Changes of Achilles Tendon Size Across Different Running Races: A Preliminary Study

A common form of physical activity is running. However, a large percentage of runners will injure a lower extremity tendon. Ultrasound imaging provides useful insight on tendon health and prevalence of structural changes. Previous research in younger adults has shown the Achilles tendon (AT) thins over the course of a distance run. This suggests that tendon structure may become altered based on the distance and surface of the course. Research studies have also found that a greater than 20% increase in AT thickness from the proximal calcaneous to the thickest portion of the tendon is associated with tendinopathy. PURPOSE: To determine if AT size is affected by the distance and surface of a running course and report on frequency of observed structural tendinopathy. METHODS: Thirty-four senior runners (f = 17, age = 70.9 ± 9.8 years) ran up to three races (5k, 5k trail, 10k) at the Huntsman World Senior Games. Each participant was imaged before and after each race, within 30 minutes of finishing. Panoramic images (pano) of the AT were measured from each imaging session. RESULTS: No statistically significant change was observed in the AT size from before and after each race (Before = 0.43 ± 0.38 cm, After = 0.38 ± 0.33 cm). AT pano (n = 94 tendons measured) was grouped as follows: <20% change (n = 30, 31.9%), <40% change (n = 22, 23.4%), <60% change (n = 19, 20.2%), <80% change (n = 9, 9.6%), ≥ 80% (n = 14, 14.9%). CONCLUSION: Despite no difference in pano before and after a race, a high frequency of participants showed potential structural signs of pathology. As many as 68% of participants could have began or ended a race with possible tendinopathy. As indicated by the >20% increase in tendon AT pano, participants may experience symptoms associated with tendon pathology. More research should be conducted to provide adequate insight on tendon health and increase quality of care among the active older adult population.