Thijs Maria Anne Ackermans1,2, Gaspar Epro1,3, Christopher McCrum1,2, Kai Daniel Oberländer4, Frank Suhr5, Maarten Robert Drost2, Kenneth Meijer2, Kiros Karamanidis6. 1. Institute of Movement and Sport Gerontology, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany. 2. Department of Human Movement Science, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Universiteitssingel 60, 6229 ER, Maastricht, The Netherlands. 3. Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany. 4. Fresenius University of Applied Sciences, Media School, Im Mediapark 4C, 50670, Cologne, Germany. 5. Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany. 6. Institute of Movement and Sport Gerontology, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany. karamanidis@dshs-koeln.de.
Abstract
PURPOSE: We aimed to determine whether there are different changes in Achilles tendon (AT) mechanical properties in middle-aged, compared to younger runners that might indicate that tendon fatigue, induced by long-distance running, is age-dependent. METHODS: 27 middle-aged (50-67 years) and 22 younger (21-29 years) participants ran a 21 km route at their own pace (mean and SD: old: 3.1 ± 0.3 m s-1; young: 3.6 ± 0.5 m s-1). We tested for changes in the AT force-elongation relationship using dynamometry and ultrasonography during isometric voluntary ankle plantarflexion ramp contractions, conducted 20-28 h pre-run, immediately pre-run, immediately post-run and 20-28 h post-run. Stride frequency and number were examined to estimate cyclic tensile loading characteristics of the tendon during running. RESULTS: Muscle strength decreased significantly (P < 0.05) in both groups immediately post-run (old: 17 %; young: 11 %) and recovered to baseline within 20-28 h post-run. AT stiffness did not change for the younger adults, whereas the middle-aged adults showed a significant (P < 0.05) decrease in AT stiffness (22 %). However, tendon stiffness recovered to baseline 20-28 h post-run. Middle-aged, compared to young adults, demonstrated significantly (P < 0.05) greater stride frequency and number, but no correlations with tendon fatigue changes were determined (R 2 ≤ 0.038). CONCLUSIONS: The results suggest that the plasticity of the AT in response to short-term mechanical loading may be age dependent and that the AT length-tension properties of middle-aged runners may be more vulnerable to change following running compared to younger athletes. However, the observed AT changes in the middle-aged runners dissipated within 20-28 h post-run, suggesting that a tendon viscoelastic recovery mechanism may occur in vivo.
PURPOSE: We aimed to determine whether there are different changes in Achilles tendon (AT) mechanical properties in middle-aged, compared to younger runners that might indicate that tendon fatigue, induced by long-distance running, is age-dependent. METHODS: 27 middle-aged (50-67 years) and 22 younger (21-29 years) participants ran a 21 km route at their own pace (mean and SD: old: 3.1 ± 0.3 m s-1; young: 3.6 ± 0.5 m s-1). We tested for changes in the AT force-elongation relationship using dynamometry and ultrasonography during isometric voluntary ankle plantarflexion ramp contractions, conducted 20-28 h pre-run, immediately pre-run, immediately post-run and 20-28 h post-run. Stride frequency and number were examined to estimate cyclic tensile loading characteristics of the tendon during running. RESULTS: Muscle strength decreased significantly (P < 0.05) in both groups immediately post-run (old: 17 %; young: 11 %) and recovered to baseline within 20-28 h post-run. AT stiffness did not change for the younger adults, whereas the middle-aged adults showed a significant (P < 0.05) decrease in AT stiffness (22 %). However, tendon stiffness recovered to baseline 20-28 h post-run. Middle-aged, compared to young adults, demonstrated significantly (P < 0.05) greater stride frequency and number, but no correlations with tendon fatigue changes were determined (R 2 ≤ 0.038). CONCLUSIONS: The results suggest that the plasticity of the AT in response to short-term mechanical loading may be age dependent and that the AT length-tension properties of middle-aged runners may be more vulnerable to change following running compared to younger athletes. However, the observed AT changes in the middle-aged runners dissipated within 20-28 h post-run, suggesting that a tendon viscoelastic recovery mechanism may occur in vivo.
Authors: Jennifer A Zellers; Daniel H Cortes; Patrick Corrigan; Laura Pontiggia; Karin Grävare Silbernagel Journal: Muscles Ligaments Tendons J Date: 2018-01-10
Authors: D Holzer; G Epro; C McCrum; J Doerner; J A Luetkens; L Scheef; G M Kukuk; H Boecker; A Mierau; G-P Brüggemann; C N Maganaris; K Karamanidis Journal: Eur J Appl Physiol Date: 2018-08-07 Impact factor: 3.078