RESUMEN
The variety of poststroke impairments and compensatory mechanisms necessitate adaptive and subject-specific approaches to locomotor rehabilitation. To implement subject-specific, adaptive training to treadmill-based gait training, we developed a user-driven treadmill (UDTM) control algorithm that adjusts the user's speed in real-time. This study examines the response of individuals poststroke to the combination of UDTM control and electrical stimulation of the paretic ankle musculature to augment forward propulsion during walking. Sixteen individuals poststroke performed a randomized series of walking tasks on an instrumented split-belt treadmill at their self-selected speeds 1) with fixed speed treadmill (FSTM) control only, 2) FSTM control and paretic limb functional electrical stimulation (FES), 3) UDTM control only, and 4) UDTM control and FES. With UDTM control and FES, participants selected speeds that were 0.13 m/s faster than their speeds with fixed speed control only. This instantaneous increase is comparable to the gains in SS speed seen after 12 weeks of training with FES and fast walking with fixed speed treadmill control by Kesar and colleagues (Δ = 0.18 m/s). However, we saw no significant differences in the corresponding push-off forces or trailing limb position. Since individuals can use a variety of strategies to change their walking speeds, it is likely that the differences among individual responses obscured trends in the group average changes in mechanics. Ultimately, the combination of UDTM control and functional electrical stimulation (FES) allows individuals to increase speeds after a short exposure and may be a beneficial addition to poststroke gait training programs.
Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Fenómenos Biomecánicos , Estimulación Eléctrica , Prueba de Esfuerzo , Marcha , Humanos , Accidente Cerebrovascular/terapia , Caminata , Velocidad al CaminarRESUMEN
BACKGROUND: Walking with user-driven treadmill control is believed to be more like overground walking than fixed-speed treadmill walking. Walking speed and ground reaction forces differ between overground and fixed-speed treadmill walking, but not between overground and user-driven treadmill walking in healthy and post-stroke subjects. However, studies assessing spatiotemporal gait parameters during user-driven treadmill walking are limited. This information may help confirm that user-driven treadmill walking is more like overground walking than fixed-speed treadmill walking, as well as inform the development of post-stroke gait rehabilitation programs. RESEARCH QUESTION: How do spatiotemporal gait parameters for individuals post-stroke differ between fixed-speed and user-driven treadmill walking? METHODS: Eighteen subjects (10 M, 8 F; 62 ± 12 years; 1.73 ± 0.12 m; 84.9 ± 12.9 kg; 40 ± 30 months post-stroke) with chronic post-stroke hemiparesis participated in this study. Participants walked on an instrumented treadmill in its fixed-speed and user-driven modes at their self-selected and fastest comfortable walking speeds. Subjects wore retroreflective markers for motion capture. Shapiro-Wilk tests were used to assess for normality and one-way repeated measures ANOVAs were used to compare between conditions with α = 0.05. Bonferroni corrections were used for multiple comparisons. RESULTS: Step width was significantly smaller with user-driven control (13.7 cm, 95 % CI: [0.131, 0.145]) than fixed-speed control (16.8 cm, 95 % CI:[0.160, 0.174]), while step length and step time did not differ across treadmill conditions. Step length and step time differed between self-selected and fast walking speeds, but not treadmill control conditions. SIGNIFICANCE: The results of this study show that user-driven treadmill control encourages healthy gait biomechanics and a greater sense of stability in post-stroke subjects. Individuals post-stroke walked with smaller step width with user-driven treadmill control, which has been associated with increased balance. Post-stroke gait rehabilitation may benefit from programs with user-driven treadmill training paradigms to improve mobility following stroke.
Asunto(s)
Prueba de Esfuerzo/métodos , Rehabilitación de Accidente Cerebrovascular/métodos , Accidente Cerebrovascular/terapia , Velocidad al Caminar/fisiología , Caminata/fisiología , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The objective of this study was to determine how individuals poststroke respond to user-driven treadmill (UDTM) controlin terms ofwalking speeds, peak anterior ground reaction forces (AGRF), peak posterior ground reaction forces (PGRF), and trailing limb angles (TLA). Twenty individuals with chronic stroke walked overground during a 10-meter walk test to determine their self-selected (SS) speeds before walking on a treadmill in its fixed-speed (FSTM) and UDTM control modes at their SS and fastest comfortable (Fast) speeds. Paired t-tests were used to compare the walking speeds, peak AGRF, peak PGRF, and TLA among test conditions (α = 0.05). Participants selected similar SS (p > 0.05) and faster Fast walking speeds (p < 0.05) with the UDTM control compared to the FSTM control. There were no changes in their peak AGRF or PGRF for either limb or speed between UDTM and FSTM conditions (p > 0.05). Individuals used greater paretic TLA at SS speeds with UDTM control (p < 0.05). There was no difference in the AGRF required at Fast speeds with FSTM and UDTM control even though participants selected faster speeds with UDTM control. In work with young, healthy adults, we found that the treadmill control condition did not affect the amount of forward propulsion needed. Therefore, it is likely that when walking with UDTM control, individuals poststroke adjust their posture to make better use of their forward propulsion. This means they can reach faster walking speeds without increasing their push-off forces. Future work should assess how to most effectively prescribe UDTM control for gait training programs.
Asunto(s)
Prueba de Esfuerzo , Accidente Cerebrovascular/fisiopatología , Velocidad al Caminar/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Implementing user-driven treadmill control in gait training programs for rehabilitation may be an effective means of enhancing motor learning and improving functional performance. This study aimed to determine the effect of a user-driven treadmill control scheme on walking speeds, anterior ground reaction forces (AGRF), and trailing limb angles (TLA) of healthy adults. Twenty-three participants completed a 10-m overground walking task to measure their overground self-selected (SS) walking speeds. Then, they walked at their SS and fastest comfortable walking speeds on an instrumented split-belt treadmill in its fixed speed and user-driven control modes. The user-driven treadmill controller combined inertial-force, gait parameter, and position based control to adjust the treadmill belt speed in real time. Walking speeds, peak AGRF, and TLA were compared among test conditions using paired t-tests (αâ¯=â¯0.05). Participants chose significantly faster SS and fast walking speeds in the user-driven mode than the fixed speed mode (pâ¯>â¯0.05). There was no significant difference between the overground SS walking speed and the SS speed from the user-driven trials (pâ¯<â¯0.05). Changes in AGRF and TLA were caused primarily by changes in walking speed, not the treadmill controller. Our findings show the user-driven treadmill controller allowed participants to select walking speeds faster than their chosen speeds on the fixed speed treadmill and similar to their overground speeds. Since user-driven treadmill walking increases cognitive activity and natural mobility, these results suggest user-driven treadmill control would be a beneficial addition to current gait training programs for rehabilitation.