Canadian paraplegic athlete and humanitarian Rick Hansen begins his circumnavigation of the globe in a wheelchair in the name of spinal cord injury medical research.

Paraplegia, or paraparesis, is an impairment in motor or sensory function of the lower extremities. The word comes from Ionic Greek (παραπληγίη) "half-stricken". It is usually caused by spinal cord injury or a congenital condition that affects the neural (brain) elements of the spinal canal. The area of the spinal canal that is affected in paraplegia is either the thoracic, lumbar, or sacral regions. If four limbs are affected by paralysis, tetraplegia or quadriplegia is the correct term. If only one limb is affected, the correct term is monoplegia. Spastic paraplegia is a form of paraplegia defined by spasticity of the affected muscles, rather than flaccid paralysis.

Richard Marvin Hansen is a Canadian track and field athlete, activist, and philanthropist for people with disabilities. When Rick was 15, he was riding in the back of a pickup truck after a fishing trip with his friend, when the driver lost control and the vehicle rolled over. Hansen was trapped on the inside of the roll and thrown to the ground, along with the equipment from the truck. As a result of the crash, Hansen broke his back, sustained a spinal cord injury and became paralyzed from the waist down.

Circumnavigation is the complete navigation around an entire island, continent, or astronomical body. This article focuses on the circumnavigation of Earth.

The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal cord is hollow and contains a structure called the central canal, which contains cerebrospinal fluid. The spinal cord is also covered by meninges and enclosed by the neural arches. Together, the brain and spinal cord make up the central nervous system.