Evidence for adaptation in pathological tendon in response to chronic load. : Does the pathological tendon adapt in respond to chronic load? A systematic Review

Abstract: ABSTRACT Background Tendinopathy is a common problem amongst especially athletes but also in nonathletic people. The area of pathology in the tendon and its relationship with pain is questioned. Whether the tendon pathology resolves and if this correlates with decreased pain levels and improved function is also questioned. A greater knowledge of whether the tendon adapts to load could improve knowledge about the pathogenesis and management of tendinopathy.   Objective To systematically review the evidence for tendon adaptation to load.  thereby answering the question: Structural and material adaptation of pathological tendons with loading - Do pathological tendons adapt to mechanical loading?   Data sources A systematic search of the databases PubMed, CINAHL, EBSCO and Google Scholar was undertaken October 2015.   Study eligibility criteria Randomized controlled trials, cohort studies and controlled trials were included. Studies investigating the response of pathological tendons response to chronic load were included.         Keywords: Tendinopathy, Tendinosis, Pathology, Adaptation, Exercise                                   Study appraisal and synthesis methods Included studies were evaluated for risk of bias using the Pedro scale. Guidelines regarding level of evidence were taken from van Tulder et al (114).   Participants and interventions Seven studies met the inclusion criteria. A total of 184 patients underwent either eccentric or heavy slow training programs. Structural and/or mechanical, and/or biochemical outcome measures were collected after intervention.   Results Overall there is limited evidence that structural changes occur within the pathological area of the tendon, especially the core of the tendon as a response to heavy load. However, there is moderate support of HSR and certain biochemical outcomes.   Conclusions and implications of key findings Limited evidence indicates a period of heavy resistance training may result in some changes in the pathological area of the tendon. The presence of tendon pathology may be a risk factor for developing pain. So, longitudinal studies with large cohorts and validated objective outcome measures are needed to further investigate the extent to which a pathological tendon adapt to heavy load and how this relates to pain and function.