Sports and Exercise-Related Tendinopathies
In September 2010, the first International Scientific Tendinopathy Symposium (ISTS) was held in Umeå, Sweden, to establish a forum for original scientific and clinical insights in this growing field of clinical research and practice. The second ISTS was organised by the same group and held in Vancouver, Canada, in September 2012. This symposium was preceded by a round-table meeting in which the participants engaged in focused discussions, resulting in the following overview of tendinopathy clinical and research issues. This paper is a narrative review and summary developed during and after the second ISTS. The document is designed to highlight some key issues raised at ISTS 2012, and to integrate them into a shared conceptual framework. It should be considered an update and a signposting document rather than a comprehensive review. The document is developed for use by physiotherapists, physicians, athletic trainers, massage therapists and other health professionals as well as team coaches and strength/conditioning managers involved in care of sportspeople or workers with tendinopathy.
As mechanical loading plays such a key role in the development, and rehabilitation, of many cases of sports-related tendinopathy, the distinct structural and functional adaptations and loading environments of tendons at different anatomical locations are important. Lower extremity tendons, such as the Achilles, store and release substantial amounts of tensile energy, whereas gliding tendons such as those at the wrist demonstrate specific adaptations to resist primarily frictional loading, such as retinaculae or synovial sheaths, whose function can be affected by injury. Thus, tendons are distinct and varied in their loading requirements.
The structure and function of tendons have been well described elsewhere. We alert the reader to recent findings regarding the scleraxis gene. Tendon cells (tenocytes) are characterised by their expression of scleraxis, both in developing tendon and ligament, as well as in adult human tenocytes. As expected, scleraxis expression is mechanically regulated, showing a reduction following tendon transection and exhibiting a dose-response with increasing strains or repetitions of movement. Scleraxis expression is increased during the repair and remodelling stages of tissue healing, as the tendon attempts to restore its phenotype—this attempt to restore normal tendon phenotype following injury is frequently imperfect, leading to metaplastic or fibrotic change in injured tendon.
Dynamic tissues like tendon shift their anabolic/catabolic balance according to their mechanical loading history. Emerging evidence suggests that local production of classically neuronal modulators, like neuropeptides, by tenocytes in response to load may regulate local tissue remodelling, in addition to their role in nociception. The tendon's surroundings are richly innervated by mechanoreceptors, including Ruffini corpuscles, Pacinian corpuscles and free nerve endings, all of which may contribute both to proprioception and to nociception. The nerve supply of tendon also includes many autonomic fibres, likely involved in regulating tendon blood flow as well as local tenocyte metabolism and pain signalling.
Abstract and Introduction
Abstract
In September 2010, the first International Scientific Tendinopathy Symposium (ISTS) was held in Umeå, Sweden, to establish a forum for original scientific and clinical insights in this growing field of clinical research and practice. The second ISTS was organised by the same group and held in Vancouver, Canada, in September 2012. This symposium was preceded by a round-table meeting in which the participants engaged in focused discussions, resulting in the following overview of tendinopathy clinical and research issues. This paper is a narrative review and summary developed during and after the second ISTS. The document is designed to highlight some key issues raised at ISTS 2012, and to integrate them into a shared conceptual framework. It should be considered an update and a signposting document rather than a comprehensive review. The document is developed for use by physiotherapists, physicians, athletic trainers, massage therapists and other health professionals as well as team coaches and strength/conditioning managers involved in care of sportspeople or workers with tendinopathy.
Introduction
As mechanical loading plays such a key role in the development, and rehabilitation, of many cases of sports-related tendinopathy, the distinct structural and functional adaptations and loading environments of tendons at different anatomical locations are important. Lower extremity tendons, such as the Achilles, store and release substantial amounts of tensile energy, whereas gliding tendons such as those at the wrist demonstrate specific adaptations to resist primarily frictional loading, such as retinaculae or synovial sheaths, whose function can be affected by injury. Thus, tendons are distinct and varied in their loading requirements.
The structure and function of tendons have been well described elsewhere. We alert the reader to recent findings regarding the scleraxis gene. Tendon cells (tenocytes) are characterised by their expression of scleraxis, both in developing tendon and ligament, as well as in adult human tenocytes. As expected, scleraxis expression is mechanically regulated, showing a reduction following tendon transection and exhibiting a dose-response with increasing strains or repetitions of movement. Scleraxis expression is increased during the repair and remodelling stages of tissue healing, as the tendon attempts to restore its phenotype—this attempt to restore normal tendon phenotype following injury is frequently imperfect, leading to metaplastic or fibrotic change in injured tendon.
Dynamic tissues like tendon shift their anabolic/catabolic balance according to their mechanical loading history. Emerging evidence suggests that local production of classically neuronal modulators, like neuropeptides, by tenocytes in response to load may regulate local tissue remodelling, in addition to their role in nociception. The tendon's surroundings are richly innervated by mechanoreceptors, including Ruffini corpuscles, Pacinian corpuscles and free nerve endings, all of which may contribute both to proprioception and to nociception. The nerve supply of tendon also includes many autonomic fibres, likely involved in regulating tendon blood flow as well as local tenocyte metabolism and pain signalling.