High-Tech Aid for Motion Problems : Space Technology Adapted to Analyze Walking Disorders
Specialized body sensors and computers are being used at Stanford’s Children’s Hospital to test the muscle functions, gait, sway and energy expenditure of patients with severe motion disorders.
Under the guidance of medical director and surgeon Eugene E. Bleck, who has worked with cerebral palsy victims for 40 years, the motion analysis laboratory performs high-tech tests on people with walking problems to provide objective data to orthopedic specialists.
Bleck said most of the lab’s 500 patients have been children who have incurred some sort of brain damage due to prematurity, head injuries or near drowning. Some sports medicine patients are also tested at the facility.
Same-Day Data
An important aspect of the pioneering program, Bleck said, is that test information is made available the same day, allowing physicians to make immediate decisions on the type of treatment or surgery needed.
Specific analysis of walking problems are made at the lab through the use of technology originally designed by NASA. The equipment helps pinpoint muscles not working properly so they can be surgically lengthened, transferred to another place, or bypassed so that walking is improved.
“The clinical use in patient care is to provide for the first time objective measurements of human motion, particularly walking before intervention of any kind, be it physical therapy, drug therapy or surgery,” Bleck said. “Only in this way can treatment programs be measured as effective or ineffective if they are thought to improve the function of the patient who has a neuromotor handicap of any kind.”
Neil Adler, a physical therapist and assistant director of the lab, said the motion analysis is a way of determining exactly what is going on with a patient’s walk.
“I could watch a patient walk and get a subjective impression based on experience and individual skill,” Adler said. “But having the patient walk with certain instrumentation on, we can get actual joint angles. By defining precisely the way a person walks we can determine how bad they are or how they’ve changed over time.
‘More Scientific’
“It gives us a base line and lets us follow the results of surgery or other treatment. So, it’s much more scientific approach.”
Adler said one test requires taping small surface electrodes to the top of a patient’s leg muscles or inserting tiny flexible wires into the muscles themselves. Each electrode or wire is then connected to a small transmitter and as the patient walks, each muscle contraction sends a radio signal to a bank of recording equipment.
The signals are graphically depicted by a computer. From these data, the timing of the muscles in relation to the gait cycle can be determined.
The laboratory also determines a patient’s limitation of movement using a digital photography system from Sweden called SELSPOT. The test quantifies the angular motion of the body in three-dimensional space.
Balance, or how much sway a patient has, is also assessed at the laboratory by having the subject stand on a pair of metal plates that transmit the forces on them to a computer, which graphically displays the information.
Adler said the testing, which also includes simple measurements of heart rate and walking speed, provides another tool to physicians and orthopedic specialists to supplement the clinical evaluations of a patient.
John Medeiros, lab director and physical therapist, said motion analysis with such sophisticated equipment is a relatively new field that is growing rapidly.
“It’s not used routinely in every case,” he said. “It’s used to tip the balance to make a decision. Our philosophy is that the lab is an objective tool and what we should produce is information, not a consulting opinion. We don’t recommend any specific treatment. The information has to be interpreted by the treating physician.”
