Exploring the clinical presentation of tibialis posterior tendinopathy

Foot pain is a common musculoskeletal complaint, that is associated with significant functional limitations and is often accompanied by systemic co-morbidities. Pain on the medial aspect of the foot and ankle between the medial malleolus and navicular is often diagnosed as dysfunction of the tibialis posterior tendon. Tibialis posterior tendinopathy (TPT) is considered to constitute the early stages of a condition that progresses to an acquired flatfoot deformity. Surgical intervention is recommended when conservative approaches are unsuccessful, with invasive and costly procedures recommended when significant deformity and dysfunction are present. Effective management in the early stages when tendon signs and symptoms predominate is desirable in order to prevent or delay progression of the condition.The overarching objective of this thesis was to inform the future development of targeted interventions for TPT. Specific thesis aims were to systematically synthesise current evidence in relation to terminology, clinical presentation and management of TPT (Part A) and to address current gaps in the literature in relation to diagnosis, and to explore the presentation of TPT using the ICF framework (Part B).The first study is a systematic review of randomised controlled trials investigating the efficacy of exercise management for TPT. Findings highlight the paucity of high-quality research for the conservative management of TPT, the lack of exercise prescription parameters reported in clinical trials and recommended that clinicians be guided by presenting impairments when prescribing exercise for TPT. Study 2 is a comprehensive review of selection criteria used in all primary research papers investigating the condition. The evidence led us to recommend that TPT is the preferred terminology when there are signs of local tendon dysfunction, with pain and/or swelling along the tendon and pain or difficulty with inversion or single leg heel raise the key clinical signs and symptoms.Studies 3 and 4 were systematic reviews and meta-analyses of existing literature. Study 3 quantified differences in clinical impairments, pain and disability between individuals with TPT and controls and investigated the relative magnitude of deficits in muscle function, foot posture and motion, pain and disability. Evidence of impaired tibialis posterior capacity and lower arch height in individuals with TPT was accompanied by self-reported stiffness, difficulties caused by foot problems and social restrictions. While there was strong evidence for lower arch height in TPT, studies stipulated requirements for arch height in TPT and control groups for eligibility and as such further research was warranted. Study 4 investigated kinematic characteristics at the foot and ankle in TPT by comparison to controls and found that individuals with TPT had significantly greater forefoot abduction, calcaneal eversion and lowering of the medial longitudinal arch during the stance phase of gait.Three studies were designed to address the gaps identified in Part A and make a significant and substantial contribution to the current understanding of TPT. In Study 5, the diagnostic utility of the clinical signs identified in Study 1 was evaluated. Participants with medial foot/ankle pain underwent assessment of 4 clinical index tests and ultrasound assessment for the presence of grey scale changes in the tibialis posterior tendon. Overall, the ability of the evaluated clinical tests for TPT to predict grey scale changes in the tibialis posterior tendon on ultrasound was poor. Pain or inability to perform a single leg heel raise had the greatest diagnostic utility to detect grey scale changes.In Study 6, foot posture, mobility and single leg heel raise capacity were investigated in individuals with TPT and compared to individuals with medial foot/ankle pain that was not attributable to TPT and controls. Consistent with the findings from Study 5, the selection criteria for TPT were the presence of medial foot/ankle pain and pain or inability to perform a single leg heel raise. In an attempt to ascertain whether arch height is a key feature of TPT, no selection criteria regarding foot posture were used. This study highlighted that more pronated foot posture, and not arch height, and bilaterally impaired single leg heel raise capacity may be useful in distinguishing TPT from medial foot/ankle pain that is not attributable to TPT. Foot-related function and quality of life were similar for all participants with medial foot/ankle pain and were significantly impaired compared to controls.Study 7 was an investigation of the impact of TPT using the International Classification of Functioning framework in order to address and incorporate impairments, limitations, and restrictions of the condition in order to understand TPT from a biopsychosocial perspective. Impairments were not limited to the symptomatic foot and ankle; bilateral deficits in hip extensor torque and single leg heel raise endurance and limitations ascending and descending stairs were demonstrated in individuals with TPT compared to controls. Clinical impairments were accompanied by poorer self-reported function and quality of life, particularly relating to independent living, mental health and pain. These findings suggest a biopsychosocial approach should be considered for TPT.