NEW YORK — Dr. Jacquelin Perry, a physician and researcher who shed light on the complexities of walking, and was a leader in treating polio victims in the 1950s and again in the ’80s when the symptoms of some returned, died on March 11 at her home in Downey, Calif. She was 94.
Her death was announced by the Rancho Los Amigos National Rehabilitation Center in Downey, where she worked for more than 60 years.
Dr. Perry earned wide attention for her work in analyzing the human gait, which she broke down into eight motion patterns governed by 28 major muscles in each leg. Her 1992 book, ‘‘Gait Analysis: Normal and Pathological Function,’’ became a standard text for orthopedists, physical therapists, and other rehabilitation professionals.
To break walking, running, stair-climbing, and other human ambulations into discrete components, illustrated with precise photographs, Dr. Perry used ultrasound studies, motion analysis, and electromyography, which traces the nerve pathways through muscle using electric charges.
‘‘The author’s level of expertise and clear, logical presentation make this text a definitive reference,’’ Suzanne R. Babyar wrote in The Journal of Physical Education. A second edition, written with Dr. Judith Burnfield, was published in 2010.
In the mid-1950s, as one of the few women to rise to orthopedic surgeon in the United States, Dr. Perry developed surgical techniques for straightening curved spines and fusing shattered vertebrae.
She collaborated with Dr. Vernon Nickel to come up with a new surgery for paralyzed polio patients after they had emerged from iron lungs. To provide stability for weakened necks, they invented a mechanical device that included a vest and a ring around the patient’s head, called a ‘‘halo.’’ The device immobilized the spine, neck, and head and became widely used in hospitals.
In the 1980s, doctors began seeing former polio patients complaining of extreme fatigue, muscle weakness, debilitating joint pain, breathing difficulty, and intolerance of cold. Dr. Perry was a leader in tracing the symptoms to the overuse of muscles and nerves in combating and recovering from polio. The condition became known as post-polio syndrome.
‘‘The people just push themselves more than most of us,’’ she said in an interview with The New York Times Magazine in 1985. ‘‘They’ve put up with signs of strain to live a normal life. I always say people who had polio are overachievers, because so many of them are out to prove they can do just as well as those who didn’t have it. But now, the strain has accumulated, and tissues are aging prematurely.’’
She traveled the world speaking about the syndrome, offering a simple remedy: rest.
Jacquelin Perry was born in Denver and was raised in Los Angeles. ‘‘I knew at about age 10 I wanted to be a doctor,’’ she said in a speech in 2000. ‘‘I read every medical book in the Los Angeles library.’’
She earned a bachelor’s degree in physical education from the University of California, Los Angeles, in 1940 and then joined the Army and trained to be a physical therapist. The Army assigned her to a hospital in Hot Springs, Ark., where polio patients were treated.
She earned a medical degree from the University of California, San Francisco, in 1950, as one of seven women in her class of 76. After completing her residency , she was recruited by El Rancho to start its physical therapy program for patients with polio and other diseases.
Dr. Perry was an active surgeon until a brain artery blockage forced her to stop operating. She then devoted much of her time to studying the biomechanics of walking. As part of her research, she investigated how muscles and joints behave when spinal-cord injury patients propel themselves in wheelchairs, and how below-the-knee amputees are able to walk with prosthetic feet.
Dr. Perry, who left no immediate survivors, taught at the University of Southern California’s medical school from 1972 to the late 1990s and established a scholarship there for the study of the human gait. She wrote more than 400 peer-reviewed papers and 38 book chapters, in addition to her classic textbook.
Though her advice to post-polio patients was to take it easy, she had little interest in doing the same. She went to work until the week before her death.