Differences Between Long Distance Road Runners and Trail Runners in Achilles Tendon Structure and Jumping and Balance Performance

Abstract

BackgroundLoad and joint kinematics change with differences in running surface. Running regularly on trails compared to roads might influence the load on the Achilles tendon and its adaptations, along with other factors such as balance, strength, and proprioception.ObjectiveTo investigate Achilles tendon structure and functional tests in road and trail runners.DesignCross‐sectional study.SettingLaboratory, sport sciences college.ParticipantsThe study included 26 road and 17 trail runners who run at least three times per week with a minimum of 20 km per week and who participated in running competitions over the preceding 2 years.MethodsEach participant was examined for Achilles tendon structure (via ultrasound tissue characterization [UTC] imaging) and underwent functional tests in addition to completing a demographic questionnaire.Main Outcome MeasurementsThe percentages of echo types I, II, III, and IV (degree of structural homogeneity) within the tendon, tendon length and width, tendon cross‐sectional area (via UTC imaging); Ankle inversion movement discrimination ability (via Active Movement Extent Discrimination Apparatus device); dynamic postural balance (via Y balance test); jumping performance (by Triple hop distance test); and Hip muscle abduction muscle strength (by hand‐held dynamometry).ResultsPercentage of echo type I was significantly lower while echo type II was higher in the road group compared with the trail group (67.3% type I and 28.9% type II in the road group compared with 74.1% type I and 22.1% type II in the trail group, P < .001). No differences between genders were found and no significant differences between groups were found for the other tests.ConclusionTendon integrity as examined with UTC is different between road and trail runners. This suggests an influence of running surface on Achilles tendon structure. This difference was not reflected in other tests, thus the influence of tendon structure on function needs further examination.

Identifying achilles tendon structure differences by ultrasound tissue characterization in asymptomatic individuals

“…All prior UTC studies have identified that the Achilles tendon consists of predominantly echo‐types I and II and minimal levels of echo‐types III and IV. Several previous studies have shown a reciprocal interplay between Echo‐types I and II 18,22–24 . Dar et al found lower levels of echo‐type I and higher levels of echo‐type II in road runners when compared to trail runner 23 .…”

“…Several previous studies have shown a reciprocal interplay between Echo‐types I and II 18,22–24 . Dar et al found lower levels of echo‐type I and higher levels of echo‐type II in road runners when compared to trail runner 23 . It has yet to be determined whether it is preferential to have higher levels of echo‐type I or II.…”

Lower-Limb Connective Tissue Morphologic Characteristics in Runners. How Do They Relate with Running Biomechanics and Tendon Pathology? A Systematic Review

“…Regarding AT, Wiesinger et al (36) and Kongsgaard et al (37) studied the differences of the AT morphologic characteristics between runners and other sport athletes. Differences in AT morphologic characteristics were also analysed in relation to other aspects: road runners and trail runners (38), running performance (39), leg dominant side (40) and nationality (Kenyan versus Japanese runners) (41). Finally, other subject characteristics such as sex, body mass, height, body mass index and running experience (35,40) were also studied in relation to the AT morphologic characteristics.…”

“…It would be worth analysing whether tendon morphological characteristics is dependent upon training level within the same sport. Other possible influencing factors that were studied but that did not show a significant relationship with the morphological characteristics of the connective tissue were running surface (38), running performance (39) and dominant side (40). The studies that have evaluated these aspects are few, so the scientific evidence is limited.…”