Human tendon adaptation in response to mechanical loading: a systematic review and meta-analysis of exercise intervention studies on healthy adults
TLDR
The present meta-analysis provides elaborate statistical evidence that tendons are highly responsive to diverse loading regimens and strongly suggests that loading magnitude in particular plays a key role for tendon adaptation in contrast to muscle contraction type.Abstract:
The present article systematically reviews recent literature on the in vivo adaptation of asymptomatic human tendons following increased chronic mechanical loading, and meta-analyzes the loading conditions, intervention outcomes, as well as methodological aspects. The search was performed in the databases PubMed, Web of Knowledge, and Scopus as well as in the reference lists of the eligible articles. A study was included if it conducted (a) a longitudinal exercise intervention (≥8 weeks) on (b) healthy humans (18 to 50 years), (c) investigating the effects on mechanical (i.e., stiffness), material (i.e., Young’s modulus) and/or morphological properties (i.e., cross-sectional area (CSA)) of tendons in vivo, and was reported (d) in English language. Weighted average effect sizes (SMD, random-effects) and heterogeneity (Q and I
2
statistics) of the intervention-induced changes of tendon stiffness, Young’s modulus, and CSA were calculated. A subgroup analysis was conducted regarding the applied loading intensity, muscle contraction type, and intervention duration. Further, the methodological study quality and the risk of bias were assessed. The review process yielded 27 studies with 37 separate interventions on either the Achilles or patellar tendon (264 participants). SMD was 0.70 (confidence interval: 0.51, 0.88) for tendon stiffness (N=37), 0.69 (0.36, 1.03) for Young’s modulus (N=17), and 0.24 (0.07, 0.42) for CSA (N=33), with significant overall intervention effects (p<0.05). The heterogeneity analysis (stiffness: I
2
=30%; Young’s modulus: I
2
=57%; CSA: I
2
=21%) indicated that differences in the loading conditions may affect the adaptive responses. The subgroup analysis confirmed that stiffness adaptation significantly (p<0.05) depends on loading intensity (I
2
=0%), but not on muscle contraction type. Although not significantly different, SMD was higher for interventions with longer duration (≥12 weeks). The average score of 71±9% in methodological quality assessment indicated an appropriate quality of most studies. The present meta-analysis provides elaborate statistical evidence that tendons are highly responsive to diverse loading regimens. However, the data strongly suggests that loading magnitude in particular plays a key role for tendon adaptation in contrast to muscle contraction type. Furthermore, intervention-induced changes in tendon stiffness seem to be more attributed to adaptations of the material rather than morphological properties.read more
Citations
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Journal ArticleDOI
Patellar Tendinopathy: Clinical Diagnosis, Load Management, and Advice for Challenging Case Presentations
Peter Malliaras,Peter Malliaras,Jill Cook,Jill Cook,Craig Purdam,Craig Purdam,Ebonie Rio,Ebonie Rio +7 more
TL;DR: Management of patellar tendinopathy should focus on progressively developing load tolerance of the tendon, the musculoskeletal unit, and the kinetic chain, as well as addressing key biomechanical and other risk factors.
Journal ArticleDOI
A framework for the etiology of running‐related injuries
Michael Lejbach Bertelsen,Adam Hulme,Jesper Petersen,René Børge Korsgaard Brund,Henrik Toft Sørensen,Caroline F. Finch,Erik T. Parner,Rasmus Nielsen +7 more
TL;DR: An evidence‐informed conceptual framework outlining the multifactorial nature of running‐related injury etiology is presented and allows researchers to move beyond traditional risk factor identification to produce research findings that are not only reliably reported in terms of the observed cause‐effect association, but also translatable in practice.
Journal ArticleDOI
Corticosteroid Injections, Eccentric Decline Squat Training and Heavy Slow Resistance Training in Patellar Tendinopathy
F. Diemer,V. Sutor,N. Goreta +2 more
Journal ArticleDOI
Effect of aging and exercise on the tendon
Rene B. Svensson,Katja M. Heinemeier,Christian Couppé,Christian Couppé,Michael Kjaer,S. Peter Magnusson,S. Peter Magnusson +6 more
TL;DR: In vitro data indicate that aging is associated with a decreased potential for cell proliferation and a reduction in the number of stem/progenitor-like cells, and there is persuasive evidence that turnover in the core of the tendon after maturity is very slow or absent.
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Chapter 9: Analysing Data and Undertaking Meta-Analyses
TL;DR: This extract is made available solely for use in the authoring, editing or refereeing of Cochrane reviews, or for training in these processes by representatives of formal entities of The Cochrane Collaboration.