Meeting Abstract
The bone strain environment in the tibiotarsus (TBT) and hindlimb kinematics were characterized relative to speed for 14 week-old male guinea fowl (n=4) during treadmill running. The animals were surgically instrumented with three rosette strain gauges around the circumference of the bone’s midshaft. In vivo bone strain and 3D kinematic data were collected from the birds while they ran at a range of speeds (0.45-2.68 m/s) on a motorized treadmill. Peak principal strains and their orientation relative to the bone’s long axis were determined for several consecutive strides for each animal across the speed range. Average peak principal strains on the posterior, anterior and medial bone surfaces ranged from -60 με, +123 με, and -96 με at 0.45m/s, respectively, to -151 με, 245 με, and -161 με at 2.68m/s, representing 2.5-, 2-, and 1.6-fold increases in strain across the range of speeds tested. Peak principal strains on the medial surface were oriented farthest from the long axis of the bone at 34 and 38 degrees for 0.45 and 2.68m/s, respectively. Changes in metatarso-phalangeal, ankle, knee, and hip joint angles relative to speed were determined and linked to changes in bone strain with speed. At certain speeds, joint angles and strain patterns for the guinea fowl were compared with previously reported data for emu and chickens. In general, TBT principal strain magnitudes in the guinea fowl were lower on all surfaces than what have previously been measured in the emu TBT and chicken TBT. Despite the difference in magnitude, posterior and medial principal compressive strains in the guinea fowl TBT were oriented similarly to those reported previously in the emu TBT and the chicken TBT while GF anterior principal tensile strains were more closely aligned to the long axis.
