Assessment of Biomechanical Predictors of Occurrence of Low-Amplitude N1 Potentials Evoked by Naturally Occurring Postural Instabilities.

Naturally occurring postural instabilities that occur while standing and walking elicit specific cortical responses in the fronto-central regions (N1 potentials) followed by corrective balance responses to prevent falling. However, no framework could simultaneously track different biomechanical parameters preceding N1s, predict N1s, and assess their predictive power. Here, we propose a framework and show its utility by examining cortical activity (through electroencephalography [EEG]), ground reaction forces, and head acceleration in the anterior-posterior (AP) direction. Ten healthy young adults carried out a balance task of standing on a support surface with or without sway referencing in the AP direction, amplifying, or dampening natural body sway. Using independent components from the fronto-central cortical region obtained from subject-specific head models, we first robustly validated a prior approach on identifying low-amplitude N1 potentials before early signs of balance corrections. Then, a machine learning algorithm was used to evaluate different biomechanical parameters obtained before N1 potentials, to predict the occurrence of N1s. When different biomechanical parameters were directly compared, the time to boundary (TTB) was found to be the best predictor of the occurrence of upcoming low-amplitude N1 potentials during a balance task. Based on these findings, we confirm that the spatio-temporal characteristics of the center of pressure (COP) might serve as an essential parameter that can facilitate the early detection of postural instability in a balance task. Extending our framework to identify such biomarkers in dynamic situations like walking might improve the implementation of corrective balance responses through brain-machine-interfaces to reduce falls in the elderly.

Challenges to the central nervous system during human spaceflight missions to Mars.

Space travel presents a number of environmental challenges to the central nervous system, including changes in gravitational acceleration that alter the terrestrial synergies between perception and action, galactic cosmic radiation that can damage sensitive neurons and structures, and multiple factors (isolation, confinement, altered atmosphere, and mission parameters, including distance from Earth) that can affect cognition and behavior. Travelers to Mars will be exposed to these environmental challenges for up to 3 years, and space-faring nations continue to direct vigorous research investments to help elucidate and mitigate the consequences of these long-duration exposures. This article reviews the findings of more than 50 years of space-related neuroscience research on humans and animals exposed to spaceflight or analogs of spaceflight environments, and projects the implications and the forward work necessary to ensure successful Mars missions. It also reviews fundamental neurophysiology responses that will help us understand and maintain human health and performance on Earth.

Changes in gain of horizontal vestibulo-ocular reflex during spaceflight.

BACKGROUND: The vestibulo-ocular reflex (VOR) is a basic function of the vestibular system that stabilizes gaze during head movement. Investigations on how spaceflight affects VOR gain and phase are few, and the magnitude of observed changes varies considerably and depends on the protocols used. OBJECTIVE: We investigated whether the gain and phase of the VOR in darkness and the visually assisted VOR were affected during and after spaceflight. METHODS: We measured the VOR gain and phase of 4 astronauts during and after a Space Shuttle spaceflight while the subjects voluntary oscillated their head around the yaw axis at 0.33 Hz or 1 Hz and fixed their gaze on a visual target (VVOR) or imagined this target when vision was occluded (DVOR). Eye position was recorded using electrooculography and angular velocity of the head was recorded with angular rate sensors. RESULTS: The VVOR gain at both oscillation frequencies remained near unity for all trials. DVOR gain was more variable inflight and postflight. Early inflight and immediately after the flight, DVOR gain was lower than before the flight. The phase between head and eye position was not altered by spaceflight. CONCLUSION: The decrease in DVOR gain early in the flight and after the flight reflects adaptive changes in central integration of vestibular and proprioceptive sensory inputs during active head movements.

Fronto-Parietal Brain Areas Contribute to the Online Control of Posture during a Continuous Balance Task.

Neuroimaging studies have provided evidence for the involvement of frontal and parietal cortices in postural control. However, the specific role of these brain areas for postural control remains to be known. Here, we investigated the effects of disruptive transcranial magnetic stimulation (TMS) over supplementary motor areas (SMA) during challenging continuous balance task in healthy young adults. We hypothesized that a virtual lesion of SMA will alter activation within the brain network identified using electroencephalography (EEG) and impair performance of the postural task. Twenty healthy young adults received either continuous theta burst stimulation (cTBS) or sham stimulation over SMA followed by the performance of a continuous balance task with or without somatosensory input distortion created by sway-referencing the support surface. cTBS over SMA compared to sham stimulation showed a smaller increase in root mean square of center of pressure as the difficulty of continuous balance task increased suggestive of altered postural control mechanisms to find a stable solution under challenging sensory conditions. Consistent with earlier studies, we found sources of EEG activation within anterior cingulate (AC), cingulate gyrus (CG), bilateral posterior parietal regions (PPC) during the balance task. Importantly, cTBS over SMA compared to sham stimulation altered EEG power within the identified fronto-parietal regions. These findings suggest that the changes in activation within distant fronto-parietal brain areas following cTBS over SMA contributed to the altered postural behavior. Our study confirms a critical role of AC, CG, and both PPC regions in calibrating online postural responses during a challenging continuous balance task.

Critical Role of Somatosensation in Postural Control Following Spaceflight: Vestibularly Deficient Astronauts Are Not Able to Maintain Upright Stance During Compromised Somatosensation.

The free-fall of orbital spaceflight effectively removes the gravitational vector used as a primary spatial orientation reference on Earth. Sustained absence of this reference drives adaptive changes in the internal perception-action models of the central nervous system (CNS), most notably in the processing of the vestibular otolith inputs. Upon landing, the return of the gravitational signal triggers a re-adaptation that restores terrestrial performance; however, during this period, the individual suffers from a functional vestibular deficiency. Here we provide evidence of a transient increase of the weighting of somatosensory inputs in postural control while the CNS resolves these vestibular deficiencies. Postural control performance was measured before and after spaceflight in 11 Shuttle astronauts and 11 matched controls and nine elderly who did not experience spaceflight. A quiet-stance paradigm was used that eliminated vision, modulated the lower extremity somatosensory cues by subtly modulating the orientation of the support surface beneath feet of subjects in all groups. Additionally, in astronauts and matched controls, we challenged the vestibular system with dynamic head tilts. Postural stability on the landing day (R+0) was substantially decreased for trials with absent visual and altered somatosensory cues, especially those also requiring dynamic head tilts ( ± 5° @ 0.33 Hz) during which 20/22 trials ended prematurely with a fall. In contrast, none of the astronauts fell during eyes-closed, dynamic head tilt trials with unaltered somatosensory cues, and only 3/22 trials resulted in falls with eyes-closed and altered somatosensory cues, but static upright head orientation. Furthermore, postural control performance of astronauts was either statistically not different or worse than that of healthy elderly subjects during the most challenging vestibular conditions on R+0. Overall, our results demonstrate a transient reweighting of sensory cues associated with microgravity-induced vestibular deficiencies, with a significant increase in reliance on somatosensory cues, which can provide an effective reference even without vision and with dynamic vestibular challenges. The translation of these results to aging population suggests that elderly individuals with visual and vestibular deficits may benefit from therapeutic interventions enhancing sensorimotor-integration to improve balance and reduce the risk of falling.

Effects of speed and direction of perturbation on electroencephalographic and balance responses.

The modulation of perturbation-evoked potential (PEP) N1 as a function of different biomechanical characteristics of perturbation has been investigated before. However, it remains unknown whether the PEP N1 modulation contributes to the shaping of the functional postural response. To improve this understanding, we examined the modulation of functional postural response in relation to the PEP N1 response in ten healthy young subjects during unpredictable perturbations to their upright stance-translations of the support surface in a forward or backward direction at two different amplitudes of constant speed. Using independent components from the fronto-central region, obtained from subject-specific head models created from the MRI, our results show that the latency of onset of the functional postural response after the PEP N1 response was faster for forward than backward perturbations at a constant speed but was not affected by the speed of perturbation. Further, our results reinforce some of the previous findings that suggested that the N1 peak amplitude and peak latency are both modulated by the speed of perturbation but not by the direction of the perturbation. Our results improve the understanding of the relation between characteristics of perturbation and the neurophysiology of reactive balance control and may have implications for the design of brain-machine interfaces for populations with a higher risk of falls.

Cortical control of upright stance in elderly.

This study examined differences between young and elderly volunteers in cortical involvement to human posture control during quiet stance with normal and altered sensory stimulation (Experiment-1), and biomechanical perturbations (Experiment-2). The primary focus of the first part was to monitor changes in cortical activity when unexpectedly altering the sensory conditions of upright stance, such as switching from stable (eyes open, fixed support surface) to less-stable (eyes closed, sway-referenced support surface) conditions. Our results demonstrate increased cortical activations in delta (0.2-4 Hz) and gamma (30-50 Hz) oscillations, primarily over central-frontal, central, and central parietal cortices during challenging postural conditions. While increased delta rhythms were observed in both groups during challenging sensory conditions, elderly individuals also showed increased gamma band activity over sensorimotor and parietal cortices, when compared to the younger group. To our knowledge, this study is the first to show age differences in balance related cortical activations during continuous postural tasks with challenging sensory conditions. Preliminary correlations also suggest that increased cerebral activity became more relevant to the control of Center of Mass (COM) dynamics when upright stance is threatened. The results of Experiment-2 also showed for the first time that oscillatory rhythms of the cortex are coherent with muscle firing characteristics suggesting increased corticospinal drive from leg motor cortex to lower limb motoneurons following postural perturbations. Finally, perturbation evoked potential (PEP) analyses suggest that, rather than motor system malfunctioning, impairments in perceptual processing of sensory afference forms the basis of prolonged muscle response delays during perturbed balance in the elderly.

Assessing multiple muscle activation during squat movements with different loading conditions - an EMG study.

Surface electromyography (EMG) is a valuable tool in clinical diagnostics and research related to human neuromotor control. Non-linear analysis of EMG data can help with detection of subtle changes of control due to changes of external or internal constraints during motor tasks. However, non-linear analysis is complex and results may be difficult to interpret, particularly in clinical environments. We developed a non-linear analysis tool (SYNERGOS) that evaluates multiple muscle activation (MMA) features and provides a single value for description of activation characteristics. To investigate the responsiveness of SYNERGOS to kinetic changes during cyclic movements, 13 healthy young adults performed squat movements under different loading conditions (100%-120% of body weight). We processed EMG data to generate SYNERGOS indices and used two-way repeated measures ANOVA to determine changes of MMA in response to loading conditions during movement. SYNERGOS values were significantly different for each loading condition. We concluded that the algorithm is sensitive to kinetic changes during cyclic movements, which may have implications for applications in a variety of experimental and diagnostic settings.

Bed Rest and Intermittent Centrifugation Effects on Human Balance and Neuromotor Reflexes.

INTRODUCTION: The effects of repeated centrifugation in association with head-down tilt (HDT) bed rest (BR) on the mediation of basic reflexes associated with the major postural muscles was investigated as a potential countermeasure for maintaining balance control and neuromotor reflex function. METHODS: There were 15 male volunteers who were exposed to 21 d of 6° HDT-BR. Eight were treated with daily 1-h artificial gravity (AG) exposures aboard a short radius centrifuge that provided 1-g footward loading at heart level. The other seven served as HDT-BR control subjects. Balance control was assessed using a standard computerized dynamic posturography (CDP) protocol that was modified by adding low-frequency pitch-plane head movements. Neuromotor reflex function was assessed using tendon stretch reflexes (MSR) and functional stretch reflex (FSR) data collected from the triceps surae muscle group. RESULTS: CDP performance was degraded by HDT-BR in both groups (ranging from 24 to 26%), but was unaffected by AG. BR also degraded MSR and FSR functions in both groups, with increased peak reflex latencies between 1.5 and 1.95 ms, but AG maintained pre-BR latencies for the MSR subjects. DISCUSSION: AG exposure did not modify balance control from pre-BR responses, but did help prevent decrements in FSR latencies post-BR.Paloski WH, Reschke MF, Feiveson AH. Bed rest and intermittent centrifugation effects on human balance and neuromotor reflexes. Aerosp Med Hum Perform. 2017; 88(9):812-818.

Cortical activity modulations underlying age-related performance differences during posture-cognition dual tasking.

To date, no systematic research investigating cortical correlates of performance changes in dual tasking has been reported in the elderly population. Thus, we monitored whole-scalp cortical activations (EEG) during both single task and posture-cognition dual tasking with the main goal of understanding cortical activity modulations underlying age-related differences on posture-cognition dual tasking conditions. Postural and cognitive data analyses showed that elderly people had decreased cognitive performance even during challenging single cognitive tasks. Working memory impairments in the elderly group can be observed when a challenging cognitive task is performed in any postural condition, while postural control performance differences only became significant during challenging dual task conditions. Behavioral performance results, in general, indicate that elderly subjects may adopt a non-automated conscious control strategy and prioritize postural performance over cognitive performance to maintain upright stance only when the cognitive load is low. EEG analyses showed increased delta, theta and gamma oscillations, primarily over frontal, central-frontal, central and central-parietal cortices during dual tasking conditions. We found that delta oscillations were more responsive to challenging postural conditions presumably related to cortical representations of changing sensory conditions in postural tasks. Theta rhythms, on the other hand, were more responsive to cognitive task difficulty in both groups, with more pronounced increases in younger subjects which may underlie neural correlates of high-level cognitive computations including encoding and retrieval. Gamma oscillations also increased in the elderly primarily over central and central-parietal cortices during challenging postural tasks, indicating increased allocation of attentional sources to postural tasks.

Motor Control Performance During Rapid Voluntary Movements of Elbow and Knee.

Knowledge of motor control differences during rapid goal-directed movements of the upper and lower limbs could be useful in improving rehabilitation protocols. The authors investigated performance and control differences between elbow and knee joints and between different contraction types (concentric vs. eccentric) during rapid movements under externally applied load. There were no significant differences in performance and control with respect to joint (elbow vs. knee) but the performance during concentric contractions was better than eccentric for both the joints. The findings indicate that despite anatomical and functional differences, the CNS is finely tuned for both the joints to maximize the efficiency of movement during a dynamic environment, but there are differences in control strategies between the 2 contraction types.

Smartphone-based tactile cueing improves motor performance in Parkinson's disease.

INTRODUCTION: Visual and auditory cueing improve functional performance in Parkinson's disease (PD) patients. However, audiovisual processing shares many cognitive resources used for attention-dependent tasks such as communication, spatial orientation, and balance. Conversely, tactile cues (TC) may be processed faster, with minimal attentional demand, and may be more efficient means for modulating motor-cognitive performance. In this study we aimed to investigate the efficacy and limitations of TC for modulating simple (heel tapping) and more complex (walking) motor tasks (1) over a range of cueing intervals, (2) with/without a secondary motor task (holding tray with cups of water). METHODS: Ten PD patients (71 ± 9 years) and 10 healthy controls (69 ± 7 years) participated in the study. TCs was delivered through a smart phone attached to subjects' dominant arm and were controlled by a custom-developed Android application. RESULTS: PD patients and healthy controls were able to use TC to modulate heel tapping (F(3.8,1866.1) = 1008.1, p < 0.001), and partially modulate walking (F(3.5,1448.7) = 187.5, p < 0.001) tasks. In the walking task, PD patients modulated performance over a narrower range of cueing intervals (R(2) = 0.56) than healthy controls (R(2) = 0.84; group difference F(3.5,1448.7) = 8.6, p < 0.001). TC diminished synchronization error associated with performance of secondary motor task during walking in PD patients and healthy controls (main effect of Task (F(1,494) = 0.4; p = 0.527), Task X Group interaction (F(1,494) = 0.5; p = 0.493)). CONCLUSION: This study expands modalities of TC usage for movement modulation and motor-cognitive integration in PD patients. The smartphone TC application was validated as a user-friendly movement modulation aid.

Measuring multiple neuromuscular activation using EMG - a generalizability analysis.

Analysis of electromyography (EMG) data has been shown to be valuable in biomedical and clinical research. However, most analysis tools do not consider the non-linearity of EMG data or the synergistic effects of multiple neuromuscular activities. The SYNERGOS algorithm was developed to assess a single index based on non-linear analysis of multiple neuromuscular activation (MNA) of different muscles. This index has shown promising results in Parkinsonian gait, but it was yet to be explored whether the SYNERGOS index is generalizable. In this study, we evaluated generalizability of the SYNERGOS index over the course of several trials and over separate days with different walking speeds. Ten healthy adults aged from 18 to 40 years walked on a treadmill on two different days, while EMG data was collected from the upper and lower right leg. SYNERGOS indices were obtained and a generalizability analysis was conducted. The algorithm detected changes in MNA in response to altering gait speed and depicted a high generalizability coefficient ( ρ^2 ${\hat \rho ^2}$ ) of 0.823 with a standard error of 5.117 with nominal inter-trial or inter-day effects. We concluded SYNERGOS may be a valuable tool in EMG analysis due to its generalizability and its sensitivity to task modifications and associated neuromotor changes.

Towards human exploration of space: the THESEUS review series on neurophysiology research priorities.

The THESEUS project (Towards Human Exploration of Space: a European Strategy), initiated within the seventh Framework Programme by the European Commission, aimed at providing a cross-cutting, life-science-based roadmap for Europe's strategy towards human exploration of long space missions, and its relevance to applications on Earth. This topic was investigated by experts in the field, in the framework of the THESEUS project whose aim was to develop an integrated life sciences research roadmap regarding human space exploration. In particular, decades of research have shown that altered gravity impairs neurological responses at large, such as perception, sleep, motor control, and cognitive factors. International experts established a list of key issues that should be addressed in that context and provided several recommendations such as a maximal exploitation of currently available resources on Earth and in space.

Assessing Sensorimotor Function Following ISS with Computerized Dynamic Posturography.

INTRODUCTION: Postflight postural ataxia reflects both the control strategies adopted for movement in microgravity and the direct effects of deconditioning. Computerized dynamic posturography (CDP) has been used during the first decade of the International Space Station (ISS) expeditions to quantify the initial postflight decrements and recovery of postural stability. METHODS: The CDP data were obtained on 37 crewmembers as part of their pre- and postflight medical examinations. Sensory organization tests evaluated the ability to make effective use of (or suppress inappropriate) visual, vestibular, and somatosensory information for balance control. This report focuses on eyes closed conditions with either a fixed or sway-referenced base of support, with the head erect or during pitch-head tilts (± 20° at 0.33 Hz). Equilibrium scores were derived from peak-to-peak anterior-posterior sway. Motor-control tests were also used to evaluate a crewmember's ability to automatically recover from unexpected support-surface perturbations. RESULTS: The standard Romberg condition was the least sensitive. Dynamic head tilts led to increased incidence of falls and revealed significantly longer recovery than head-erect conditions. Improvements in postflight postural performance during the later expeditions may be attributable to higher preflight baselines and/or advanced exercise capabilities aboard the ISS. CONCLUSIONS: The diagnostic assessment of postural instability is more pronounced during unstable-support conditions requiring active head movements. In addition to supporting return-to-duty decisions by flight surgeons, the CDP provides a standardized sensorimotor measure that can be used to evaluate the effectiveness of countermeasures designed to either minimize deconditioning on orbit or promote reconditioning upon return to Earth.

Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions.

In spite of the experience gained in human space flight since Yuri Gagarin's historical flight in 1961, there has yet to be identified a completely effective countermeasure for mitigating the effects of weightlessness on humans. Were astronauts to embark upon a journey to Mars today, the 6-month exposure to weightlessness en route would leave them considerably debilitated, even with the implementation of the suite of piece-meal countermeasures currently employed. Continuous or intermittent exposure to simulated gravitational states on board the spacecraft while traveling to and from Mars, also known as artificial gravity, has the potential for enhancing adaptation to Mars gravity and re-adaptation to Earth gravity. Many physiological functions are adversely affected by the weightless environment of spaceflight because they are calibrated for normal, Earth's gravity. Hence, the concept of artificial gravity is to provide a broad-spectrum replacement for the gravitational forces that naturally occur on the Earth's surface, thereby avoiding the physiological deconditioning that takes place in weightlessness. Because researchers have long been concerned by the adverse sensorimotor effects that occur in weightlessness as well as in rotating environments, additional study of the complex interactions among sensorimotor and other physiological systems in rotating environments must be undertaken both on Earth and in space before artificial gravity can be implemented.

Short-arm centrifugation as a partially effective musculoskeletal countermeasure during 5-day head-down tilt bed rest--results from the BRAG1 study.

PURPOSE: Human centrifugation, also called artificial gravity (AG), is proposed as a combined strategy against detrimental effects of microgravity in long-term space missions. This study scrutinized human short-arm centrifugation as countermeasure against musculoskeletal de-conditioning. METHOD: Eleven healthy male subjects [mean age of 34 (SD 7) years] completed the cross-over trial, including three campaigns of -6° head-down tilt bed rest (HDT) for 5 days, with preceding baseline data collection and recovery phases. Bed rest without AG was used as control condition (Ctrl), and AG with 1 g at the center of mass applied once per day for 30 min in one bout (AG1×30) and in 6 bouts of 5 min (AG6×5, 3-min rest between bouts) as experimental conditions. End-points were muscle strength, vertical jump performance, and biomarkers of bone and protein metabolism. RESULT: AG6×5 was better tolerated than AG1×30. Bone resorption markers CTX, NTX, and DPD all increased by approximately 25 % toward the end of bed rest (P < 0.001), and nitrogen balance decreased by approximately 3 g/day (P < 0.001), without any protection by AG (P > 0.4). Decreases in vertical jump height by 2.1 (SE 0.6) cm after Ctrl bed rest was prevented by either of the AG protocols (P = 0.039). CONCLUSION: The present study yielded succinct catabolic effects upon muscle and bone metabolism that were un-prevented by AG. The preservation of vertical jump performance by AG in this study is likely caused by central nervous rather than by peripheral musculoskeletal effects.

Identification of Changing Lower Limb Neuromuscular Activation in Parkinson's Disease during Treadmill Gait with and without Levodopa Using a Nonlinear Analysis Index.

Analysis of electromyographic (EMG) data is a cornerstone of research related to motor control in Parkinson's disease. Nonlinear EMG analysis tools have shown to be valuable, but analysis is often complex and interpretation of the data may be difficult. A previously introduced algorithm (SYNERGOS) that provides a single index value based on simultaneous multiple muscle activations (MMA) has been shown to be effective in detecting changes in EMG activation due to modifications of walking speeds in healthy adults. In this study, we investigated if SYNERGOS detects MMA changes associated with both different walking speeds and levodopa intake. Nine male Parkinsonian patients walked on a treadmill with increasing speed while on or off medication. We collected EMG data and computed SYNERGOS indices and employed a restricted maximum likelihood linear mixed model to the values. SYNERGOS was sensitive to neuromuscular modifications due to both alterations of gait speed and intake of levodopa. We believe that the current experiment provides evidence for the potential value of SYNERGOS as a nonlinear tool in clinical settings, by providing a single value index of MMA. This could help clinicians to evaluate the efficacy of interventions and treatments in Parkinson's disease in a simple manner.

Effects of an artificial gravity countermeasure on orthostatic tolerance, blood volumes and aerobic power after short-term bed rest (BR-AG1).

Exposure to artificial gravity (AG) in a short-arm centrifuge has potential benefits for maintaining human performance during long-term space missions. Eleven subjects were investigated during three campaigns of 5 days head-down bed rest: 1) bed rest without countermeasures (control), 2) bed rest and 30 min of AG (AG1) daily, and 3) bed rest and six periods of 5 min AG (AG2) daily. During centrifugation, the supine subjects were exposed to AG in the head-to-feet direction with 1 G at the center of mass. Subjects participated in the three campaigns in random order. The cardiovascular effects of bed rest and countermeasures were determined from changes in tolerance to a head-up tilt test with superimposed lower body negative pressure (HUT), from changes in plasma volume (PV) and from changes in maximum aerobic power (V̇o2 peak) during upright work on a cycle ergometer. Complete data sets were obtained in eight subjects. After bed rest, HUT tolerance times were 36, 64, and 78% of pre-bed rest baseline during control, AG1 and AG2, respectively, with a significant difference between AG2 and control. PV and V̇o2 peak decreased to 85 and 95% of pre-bed rest baseline, respectively, with no differences between the treatments. It was concluded that the AG2 countermeasure should be further investigated during future long-term bed rest studies, especially as it was better tolerated than AG1. The superior effect of AG2 on orthostatic tolerance could not be related to concomitant changes in PV or aerobic power.

Simultaneous scalp electroencephalography (EEG), electromyography (EMG), and whole-body segmental inertial recording for multi-modal neural decoding.

Recent studies support the involvement of supraspinal networks in control of bipedal human walking. Part of this evidence encompasses studies, including our previous work, demonstrating that gait kinematics and limb coordination during treadmill walking can be inferred from the scalp electroencephalogram (EEG) with reasonably high decoding accuracies. These results provide impetus for development of non-invasive brain-machine-interface (BMI) systems for use in restoration and/or augmentation of gait- a primary goal of rehabilitation research. To date, studies examining EEG decoding of activity during gait have been limited to treadmill walking in a controlled environment. However, to be practically viable a BMI system must be applicable for use in everyday locomotor tasks such as over ground walking and turning. Here, we present a novel protocol for non-invasive collection of brain activity (EEG), muscle activity (electromyography (EMG)), and whole-body kinematic data (head, torso, and limb trajectories) during both treadmill and over ground walking tasks. By collecting these data in the uncontrolled environment insight can be gained regarding the feasibility of decoding unconstrained gait and surface EMG from scalp EEG.