fatigued muscle

Tendon disorders are frequent, and are responsible for much morbidity both in sport and the workplace. Although the presence of degenerative changes does not always lead to symptoms, pre-existing degeneration has been implicated as a risk factor for acute tendon rupture. The term tendinopathy is a generic descriptor of the clinical conditions in and around tendons arising from overuse. The terms "tendinosis" and "tendinitis/tendonitis" should only be used after histopathological examination. Disordered healing is seen in tendinopathy, and inflammation is not typically seen. In acute injuries, the process of tendon healing is an indivisible process that can be categorized into three overlapping phases for descriptive purposes. Tendon healing can occur intrinsically, via proliferation of epitenon and endotenon tenocytes, or extrinsically, by invasion of cells from the surrounding sheath and synovium. Despite remodeling, the biochemical and mechanical properties of healed tendon tissue never match those of intact tendon. Tendon injuries account for considerable morbidity, and often prove disabling for several months, despite what is considered appropriate management. Chronic problems caused by overuse of tendons probably account for 30% of all running-related injuries, and the prevalence of elbow tendinopathy in tennis players can be as high as 40%. The basic cell biology of tendons is still not fully understood, and the management of tendon injury poses a considerable challenge for clinicians. This article describes the structure of tendons, and reviews the pathophysiology of tendon injury and healing.

Biology of tendon injury: healing, modeling and remodeling

Achilles, the warrior and hero of Homer's Iliad, lends his name to the Achilles tendon, the thickest and strongest tendon in the human body138. Thetis, Achilles's mother, made him invulnerable to physical harm by immersing him in the river Styx after learning of a prophecy that Achilles would die in battle. However, the heel by which he was held remained untouched by the water and thus Achilles had a vulnerable point. Achilles led the Greek military forces, which captured and destroyed Troy after killing the Trojan prince Hector. However, Hector's brother Paris killed Achilles by firing a poisoned arrow into his heel164.

Hippocrates, in the first recorded description of an injury to the Achilles tendon, stated that “this tendon, if bruised or cut, causes the most acute fevers, induces choking, deranges the mind and at length brings death.”26 Ambroise Pare, in 1575, recommended that a ruptured Achilles tendon be strapped with bandages dipped in wine and spices, but advised that the result was dubious27. Operative repair of a ruptured Achilles tendon was advocated in 1888 by another Frenchman, Gustave Polaillon27, although an Arabian physician performed such procedures as early as the tenth century A.D. In the twelfth century, an Italian surgeon, Guglielmo di Faliceto, believed that nature was unable to unite divided tendons and that operative treatment was necessary27.

Much research has been performed to elucidate the etiology of a rupture of the Achilles tendon, but its true nature still remains unclear190. Also, the best method of treatment is still fiercely debated. Some physicians advocate operative repair, whereas others insist that an operation is unnecessary and poses an unacceptable risk.

The tendinous portions of the gastrocnemius and soleus muscles merge to form the Achilles tendon. The plantaris …

Rupture of the Achilles Tendon

Foot plantar pressure is the pressure field that acts between the foot and the support surface during everyday locomotor activities. Information derived from such pressure measures is important in gait and posture research for diagnosing lower limb problems, footwear design, sport biomechanics, injury prevention and other applications. This paper reviews foot plantar sensors characteristics as reported in the literature in addition to foot plantar pressure measurement systems applied to a variety of research problems. Strengths and limitations of current systems are discussed and a wireless foot plantar pressure system is proposed suitable for measuring high pressure distributions under the foot with high accuracy and reliability. The novel system is based on highly linear pressure sensors with no hysteresis.

Foot plantar pressure measurement system: a review.

https://me.queensu.ca/People/Deluzio/JAM/files/Lundgren2007_01.pdf

Invasive in vivo measurement of rear-, mid- and forefoot motion during walking

Foot kinematics during walking measured using bone and surface mounted markers.

Individual muscle contributions to the in vivo achilles tendon force

Intrinsic foot kinematics measured in vivo during the stance phase of slow running

Background:The absence of external landmarks on the talus has rendered the description of ankle and subtalar joint kinematics difficult. Abnormal motion at these joints has, however, been implied i...

Anton Arndt

Papers

Invasive in vivo measurement of rear-, mid- and forefoot motion during walking

Foot kinematics during walking measured using bone and surface mounted markers.

Individual muscle contributions to the in vivo achilles tendon force

Intrinsic foot kinematics measured in vivo during the stance phase of slow running

Ankle and subtalar kinematics measured with intracortical pins during the stance phase of walking.