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Background: Ankle dorsiflexion function during swing phase contributes to foot clearance and plays an important role in walking ability post-stroke. Commonly used biomechanical measures such as foot clearance and ankle joint excursion have limited ability to accurately evaluate impaired dorsiflexor function., Research Question: Can ankle angular velocity and acceleration be used as reliable measurers of dorsiflexion function in post-stroke gait?, Methods: Using linear regression and Pearson's correlation we retrospectively compared peak ankle angular velocity (Aω P ), peak ankle angular acceleration (Aα P ), peak dorsiflexion angle (DFA P ) and peak foot clearance (FCL P ) as direct measures for swing phase dorsiflexor function in 60 chronic stroke survivors. Intraclass correlation coefficient (ICC) analysis was used for test-retest reliability of Aω P and Aα P. RESULTS: Linear regression models revealed that Aω P , Aα P , DFA P , FCL P had a significant relationship (p < 0.05) with impaired dorsiflexion function. Aα P and DFA P accounted for the most variance of dorsiflexion function. Aω P , Aα P , FCL P , correlated significantly with all clinical outcome measures of walking ability. DFA P had a positive correlation only with FMA-LE. Post-hoc William's t-tests, used to compare the magnitude of difference between two non-independent correlations, revealed that the correlation between all clinical measures and DFA P were significantly weaker than with Aω P and Aα P . Correlation between FMA-LE and FCL P was weaker than with Aω P and Aα P . Excellent test-retest reliability for both Aω P (ICC = 0.968) and Aα P (ICC = 0.947) was observed., Significance: These results suggest that DFA P may only be associated with dorsiflexion function during non-task specific isolated movements, but not during walking. FCL P is associated with dorsiflexion function and walking ability measures but not as strongly as Aω P and Aα P possibly because FCL P is influenced by contribution from hip and knee joint movements. Therefore, Aω P and Aα P are reliable measures and represent dorsiflexion function more accurately than DFA P , and FCL P ., Competing Interests: Declaration of Competing Interest The authors have no disclosures to report., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Although walking speed is the most common measure of gait performance post-stroke, improved walking speed following rehabilitation does not always indicate the recovery of paretic limb function. Over the last decade, the measure paretic propulsion (Pp, defined as the propulsive impulse generated by the paretic leg divided by the sum of the propulsive impulses of both legs) has been established as a measure of paretic limb output and recently targeted in post-stroke rehabilitation paradigms. However, the literature lacks a detailed synthesis of how paretic propulsion, walking speed, and other biomechanical and neuromuscular measures collectively relate to post-stroke walking performance and motor recovery., Objective: The aim of this review was to assess factors associated with the ability to generate Pp and identify rehabilitation targets aimed at improving Pp and paretic limb function., Methods: Relevant literature was collected in which paretic propulsion was used to quantify and assess propulsion symmetry and function in hemiparetic gait., Results: Paretic leg extension during terminal stance is strongly associated with Pp. Both paretic leg extension and propulsion are related to step length asymmetry, revealing an interaction between spatiotemporal, kinematic and kinetic metrics that underlies hemiparetic walking performance. The importance of plantarflexor function in producing propulsion is highlighted by the association of an independent plantarflexor excitation module with increased Pp. Furthermore, the literature suggests that although current rehabilitation techniques can improve Pp, these improvements depend on the patient's baseline plantarflexor function., Significance: Pp provides a quantitative measure of propulsion symmetry and should be a primary target of post-stroke gait rehabilitation. The current literature suggests rehabilitation techniques that target both plantarflexor function and leg extension may restore paretic limb function and improve gait asymmetries in individuals post stroke., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Recent studies have suggested the biomechanical subtasks of walking can be produced by a reduced set of co-excited muscles or modules. Individuals post-stroke often exhibit poor inter-muscular coordination characterized by poor timing and merging of modules that are normally independent in healthy individuals. However, whether locomotor therapy can influence module composition and timing and whether these improvements lead to improved walking performance is unclear. The goal of this study was to examine the influence of a locomotor rehabilitation therapy on module composition and timing and post-stroke hemiparetic walking performance. Twenty-seven post-stroke hemiparetic subjects participated in a 12-week locomotor intervention incorporating treadmill training with body weight support and manual trainers accompanied by training overground walking. Electromyography (EMG), kinematic and ground reaction force data were collected from subjects both pre- and post-therapy and from 19 age-matched healthy controls walking on an instrumented treadmill at their self-selected speed. Non-negative matrix factorization was used to identify the module composition and timing from the EMG data. Module timing and composition, and various measures of walking performance were compared pre- and post-therapy. In subjects with four modules pre- and post-therapy, locomotor training resulted in improved timing of the ankle plantarflexor module and a more extended paretic leg angle that allowed the subjects to walk faster and with more symmetrical propulsion. In addition, subjects with three modules pre-therapy increased their number of modules and improved walking performance post-therapy. Thus, locomotor training has the potential to influence module composition and timing, which can lead to improvements walking performance., (Copyright © 2013 Elsevier B.V. All rights reserved.)