|
Many children with cerebral palsy (CP) develop a typical walking pattern that incorporates their disability. They employ the stiffness of the affected leg as a kind of vertical spring, or pogo stick, and the nonaffected leg as a pendulum to propel themselves foward. Although this adaptation allows the child to walk, says Ken Holt, an associate professor of physical therapy and director of the program in movement and rehabilitation sciences at Sargent College, it is not an ideal solution. The combination of asymmetry and increased force on the joints tends to produce serious musculoskeletal injuries over time, further impinging on the quality of life for these individuals.
Traditionally, rehabilitation therapists have sought to improve the gait of such childen by directing them in a more normal walking pattern. This approach has had limited success, according to Holt, because the children do not have the dynamic resources necessary for normal walking. Using biomechanical models, Holt and his colleagues are now developing a radically new way to improve walking patterns for children with CP.
Holt explains that three major forces come into play during walking: muscles contract, creating force; tendons stretch to produce a springing motion; and body mass, swinging back and forth, acts as a pendulum. All three forces, working in concert at precisely the appropriate time, enable people to walk normally. The gait of children with CP is thrown off because of their inability to contract their muscles at the right time.
Holt’s solution, being developed with support from the United Cerebral Palsy Foundation, relies on functional electrical stimulation (FES) to activate the leg muscles and provide the force needed at the right time in the gait cycle. He believes that by addressing the underlying muscle weakness and incorrect timing, the gait pattern can be corrected.
Although he cautions that the results are preliminary, a number of children with CP have shown improvement with FES. The ongoing study will determine if improved patterns continue after training, and will help identify the types of CP that respond to this approach. |
