The Walking Brain: factors influencing human gait

Human walking is a standardized, repeatable and rhythmic locomotor act, with biomechanical patterns reported as roughly common to all healthy individuals. However, some gait patterns could be affected by cognitive, social and cultural factors. This mini-review aims at investigating top-down related differences in walking healthy patterns due to the above factors. The reviewed literature reported that socio-economic factors are at the basis of differences in pedestrian walking speed, related to the pace of life: faster speed was found in industrialized countries than in developing ones. Furthermore, it was suggested that the ancient division between men and women in hunters and gatherers, respectively, could be at the basis of gender visual differences and, in turn, in upper body movements during walking, with women walking with a more stable head. Interestingly, changes in gait speed did not affect cortical resources needed for spatial cognition, whereas a cognitive task may affect the gait speed. The most reliable parameters, poorly affected by psycho-social factors, resulted the symmetry of limb movements and the ratio between stance and swing duration. The latter was found close to the irrational number called golden ratio, providing a fractal structure to human gait cycle. Both these parameters are at the basis of the harmony of human walking, a feature maintained also in presence of top-down driven gait modifications

A Dance to the Music of Time: Aesthetically-Relevant Changes in Body Posture in Performing Art

In performing arts, body postures are both means for expressing an artist's intentions, and also artistic objects, appealing to the audience. The postures of classical ballet obey the body's biomechanical limits, but also follow strict rules established by tradition. This combination offers a perfect milieu for assessing scientifically how the execution of this particular artistic activity has changed over time, and evaluating what factors may induce such changes. We quantified angles between body segments in archive material showing dancers from a leading company over a 60-year period. The data showed that body positions supposedly fixed by codified choreography were in fact implemented by very different elevation angles, according to the year of ballet production. Progressive changes lead to increasingly vertical positions of the dancer's body over the period studied. Experimental data showed that these change reflected aesthetic choices of naïve modern observers. Even when reduced to stick figures and unrecognisable shapes, the more vertical postures drawn from later productions were systematically preferred to less vertical postures from earlier productions. This gradual change within a conservative art form provides scientific evidence that aesthetic change may arise from continuous interaction between artistic tradition, individual artists' creativity, and a wider environmental context. This context may include social aesthetic pressure from audiences

Effects of Visual Deprivation on Gait Dynamic Stability

Vision can improve bipedal upright stability during standing and affect spatiotemporal parameters during walking. However, little is known about the effects of visual deprivation on gait dynamic stability. We have tested 28 subjects during walking under two different visual conditions, full vision (FV) and no vision (NV), measuring their upper body accelerations. Lower accelerations were found in NV for the reduced walking speed. However, the normalized accelerations were higher in the NV than in the FV condition, both in anteroposterior (1.05 ± 0.21 versus 0.88 ± 0.16, P = 0.001) and laterolateral (0.99 ± 0.26 versus 0.78 ± 0.19, P < 0.001) directions. Vision also affected the gait anteroposterior harmony (P = 0.026) and, interacting with the environment, also the latero-lateral one (P = 0.017). Directly (as main factor of the ANOVA) or indirectly (by means of significant interactions with other factors), vision affected all the measured parameters. In conclusion, participants showed an environment-dependent reduction of upper body stability and harmony when deprived by visual feedback

Control of the upper body accelerations in young and elderly women during level walking

<p>Abstract</p> <p>Background</p> <p>The control of the head movements during walking allows for the stabilisation of the optic flow, for a more effective processing of the vestibular system signals, and for the consequent control of equilibrium.</p> <p>In young individuals, the oscillations of the upper body during level walking are characterised by an attenuation of the linear acceleration going from pelvis to head level. In elderly subjects the ability to implement this motor strategy is reduced. The aim of this paper is to go deeper into the mechanisms through which the head accelerations are controlled during level walking, in both young and elderly women specifically.</p> <p>Methods</p> <p>A stereophotogrammetric system was used to reconstruct the displacement of markers located at head, shoulder, and pelvis level while 16 young (age: 24 ± 4 years) and 20 older (age: 72 ± 4 years) female volunteers walked at comfortable and fast speed along a linear pathway. The harmonic coefficients of the displacements in the medio-lateral (ML), antero-posterior (AP), and vertical (V) directions were calculated via discrete Fourier transform, and relevant accelerations were computed by analytical double differentiation. The root mean square of the accelerations were used to define three coefficients for quantifying the attenuations of the accelerations from pelvis to head, from pelvis to shoulder, and from shoulder to head.</p> <p>Results</p> <p>The coefficients of attenuation were shown to be independent from the walking speed, and hence suitable for group and subject comparison.</p> <p>The acceleration in the AP direction was attenuated by the two groups both from pelvis to shoulder and from shoulder to head. The reduction of the shoulder to head acceleration, however, was less effective in older women, suggesting that the ability to exploit the cervical hinge to attenuate the AP acceleration is challenged in this population. Young women managed to exploit a pelvis to shoulder attenuation strategy also in the ML direction, whereas in the elderly group the head acceleration was even larger than the pelvis acceleration.</p> <p>Conclusion</p> <p>The control of the head acceleration is fundamental when implementing a locomotor strategy and its loss could be one of the causes for walking instability in elderly women.</p

Physiological responses and energy cost of walking on the Gait Trainer with and without body weight support in subacute stroke patients

BACKGROUND: Robotic-assisted walking after stroke provides intensive task-oriented training. But, despite the growing diffusion of robotic devices little information is available about cardiorespiratory and metabolic responses during electromechanically-assisted repetitive walking exercise. Aim of the study was to determine whether use of an end-effector gait training (GT) machine with body weight support (BWS) would affect physiological responses and energy cost of walking (ECW) in subacute post-stroke hemiplegic patients. METHODS: Participants: six patients (patient group: PG) with hemiplegia due to stroke (age: 66 ± 15y; time since stroke: 8 ± 3 weeks; four men) and 6 healthy subjects as control group (CG: age, 76 ± 7y; six men). Interventions: overground walking test (OWT) and GT-assisted walking with 0%, 30% and 50% BWS (GT-BWS0%, 30% and 50%). Main Outcome Measures: heart rate (HR), pulmonary ventilation, oxygen consumption, respiratory exchange ratio (RER) and ECW. RESULTS: Intervention conditions significantly affected parameter values in steady state (HR: p = 0.005, V’E: p = 0.001, V'O(2): p < 0.001) and the interaction condition per group affected ECW (p = 0.002). For PG, the most energy (V’O(2) and ECW) demanding conditions were OWT and GT-BWS0%. On the contrary, for CG the least demanding condition was OWT. On the GT, increasing BWS produced a decrease in energy and cardiac demand in both groups. CONCLUSIONS: In PG, GT-BWS walking resulted in less cardiometabolic demand than overground walking. This suggests that GT-BWS walking training might be safer than overground walking training in subacute stroke patients

Evaluation of cervical posture improvement of children with cerebral palsy after physical therapy based on head movements and serious games

Background: This paper presents the preliminary results of a novel rehabilitation therapy for cervical and trunk control of children with cerebral palsy (CP) based on serious videogames and physical exercise. Materials: The therapy is based on the use of the ENLAZA Interface, a head mouse based on inertial technology that will be used to control a set of serious videogames with movements of the head. Methods: Ten users with CP participated in the study. Whereas the control group (n=5) followed traditional therapies, the experimental group (n=5) complemented these therapies with a series of ten sessions of gaming with ENLAZA to exercise cervical flexion-extensions, rotations and inclinations in a controlled, engaging environment. Results: The ten work sessions yielded improvements in head and trunk control that were higher in the experimental group for Visual Analogue Scale, Goal Attainment Scaling and Trunk Control Measurement Scale (TCMS). Significant differences (27% vs. 2% of percentage improvement) were found between the experimental and control groups for TCMS (p<0.05). The kinematic assessment shows that there were some improvements in the active and the passive range of motion. However, no significant differences were found pre- and post-intervention. Conclusions:Physical therapy that combines serious games with traditional rehabilitation could allow children with CP to achieve larger function improvements in the trunk and cervical regions. However, given the limited scope of this trial (n=10) additional studies are needed to corroborate this hypothesis

Rehabilitative devices for a top-down approach

In recent years, neurorehabilitation has moved from a "bottom-up" to a "top down" approach. This change has also involved the technological devices developed for motor and cognitive rehabilitation. It implies that during a task or during therapeutic exercises, new "top-down" approaches are being used to stimulate the brain in a more direct way to elicit plasticity-mediated motor re-learning. This is opposed to "Bottom up" approaches, which act at the physical level and attempt to bring about changes at the level of the central neural system. Areas covered: In the present unsystematic review, we present the most promising innovative technological devices that can effectively support rehabilitation based on a top-down approach, according to the most recent neuroscientific and neurocognitive findings. In particular, we explore if and how the use of new technological devices comprising serious exergames, virtual reality, robots, brain computer interfaces, rhythmic music and biofeedback devices might provide a top-down based approach. Expert commentary: Motor and cognitive systems are strongly harnessed in humans and thus cannot be separated in neurorehabilitation. Recently developed technologies in motor-cognitive rehabilitation might have a greater positive effect than conventional therapies

Artificial Neural Network Detects Hip Muscle Forces as Determinant for Harmonic Walking in People after Stroke

Many recent studies have highlighted that the harmony of physiological walking is based on a specific proportion between the durations of the phases of the gait cycle. When this proportion is close to the so-called golden ratio (about 1.618), the gait cycle assumes an autosimilar fractal structure. In stroke patients this harmony is altered, but it is unclear which factor is associated with the ratios between gait phases because these relationships are probably not linear. We used an artificial neural network to determine the weights associable to each factor for determining the ratio between gait phases and hence the harmony of walking. As expected, the gait ratio obtained as the ratio between stride duration and stance duration was found to be associated with walking speed and stride length, but also with hip muscle forces. These muscles could be important for exploiting the recovery of energy typical of the pendular mechanism of walking. Our study also highlighted that the results of an artificial neural network should be associated with a reliability analysis, being a non-deterministic approach. A good level of reliability was found for the findings of our study

Motor imagery for paediatric neurorehabilitation: how much do we know? Perspectives from a systematic review

BackgroundMotor Imagery (MI) is a cognitive process consisting in mental simulation of body movements without executing physical actions: its clinical use has been investigated prevalently in adults with neurological disorders.ObjectivesReview of the best-available evidence on the use and efficacy of MI interventions for neurorehabilitation purposes in common and rare childhood neurological disorders.Methodssystematic literature search conducted according to PRISMA by using the Scopus, PsycArticles, Cinahl, PUBMED, Web of Science (Clarivate), EMBASE, PsychINFO, and COCHRANE databases, with levels of evidence scored by OCEBM and PEDro Scales.ResultsTwenty-two original studies were retrieved and included for the analysis; MI was the unique or complementary rehabilitative treatment in 476 individuals (aged 5 to 18 years) with 10 different neurological conditions including, cerebral palsies, stroke, coordination disorders, intellectual disabilities, brain and/or spinal cord injuries, autism, pain syndromes, and hyperactivity. The sample size ranged from single case reports to cohorts and control groups. Treatment lasted 2 days to 6 months with 1 to 24 sessions. MI tasks were conventional, graded or ad-hoc. MI measurement tools included movement assessment batteries, mental chronometry tests, scales, and questionnaires, EEG, and EMG. Overall, the use of MI was stated as effective in 19/22, and uncertain in the remnant studies.ConclusionMI could be a reliable supportive/add-on (home-based) rehabilitative tool for pediatric neurorehabilitation; its clinical use, in children, is highly dependent on the complexity of MI mechanisms, which are related to the underlying neurodevelopmental disorder