Researcher(s)
- Terrence Proctor-Rangel, Medical Diagnostics-Pre Physician Assistant, University of Delaware
Faculty Mentor(s)
- Karin Silbernagel, Physical Therapy, University of Delaware
Abstract
Achilles tendinopathy (AT) is an overuse injury resulting in pain, functional deficits, and altered tendon structure. Ultrasound imaging is commonly used to assess Achilles tendon thickness and echogenicity, but tendon geometry has not been previously assessed. This study aimed to analyze differences in tendon geometry between healthy and injured individuals and relationships with symptom severity.
Individuals with midportion AT with ≥2mm thickening (AT+, n=83, 35M,51.1yrs ± 9.4), ≤2mm thickening (AT, n=95, 42M, 44.2yrs ± 13.91), and individuals without AT (H, n=121, 48M, 32±17.06yrs,) were included.
The most symptomatic side for injured and the dominant side for healthy individuals were assessed. B-mode ultrasound was used to measure cross-sectional area (CSA) at the thickest portion and the degree of thickening (thickest portion – healthy thickness). Tendon geometry was measured as the percent of the centroid’s displacement. The Victorian Institute of Sports Assessment-Achilles, pain on palpation, pain pressure threshold, and heel rise work were also evaluated. Linear Regression Models and one-way ANOVAs were used (α=0.05).
CD percentage differed in the y-axis between the groups (mean±SD,p) (H -0.556±1.529, AT -0.0291±1.64, AT+ -0.0452±1.79, p=0.017) but not in the x-axis. H and AT+ had a significant positive association between their respective x/y-axis displacements (β=0.53, R²=0.515, p<.001), (β=0.52, R²=0.144, p = .004). There was no association between CD and patient reported outcomes or functional performance (p = 0.488-0.943).
CD only differed in the superficial-deep direction between groups and was not associated with patient-reported outcomes or functional performance. A distinct pattern between H and AT+ was observed, with deeper centroids located medially and superficial centroids laterally. These findings provide evidence that tendon geometry differs between injured and healthy tendons.