A hit-and-run victim who was completely paralysed from the waist down has stood up on his own and taken faltering steps on a treadmill after pioneering treatment.

American Rob Summers, 25, is the first patient to respond to the groundbreaking therapy, which involves many hours of training combined with electrical stimulus.

He said: “This procedure has completely changed my life.”

The treatment, which took 30 years to develop, by-passes the brain and “teaches” the spinal cord to control limbs and body functions independently.

As a result, Mr Summers, who is normally confined to a wheelchair, has been able to push himself up and stand for several minutes without assistance.

With help, he has also made repeated stepping motions on a treadmill and voluntarily moved his hips, knees, ankles and toes. In addition, he has regained some sexual and bladder function.

Scientists described the success, reported in The Lancet medical journal, as “a breakthrough” but cautioned that there was still much more work to be done.

Mr Summers was walking by a road in Portland, Oregon, US, when a car mounted the kerb and smashed into him on July 12, 2006.

Previously an athlete in peak physical condition, he suffered serious spinal cord damage which left him paraplegic.

Five patients in total are taking part in the trial which follows promising results with animals.

A key element of the treatment involves stimulating nerves with a 16-electrode implant inserted into the spinal cord.

The signals mimic those which would normally be transmitted by the brain.

An intensive regime of movement training, delivered with the help of rehabilitation specialists, comprises the other half of the therapy.

Sensory inputs from the legs combined with the electrical stimulation help the spine’s own neural network to reactivate muscles and joints.

Reggie Edgerton, professor at the University of California at Los Angeles, a leading member of the 11-person team of researchers, said: “The spinal cord is smart. The neural networks in the lumbosacral spinal cord are capable of initiating full weight bearing and relatively co-ordinated stepping without any input from the brain. This is possible, in part, due to information that is sent back from the legs directly to the spinal cord.

Colleague professor Susan Harkema, from the Kentucky Spinal Cord Research Centre at the University of Louisville, said: “This is a breakthrough. It opens up a huge opportunity to improve the daily functioning of these individuals, but we have a long road ahead.”

Mr Summers described what it meant to him to gain even inches of ground in his battle with paralysis.

The scientists hope that in future some severely paralysed patients at least will be able to recover enough independent movement to stand, maintain balance and even begin to walk.

However, they acknowledge that the technique is still far from being a practical treatment.

One unanswered question is whether it can help patients even more severely handicapped than Mr Summers.

The research was supported by the Christopher & Dana Reeve Foundation, the charitable organisation founded by the late Superman actor Christopher Reeve and his wife.

Spinal cord anatomy

The spinal cord is connected to the brain and is about the diameter of a human finger. From the brain the spinal cord descends down the middle of the back and is surrounded and protected by the bony vertebral column.

The spinal cord is surrounded by a clear fluid called cerebral spinal fluid, that acts as a cushion to protect the delicate nerve tissues against damage from banging against the inside of the vertebrae.

The anatomy of the spinal cord itself, consists of millions of nerve fibres which transmit electrical information to and from the limbs, trunk and organs of the body, back to and from the brain. The brain and spinal cord are referred to as the central nervous system, whilst the nerves connecting the spinal cord to the body are referred to as the Peripheral Nervous System.

Ascending and descending spinal tracts

The nerves within the spinal cord are grouped together in different bundles called ascending and descending tracts.

Ascending tracts within the spinal cord carry information from the body, upwards to the brain, such as touch, skin temperature, pain and joint position.

Descending tracts within the spinal cord carry information from the brain downwards to initiate movement and control body functions.

Spinal nerves

Nerves called the spinal nerves or nerve roots come off the spinal cord and pass out through a hole in each of the vertebrae called the foramen to carry the information from the spinal cord to the rest of the body, and from the body back up to the brain

There are four main groups of spinal nerves which exit different levels of the spinal cord.

The spinal nerves carry information to and from different levels (segments) in the spinal cord. Both the nerves and the segments in the spinal cord are numbered in a similar way to the vertebrae.

There are 31 pairs of spinal nerves which branch off from the spinal cord. In the cervical region of the spinal cord, the spinal nerves exit above the vertebrae.

The spinal nerves which leave the spinal cord are numbered according to the vertebra at which they exit the spinal column.

The level of the spinal cord segments do not relate exactly to the level of the vertebral bodies.