Study Design: Prospective single-center randomized clinical trial.Objectives: To evaluate the effects of progressive resistance training (RT) alone and in combination with focused extracorporeal shockwave therapy (ESWT) on tendon macromorphology measured by ultrasound (US) and micromorphology using Spatial Frequency Analysis (SFA) in chronic midportion Achilles tendinopathy (AT).Background: RT is the cornerstone of AT management, while ESWT is frequently applied as an adjunct.Both interventions are clinically effective, yet their influence on tendon micromorphology in vivo remains insufficiently characterized.Methods: 41 participants with unilateral chronic midportion AT were randomized to either RT alone or RT + ESWT.Both groups performed a 12-week progressive loading program; the combined group additionally received four ESWT sessions.Examinations were performed at baseline, weeks 6, 12, and 26 to assess tendon thickness (TD), cross-sectional area (CSA), and micromorphological parameters (PSFR, P6, Q6, PPP, SUM).Pain (NRS) and function (VISA-A) were evaluated concurrently.Contralateral asymptomatic tendons served as referenced values.Results: Both groups showed significant pain reduction and VISA-A improvement (p < 0.001).Macromorphological parameters changed minimally; a significant CSA reduction occurred only at week 26 in the RT + ESWT group (p = 0.031).SFA revealed progressive micromorphological remodeling with decreased P6 and SUM and increased PPP and Q6, consistent with improved collagen organization and tissue homogeneity.These changes appeared with greater magnitude in the combined group.
Katolický et al. (Wed,) studied this question.