An exoskeleton structure includes a pelvis assembly, a first lower limb assembly, a second lower limb assembly and a back assembly. The exoskeleton structure includes pivot joints connecting each of the lower limb assemblies and the back assembly to the pelvis assembly and permitting movements of abduction or adduction of the lower limbs of the user, a relative movement of lateral inclination of the spine of the user with respect to the pelvis of the user, and a twisting movement of the spine.