Locomotory stresses in the limb bones of two small mammals: the ground squirrel and chipmunk.

摘要: Peak stresses acting in limb bones should increase with increasing size if the forces on direct proportion to animal9s body weight. This is a consequence of scaling bone geometry over wide range mammals. In addition, recent work has shown that material strength similar large and small animals. If assumptions this analysis are correct, animals would have lower safety factor failure than The purpose study was measure peak during locomotion compare results measurements available for larger Locomotory fore hindlimb two rodents, ground squirrel (Spermophilus tridecemlineatus) chipmunk (Tamais striatus), were calculated using force recordings position taken from high speed x-ray cine films. (compressive) act these (−31 −86 MN/m2) magnitude those determined much more proximal hindlimb, humerus femur, found develop −42 significantly distal each limb: radius, ulna tibia (−58 MN/m2). All long both species, except their femora, be loaded principally bending. caudal cortices developed compressive stress, whereas cranial tension. Various features musculo-skeletal organization manner rodents considered explain how different maintain uniform failure.