## 3 Results
### General Characteristics of the Studies Assessed

Table 1: _Cont._The inclusion criteria varied among the studies, with some studies having strict criteria and others being more generalized. Some participants with a previous PTTD diagnosis or medical history indicating PTTD were included; however, no further examination was undertaken to confirm this [18; 19; 31]. Other participants were included based on signs and symptoms, such as localized oedema, asymmetric acquired flatfoot deformity, and pain [23]. Other papers described a physical examination, some of which provided details of how this was undertaken [17; 20; 22; 24; 25; 28; 29], and others only defining that an examination took place [26; 27; 30]. The tests used within the physical examination were a combination of the tests previously described in this review, as well as other measurements of foot posture and/or localized weakness. In the papers reviewed, none of them provided any detail as to how the results of the tests would aid in classification or to inform the treatment methodology used. [PERSON] et al. indicated that some of the included patients went on to have custom-made shoes or ankle-foot orthoses, but not how these were designed [28]. [PERSON] et al. also described that the included patients went on to have conservative treatment, such as physical therapy, immobilization, or orthotic devices [30]. [PERSON] et al. described that, while the foot is flexible, it can be treated with a corrective orthotic device such as the University of California Biomechanics Laboratory brace, a moulded ankle-foot orthosis, an articulated moulded ankle-foot orthosis, or a Marzano brace. If the deformity is rigid, then the suggested orthosis is something that would accommodate the bony deformity [29]. [PERSON] et al. describe the importance of early detection, so that early conservative treatment such as orthotics and physiotherapy can prevent progression to later stages [20]. Although these papers mention orthotics and physiotherapy and discuss their importance, none of them link the findings of their assessments to specific treatments. The results include several different methods for the assessment and diagnostics of PTTD; these include a variety of physical and imaging assessments, as well as subjective verbal assessments (Table S1: results of the included studies). * Verbal Assessment  
One paper focused on verbal assessment for the diagnosis of PTTD, which could then later warrant further investigation by a clinician to provide a definitive diagnosis. This was the only non-clinician-based assessment found in the search [28]. * Physical assessments  
The physical examinations included as comparisons were the following: posterior tibial oedema sign (PTE) [17; 26], first metatarsal rise (FMR) sign [31], first ray mobility test [22], unipedal standing balance test (USBT) [25], pain on palpation TP tendon [17], weakness with contraction [17], single-heel rise test (SHRT) [17; 21; 25], double-heel rise test (DHRT) [31], and the too-many-toes (TMT) sign [31]. The test which was mentioned the most in the included papers was the SHRT. This was used as a baseline comparison for other tests, such as the USBT, which showed a high success rate compared to controls [25]. One paper looked at the validity of the SHRT, pain on tendon palpation, swelling around the tendon, and pain/weakness with tibialis posterior contraction compared to ultrasound (US) findings. It concluded that the SHRT has good reliability. However, the other tests obtained only moderate reliability. The paper highlighted that, after using clinical findings, a diagnosis can be confirmed with US. However, US and clinical findings on their own are not sufficient [17]. The findings of this paper related to the PTE contradicts the findings of one paper, which found that, compared to magnetic resonance imaging (MRI), PTE had a sensitivity of 86% and a specificity of 100% [26]. Another paper looks at the FMR test, which has been shown to be more reliable than SHRT, DHRT, TMT, MRI, and radiographs, even at early stages.