Diagnosis
Diagnosis of AT
Though several attempts have been made, no classification system has been commonly accepted for use in AT (Puffer & Zachazewski, 1988). Thus, the diagnosis of AT relies on a thorough subjective examination in combination with a physical assessment including palpation and functional movements. A study by Hutchinson et al (2013) featured an assessment of 10 tests for AT (Figure 2.2). These included; subjective self-reported pain, subjective reporting of morning stiffness, tendon thickening, crepitus, palpation, The Royal London test, the arc sign, the stretch of passive dorsiflexion test, single heel raise and hop test. These included 2 subjective measures, 5 palpation tests and 3 tendon loading tests. With ultrasound used as the diagnostic standard in this study, Hutchinson and colleagues (2013) assessed the clinical utility and reproducibility of these test in the diagnosis of AT. The review of clinical tests found that only 2 of the tests were sufficiently valid and reliable for use in a clinical setting, and these were the location of self-reported pain and pain on palpation (Hutchinson et al, 2013). Another study found good overall level of sensitivity for the Royal London Hospital test and the palpation of the painful arc sign (Figure 2.3) (Maffuli et al, 2003). These authors concluded that in a painful tendon where the area of tenderness presents with swelling that moves with the tendon, and whose tenderness decreases in dorsiflexion, a diagnosis of tendinopathy may be appropriate (Maffuli et al, 2003).
Fig 2.2: Overview of tests for AT (Hutchinson et al, 2013)
Fig 2.3: Overview of most clinically relevant Achilles tests (Carcia et al, 2010).
Other subjective symptoms that have been reported as clinical determinants of a diagnosis of tendinopathy include intermittent activity related pain, stiffness upon immobility and increased pain upon recurrence of activity, and stiffness/pain at the commencement of exercise that decreases during exercise only to return shortly after exercise (Carcia et al, 2010). These symptoms are reported across the literature, though there has been very little high quality research published to support their association with AT.
A further systematic review of the diagnosis and assessment of AT found interesting results (Reiman et al, 2014). This review found that some measures that have been used for assessment may be more applicable when used for screening and vice versa. The report found strong specificity for the use of crepitus, the arc sign, the Royal London Hospital (RHL) test, single-legged heel raise and tendon thickening in the assessment of AT. This review also found excellent intra-rater reliability for the RHL test, self-report of pain and morning stiffness, palpation and the arc sign (Reiman et al, 2014). Similar tests showed sufficient to excellent levels of inter-rater reliability, with the exception of the RHL test, which displayed moderate inter-rater reliability. The findings of this systematic review indicated that self-report of pain and morning stiffness are more applicable in the screening process than for diagnosis. Conversely, it was displayed that TA thickening, crepitus and all tendon loading measures are better when used in the diagnostic process than for screening (Reiman et al, 2014).
In order to add to the body of literature and assessment of AT, Sibernagel and colleagues developed a test battery to evaluate if AT caused functional deficits on the injured side compared to the non/less injured side in patients (Sibernagel et al, 2006). The test battery consist of 6 tests, three jump tests (counter movement jumps, drop counter movement jump & hopping), two strength tests (concentric toe-raises & concentric-eccentric toe-raises) as well as toe-raises for endurance. The study found that AT not only presented with pain and AT related symptoms, but also with impairments in lower limb function. The battery was reliable and was able to differentiate between the “most” symptomatic and “least” symptomatic leg in patients with bilateral AT. The tests in the battery were shown to have an excellent level of interrater reliability (ICC 0.76-0.94), with the concentric toe-raise test have fair interrater reliability (0.73). Very good results were also shown for the sensitivity of the tests, with individual sensitivities ranging from 33-48%, but the whole test battery having a sensitivity of 88% (Figure 2.4) (Sibernagel et al, 2006).
Fig 2.4: Sensitivity of Sibernagel functional assessment tests (Sibernagel et al, 2006)
