Mr. Abicca, a 17-year-old from San Diego, is essentially wearing a robot. His bionic suit consists of a pair of mechanical braces wrapped around his legs and electric muscles that do much of the work of walking. It is controlled by a computer on his back and a pair of crutches held in his arms that look like futuristic ski poles.

Since an accident involving earth-moving equipment three years ago that damaged his spinal cord, Mr. Abicca has been unable to walk on his own. The suit, made by a company called Ekso Bionics, is an effort to change that.