Meeting Abstract

P3.133  Thursday, Jan. 6  Variations in tendon material properties among muscles MATSON, A.P.*; KONOW, P.; KONOW, N.; ROBERTS, T.J.; Brown University; Brown University; Brown University; Brown University Andrew_Matson@Brown.edu

A tendon’s stiffness affects its ability store elastic energy, provide mechanical feedback, and amplify or attenuate muscle power. Variation in elastic modulus (material stiffness) among different tendons could provide a mechanism to tune tendon properties to function, but it is unclear whether significant variation in vertebrate tendon properties is common. We studied tendons of 10 different leg muscles in Eastern wild turkeys to determine if elastic modulus varied among muscles. A dual-mode servomotor was used to measure tendon force during quasi-static lengthening, and stiffness was measured as the slope of the linear region of the stress-strain curve. Tendon cross-sectional area was calculated from tendon length and mass, assuming a density of 1.12 g/cm3. Average elastic modulus values for individual tendons ranged from 118 ± 73 to 1352 ± 220 MPa (N=6 animals). The two most compliant tendons belonged to the medial gastrocnemius (MG) and tibialis anterior (TA) muscles, with elastic modulus values of 118 ± 73 MPa and 137 ± 108 MPa, respectively. The next closest modulus value, for the extensor digitorum longus (EDL), was 692 ± 121 MPa. The seven other tendons studied were stiffer, with elastic modulus values exceeding 1 GPa. These stiff tendons were all associated with toe flexor muscles, and involved long free tendons that span multiple joints, while the three most compliant tendons all span a shorter total distance. Our results indicate that there may be considerable variation in the elastic modulus among different muscles. This variability in tendon material properties may accommodate different functions, and it should be taken into account when modeling the biomechanical behavior of muscle-tendon units. Supported by NIH #AR055295.