The use of body weight support on ground level: an alternative strategy for gait training of individuals with stroke

Abstract

BackgroundBody weight support (BWS) systems on treadmill have been proposed as a strategy for gait training of subjects with stroke. Considering that ground level is the most common locomotion surface and that there is little information about individuals with stroke walking with BWS on ground level, it is important to investigate the use of BWS on ground level in these individuals as a possible alternative strategy for gait training.MethodsThirteen individuals with chronic stroke (four women and nine men; mean age 54.46 years) were videotaped walking on ground level in three experimental conditions: with no harness, with harness bearing full body weight, and with harness bearing 30% of full body weight. Measurements were recorded for mean walking speed, cadence, stride length, stride speed, durations of initial and terminal double stance, single limb support, swing period, and range of motion of ankle, knee, and hip joints; and foot, shank, thigh, and trunk segments.ResultsThe use of BWS system leads to changes in stride length and speed, but not in stance and swing period duration. Only the hip joint was influenced by the BWS system in the 30% BWS condition. Shank and thigh segments presented less range of motion in the 30% BWS condition than in the other conditions, and the trunk was held straighter in the 30% BWS condition than in the other conditions.ConclusionIndividuals with stroke using BWS system on ground level walked slower and with shorter stride length than with no harness. BWS also led to reduction of hip, shank, and thigh range of motion. However, this system did not change walking temporal organization and body side asymmetry of individuals with stroke. On the other hand, the BWS system enabled individuals with chronic stroke to walk safely and without physical assistance. In interventions, the physical therapist can watch and correct gait pattern in patients' performance without the need to provide physical assistance.

Muscle activation during body weight-supported locomotion while using the ZeroG

“…This indicates that, at higher levels of BWS, individuals spend significantly more time balancing a portion of their body weight on one limb, while the opposite limb completes swing phase. This is in contrast to a previous overground BWS training study in persons with stroke, in which no changes in stance or swing period duration were evident with increasing BWS [5]. These differences may be attributed to the clinical population, who potentially responded differently to the BWS, in addition to the different overground training devices used; the study by Sousa et al used a device with an electric motor that relied on the individual for movement [5] versus the current study in which the ZeroG uses a custom-series elastic actuator that moves independently of the participant.…”

“…Each training approach has its respective advantages and disadvantages; for example, robotic-assisted training provides stepping consistency but does not allow the movement variability associated with overground walking [7]. In addition, this therapeutic option is treadmill-based and, as a result, is not as taskspecific or transferable to daily living as overground training programs [5].…”

“…Persons with spinal cord injury (complete and incomplete) have demonstrated the ability to increase weight-bearing capacity of lower-limb extensors through body weight-supported treadmill training, in addition to increasing appropriate gastrocnemius and decreasing inappropriate tibialis anterior (TA) activation [4]. An overground body weight-supported walking study (0/30/100% BWS at natural cadence) in individuals with chronic stroke found offloading resulted in reduced hip range of motion, with individuals responding to the support by decreasing their walking speed and taking shorter strides [5].…”

“…Currently, there is a need for a body weight-supported overground walking device equipped with a motor that moves along an overhead track independent of the user in order to eliminate the possibility that a drag force created by the system itself affects gait performance [5]. The newly developed ZeroG system (Aretech LLC; Ashburn, Virginia), created by Hidler et al, attempts to provide this dynamic BWS through the use of a custom-series elastic actuator during overground walking and balance training (Figure 1) [8].…”

Assessment of non-disabled individuals walking with partial body weight support over ground and on treadmill

“…17 Previous study had investigated individuals with stroke walking over the ground with BWS, 18 and exposed them to over ground gait training with BWS. 19 Therefore, walking with BWS over the ground might constitute an alternative and important gait training protocol for individuals with gait impairments.…”