Final answer:
The femur was loaded in the elastic region of the stress-strain curve, which allows it to return to its original dimensions upon removing the load.
Step-by-step explanation:
When the bending load is removed from the femur, and it returns to its original dimensions, this indicates that the femur was loaded within the elastic region of the stress-strain relationship curve. Within this region, including both the linear portion where Hooke's law is applicable and the non-linear elastic region that still allows for return to original shape upon unloading, the material's deformation is temporary, and it returns to zero when the force is removed. Beyond the elasticity limit, into the plastic region, permanent deformation occurs, and the material will not recover its initial dimensions once the load is removed.