strength abilities.  Because we find that the administrative law judge (ALJ) misapplied the Secretary's new Medical-Vocational Guidelines in his decision, we vacate the Secretary's determination and remand to the Secretary for further proceedings and findings.


2
Roger Gagnon, who was born in 1926, suffered amputation of his right leg, below the knee, after a train accident when he was two years old.  Through the use of a prosthesis, Gagnon was able to stand and walk adequately for most of his life.  Although he earned a college degree in pharmacy, he never worked in this field.  Instead, he spent some 21 years in the construction industry as a member of a team of workers operating a pile driver, equipment used to place the foundations of large buildings. Gagnon testified at the administrative hearing that, while this was "very heavy" and "exceedingly dangerous" work involving the lifting of heavy weights, he was able to sit frequently while the machines were in operation.  For this reason and because he "was brought up ... in the construction business," he found this work easier than pharmacy, in which "I was on my leg constantly."


3
In September 1978 at the age of 52, Gagnon applied for disability benefits.  He complained that he was unable to return to his construction job or to do any other work because his amputated leg was infected and because he found it difficult to use his prosthesis.  He further claimed that he was prevented from working because of back pain caused by