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This study aimed to investigate how external perturbations caused by the treadmill belt's deceleration during the pre-swing phase affect gait kinematics and kinetics in young adults. Twenty-one healthy young females walked on a treadmill in a virtual environment (GRAIL, Motek), where unexpected perturbations were applied to the left belt, mimicking a 'trip-like' effect at toe-off. The spatiotemporal, kinematic, and kinetic parameters were analyzed during two cycles. The first cycle involved the first perturbation and the response to it. The second included a gait cycle without the perturbation (treadmill gait). The perturbation resulted in an increased stride duration for both limbs when compared to the treadmill gait. The perturbed limb had a longer support phase, while the reactive limb had the longest double stance phase. The responding limb exhibited more than double the ankle plantarflexion compared to the normal treadmill gait and the perturbed limb. At the hip joint, both limbs showed significantly higher values, with a 40.8% increase in flexion and a 227% increase in extension for the perturbed limb, and a 24.5% increase in flexion and a 212% increase in extension for the responding limb, compared to the treadmill gait. Muscle torque was generally lower in most joints for both limbs, except for notably higher hip and knee extensor values for the perturbed limb. The responding limb exhibited lower values for the ankle, knee, and hip joints, indicating unexpected muscle activity patterns. Studying treadmill belt deceleration during pre-swing gait can provide valuable insights into biomechanical adaptations and motor control strategies. [ABSTRACT FROM AUTHOR]

Background: Gait disturbances in children with cerebral palsy can increase the hindrance caused by loss of independence and social engagement. The Lokomat, developed by Hocoma, shows promise as a supplementary tool for gait rehabilitation. This study investigates the impact of Lokomat training on gait parameters and trends observed during training. Methods: A total of 26 children (13 male individuals) with a diagnosis of cerebral palsy (CP), aged 4 to 23 years, were enrolled in the study. Patients participated in a standard comprehensive rehabilitation program with additional Lokomat training sessions. Gait function was assessed using the Timed Up and Go Test (TUG) and the 10 m walking test (10mWT) at the beginning and end of the rehabilitation period. Changes in Lokomat parameters (step number, session duration, speed, body weight support, and guidance force) were also analysed. Results: The median duration of the 10mWT and TUG significantly decreased across the groups after the treatment program. The highest increases were observed for the number of steps taken. Across the entire cohort, the linear trend curves for distance and number of steps exhibited near-perpendicular alignment with the horizontal axis, suggesting significant improvement in these parameters. A consistent trend was noted for speed, with the trend line aligned parallel with the horizontal axis. Decreasing trends were observed for body weight support and guidance force. Conclusions: Therapy with the Lokomat functioning as the active gait orthosis can be used as a form of support to the standard rehabilitation protocol for patients with CP. [ABSTRACT FROM AUTHOR]

Background: Humans encounter disturbances like slips, pushes, and trips while walking, mainly from external forces. Technological advances have improved methods to study these impacts on gait, with split-belt treadmills being particularly effective. This scoping review aims to examine the types of perturbations used during split-belt treadmill gait, explore the methods used to induce them, and consolidate current knowledge on the effects of split-belt treadmill-induced gait perturbations. Methods: The review included publications from January 2015 to May 2024, as searched via PubMed, EBSCO, and ScienceDirect. Results: The review examined 33 studies on split-belt treadmills, focusing on perturbations like slip-like, trip-like, lateral displacements, and tilts, with speed changes being the most common. Perturbations were mainly applied during initial contact. The results show that young, healthy adults adapt quickly to anticipatory and reactive adjustments, while older adults and those with neurological impairments use less efficient strategies like increased muscular co-contraction. Asymmetrical gait adaptations persist after perturbations, highlighting motor learning and the role of the central nervous system and sensory feedback. Conclusions: Despite their precision, split-belt and tilting treadmills may not fully replicate real-world walking complexities. The review highlights the strengths and limitations of split-belt treadmills, emphasizing the need to integrate diverse methods to enhance rehabilitation and improve gait stability. [ABSTRACT FROM AUTHOR]

Study aim: To investigate the effect of wearing ski boots on kinematic and kinetic parameters of lower limbs during gait. Furthermore, loads in lower limb joints were assessed using the musculoskeletal model.

Background: The prevalence of falls among the older population underscores the imperative of comprehending human adaptations to gait perturbations. Dual-belt treadmills offer a controlled setting for such investigations. The purpose of this study was to examine the effect of the acceleration of one belt of the treadmill during three different phases of the gait cycle on kinematic and kinetic parameters and relate these changes to unperturbed gait. Methods: Twenty-one healthy young females walked on a treadmill in a virtual environment, in which five unexpected perturbations were applied to the left belt at the Initial Contact (IC), Mid Stance (MS), and Pre-Swing (PS) phase of the gait cycle. Data from the undisturbed gait and the first disturbance of each trial were extracted for analysis. Results: All perturbations significantly affected the gait pattern, mainly by decreasing the knee extension angle. The perturbation in the IC phase had the most significant effect, resulting in a 248.48% increase in knee flexion torque. The perturbation in the MS phase mainly affected plantar flexion torque, increasing it by 118.18%, while perturbation in the PS phase primarily increased the hip extension torque by 73.02%. Conclusions: The presence of perturbations in the IC and PS phases caused the most aggressive and significant changes in gait parameters. [ABSTRACT FROM AUTHOR]

Purpose: External factors can disrupt postural control, but the intricate workings of the postural control system enable an appropriate response. This study seeks to assess how external perturbations affect postural control. Methods: Twenty women participated in study, which consisted four trials involved quiet standing and experiencing induced perturbations by being struck with a boxing bag from the back, right, and left sides, respectively. The center of pressure (CoP) path length was recorded for each of the mentioned trials. Sample Entropy (SampEn), Lyapunov Exponent (LyE), and Fractal Dimension (FD) were computed for the CoP time series, separately for the anterior-posterior (AP) and mediolateral (ML) directions. The nonparametric Friedman ANOVA with Dunn-Bonferroni post-hoc analysis was employed to investigate the influence of external perturbations on both linear and nonlinear parameters on postural control. Results: The post-hoc analysis showed for LyE_AP_quiet (1.02 ± 0.18) significantly higher values than for LyE_AP_right (0.92 ± 0.22) and significantly higher for LyE_AP_left. Lyapunov Exponent was the parameter that differentiated the most between samples. Conclusions: The greatest number of significant differences between samples were demonstrated by the Lyapunov Exponent. This non-linear parameter should be used to evaluate various perturbations during upright position in healthy subjects. [ABSTRACT FROM AUTHOR]

Study aim: Step aerobics is a form of aerobic power distinguished from other types of aerobic exercise by its use of an elevated platform. The purpose of this study was to examine how the aerobic exercise “knee up” affects kinematic and kinetic parameters and, above all, the length of the muscle contractions.