20.500.12556/RUP-22907 Myotonometric assessment of achilles tendon and gastrocnemius stiffness in recreationally active young adults reliability, impact of sex, and links to linear sprint This study examined the relationship between passive Achilles tendon (AT) and gastrocnemius (GAS) stiffness, measured by myotonometry, and 40-m sprint performance across acceleration and maximal velocity phases, while accounting for sex differences. Twenty-one student athletes (10 males, 11 females) underwent bilateral passive stiffness assessments of the AT and GAS using MyotonPRO, followed by 40-m sprint testing with 10, 20, 30, and 40 m splits. Reliability was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV). Sex differences were examined with independent t-tests. Partial correlations controlling for sex were used to assess associations between passive stiffness and sprint performance. Passive stiffness and sprint variables demonstrated excellent within-session reliability (ICC = 0.95–0.99; CV < 5%). Males showed significantly greater passive GAS stiffness bilaterally (p = 0.006–0.049) and faster sprint times at 30 m (p = 0.040) and 40 m (p < 0.001), while passive AT stiffness did not differ significantly between sexes. Partial correlations indicated that greater passive AT stiffness in both legs was associated with faster sprint times at 10 m (r = -0.46 and -0.58, p = 0.008 and 0.043) and 20 m (r = -0.49 and -0.58, p = 0.008 and 0.029). No associations were observed at 30 m or 40 m, nor between passive GAS stiffness and sprint performance. Myotonometry provides reliable measures of AT and GAS stiffness. Greater passive AT stiffness is associated with faster acceleration sprint performance independent of sex. stiffness muscle tendon sprint togost mišica tetiva sprint true false true Angleški jezik Slovenski jezik Članek v reviji 2026-04-06 18:22:47 2026-04-06 18:22:51 2026-04-07 03:09:47 0000-00-00 00:00:00 2026 0 0 str. 3-8 iss. 2 Vol. 15 2026 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 2026-03-01 796.02 1800-8755 10.26773/mjssm.260901 274287619 https://doi.org./10.26773/mjssm.260901 1 d1cc73d9-31d4-11f1-9e8d-005056ac49c0 https://repozitorij.upr.si/Dokument.php?lang=slv&id=33448 https://www.mjssm.me/?sekcija=article&artid=316 1 d12e741d-31d4-11f1-9e8d-005056ac49c0 https://repozitorij.upr.si/Dokument.php?lang=slv&id=33447 RAZ_Sasek_Matic_2026.pdf RAZ_Sasek_Matic_2026.pdf 1 599161E476A1D546C220084921908D87 0743f4d886b544d144395ddf77303b8f89e6e2f76a026bcab093e58355529839 23eca1ed-31d5-11f1-9e8d-005056ac49c0 https://repozitorij.upr.si/Dokument.php?lang=slv&id=33449 Fakulteta za vede o zdravju 0 0 0