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Betschart M1,2, Nadeau S1,3, McFadyen BJ4,5
1Université de Montréal, École de Réadaptation, Montréal, Canada, 2Centre for Interdisciplinary Research in Rehabilitation of greater Montreal, Montreal, Canada, 3Centre de Recherche Interdisciplinaire en Réadaptation (CRIR), Institut de Réadaptation Gingras-Lindsay de Montréal (IRGLM), CIUSSS Centre-Sud-de-l'Île-de-Montréal, Recherche, Montréal, Canada, 4Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale (CIRRIS), CIUSSS de la Capitale-Nationale, Recherche, Québec, Canada, 5Université de Laval, Département de Réadaptation, Québec, Canada
Background: Individuals post-stroke regain walking function; however, when compared to healthy controls, deficits often remain in speed, endurance and symmetry. Particularly, step length (SL) asymmetry observed in about a third of individuals tends to be more resistant to physiotherapy interventions when compared to other parameters. Knowledge about the possible strategies to adapt and correct stroke induced SL asymmetry is still missing. The effects of repeated exposure to split-belt treadmill (SBT) walking was investigated and revealed interesting findings on the capacity of individuals post-stroke to improve SL asymmetry over one month and to their capacity to adjust their gait pattern. However, this promising intervention has not yet been investigated with respect to the biomechanical and muscular contributions to, or effects on, SL asymmetry changes.
Purpose: This pilot study investigated the feasibility and effects of repeated exposure to SBT walking on gait ability (i.e. symmetry, speed, and endurance of gait) in individuals post-stroke. Furthermore, this study included the analysis of changes in muscle activity and joint moments related to SL asymmetry improvements in individuals post-stroke following repeated SBT walking.
Methods: Twelve individuals with a first unilateral cerebral stroke presenting initial SL asymmetry (ratio=1.10-2.05) (10 males; mean age 52 (SD 9.3 years); mean time post stroke 23 (SD 24.7 months); 9 left-sided stroke) were included. Clinical and biomechanical data were collected at one week prior, one day and four weeks post-training. Clinical parameters included step length symmetry, gait speed (10MWT), endurance (6-Minute Walk Test) and functional mobility (timed Up and Go test). For biomechanical analysis muscle activity of from 5 lower limb muscles, ground reaction forces and 3-dimensional kinematic data were collected while participants walked over level ground at comfortable speed. Participants were trained during six sessions of SBT walking using an error-augmentation protocol.
Results: After training, all participants reduced their SL asymmetry from an average ratio of 1.39 to 1.17 (p=0.002) and as a group, they increased their walking speed (p≤0.014) and showed a tendency to improve functional mobility (p≤0.058). No effect was observed in their endurance. Significant increases in SL and joint moments (plantarflexors: 20-60%, knee flexors: 20-60% and hip extensors: 0-20% of the gait cycle) were observed on the side trained on the fast belt (effect sizes from 0.41 to 0.60). The improvement in SL symmetry was observed with an increase in plantarflexion joint moment symmetry suggesting a particular contribution to the reduction in SL asymmetry by this muscle group. Changes in muscle activity varied among participants and were non-significant.
Conclusion(s): These findings suggest that the SBT protocol could improve gait ability, but a randomised controlled trial would have to demonstrate its superiority to conventional gait training.
Implications: The findings of this pilot study support larger trials to gain more solid information on the current protocol which appears as an efficient training for long-term recovery on SL asymmetry and on affected plantarflexors.
Keywords: Gait symmetry post-stroke, training, movement analysis
Funding acknowledgements: Fundings obtainded by the Canada Foundation for Innovation (CFI), and the SensoriMotor Rehabilitation Research Team University of Montreal
Purpose: This pilot study investigated the feasibility and effects of repeated exposure to SBT walking on gait ability (i.e. symmetry, speed, and endurance of gait) in individuals post-stroke. Furthermore, this study included the analysis of changes in muscle activity and joint moments related to SL asymmetry improvements in individuals post-stroke following repeated SBT walking.
Methods: Twelve individuals with a first unilateral cerebral stroke presenting initial SL asymmetry (ratio=1.10-2.05) (10 males; mean age 52 (SD 9.3 years); mean time post stroke 23 (SD 24.7 months); 9 left-sided stroke) were included. Clinical and biomechanical data were collected at one week prior, one day and four weeks post-training. Clinical parameters included step length symmetry, gait speed (10MWT), endurance (6-Minute Walk Test) and functional mobility (timed Up and Go test). For biomechanical analysis muscle activity of from 5 lower limb muscles, ground reaction forces and 3-dimensional kinematic data were collected while participants walked over level ground at comfortable speed. Participants were trained during six sessions of SBT walking using an error-augmentation protocol.
Results: After training, all participants reduced their SL asymmetry from an average ratio of 1.39 to 1.17 (p=0.002) and as a group, they increased their walking speed (p≤0.014) and showed a tendency to improve functional mobility (p≤0.058). No effect was observed in their endurance. Significant increases in SL and joint moments (plantarflexors: 20-60%, knee flexors: 20-60% and hip extensors: 0-20% of the gait cycle) were observed on the side trained on the fast belt (effect sizes from 0.41 to 0.60). The improvement in SL symmetry was observed with an increase in plantarflexion joint moment symmetry suggesting a particular contribution to the reduction in SL asymmetry by this muscle group. Changes in muscle activity varied among participants and were non-significant.
Conclusion(s): These findings suggest that the SBT protocol could improve gait ability, but a randomised controlled trial would have to demonstrate its superiority to conventional gait training.
Implications: The findings of this pilot study support larger trials to gain more solid information on the current protocol which appears as an efficient training for long-term recovery on SL asymmetry and on affected plantarflexors.
Keywords: Gait symmetry post-stroke, training, movement analysis
Funding acknowledgements: Fundings obtainded by the Canada Foundation for Innovation (CFI), and the SensoriMotor Rehabilitation Research Team University of Montreal
Topic: Disability & rehabilitation; Human movement analysis
Ethics approval required: Yes
Institution: Center for interdisciplinary research in rehabilitation (CRIR)
Ethics committee: Comité d'éthique de la recherche des établissements du CRIR
Ethics number: CRIR-951-0314
All authors, affiliations and abstracts have been published as submitted.
