BACKGROUND:Clinicians manage midportion Achilles tendinopathy (AT) using complex clinical reasoning underpinned by a rapidly developing evidence base. OBJECTIVES:The objectives of the study were to develop an inclusive, accessible review of the literature in combination with an account of expert therapists' related clinical reasoning to guide clinical practice and future research. METHODS:Searches of the electronic databases, PubMed, ISI Web of Science, PEDro, CINAHL, EMBASE, and Google Scholar were conducted for all papers published from inception to November 2011. Reference lists and citing articles were searched for further relevant articles. Inclusion required studies to evaluate the effectiveness of any conservative intervention for midportion AT. Exclusion criteria included in vitro, animal and cadaver studies and tendinopathies in other locations (e.g. patella, supraspinatus). From a total of 3497 identified in the initial search, 47 studies fulfilled the inclusion criteria. Studies were scored according to the PEDro scale, with a score of ≥ 8/10 considered of excellent quality, 5-7/10 good, and ≤ 4/10 poor. The strength of evidence supporting each treatment modality was then rated as 'strong', 'moderate', 'limited', 'conflicting' or 'no evidence' according to the number and quality of articles supporting that modality. Additionally, semi-structured interviews were conducted with physiotherapists to explore clinical reasoning related to the use of various interventions with and without an evidence base, and their perceptions of available evidence. RESULTS:Evidence was strong for eccentric loading exercises and extracorporeal shockwave therapy; moderate for splinting/bracing, active rest, low-level laser therapy and concentric exercises (i.e. inferior to eccentric exercise). In-shoe foot orthoses and therapeutic ultrasound had limited evidence. There was conflicting evidence for topical glycerin trinitrate. Taping techniques and soft-tissue mobilization were not yet examined but featured in case studies and in the interview data. Framework analysis of interview transcripts yielded multiple themes relating to physiotherapists' clinical reasoning and perceptions of the evidence, including the difficulty in causing pain while treating the condition and the need to vary research protocols for specific client groups--such as those with the metabolic syndrome as a likely etiological factor. Physiotherapists were commonly applying the modality with the strongest evidence base, eccentric loading exercises. Barriers to research being translated into practice identified included the lack of consistency of outcome measures, excessive stringency of some authoritative reviews and difficulty in accessing primary research reports. The broad inclusion criteria meant some lower quality studies were included in this review. However, this was deliberate to ensure that all available research evidence for the management of midportion AT, and all studies were evaluated using the PEDro scale to compensate for the lack of stringent inclusion criteria. CONCLUSION:Graded evidence combined with qualitative analysis of clinical reasoning produced a novel and clinically applicable guide to conservative management of midportion AT. This guide will be useful to novice clinicians learning how to manage this treatment-resistant condition and to expert clinicians reviewing their evidence-based practice and developing their clinical reasoning. Important areas requiring future research were identified including the effectiveness of orthoses, the effectiveness of manual therapy, etiological factors, optimal application of loading related to stage of presentation and how to optimize protocols for different types of patients such as the older patient with the metabolic syndrome as opposed to the athletically active.