TY - JOUR T1 - Variability in forelimb bone strains during non-steady locomotor activities in goats JF - J Exp BiolJ Exp BiolJ Exp Biol Y1 - 2008 A1 - Moreno, C. A. A1 - Main, R. P. A1 - Biewener, A. A. KW - Animals KW - Behavior, Animal KW - Bone and Bones/*physiopathology KW - Compressive Strength KW - Forelimb/*physiopathology KW - Goats/*physiology KW - Motor Activity/*physiology KW - Organ Size KW - Physical Conditioning, Animal KW - Sprains and Strains/*physiopathology KW - Tensile Strength KW - Weight-Bearing AB - The purpose of this study was to investigate the effects of non-steady locomotor activities on load predictability in two goat forelimb bones and to explore the degree to which bone curvature influences load predictability. We measured in vivo bone strains in the radius and metacarpus of juvenile goats performing a variety of natural behaviors in an outdoor arena and compared these strain magnitudes and loading patterns with those measured during steady-state treadmill locomotion. We sought to test two hypotheses: our first hypothesis expects an increase in the variability of strain magnitude and pattern during outdoor non-steady behavior when compared to treadmill locomotion. Our second hypothesis was that the curved radius experiences higher peak strains but less variability during non-steady activities than the straighter metacarpus. We found that unsteady, outdoor locomotion generally caused more variable strain patterns (consistent with the first hypothesis), but not more variable strain magnitudes, than treadmill locomotion in both bones. During outdoor locomotion, higher magnitude strain events in the radius showed more constrained loading patterns than in the metacarpus (consistent with the second hypothesis). In addition to the radius experiencing significantly greater bending strains compared to the straighter metacarpus, these results support the idea of a trade-off between increased predictability of loading pattern and increased bending-induced strain. Strain magnitudes recorded during both outdoor and treadmill locomotion showed a lognormal frequency distribution, but the outdoor bone strain distributions had a greater range because they included high magnitude loading events that did not occur during steady treadmill locomotion. VL - 211 SN - 0022-0949 (Print)0022-0949 (Linking) N1 - Moreno, Carlos AMain, Russell PBiewener, Andrew AengEngland2008/03/18 09:00J Exp Biol. 2008 Apr;211(Pt 7):1148-62. doi: 10.1242/jeb.012419. JO - The Journal of experimental biologyThe Journal of experimental biology ER -