###### Abstract  
Objectives: To investigate the efficacy of the assessment methods that are used to diagnose posterior tibialis tendon dysfunction (PTTD) and investigate how the results of these assessments can be used to instruct non-surgical treatments. Design: Systematic review. Data sources: Searches were conducted up to January 2023 in the PubMed, Scopus, Science Direct, Embase, Web of Science and Lilacs databases. Study eligibility criteria: Studies which included patients over 18 years of age, diagnosed with PTTD, which describe the assessments used to aid in the non-surgical treatment of PTTD in comparison with another type of assessment. All types of studies apart from protocols, letters to editor and other systematic reviews and meta-analysis were included. Study appraisal and synthesis methods: Two blinded reviewers performed screening, data extraction, and methodological quality assessments using the QUADAS-2. Results: A total of 15 observational studies were included in the review. Assessment methods included were verbal assessments, physical examinations, and imaging (magnetic resonance imaging (MRI), ultrasound (US), and radiographs). The single-heel rise test was a commonly mentioned physical examination, showing reliability in one study but contradicting in another. MRI was frequently described as the \"gold standard\". However, US showed both comparable accuracy and advantages compared to MRI, such as cost-effectiveness and real-time examinations. Conclusions: There are many assessment methods described in the literature and, due to the lack of accuracy of the tests, a mixture of tests should be used to assess PTTD. The parameters from the tests can provide a diagnosis of PTTD, but do not offer detail on how they assist the non-surgical treatment of the condition.  
posterior tibialis tendon; dysfunction; assessment; treatment; orthotics; physiotherapy diagnostics; ultrasound; magnetic resonance imaging +
Footnote †: journal: _Sciences_
pain [3]. PTTD is a condition which mainly affects women and has been shown to have a prevalence of over 3% in women over 40 years of age [4].  
Due to the evolving nature of the condition, many authors have divided the condition into stages, to better guide treatment methodology. [PERSON] and [PERSON] were the first to stage the condition in 1989 [6]. This was later revised by multiple authors, including [PERSON] in 1996 [7], and further by [PERSON] et al. in 2007 [8]. In 2012, [PERSON] et al. developed the Rearfoot Ankle Midfoot (RAM) classification, which has also been modified from the original [PERSON] and Storm system, and introduces more detail regarding the rearfoot, ankle, and midfoot [9]. Other classifications systems have been suggested, such as the \"Grand Rapids Arch Collapse Classification\" in 2019 [10] as well as a consensus group classification in 2020 [11]. It has been described in one paper that the most commonly used system is still the original Johnson and Storm classification; this has not been validated [12]. All the described classification systems provide an algorithmic approach and suggest treatment methodologies. However, although the more recent systems provide more detail, they still categorize patient presentations into types and provide generic treatment suggestions such as orthotics and physiotherapy.  
All these category systems require an initial assessment of the foot and ankle, to determine the condition of the tendon, function, and deformity of the foot. The aim of this study is to look at the efficacy of the assessment methods used to diagnose PTTD, defined in the research, as well as how the results of these assessments are used to instruct non-surgical treatments. This review holds the idea that, perhaps, individual assessments provide more data than the categorization systems, and can be used for the effective non-surgical treatment of PTTD.