Patterns of movement-evoked pain during tendon loading and stretching tasks in Achilles tendinopathy: A secondary analysis of a randomized controlled trial.

BACKGROUND: This study aimed to characterize movement-evoked pain during tendon loading and stretching tasks in individuals with Achilles tendinopathy, and to examine the association between movement-evoked pain with the Achilles tendinopathy type (insertional and midportion), biomechanical, and psychological variables. METHODS: In this laboratory-based, cross-sectional study, 37 individuals with chronic Achilles tendinopathy participated. Movement-evoked pain intensity (Numeric Rating Scale: 0 to 10) and sagittal-plane ankle biomechanics were collected simultaneously during standing, fast walking, single-leg heel raises, and weight-bearing calf stretch. Description of symptoms, including location of Achilles tendon pain and duration of tendon morning stiffness, as well as pain-related psychological measures, including the Tampa Scale of Kinesiophobia were collected. Linear mixed effects models were built around two paradigms of movement-evoked pain (tendon loading and stretching tasks) with each model anchored with pain at rest. FINDINGS: Movement-evoked pain intensity increased as task demand increased in both models. Lower peak dorsiflexion with walking (ß = -0.187, 95% CI: -0.305, -0.069), higher fear of movement (ß = 0.082, 95% CI: 0.018, 0.145), and longer duration of tendon morning stiffness (ß = 0.183, 95% CI: 0.07, 0.296) were associated with greater pain across tendon loading tasks (R2 = 0.47). Lower peak dorsiflexion with walking (ß = -0.27, 95% CI: -0.41, -0.14), higher dorsiflexion with the calf stretch (ß = 0.095, 95% CI: 0.02, 0.16), and insertional Achilles tendinopathy (ß = -0.93, 95% CI: -1.65, -0.21) were associated with higher pain across tendon stretching tasks (R2 = 0.53). INTERPRETATION: In addition to exercise, the ideal management of Achilles tendinopathy may require adjunct treatments to address the multifactorial aspects of movement-evoked pain.

The effects of pain science education plus exercise on pain and function in chronic Achilles tendinopathy: a blinded, placebo-controlled, explanatory, randomized trial.

ABSTRACT: Exercise is the standard of care for Achilles tendinopathy (AT), but 20% to 50% of patients continue to have pain following rehabilitation. The addition of pain science education (PSE) to an exercise program may enhance clinical outcomes, yet this has not been examined in patients with AT. Furthermore, little is known about how rehabilitation for AT alters the fear of movement and central nervous system nociceptive processing. Participants with chronic AT (N = 66) were randomized to receive education about AT either from a biopsychosocial (PSE) or from a biomedical (pathoanatomical education [PAE]) perspective. Simultaneously, all participants completed an exercise program over 8 weeks. Linear mixed models indicated that there were no differences between groups in (1) movement-evoked pain with both groups achieving a clinically meaningful reduction (mean change [95% CI], PSE: -3.0 [-3.8 to -2.2], PAE = -3.6 [-4.4 to -2.8]) and (2) self-reported function, with neither group achieving a clinically meaningful improvement (Patient-Reported Outcomes Measurement Information System Physical Function-PSE: 1.8 [0.3-3.4], PAE: 2.5 [0.8-4.2]). After rehabilitation, performance-based function improved (number of heel raises: 5.2 [1.6-8.8]), central nervous system nociceptive processing remained the same (conditioned pain modulation: -11.4% [0.2 to -17.3]), and fear of movement decreased (Tampa Scale of Kinesiophobia, TSK-17: -6.5 [-4.4 to -8.6]). Linear regression models indicated that baseline levels of pain and function along with improvements in self-efficacy and knowledge gain were associated with a greater improvement in pain and function, respectively. Thus, acquiring skills for symptom self-management and the process of learning may be more important than the specific educational approach for short-term clinical outcomes in patients with AT.

Reliability and validity of two-dimensional motion capture to assess ankle dorsiflexion motion and heel raise work.

OBJECTIVES: To determine the inter-rater reliability and criterion validity of two-dimensional (2D) measures of ankle function in the sagittal plane for participants with Achilles tendinopathy (AT). DESIGN: Cohort study. SETTING: University Laboratory, Participants, Adults with AT (N = 18, Women: 72.2%, Age = 43.4 ± 15.8 years, BMI = 28.7 ± 8.9 kg/m2) MAIN OUTCOME MEASURES: Reliability and validity were determined with intra-class correlation coefficients (ICC), standard error of the measurement (SEM), minimal detectable change (MDC), and Bland-Altman plots for ankle dorsiflexion and positive work during heel raises. RESULTS: Inter-rater reliability between three raters for all 2D motion analysis tasks was good to excellent (ICC = 0.88 to 0.99). Criterion validity between 2D and 3D motion analyses for all tasks was good to excellent (ICC = 0.76 to 0.98). 2D motion analysis overestimated ankle dorsiflexion motion by 1.0-1.7° (3% of mean sample value) and positive ankle joint work by 76.8 J (9% of mean) compared to 3D motion analysis. CONCLUSION: Although 2D and 3D measures are not interchangeable, the good to excellent reliability and validity of 2D measures in the sagittal plane support the use of video analysis to quantify ankle function for individuals with foot and ankle pain.