The clinical diagnosis of Achilles tendinopathy: a scoping review

Study design

A scoping review was conducted to synthesise available evidence on the clinical diagnosis and clinical outcome measures of Achilles tendinopathy. Due to the wide-ranging nature of the topic, a scoping review was used to facilitate the collection and charting of evidence with the aim of identifying key themes, knowledge gaps and types of evidence currently available. Figure 1 provides an overview of the overall study design and process to answer the primary aim and specific objectives.

Search strategy

A single researcher (WM) completed a literature search to identify, screen and select studies in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews (PRISMA-ScR) (Tricco et al., 2018). A detailed, multistep search of PubMed, CINAHL, ProQuest and SPORTDiscus was conducted between May 2020 and July 2020, before being updated in April 2021. In addition to the electronic database search, reference lists from included articles were reviewed for additional articles. To ensure a broad search, key words were truncated to allow for variations in spelling and combined using Boolean operators in addition to the use of MeSH terms to allow for review of all relevant articles. The full electronic search for the PubMed database is provided in Table 2.

Eligibility criteria

Methods for data extraction specific to scoping reviews were informed by the Population-Concept-Context framework as recommended by the Joanna Briggs Institute (JBI) Reviewer’s Manual (Peters et al., 2020). Population was defined as any person clinically diagnosed with Achilles tendinopathy regardless of location (insertional or midportion). Concept included any study reporting on the methods used to clinically diagnose Achilles tendinopathy including subjective measures, objective measures and outcome measures. Context included all periods of time, outcomes, comparators, follow-up, rehabilitation settings and duration and type of intervention.

Eligible articles were full-text and included original research, reviews, scoping reviews, systematic reviews, meta-analyses, case-series and clinical commentaries. Studies were included if they provided adequate information on the method of clinical diagnosis (either subjective measures, objective measures or both subjective and objective measures), and clinical outcome measures used. Studies were excluded if they were non-English, had no description of clinical diagnosis, not specific to Achilles tendinopathy or included asymptomatic Achilles tendon states only.

Data extraction and synthesis

WM extracted data from publications meeting the inclusion criteria into an Excel spreadsheet. Data extraction, grouping and plotting were performed by WM in line with previously published recommendations (Peters et al., 2020), where extracted data included author, year of publication, participant characteristics, methods for diagnosing Achilles tendinopathy and outcome measures. Data was extracted in tabular and graphical forms with results grouped by study design and categorised according to the hierarchy of evidence (Daly et al., 2006; Evans, 2003; Merlin, Weston & Tooher, 2009). Diagnostic criteria were presented in tabular form including year of publication, population, subjective and objective measures. Terminology and outcome measures were presented in graphical form with terminology grouped by publication year and outcome measures grouped by purpose of measure (disability, pain, psychological, quality of life).

Following data extraction, data synthesis was performed according to a previously published methodological framework (Thomas & Harden, 2008). Data was synthesised into the following categories: (1) subjective measures, (2) objective measures and (3) outcome measures. Results were plotted according to publication date, terminology, study design and clinical diagnostic measures. Results were then compared to the nine core health domains of tendinopathy (Vicenzino et al., 2020) to identify areas of overlap and gaps in the current evidence. Studies could be allocated to multiple groups. Quality appraisal was not required as per recommended methodology for scoping reviews (Peters et al., 2020; Arksey & O’Malley, 2005).

Selection of sources of evidence

The search results are displayed in the PRISMA Flow Diagram (Fig. 2). The search strategy generated 11,561 results with two further results identified via reference list searching. Following duplicate removal and title and abstract screening, 554 full-text articles were reviewed for inclusion in the study. Of these, 395 were excluded for the following reasons: 240 provided insufficient information on the method of diagnosing Achilles tendinopathy, 11 assessed asymptomatic Achilles tendons only, 46 did not have access to the full text, 52 were not in English and 47 were not specific to Achilles tendinopathy. Thus, 159 articles (Millar et al., 2021; Hutchison et al., 2013; Reiman et al., 2014; Abate & Salini, 2019; Aiyegbusi, Tella & Sanusi, 2020; Aldridge, 2004; Alfredson, 2003; Alfredson & Cook, 2007; Alfredson & Spang, 2018; Aronow, 2005; Asplund & Best, 2013; Azevedo et al., 2009; Bains & Porter, 2006; Barge-Caballero et al., 2008; Barker-Davies et al., 2017; Baskerville et al., 2018; Benazzo, Todesca & Ceciliani, 1997; Benito, 2016; Bhatty, Khan & Zubairy, 2019; Bjordal, Lopes-Martins & Iversen, 2006; Boesen et al., 2017; Borda & Selhorst, 2017; Brown et al., 2006; Carcia et al., 2010; Cassel et al., 2018; Chazan, 1998; Cheng, Zhang & Cai, 2016; Chester et al., 2008; Chimenti et al., 2016; Chimenti et al., 2017; Chimenti et al., 2020; Cook, Khan & Purdam, 2002; Coombes et al., 2018; Courville, Coe & Hecht, 2009; Creaby et al., 2017; Crill, Berlet & Hyer, 2014; De Jonge et al., 2011; De Marchi et al., 2018; Den Hartog, 2009; Divani et al., 2010; Docking et al., 2015; Duthon et al., 2011; Ebbesen et al., 2018; Eckenrode, Kietrys & Stackhouse, 2019; Feilmeier, 2017; Finnamore et al., 2019; Florit et al., 2019; Fredericson, 1996; Furia & Rompe, 2007; Gärdin et al., 2016; Gatz et al., 2020; Habets et al., 2017; Hasani et al., 2020; Hernández-Sánchez et al., 2018; Holmes & Lin, 2006; Horn & McCollum, 2015; Hu & Flemister, 2008; Hutchison et al., 2011; Irwin, 2010; Järvinen et al., 2001; Jayaseelan, Weber & Jonely, 2019; Jewson et al., 2017; Jowett, Richmond & Bedi, 2018; Jukes, Scott & Solan, 2020; Kader et al., 2002; Karjalainen et al., 2000; Khan et al., 2003; Knobloch, 2007; Knobloch et al., 2007; Knobloch et al., 2008; Kragsnaes et al., 2014; Krogh et al., 2016; Lakshmanan & O’Doherty, 2004; Leung & Griffith, 2008; Lohrer & Nauck, 2009; Longo et al., 2009; Longo, Ronga & Maffulli, 2009; Maffulli, Giai Via & Oliva, 2015; Maffulli, Giuseppe Longo & Denaro, 2012; Maffulli & Kader, 2002; Maffulli et al., 2003; Maffulli et al., 2011; Maffulli et al., 2020; Maffulli et al., 2012; Maffulli et al., 2008; Maffulli et al., 2019; Maffulli, Sharma & Luscombe, 2004; Maffulli, Via & Oliva, 2014; Maffulli et al., 2008; Mafi, Lorentzon & Alfredson, 2001; Magnussen, Dunn & Thomson, 2009; Mansur et al., 2019; Mansur et al., 2017; Mantovani et al., 2020; Martin et al., 2018; Mayer et al., 2007; McCormack et al., 2015; McShane, Ostick & McCabe, 2007; Murawski et al., 2014; Nadeau et al., 2016; Neeter et al., 2003; Nichols, 1989; De Mesquita et al., 2018; O’Neill et al., 2019; Oloff et al., 2015; Ooi et al., 2015; Paavola et al., 2002; Paavola et al., 2002; Paavola et al., 2000; Paoloni et al., 2004; Papa, 2012; Pedowitz & Beck, 2017; Petersen, Welp & Rosenbaum, 2007; Pingel et al., 2013; Post et al., 2020; Praet et al., 2018; Rabello et al., 2020; Rasmussen et al., 2008; Reid et al., 2012; Reiter et al., 2004; Romero-Morales et al., 2019a; Rompe, Furia & Maffulli, 2009; Rompe et al., 2008; Rompe et al., 2007; Roos et al., 2004; Ryan et al., 2009; Saini et al., 2015; Santamato et al., 2019; Sayana & Maffulli, 2007; Scholes et al., 2018; Scott, Huisman & Khan, 2011; Sengkerij et al., 2009; Sharma & Maffulli, 2006; Silbernagel et al., 2007; Silbernagel et al., 2001; Simpson & Howard, 2009; Solomons et al., 2020; Sorosky et al., 2004; Stenson et al., 2018; Stergioulas et al., 2008; Syvertson et al., 2017; Tan & Chan, 2008; Thomas et al., 2010; Turner et al., 2020; Vallance et al., 2020; Van der Vlist et al., 2020; Van der Vlist et al., 2020; Van Sterkenburg et al., 2011; Verrall, Schofield & Brustad, 2011; Von Wehren et al., 2019; Wang et al., 2012; Wei et al., 2017; Welsh & Clodman, 1980; Xu et al., 2019; Zellers et al., 2019; Zhang et al., 2017; Zhang et al., 2020; Zhuang et al., 2019; Romero-Morales et al., 2019b) were included in this scoping review.

Characteristics of sources of evidence

In grouping the included articles by publication type, narrative reviews were the most common (27.2%) followed by cohort studies (19.6%), case control studies (18.8%), randomised controlled trials (12.7%), cross-sectional studies (10.8%), case reports (3.8%), protocols (3.2%), systematic reviews (1.9%), clinical guidelines (1.9%) and one consensus statement (0.6%). The years of publication of included studies ranged from 1980 to 2021, with 2017 to 2020 producing the most publications. Table 3 provides the general characteristics of the reviewed studies, including year of publication, type of publication, terminology and tendinopathy location.

As highlighted in Fig. 3, the terminology used to describe tendon pain varied, with ‘tendinopathy’ being the most prevalent term used to describe tendon pain. Thus, during this scoping review, tendinopathy, will be used to describe pain located in the Achilles tendon that impairs function.

Results of individual sources of evidence

Outcome measures

Within the 159 included articles there were 42 different outcome measures in the clinical diagnosis of Achilles tendinopathy, with 49 studies (Millar et al., 2021; Reiman et al., 2014; Aldridge, 2004; Alfredson & Cook, 2007; Aronow, 2005; Barge-Caballero et al., 2008; Baskerville et al., 2018; Benazzo, Todesca & Ceciliani, 1997; Bhatty, Khan & Zubairy, 2019; Bjordal, Lopes-Martins & Iversen, 2006; Cassel et al., 2018; Chazan, 1998; Chimenti et al., 2017; Courville, Coe & Hecht, 2009; De Jonge et al., 2011; Den Hartog, 2009; Docking et al., 2015; Florit et al., 2019; Fredericson, 1996; Furia & Rompe, 2007; Holmes & Lin, 2006; Horn & McCollum, 2015; Irwin, 2010; Järvinen et al., 2001; Jukes, Scott & Solan, 2020; Kader et al., 2002; Knobloch et al., 2008; Maffulli, Giai Via & Oliva, 2015; Maffulli & Kader, 2002; Maffulli et al., 2003; Maffulli et al., 2011; Maffulli et al., 2020; Maffulli et al., 2012; Maffulli, Sharma & Luscombe, 2004; Maffulli, Via & Oliva, 2014; McShane, Ostick & McCabe, 2007; Nichols, 1989; Paavola et al., 2002; Paavola et al., 2002; Pedowitz & Beck, 2017; Ryan et al., 2009; Saini et al., 2015; Sharma & Maffulli, 2006; Simpson & Howard, 2009; Sorosky et al., 2004; Thomas et al., 2010; Welsh & Clodman, 1980; Xu et al., 2019; Zhang et al., 2017) not reporting any outcome measures. Of the 110 included studies to report on outcome measures (Hutchison et al., 2013; Abate & Salini, 2019; Aiyegbusi, Tella & Sanusi, 2020; Alfredson, 2003; Alfredson & Spang, 2018; Asplund & Best, 2013; Azevedo et al., 2009; Bains & Porter, 2006; Barker-Davies et al., 2017; Benito, 2016; Boesen et al., 2017; Borda & Selhorst, 2017; Brown et al., 2006; Carcia et al., 2010; Cheng, Zhang & Cai, 2016; Chester et al., 2008; Chimenti et al., 2016; Chimenti et al., 2020; Cook, Khan & Purdam, 2002; Coombes et al., 2018; Creaby et al., 2017; Crill, Berlet & Hyer, 2014; De Marchi et al., 2018; Divani et al., 2010; Duthon et al., 2011; Ebbesen et al., 2018; Eckenrode, Kietrys & Stackhouse, 2019; Feilmeier, 2017; Finnamore et al., 2019; Gärdin et al., 2016; Gatz et al., 2020; Habets et al., 2017; Hasani et al., 2020; Hernández-Sánchez et al., 2018; Hu & Flemister, 2008; Hutchison et al., 2011; Jayaseelan, Weber & Jonely, 2019; Jewson et al., 2017; Jowett, Richmond & Bedi, 2018; Karjalainen et al., 2000; Khan et al., 2003; Knobloch, 2007; Knobloch et al., 2007; Kragsnaes et al., 2014; Krogh et al., 2016; Lakshmanan & O’Doherty, 2004; Leung & Griffith, 2008; Lohrer & Nauck, 2009; Longo et al., 2009; Longo, Ronga & Maffulli, 2009; Maffulli, Giuseppe Longo & Denaro, 2012; Maffulli et al., 2008; Maffulli et al., 2019; Maffulli et al., 2008; Mafi, Lorentzon & Alfredson, 2001; Magnussen, Dunn & Thomson, 2009; Mansur et al., 2019; Mansur et al., 2017; Mantovani et al., 2020; Martin et al., 2018; Mayer et al., 2007; McCormack et al., 2015; Murawski et al., 2014; Nadeau et al., 2016; Neeter et al., 2003; De Mesquita et al., 2018; O’Neill et al., 2019; Oloff et al., 2015; Ooi et al., 2015; Paavola et al., 2000; Paoloni et al., 2004; Papa, 2012; Petersen, Welp & Rosenbaum, 2007; Pingel et al., 2013; Post et al., 2020; Praet et al., 2018; Rabello et al., 2020; Rasmussen et al., 2008; Reid et al., 2012; Reiter et al., 2004; Romero-Morales et al., 2019a; Rompe, Furia & Maffulli, 2009; Rompe et al., 2008; Rompe et al., 2007; Roos et al., 2004; Santamato et al., 2019; Sayana & Maffulli, 2007; Scholes et al., 2018; Scott, Huisman & Khan, 2011; Sengkerij et al., 2009; Silbernagel et al., 2007; Silbernagel et al., 2001; Solomons et al., 2020; Stenson et al., 2018; Stergioulas et al., 2008; Syvertson et al., 2017; Tan & Chan, 2008; Turner et al., 2020; Vallance et al., 2020; Van der Vlist et al., 2020; Van der Vlist et al., 2020; Van Sterkenburg et al., 2011; Verrall, Schofield & Brustad, 2011; Von Wehren et al., 2019; Wang et al., 2012; Wei et al., 2017; Zellers et al., 2019; Zhang et al., 2020; Zhuang et al., 2019; Romero-Morales et al., 2019b), 42 different outcome measures were utilised. Disability was the most commonly measured outcome, with 28 different outcome measures for disability being applied 135 times (Fig. 4). The most common outcome measure for disability was the VISA-A questionnaire, being used in 75% of the studies reporting outcome meaures (Abate & Salini, 2019; Aiyegbusi, Tella & Sanusi, 2020; Alfredson & Spang, 2018; Asplund & Best, 2013; Bains & Porter, 2006; Barker-Davies et al., 2017; Benito, 2016; Boesen et al., 2017; Brown et al., 2006; Carcia et al., 2010; Cheng, Zhang & Cai, 2016; Chimenti et al., 2016; Chimenti et al., 2020; Cook, Khan & Purdam, 2002; Coombes et al., 2018; Creaby et al., 2017; Divani et al., 2010; Ebbesen et al., 2018; Eckenrode, Kietrys & Stackhouse, 2019; Feilmeier, 2017; Finnamore et al., 2019; Gärdin et al., 2016; Gatz et al., 2020; Habets et al., 2017; Hasani et al., 2020; Hernández-Sánchez et al., 2018; Hutchison et al., 2011; Jayaseelan, Weber & Jonely, 2019; Jewson et al., 2017; Jowett, Richmond & Bedi, 2018; Khan et al., 2003; Kragsnaes et al., 2014; Krogh et al., 2016; Lakshmanan & O’Doherty, 2004; Leung & Griffith, 2008; Lohrer & Nauck, 2009; Longo et al., 2009; Longo, Ronga & Maffulli, 2009; Maffulli, Giuseppe Longo & Denaro, 2012; Maffulli et al., 2008; Maffulli et al., 2019; Maffulli et al., 2008; Magnussen, Dunn & Thomson, 2009; Mansur et al., 2019; Mansur et al., 2017; Mantovani et al., 2020; Martin et al., 2018; McCormack et al., 2015; Nadeau et al., 2016; De Mesquita et al., 2018; O’Neill et al., 2019; Oloff et al., 2015; Ooi et al., 2015; Pingel et al., 2013; Praet et al., 2018; Rabello et al., 2020; Reid et al., 2012; Reiter et al., 2004; Romero-Morales et al., 2019a; Rompe, Furia & Maffulli, 2009; Rompe et al., 2008; Rompe et al., 2007; Santamato et al., 2019; Sayana & Maffulli, 2007; Scholes et al., 2018; Scott, Huisman & Khan, 2011; Sengkerij et al., 2009; Silbernagel et al., 2007; Solomons et al., 2020; Syvertson et al., 2017; Tan & Chan, 2008; Turner et al., 2020; Vallance et al., 2020; Van der Vlist et al., 2020; Van der Vlist et al., 2020; Van Sterkenburg et al., 2011; Von Wehren et al., 2019; Wang et al., 2012; Wei et al., 2017; Zellers et al., 2019; Zhang et al., 2020; Romero-Morales et al., 2019b). Following, disability, the second most common outcome measure was pain with the VAS (Hutchison et al., 2013; Alfredson, 2003; Alfredson & Spang, 2018; Barker-Davies et al., 2017; Boesen et al., 2017; Chester et al., 2008; Ebbesen et al., 2018; Habets et al., 2017; Hutchison et al., 2011; Knobloch, 2007; Knobloch et al., 2007; Maffulli et al., 2019; Mafi, Lorentzon & Alfredson, 2001; Magnussen, Dunn & Thomson, 2009; Mansur et al., 2019; Mansur et al., 2017; Petersen, Welp & Rosenbaum, 2007; Rasmussen et al., 2008; Reid et al., 2012; Romero-Morales et al., 2019a; Santamato et al., 2019; Scott, Huisman & Khan, 2011; Silbernagel et al., 2001; Stenson et al., 2018; Stergioulas et al., 2008; Turner et al., 2020; Van der Vlist et al., 2020; Van Sterkenburg et al., 2011; Verrall, Schofield & Brustad, 2011; Wei et al., 2017; Zhang et al., 2020; Zhuang et al., 2019; Romero-Morales et al., 2019b) being used in 30% of studies reporting outcome measures and numerical pain rating scale (NPRS) (Borda & Selhorst, 2017; Brown et al., 2006; Chimenti et al., 2016; Chimenti et al., 2020; Coombes et al., 2018; Hasani et al., 2020; Jayaseelan, Weber & Jonely, 2019; Krogh et al., 2016; Mantovani et al., 2020; O’Neill et al., 2019; Paoloni et al., 2004; Papa, 2012; Post et al., 2020; Rompe, Furia & Maffulli, 2009; Rompe et al., 2008; Rompe et al., 2007; Syvertson et al., 2017; Vallance et al., 2020) being used in 17% of studies reporting outcome measures. Outcome measures related to quality of life were utilised within 12 studies, with the most common outcome measures used being the 12-Item Short Form Survey (SF-12) (Duthon et al., 2011; Habets et al., 2017; Mansur et al., 2017; Murawski et al., 2014; Stenson et al., 2018), EuroQol 5 Dimension 5 Level Questionnaire (EQ-5D-5L) (Chester et al., 2008; De Marchi et al., 2018; Habets et al., 2017; Hasani et al., 2020) and 36-Item Short Form Survey (SF-36) (Hutchison et al., 2011; Maffulli et al., 2019; Petersen, Welp & Rosenbaum, 2007). Similarly, psychosocial outcomes were poorly measured, being utilised on 11 occasions, with the most common outcome measures being the Pain Catastrophizing Scale (PCS) (Chimenti et al., 2020; Eckenrode, Kietrys & Stackhouse, 2019; Hasani et al., 2020; Post et al., 2020; Vallance et al., 2020), Tampa Kinesiophobia Scale (TKS) (Chimenti et al., 2020; Hasani et al., 2020; Post et al., 2020; Vallance et al., 2020), Pain Disability Index (PDI) (Mayer et al., 2007; Scott, Huisman & Khan, 2011) and Pain Efficacy Scale (PES) (Mayer et al., 2007; Scott, Huisman & Khan, 2011).

Overview

The clinical diagnosis of tendinopathy is commonly determined via both patient history and clinical tests (Cook et al., 2016; Coombes, Bisset & Vicenzino, 2015; Lewis, 2016; Lewis et al., 2015; Maffulli, Khan & Puddu, 1998; Malliaras et al., 2015; Scott et al., 2013). However, with no consensus on gold standard clinical tests with which to diagnose tendinopathy (Docking, Ooi & Connell, 2015), many research studies utilise a variety of measures to diagnose Achilles tendinopathy (Hutchison et al., 2013). The primary aim of this scoping review was to provide a method for clinically diagnosing Achilles tendinopathy that aligns with the nine core health domains. In order to achieve this, specific objectives were determined that included identifying the most common clinical tests used to diagnose Achilles tendinopathy, identifying the most common outcome measures used to assess Achilles tendinopathy, and summarising the studies to date. This will allow for greater consistency in both research and clinical settings. Additionally, this review aimed to identify the both the areas of strength and weakness

Terminology

As highlighted in Fig. 3, ‘Tendinopathy’ was the most commonly term used to describe persistent Achilles tendon pain, particularly in more recent studies. This scoping review aligns with the previous consensus statements advocating the consistent use of the term tendinopathy to describe persistent Achilles tendon pain and associated loss of function in relation to mechanical loading (Scott et al., 2020). There was a noticeable reduction of the use of alternative terms such as tendinitis and tendinosis, particularly since 2018, indicating progression towards unifying the terminology used to describe the clinical condition of persistent pain and dysfunction in the Achilles tendon that is associated with mechanical loading.

A difficulty identified in this scoping review was the inclusion of symptom duration as a measure to diagnose Achilles tendinopathy (Tables 6, 7, 8 and 9). When used as a measure, duration of symptoms varied significantly from four weeks up to 12 months, making identifying a consistent duration of symptoms to diagnose Achilles tendinopathy difficult and potentially contributing to the different terminology used within research and clinical practice. The term tendinitis indicates an inflammatory condition of the Achilles tendon that may develop symptoms in a shorter duration of time, whereas tendinosis indicates a change in tendon structure that would require a longer duration of time for symptoms to develop (Scott et al., 2020). Additionally, the clinical condition of Achilles tendinopathy does not display the characteristics of an inflammatory response such as with tissue tearing (Cook et al., 2016), and the structural changes, as those expected in tendinosis, are not required to be present for pain or dysfunction to develop (Cook et al., 2016).

The nine core health domains of tendinopathy

Vicenzino et al. (2020) reported that the lack of agreed upon tendon health related domains impedes the progress of tendinopathy research. The nine identified domains (patient rating of overall condition, pain on activity or loading, participation, function, psychological factors, disability, physical function capacity, quality of life, and pain over a specified timeframe) should allow for greater consistency in the reporting of tendon research (Vicenzino et al., 2020). This scoping review further highlights the inconsistency in the methods used to diagnose and assess Achilles tendinopathy. There was variation in the methodology used to clinically diagnose and assess Achilles tendinopathy for all key themes; subjective history, clinical tests and outcome measures.

Subjective history

Multiple measures were identified to determine a diagnosis of Achilles tendinopathy from the subjective interview (Tables 4, 5, 6, 7, 8, 9, 10, 11 and 12). The most commonly used measure was self-reported location of pain, with midportion Achilles tendinopathy most commonly being defined as an area located 2–6 cm above the calcaneal insertion of the Achilles tendon. Insertional tendinopathy was most commonly defined as the distal 2 cm of the Achilles tendon. Additional measures included pain with tendon loading activity, duration of symptoms, and tendon stiffness following tendon loading or at a particular time of the day (i.e. morning stiffness). Interestingly, while a change in Achilles tendon loading activity (both an increase and decrease) is considered a catalyst for Achilles tendinopathy (Cook et al., 2016), it was only utilised as a specific criterion in nine of the included studies (Bains & Porter, 2006; Barker-Davies et al., 2017; Cook, Khan & Purdam, 2002; Courville, Coe & Hecht, 2009; Feilmeier, 2017; Maffulli et al., 2012; Nichols, 1989; Simpson & Howard, 2009; Sorosky et al., 2004).

Objective clinical tests

As with subjective history, numerous clinical tests were identified to diagnose Achilles tendinopathy (Tables 4, 5, 6, 7, 8, 9, 10, 11 and 12). The most commonly identified clinical test for Achilles tendinopathy was tendon palpation (including pain on palpation, localised tendon thickening or localised swelling). Although, palpation is commonly used to identify the region of pain and is a common clinical measure used to diagnose Achilles tendinopathy (Hutchison et al., 2013; Reiman et al., 2014; Maffulli et al., 2003; Martin et al., 2018), studies reported multiple regions of interest for midportion Achilles tendinopathy. Painful regions were described as the ‘midportion’, ‘middle third’, 2 to 4, 2 to 5, 2 to 6, 2 to 7, 4 to 6 and 4 to 7 cm above the calcaneal insertion. Similarly, the region of interest in insertional Achilles tendinopathy was described as the ‘insertion’, calcaneal tuberosity, distal 2 cm, and distal 5 cm.

While there was consistency in the included studies in their use of palpation as a clinical test, there is significant variation in the additional clinical tests used to confirm a diagnosis of Achilles tendinopathy (Tables 4, 5, 6, 7, 8, 9, 10, 11 and 12). Further clinical tests used to assess Achilles tendinopathy included tendon pain during loading activities (single-leg heel raises and hopping). The most frequently used clinical, tendinopathy specific tests, were the Royal London Hospital Test and the Painful Arc Sign. The Royal London Hospital Test is considered positive when the is a reduction in palpable Achilles tendon pain on ankle dorsiflexion (Maffulli et al., 2003). The Painful Arc Sign is considered positive when the area of swelling identified with palpation moves with active ankle plantarflexion and dorsiflexion (Maffulli et al., 2003).

Outcome measures

As was the case for the clinical features, there were significant variations in the outcome measures utilised for making a diagnosis of Achilles tendinopathy (Fig. 4). While overall disability and participant perceived pain were commonly measured, the impact of Achilles tendinopathy on quality of life and psychological factors were rarely measured. Psychological factors such as pain efficacy, catastrophisation and kinesiophobia scales were identified as important outcome measures in the diagnosis tendinopathy (Vicenzino et al., 2020), which aligns with the identified psychological outcome measures (PES, TKS and PCS). Similarly, disability measures that combine patient rated pain and function in relation to tendon-specific activities were identified as integral to monitoring tendinopathy outcomes. This scoping review identified the VISA-A questionnaire as the most commonly used outcome measure to monitor Achilles tendinopathy. In addition to psychological factors and disability, overall quality of life was identified as a core health domain in tendinopathy (Vicenzino et al., 2020). The scoping review identified three different outcome measures (SF-12, SF-36 and EQ-5D-5L) that were utilised to assess participant quality of life.

An example evidence-based method for clinically diagnosing Achilles tendinopathy

While there was significant variation in the methods used to diagnose Achilles tendinopathy, some common themes can be identified. When considering a consistent method for diagnosing and assessing Achilles tendinopathy, it is important to ensure research follows consensus recommendations on both terminology used and reporting outcomes (Scott et al., 2020; Vicenzino et al., 2020). Thus, Table 13 provides an amalgamation of the common features used to diagnose Achilles tendinopathy identified in the scoping review and the previously identified nine core health domains for tendinopathy (Vicenzino et al., 2020). While the VISA-A is Achilles tendon specific, any validated and reliable pain questionnaire and quality of life questionnaire may be used in place of the Pain Catastrophising Scale and SF-12.

Limitations

This review was limited to publications in English, which may have excluded key studies published in other languages. Additionally, the screening, inclusion, exclusion and data extraction was performed by one reviewer (WM), which decreases the probability all relevant studies were identified for review and could lead to reviewer bias. The methodological quality of the studies was not assessed as per guidelines for completing scoping reviews (Peters et al., 2020; Arksey & O’Malley, 2005), meaning studies of poor design are given equal weighting to those of better quality, however, the descriptive nature of the scoping review limits the potential impact of individual studies’ methodological quality on results. The aim of a scoping review is to provide an overview of all literature within a field of evidence (Pham et al., 2014), and while there is no specific requirement for methodological quality appraisal, assessing individual literature methodological quality utilising a standardised tool may help authors identify gaps in the literature related to low quality research in addition to lack of research.