Underwater treadmill training in adults with incomplete spinal cord injuries

Abstract

Gravity. We spend our lives fighting it . One day it will win, as it always does. Until then, much of what we call quality of life is based on our ability to resist the effects of gravity and to be functionally mobile at home, at school, at work, and in our community. For those with physic al disabilities, the challenge is greater and the stakes are higher. To counter the loss of mobility , strength, and endurance that often accompanies a disabling condition, a variety of interventions has been studied to improve physical fitness and reduce the weight-bearing challenges associated with walking. Several of these systems involve supporting a portion of a person's body weight with a harness during overground walking or land-based treadmill exercise [1]. This editorial describes an innovative method to unload body weight that allows a person with a gait impairment to walk on a treadmill submerged in a water tank (see Underwater Treadmill Training Videos 1 and 2). UNDERWATER TREADMILL Our interest in this unique therapeutic approach follows earlier studies that examined the evolution of gait in nondisabled youth and documented the influence of growth and maturation on the energy cost of walking. This research effort compared the aerobic demands of walking in nondisabled youth and children with cerebral palsy (CP). Results indicated that locomotor energy use was much higher in youth with CP [2]. Realizing that higher ambulatory energy use could help explain the fatigue often experienced by children with CP during extended walking bouts, training interventions to improve locomotor efficiency in this population were investigated. One such intervention was the implementation of an aquatics-based treadmill walking program to reduce the energy cost of walking and increase overall fitness and mobility in youth with CP. Because aquatic exercise is less damaging to joint integrity , it can be an effective alternative to land-based exercise programs in persons with lower-limb joint weakness and balance problems. Gait training can also be performed in a very controlled setting with an underwater treadmill because speed, water depth, and water temperature can be easily manipulated and reproduced. Other advantages of underwater treadmill exercise include the similarity of muscle activity and gait patterns used in land walking, minimization of postural distortions, greater weight-bearing support for deconditioned individuals, increased leg strength gained by overcoming water resistance and turbulence, and decreased pain levels. The preliminary findings from this research in ambulatory youth with CP suggest that a number of fitness a nd mobility variables can be improved following an underwater treadmill training program incorporating the gradual, systematic, and overlapping manipulation of water height, gait speed, and walking duration. UNDERWATER TREADMILL WITH SPINAL CORD INJURIES Based on these initial findings we explored the possibility of applying this therapeutic regimen to individuals experiencing a greater degree of mobility impairment. After much dicussion, we decided to document the impact of underwater treadmill training in adults with incomplete spinal cord injuries (SCIs). Because impairments associated with SCI are often considered permanent and ireparable, even slight improvements in physical function are noteworthy. We chose to train adults with SCI to differentiate their responses from those of children with neural impairment, who exhibit nervous systems that are still somewhat plastic and whose ability to recover from injury is more dynamic than adults. In addition, SCIs are stable and do not progressively worsen like diseases such as cancer or multiple sclerosis. Accordingly, factors that could potentially confound the interpretation of study findings are often not present. Because individuals with SCI typically experience some degree of injury resolution during the initial healing period, we enrolled participants whose injuries were more than a year old and unlikely to improve without some type of clinical intervention. …