ARCADIA, Calif., April 14 — He wants it to be about the horse, about how this chestnut that is snatching the carrot from his hand has become a favorite to win the Kentucky Derby. Instead, Dan Hendricks knows that every morning until the first Saturday in May, when reporters come calling, it is going to be about the wheelchair.

Monica Almeida/The New York Times
Dan Hendricks and his assistant, Francisco Alvarado, with Brother Derek. "I think I know what he is capable of, and I'm looking forward to seeing him do it," Hendricks said of the colt, who has won four races in a row.
It is a six-wheeler with a motor that zips him through the soft dirt of the backside and into the shedrow of his barn here at Santa Anita Race Track. Hendricks has used the chair, and loathed it, since July 2004, when he crashed his dirt bike on a groomed motocross course and was paralyzed from the waist down.

He is quick to say that the chair has not affected his horse training. Brother Derek, the colt who has just snatched a $30 glove off his hand, is Exhibit A.

The colt, a son of the little-known sire Benchmark, has won four races in a row. In the last, the Santa Anita Derby on April 8, he powered to a three-and-a-quarter-length victory despite the fact that his jockey, Alex Solis, was holding him back with all his might for the better part of the mile-and-an-eighth race.

Hendricks, 47, listed the trainers in the sport who rarely mounted a track pony, headed by Charlie Whittingham, the Hall of Famer and two-time Kentucky Derby-winning legend. He told of the boyhood years he spent around his grandfather's riding stable near Del Mar Race Track in California and of his 31 years around racehorses.