Abstract
Studies have suggested that distance runners have decreased calf muscle-tendon unit (MTU) flexibility, which is related to improved running economy. This study examined the passive elastic properties of the calf MTU of distance runners to test the hypothesis that they have increased passive elastic properties measured in viva. Ten distance runners (aged 18-21 years) and 10 untrained men (aged 23-28 years) were tested. A Kin-Corn® dynamometer stretched the right calf MTU from plantarflexion (PF) to maximal dorsiflexion (DF) at 5°.s -1 (0.087 rad.s -1 ) with minimal surface electromyogram activity in the soleus, gastrocnemius, and tibialis anterior muscles. ANOVA analyses indicated that the maximal DF ROM did not differ between groups, but the maximal passive DF torque (Nm), total absorbed passive elastic energy (area under full stretch curve [°.Nm]) and passive elastic stiffness (Nm.° -1 ) within the last 10° of the stretch were greater for the distance runners when controlled for body mass (P ≤ 0.007). The maximal passive DF torque and the passive elastic stiffness were greater when controlled for PF maximal voluntary isometric contraction torque (P < 0.028). The increased passive resistive properties suggested structural adaptations in the calf MTU, possibly the result of eccentric loading and stretching, which would contribute to improved running economy.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
