Time profile of kinematic synergies of stroke gait

• Published in: Clinical biomechanics (Bristol) Vol. 106; p. 105990
• Main Authors: Devetak, Gisele Francini, Bohrer, Roberta Castilhos Detanico, Rinaldin, Carla, Rodacki, André Luiz Felix, Manffra, Elisangela Ferretti
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2023
• Subjects: Biomechanical Phenomena; Center of mass; Extremities; Gait; Humans; Paresis; Physical Medicine and Rehabilitation; Stroke; Stroke - complications; Stroke Rehabilitation; Synergy, statistical parametric mapping; Uncontrolled manifold; Walking; Uncontrolled manifold; Synergy, statistical parametric mapping; Stroke; Gait; Center of mass
• ISSN: 0268-0033; 1879-1271; 1879-1271
• DOI: 10.1016/j.clinbiomech.2023.105990

In stroke subjects, the motor skills differ between sides and among subjects with different levels of motor recovery, impacting inter-joint coordination. How these factors can affect the kinematic synergies over time during gait has not been investigated yet. This work aimed to determine the time profile of kinematic synergies of stroke patients throughout the single support phase of gait. Kinematic data from 17 stroke and 11 healthy individuals was recorded using a Vicon System. The Uncontrolled Manifold approach was employed to determine the distribution of components of variability and the synergy index. To analyze the time profile of kinematic synergies, we applied the statistical parametric mapping method. Comparisons were made within the stroke group (paretic and non-paretic limbs) and between groups (stroke and healthy). The stroke group was also subdivided into subgroups with worse and better motor recovery. There are significant differences in synergy index at the end of the single support phase between stroke and healthy subjects; paretic and non-paretic limbs; and paretic limb according to the motor recovery. Comparisons of mean values showed significantly larger values of synergy index for the paretic limb compared to the non-paretic and healthy. Despite the sensory-motor deficits and the atypical kinematic behavior, stroke patients can produce joint covariations to control the center of mass trajectory in the forward progression plane, but the modulation of the synergy is impaired, reflecting altered adjustments, especially in the paretic limb of subjects with worse levels of motor recovery. •Kinematic synergies to control the center of mass are present in healthy and stroke conditions.•In a healthy gait, the strength of synergy decreases over time along the single support phase.•Stroke subjects exhibit reduced capacity to modulate the strength of synergies.•Worse levels of motor recovery result in impaired modulation of the synergy strength.