How Compliance of Surfaces Affects Ankle Moment and Stiffness Regulation During Walking

Humans can regulate ankle moment and stiffness to cope with various surfaces during walking, while the effect of surfaces compliance on ankle moment and stiffness regulations remains unclear. In order to find the underlying mechanism, ten healthy subjects were recruited to walk across surfaces with different levels of compliance. Electromyography (EMG), ground reaction forces (GRFs), and three-dimensional reflective marker trajectories were recorded synchronously. Ankle moment and stiffness were estimated using an EMG-driven musculoskeletal model. Our results showed that the compliance of surfaces can affect both ankle moment and stiffness regulations during walking. When the compliance of surfaces increased, the ankle moment increased to prevent lower limb collapse and the ankle stiffness increased to maintain stability during the mid-stance phase of gait. Our work improved the understanding of gait biomechanics and might be instructive to sports surface design and passive multibody model development.

Differences in Gait Cycle and Biomechanical Lower-Limb Joint Function between Elderly People with and without Cognitive Decline

Because dementia is difficult to treat, the best way is to detect the prodromal stage; this can identify those at high risk of dementia and help to delay its onset. It is a well-known fact that gait has a high correlation with cognitive function. Considering that dementia starts with cognitive decline, investigating the association between cognitive decline and gait may contribute to the detection of elderly individuals at high risk of dementia and even the prevention of dementia. The purpose of the present study was to investigate the gait cycle and biomechanics of elderly people with and without cognitive decline. A three-dimensional motion analysis system was used, and older adults over 65 participated in this study. K-MoCA was used to assess cognitive function and, according to the results of a cognition function assessment, they were classified into two groups. Spatiotemporal variables, subdivisions of the gait cycle, joint angle, joint moment, joint power, and support moment were investigated. Significant differences between both groups appeared in the subdivisions of the gait cycle, and parameters of gait biomechanics were established. These results provide insight into the mechanism dictating the gait of elderly individuals with cognitive decline.

Weaker Connectivity of the Cortical Networks Is Linked with the Uncharacteristic Gait in Youth with Cerebral Palsy

Cerebral palsy (CP) is the most prevalent pediatric neurologic impairment and is associated with major mobility deficiencies. This has led to extensive investigations of the sensorimotor network, with far less research focusing on other major networks. The aim of this study was to investigate the functional connectivity (FC) of the main sensory networks (i.e., visual and auditory) and the sensorimotor network, and to link FC to the gait biomechanics of youth with CP. Using resting-state functional magnetic resonance imaging, we first identified the sensorimotor, visual and auditory networks in youth with CP and neurotypical controls. Our analysis revealed reduced FC among the networks in the youth with CP relative to the controls. Notably, the visual network showed lower FC with both the sensorimotor and auditory networks. Furthermore, higher FC between the visual and sensorimotor cortices was associated with larger step length (r = 0.74, pFDR = 0.04) in youth with CP. These results confirm that CP is associated with functional brain abnormalities beyond the sensorimotor network, suggesting abnormal functional integration of the brain’s motor and primary sensory systems. The significant association between abnormal visuo-motor FC and gait could indicate a link with visuomotor disorders in this patient population.

Changes In Gait Biomechanics As Functional Symptom Of Chondromalacia Patella

The goal of this research was to investigate functional and biomechanical symptoms in patients with chondromalacia patella. Material and Methods — Gait biomechanics was assessed in 35 patients with diagnosed unilateral chondromalacia patella and in 20 healthy adult controls. We recorded hip and knee movements, impact loads and temporal characteristics of the gait cycle (GC) during self-paced walking. Results — The temporal characteristics of gait and the impact loads remained normal in the patient population. Hip flexion amplitude decreased both on the affected (p=0.002) vs. unaffected (p=0.016) sides, compared to healthy control, whereas the amplitude phase increased on the affected (p=0.012) vs. unaffected (p=0.001) sides, versus healthy control. Hip extension and adduction-abduction amplitudes did not change significantly. Stance-phase and swing-phase knee flexion amplitudes did not change significantly. Knee extension amplitude on the affected limb increased (p=0.015), and knee rotation on the unaffected limb decreased versus control (p=0.016). The so-called stairstep symptom defined in the study was found in 83% of patients: in 23 patients bilaterally and in 6 patients unilaterally. Conclusion — Chondromalacia patella affected the gait biomechanics on both sides. The changes in the kinematic patterns during the flat-surface walking were not substantial. The only pathognomonic functional symptom of the condition was the stairstep symptom.