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Rod and Frame Testing (RFT) has been used to investigate the effects of an altered visual frame of reference on subjective visual vertical. RFT requires an individual to align a luminous rod as best they can with true vertical.

Individuals with Rett syndrome (RTT) exhibit impaired motor performance and gait performance, leading to decreased quality of life. Currently, there is no robust observational instrument to identify gait characteristics in RTT. Current scales are limited as individuals with intellectual disorders may be unable to understand instructions. Our primary purpose was to utilize video analysis to characterize the behaviors associated with walking in individuals with RTT and explore the relationship between behaviors during overground and during treadmill walking.Fourteen independently ambulatory females with RTT were video-taped and observed during overground and treadmill walking. Their gait was codified into an observational checklist to reveal prominent features associated with gait in this population.Participants exhibited similar rates of freezing, veering, and hand stereotypies between overground and treadmill walking; however, freeze duration was shortened during treadmill walking. Toe walking was prominently exhibited during overground, but not treadmill walking. During both walking modes, participants required extensive external motivation to maintain their walking patterns.Results identify several gait characteristics observable during overground and treadmill walking. In general, participants behaved similarly during overground and treadmill walking. We conclude that both overground and treadmill walking are appropriate tools to evaluate gait in this population.Implications for rehabilitationLocomotor rehabilitation may increase the quantity of walking performed by the patients, which can alleviate negative effects of the sedentary lifestyle commonly observed in patients with Rett syndrome (RTT).Video analysis of natural walking can be an effective tool to characterize gait in patients with RTT which does not require particular instructions which may not be fully understood.Both overground and treadmill walking are appropriate means of evaluating gait in individuals with RTT.

Fear of falling is a critical component in fall prevention approaches; however, it is often overlooked in the majority of fall prevention exercises. Alternative fall prevention approaches that take fear of falling into account are necessary. This article discusses fall prevention activities that are feasible for individuals with limited mobility who have an increased fear of falling. Health care providers should consider the degree to which a patient has a fear of falling and recommend activities that fit most to their patient’s comfort level.

Background and purpose Individuals with Rett syndrome suffer from severely impaired cognitive and motor performance. Current movement-related therapeutic programs often include traditional physical therapy activities and assisted treadmill walking routines for those individuals who are ambulatory. However, there are no quantitative reports of kinematic gait parameters obtained during treadmill walking. The purpose of this research was to characterize the kinematic patterns of the lower limbs during treadmill walking as speed was slowly increased. Methods Seventeen independently ambulatory females diagnosed with a methyl-CpG-binding protein 2 gene mutation walked on a motorized treadmill while joint kinematics were obtained by a camera-based motion capture system and analysis software. Results Stride times progressively decreased as treadmill speeds increased. There were significant main effects of speed on sagittal knee and hip ranges of motion and hip velocity. There were large joint asymmetries and variance values relative to other ambulatory patient populations, although variance values decreased as walking speed increased. Conclusions The results indicate that individuals with Rett syndrome can adapt their kinematic gait patterns in response to increasing treadmill speed, but only within a narrow range of speeds. We suggest that treadmill training for ambulatory individuals with Rett syndrome may promote improved walking kinematics and possibly provide overall health benefits.Implications for rehabilitationWalking is an activity that can counter the negative impacts of the sedentary lifestyle of many individuals with disabilities, including those individuals with Rett syndrome.Documentation of the lower limb kinematic patterns displayed during walking by ambulatory females with Rett syndrome can be used by clinicians to evaluate their patients' gait performance in response to therapeutic and pharmacological interventions designed to promote walking.The ability to adapt to increases in treadmill speed suggests that a training program of treadmill walking may be effective in promoting improved gait performance in individuals with Rett syndrome.

Wearable robotic devices are being designed to assist the elderly population and other patients with locomotion disabilities. However, wearable robotics increases the risk from falling. Neuroimaging studies have provided evidence for the involvement of frontocentral and parietal cortices in postural control and this opens up the possibility of using decoders for early detection of balance loss by using electroencephalography (EEG). This study investigates the presence of commonly identified components of the perturbation evoked responses (PEP) when a person is in an exoskeleton. We also evaluated the feasibility of using single-trial EEG to predict the loss of balance using a convolution neural network. Overall, the model achieved a mean 5-fold cross-validation test accuracy of 75.2 % across six subjects with 50% as the chance level. We employed a gradient class activation map-based visualization technique for interpreting the decisions of the CNN and demonstrated that the network learns from PEP components present in these single trials. The high localization ability of Grad-CAM demonstrated here, opens up the possibilities for deploying CNN for ERP/PEP analysis while emphasizing on model interpretability.

Postural adaptability is related to central sensory integration and reweighting efficiency. Incline-interventions lead to lean after-effect (LAE), but it is not fully known how sensory reweighting may affect the magnitude and duration of LAE. We tasked fifteen young and healthy subjects with performing incline-interventions under conditions designed to perturb proprioception during or after the incline-intervention. We found that support surface configuration affected responses to tendon vibration. Additionally, vibration during an incline-intervention did not inhibit LAE, but vibration during an after-effect significantly affected LAE. Results reinforce claims that postural adaptation is based on modifications of central mechanisms of perception, not peripheral shank proprioceptors and improve our understanding of the role of sensory reweighting and sensory integration into postural adaptability.

Background Vibration applied on the mastoid has been shown to be an excitatory stimulus to the vestibular receptors, but its effect on vestibular perception is unknown. Objective Determine whether mastoid vibration affects yaw rotation perception using a self-motion perceptual direction-recognition task. Methods We used continuous, bilateral, mechanical mastoid vibration using a stimulus with frequency content between 1 and 500 Hz. Vestibular perception of 10 healthy adults (M±S.D. = 34.3±12 years old) was tested with and without vibration. Subjects repeatedly reported the perceived direction of threshold-level yaw rotations administered at 1 Hz by a motorized platform. A cumulative Gaussian distribution function was fit to subjects' responses, which was described by two parameters: bias and threshold. Bias was defined as the mean of the Gaussian distribution, and equal to the motion perceived on average when exposed to null stimuli. Threshold was defined as the standard deviation of the distribution and corresponded to the stimulus the subject could reliably perceive. Results The results show that mastoid vibration may reduce bias, although two statistical tests yield different conclusions. There was no evidence that yaw rotation thresholds were affected. Conclusions Bilateral mastoid vibration may reduce left-right asymmetry in motion perception.

Rett syndrome is a severe neurodevelopmental disorder leading to intellectual impairment and global developmental delays, including difficulty or inability to walk. Assessing differences in temporal parameters and associated variability between overground and treadmill walking is important if gait training is to be incorporated into intervention protocols. Fourteen female patients with Rett syndrome (mean age 10.4 years ± SD 5.1) were evaluated during overground and treadmill walking. Stride, stance, swing, and double support times, and the variance of these measures, were obtained. Wilcoxon signed-rank tests were used to assess for potential differences between overground and treadmill measures. Treadmill gait resulted in decreases in swing and double support times. When normalized to stride time, treadmill gait displayed an increase in stance time with decreases in swing and double support times. Excepting stance time, treadmill gait resulted in decreased variability, indicating a more regularized gait while walking on the treadmill. These results suggest that treadmill walking can be beneficial for ambulatory patients with Rett syndrome and could be incorporated into a therapeutic protocol designed to maintain the maximum degree of mobility and overall general health as part of a comprehensive health management approach.

Effective fall prevention technologies need to detect and transmit the key information that will alert an individual in advance about a potential fall. This study investigated advanced vibrotactile cuing that may facilitate trip recovery for balance-impaired individuals who are prone to falling. A split-belt treadmill that simulated unpredictable trip perturbations was developed to compare balance recovery without and with cuing. Kinetic and kinematic measures from force plates and full body motion capture system were used to characterize the recovery responses. Experiment I evaluated recovery adaptation resulting from repeated trip exposure without vibrotactile cuing. Experiment II investigated the effects of vibrotactile cuing as a function of cuing location (upper arm, trunk, lower leg) and lead time prior to a trip (250, 500 ms). Experiment I showed that trip recovery improved progressively from the fourth to the eighth trial. Experiment II showed that trip recovery was almost the same as the eighth trial in Experiment I, regardless of the location of the cuing stimulus and lead time. The results suggest that a combination of vibrotactile cuing and hazard detection technology could reduce the risk of trips and falls.

Obesity has been associated with negative effects on postural control, including falls. Previous studies revealed different outcomes regarding the effects of obesity on gait features, and the use of BMI may lead to bias in assessing the true effects of obesity on gait. To better understand the effects of obesity on gait, it is important to examine gait features and associated body composition measures. The purpose of this study was: (1) to assess gait features of normal weight, overweight and obese adults, and (2) to assess the relationship between body composition measures and gait features. Thirty participants were assigned to one of three groups based upon their BMI at the onset of the study: healthy weight (BMI: 18.5-24.9kg/m2), overweight (BMI: 25-29.9kg/m2), or obese (BMI: 30-40kg/m2). Participants performed straight-line over-ground walking through a 200m hallway at their natural preferred speed while wearing their own shoes. The angular displacements, range of motion (ROM), and approximate entropy of kinematic data of the bilateral hips, knees, and ankles in the sagittal plane were computed. Walking speed, step length, stride length, single leg support phase, double leg support phase, swing phase and bilateral stance phase times were extracted from the GaitRite data. Overall, body mass and BMI were associated with peak flexion and ROM in the knees as well as single support, double support, stance, and swing phases. Body fat percentage did not exhibit correlations with measured gait features. Gait variables were more highly correlated with BMI and body mass instead of percent body fat, suggesting that absolute mass is more influential on gait features rather than amount of fat tissue.

Background: The purpose of the review is to summarize the literature surrounding the use of muscle vibration as it relates to modifying human gait. Methods: After a brief introduction concerning historical uses and early research identifying the effect of vibration on muscle activation, we reviewed 32 articles that used muscle vibration during walking. The review is structured to address the literature within four broad categories: the effect of vibration to 'trigger' gait-like lower limb motions, the effect of vibration on gait control of healthy individuals and individuals with clinical conditions in which gait disorders are a prominent feature, and the effect of vibration training protocols on gait. Results: The acute effects of vibration during gait involving healthy participants is varied. Some authors reported differences in segmental kinematic and spatiotemporal measures while other authors reported no differences in these outcome measures. The literature involving participants with clinical conditions revealed that vibration consistently had a significant impact on gait, suggesting vibration may be an effective rehabilitation tool. All of the studies that used vibration therapy over time reported significant improvement in gait performance. Conclusions: This review highlights the difficulties in drawing definitive conclusions as to the impact of vibration on gait control, partly because of differences in walking protocols, site of vibration application, and outcome measures used across different investigative teams. It is suggested that the development of common investigative methodologies and outcome measures would accelerate the identification of techniques that may provide optimal rehabilitation protocols for individuals experiencing disordered gait control.

Motor responses to unexpected external perturbations require the adjustment of the motor commands driving the ongoing activity. Strategies can be learned with practice to compensate for these unpredictable perturbations (e.g., externally induced slips and trips). It has been hypothesized that response improvements reflect the adaptation of motor commands through updates of an internal model. This hypothesis may be nuanced when a pre-existing motor response could be used. In that case, since a relatively adequate response is known, only the timing of the command needs to be determined. If so, then it could be inferred that the timing of movement initiation and the specific sequence of motor commands can be dissociated. Previously, we quantified the benefits of cuing vs. learning on recovery motor responses resulting from a trip induced by the abrupt stop of one side of a split belt treadmill. Trip occurrence was randomized within a series of strides. Two groups of young adults participated to two distinct experiments (learning, cuing). In the learning experiment, trip recovery improved progressively from the 4th to the 8th trial to reach an "adapted response". In the cuing experiment, trip recovery was immediate (from 1st trial). Expanding from these results, the aim of the present work was to differentiate the processes underlying the generation of motor compensation strategies in response to an external perturbation under time uncertainty. A supplementary analysis revealed that "cued" responses were kinematically similar to the "adapted response" and remained invariant regardless of cue lead time (250, 500 ms before trip) and application location of the cue (arm, trunk, lower leg). It is posited that all responses (cued and non-cued) are the expression of a pre-existing motor program derived from life experiences. Here, the cue significantly reduces time uncertainty and adaptation consists primarily in resolving time uncertainty based on the trial-by-trial learning of the stochastic property of trip occurrence in order to reduce the response delay. Hence, response time delay and motor program parameters appear to stem from two distinct processes.

The Zibrio SmartScale is a low-cost, portable force platform designed to perform an objective assessment of postural stability. The purpose of the present study was to validate the center of pressure (COP) measurements in the Zibrio SmartScale. Simultaneous COP data was collected by a Zibrio SmartScale and a laboratory-grade force platform (LFP) under the dynamic motion of an inverted pendulum device intended to mimic the sway of a standing human. The inverted pendulum was placed on the Zibrio SmartScale which was placed on the LFP. The pendulum was then displaced to angles of 3° and 5° in both the anterior-posterior (AP) and medial–lateral (ML) directions. The findings of this study show low mean average error (MAE) among the measures taken simultaneously upon the LFP and Zibrio SmartScale with no appreciable difference in error in either AP or ML COP directions. Averaged over repeated trials, the MAE did not surpass 0.5 mm. This represented 0.4% of the total range (±50 to 60 mm in 5° displacement trials) of simulated COP. The results of this study strongly indicate that the Zibrio SmartScale can perform adequately as a light-weight and low-cost alternative method of COP measurement in comparison to a traditional LFP.

The sensory re-weighting theory suggests unreliable inputs may be down-weighted to favor more reliable sensory information and thus maintain proper postural control. This study investigated the effects of tibialis anterior (TA) vibration on center of pressure (COP) motion in healthy individuals exposed to support surface translations to further explore the concept of sensory re-weighting. Twenty healthy young adults stood with eyes closed and arms across their chest while exposed to randomized blocks of five trials. Each trial lasted 8 s, with TA vibration either on or off. After 2 s, a sudden backward or forward translation occurred. Anterior-posterior (A/P) COP data were evaluated during the preparatory (first 2 s), perturbation (next 3 s), and recovery (last 3 s) phases to assess the effect of vibration on perturbation response features. The knowledge of an impending perturbation resulted in reduced anterior COP motion with TA vibration in the preparatory phase relative to the magnitude of anterior motion typically observed during TA vibration. During the perturbation phase, vibration did not influence COP motion. However, during the recovery phase vibration induced greater anterior COP motion than during trials without vibration. The fact that TA vibration produced differing effects on COP motion depending upon the phase of the perturbation response may suggest that the immediate context during which postural control is being regulated affects A/P COP responses to TA vibration. This indicates that proprioceptive information is likely continuously re-weighted according to the context in order to maintain effective postural control.

Specific activities that require concurrent processing of postural and cognitive tasks may increase the risk for falls in older adults. We investigated whether peripheral receptor sensitivity was associated with postural performance in a dual-task and whether an intervention in form of subthreshold vibration could affect performance. Ten younger (age: 20–35 years) and ten older adults (70–85 years) performed repeated auditory-verbal 1-back tasks while standing quietly on a force platform. Foot sole vibration was randomly added during several trials. Several postural control and performance measures were assessed and statistically analyzed (significance set toα-levels of .05). There were moderate correlations between peripheral sensitivity and several postural performance and control measures (r=.45to .59). Several postural performance measures differed significantly between older and younger adults (p<0.05); addition of vibration did not affect outcome measures. Aging affects healthy older adults’ performance in dual-tasks, and peripheral sensitivity may be a contributor to the observed differences. A vibration intervention may only be useful when there are more severe impairments of the sensorimotor system. Hence, future research regarding the efficacy of sensorimotor interventions in the form of vibrotactile stimulation should focus on older adults whose balance is significantly affected.

The Childhood Obesity Research Demonstration (CORD) project links public health and primary care interventions in three projects described in detail in accompanying articles in this issue of Childhood Obesity. This article describes a comprehensive evaluation plan to determine the extent to which the CORD model is associated with changes in behavior, body weight, BMI, quality of life, and healthcare satisfaction in children 2-12 years of age.The CORD Evaluation Center (EC-CORD) will analyze the pooled data from three independent demonstration projects that each integrate public health and primary care childhood obesity interventions. An extensive set of common measures at the family, facility, and community levels were defined by consensus among the CORD projects and EC-CORD. Process evaluation will assess reach, dose delivered, and fidelity of intervention components. Impact evaluation will use a mixed linear models approach to account for heterogeneity among project-site populations and interventions. Sustainability evaluation will assess the potential for replicability, continuation of benefits beyond the funding period, institutionalization of the intervention activities, and community capacity to support ongoing program delivery. Finally, cost analyses will assess how much benefit can potentially be gained per dollar invested in programs based on the CORD model.The keys to combining and analyzing data across multiple projects include the CORD model framework and common measures for the behavioral and health outcomes along with important covariates at the individual, setting, and community levels. The overall objective of the comprehensive evaluation will develop evidence-based recommendations for replicating and disseminating community-wide, integrated public health and primary care programs based on the CORD model.

With human exploration of the Moon and Mars on the horizon, research considerations for space suit redesign have surfaced. Review of Apollo mission videos revealed repeated instance of falling during extravehicular activities. A better understanding of how suit weight influences the sagittal dynamic stability of the gait pattern may provide insight for new suit design such that space missions may have more productive extravehicular activities and smaller risk of falls that may cause injuries and damage equipment. Participants walked for 4 min in simulated Martian gravity with additional loads of 0%, 15%, 30% and 45% of their body weight. Floquet and Lyapunov analysis techniques were used to quantify the dynamic stability of the sagittal plane gait pattern. Additionally, sagittal plane joint kinematics were evaluated to determine if any modification occurred. Results indicated that weight (i.e., added load) had little effect on the sagittal dynamic stability or joint kinematics while in simulated Martian gravity. Potentially, suit weight may not be a priority for space suit redesign.

We propose that a passive countermeasure employing mechanical stimulation of the feet can be used during spaceflight to attenuate neuromotor degradation. The purpose of this investigation was to determine whether the time between consecutive stimuli to the human sole influences the subsequent muscle contraction response. Participants were exposed to mechanical stimulation of the right sole in a protocol of six conditions of stimulation couplets. Stimulation couplets consisted of two closely timed stimuli separated by an interstimulus interval (ISI) of either 100, 140, 180, 220, 260, or 300 ms. Electromyography of the leg musculature was collected. The focus of the analyses was the amplitude of the response to the second stimulus of each couplet relative to the isolated baseline response. The results indicate that the second response in a couplet was inhibited up to 220 ms ISI, but returned to baseline with greater ISIs. When developing an inflight dynamic foot stimulator it will be important to ensure that the timing between the stimulations is separated by ISIs that prevents the inhibition of neuromuscular activation.

Appropriate neuromuscular responses to support surface perturbations are crucial to prevent falls, but aging-related anatomical and physiological changes affect the appropriateness and efficiency of such responses. Low-level noise application to sensory receptors has shown to be effective for postural improvement in a variety of different balance tasks, but it is unknown whether this intervention may have value for improvement of corrective postural responses. Ten healthy younger and ten healthy older adults were exposed to sudden backward translations of the support surface. Low-level noise (mechanical vibration) to the foot soles was added during random trials and temporal (response latency) and spatial characteristics (maximum center-of-pressure excursion and anterior-posterior path length) of postural responses were assessed. Mixed-model ANOVA was applied for analysis of postural response differences based on age and vibration condition. Age affected postural response characteristics, but older adults were well able to maintain balance when exposed to a postural perturbation. Low-level noise application did not affect any postural outcomes. Healthy aging affects some specific measures of postural stability, and in high-functioning older individuals, a low-level noise intervention may not be valuable. More research is needed to investigate if recurring fallers and neuropathy patients could benefit from the intervention in postural perturbation tasks.

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.

Purpose: Leg muscle strength and power are increased after whole-body vibration (WBV) exercise. These effects may result from increased neuromuscular activation during WBV; however, previous studies of neuromuscular responses during WBV have not accounted for motion artifact. Methods: Sixteen healthy adults performed a series of static and dynamic unloaded squats with and without two different directions of WBV (rotational vibration, RV; and vertical vibration, VV; 30 Hz; 4 mmp-p). Activation of unilateral vastus lateralis, biceps femoris, gastrocnemius, and tibialis anterior was recorded using EMG. During RV and VV, increases in EMG relative to baseline were compared over a range of knee angles, contraction types (concentric, eccentric, isometric), and squatting types (static, dynamic). Results: After removing large, vibration-induced artifacts from EMG data using digital band-stop filters, neuromuscular activation of all four muscles increased significantly (P = 0.05) during RV and VV. Average responses of the extensors were significantly greater during RV than VV, whereas responses of the tibialis anterior were significantly greater during VV than RV. For all four muscles, responses during static squatting were greater than or equal to responses during dynamic squatting, whereas responses during eccentric contractions were equal to or smaller than responses during concentric and isometric contractions. Neuromuscular responses of vastus lateralis, gastrocnemius, and tibialis anterior were affected by knee angle, with greatest responses at small knee angles. Conclusions: Motion artifacts should be removed from EMG data collected during WBV. We propose that neuromuscular responses during WBV may be modulated by leg muscle cocontraction as a postural control strategy and/or muscle tuning by the CNS intended to minimize soft-tissue vibration.

Previous studies have shown that men can balance a dowel rod on the index finger for a longer time than women can. The factors that account for the difference are unknown, but the difference may be attributable either to a difference in whole-body agility or a difference in the use of visual cues. Three experiments involving a total of 62 adult women with a mean age of 21.2yr. ( SD = 3.8) and 62 adult men with a mean age of 21.9yr. ( SD = 6.6) tested these potential explanations. Experiment 1 replicated the sex difference and assessed the relevance of whole-body agility by comparing standing and seated conditions. Experiments 2 and 3 explored the role of rod length and visual fixation point, respectively. Each experiment yielded a significant sex difference, but the difference was not affected by the participant's posture, the length of the rod, or the fixation point. Possible alternative explanations for the difference include differences in (1) the speed of processing degree of visual tilt; (2) arm mass, which affects the inertia of the balancing system; and (3) experience in open-skill sports.

This paper describes the design of a smartphone based fall detection system and characterizes the preliminary efficacy of the proposed system in activities of daily living (ADLs). Using the embedded sensors available in a smartphone (i.e., accelerometer, gyroscope and magnetometer), kinematic analysis of movement can be performed in real-time, allowing for continuous monitoring of fall status. Fall sensing thresholds are defined based on angular rate of change (TH1), maximum acceleration (TH2), and maximum attitude change (TH3). TH1 is measured from the resultant pitch and roll angular velocity vector and defined as 3.1 rad/s (∼180°/s). TH2 is measured from the resultant acceleration vector and defined as 1.6 g. TH3 is measured from the resultant vector of the pitch and roll angles, and defined at 0.59 rad (39°). A proof-of-concept study was performed on five ADL tasks: 1) comfortable walking, 2) stand-to-seated posture, 3) seated-to-standing posture, 4) pivoting at the waist to pick up an object, and 5) stand-to-seated-to-laying transition. No trials violated the defined thresholds for fall detection, signifying no false positives. These results are important for the definition of machine learning algorithms, currently under development, to minimize false positive and false negative fall detection events.

Background Continuous monitoring technologies such as accelerometers and pedometers are the gold standard for physical activity (PA) measurement. However, inconsistencies in use, analysis, and reporting limit the understanding of dose–response relationships involving PA and the ability to make comparisons across studies and population subgroups. These issues are particularly detrimental to the study of PA across different ethnicities with different PA habits. This systematic review examined the inclusion of published guidelines involving data collection, processing, and reporting among articles using accelerometers or pedometers in Hispanic or Latino populations. Methods English (PubMed; EbscoHost) and Spanish (SCIELO; Biblioteca Virtual en Salud) articles published between 2000 and 2013 using accelerometers or pedometers to measure PA among Hispanics or Latinos were identified through systematic literature searches. Of the 253 abstracts which were initially reviewed, 57 met eligibility criteria (44 accelerometer, 13 pedometer). Articles were coded and reviewed to evaluate compliance with recommended guidelines (N = 20), and the percentage of accelerometer and pedometer articles following each guideline were computed and reported. Results On average, 57.1 % of accelerometer and 62.2 % of pedometer articles reported each recommended guideline for data collection. Device manufacturer and model were reported most frequently, and provision of instructions for device wear in Spanish was reported least frequently. On average, 29.6 % of accelerometer articles reported each guideline for data processing. Definitions of an acceptable day for inclusion in analyses were reported most frequently, and definitions of an acceptable hour for inclusion in analyses were reported least frequently. On average, 18.8 % of accelerometer and 85.7 % of pedometer articles included each guideline for data reporting. Accelerometer articles most frequently included average number of valid days and least frequently included percentage of wear time. Discussion Inclusion of standard collection and reporting procedures in studies using continuous monitoring devices in Hispanic or Latino population is generally low. Conclusions Lack of reporting consistency in continuous monitoring studies limits researchers' ability to compare studies or draw meaningful conclusions concerning amounts, quality, and benefits of PA among Hispanic or Latino populations. Reporting data collection, computation, and decision-making standards should be required. Improved interpretability would allow practitioners and researchers to apply scientific findings to promote PA.

In the U.S., it is estimated that over one-third of adults are obese (Body Mass Index (BMI)>30kg/m(2)). Previous studies suggest that obesity may be associated with deficits in cognitive performance and postural control. Increased BMI may challenge cognitive and postural performance in a variety of populations; however, most relevant studies have classified participants based on BMI values, which cannot be used to accurately assess the effects of adiposity on cognitive performance and postural control. The objective of the current study was to examine motor and cognitive responses for overweight and obese adults compared to normal weight individuals by using both BMI and adiposity measures. Ten normal weight (BMI=18-24.9kg/m(2)), ten overweight (BMI=25-29.9kg/m(2)), and ten obese (BMI=30-40kg/m(2)) adults were evaluated (age: 24±4 years). Participants were classified into three groups based on BMI values at the onset of the study, prior to body composition analysis. Participants performed (1) working memory task while maintaining upright stance, and (2) a battery of sensorimotor evaluations. Working memory reaction times, response accuracy, center-of-pressure (COP) path length, velocity, migration area, time to boundary values in anterior-posterior direction, and ankle-hip strategy-scores were calculated to evaluate cognitive-motor performance. No significant deficits in working memory performance were observed. Overall, measures of motor function deteriorated as BMI and body fat percentage increased. The relationship between deteriorating postural performance indices and body fat percentage were greater than those found between BMI and postural performance indices.

Unloading-induced muscle atrophy occurs in the aging population, bed-ridden patients, and astronauts. This study was designed to determine whether dynamic foot stimulation (DFS) applied to the plantar surface of the rat foot can serve as a countermeasure to soleus muscle atrophy normally observed in hindlimb unloaded (HU) rats. Forty-four mature (6 mo old), male Wistar rats were randomly assigned to ambulatory control, HU alone, HU with active DFS (i.e., plantar contact with active inflation), HU with passive DFS (i.e., plantar contact without active inflation), and HU while wearing a DFS boot with no plantar contact groups. Application of active DFS during HU significantly counteracted the atrophic response by preventing approximately 85% of the reduction in type I myofiber cross-sectional area (CSA) in the soleus while preventing approximately 57% of the reduction in type I myofiber CSA and 43% of the reduction in type IIA myofiber CSA of the medial gastrocnemius muscle. Wearing of a DFS boot without active inflation prevented myofiber atrophy in the soleus of HU animals in a fashion similar to that observed in HU animals that wore an actively inflated DFS boot. However, when a DFS boot without plantar surface contact was worn during HU, no significant protection from HU-induced myofiber atrophy was observed. These results illustrate that the application of mechanical foot stimulation to the plantar surface of the rat foot is an effective countermeasure to muscle atrophy induced by HU.

The purpose of this investigation was to determine if the location and the timing relative to muscle activation onset, of a mechanical stimulus applied to the soles impacted the neuromuscular activation associated with a voluntary movement. The subjects completed a series of dorsiflexion or plantarflexion movements during which a stimulus was applied to either the heel or ball of the foot at one of three time periods relative to the initiation of the agonist muscle. Surface electromyography from the tibialis anterior and soleus was collected during the movements. The results show that if the stimulus was applied shortly before agonist muscle activation, regardless of stimulation site, the neuromuscular activity associated with the movement was greatly increased.

It has been proposed that proprioceptive input is essential to the development of a locomotor body schema that is used to guide the assembly of successful walking. Proprioceptive information is used to signal the need for, and promotion of, locomotor adaptation in response to environmental or internal modifications. The purpose of this investigation was to determine if tendon vibration applied to either the hamstrings or quadriceps of participants experiencing split-belt treadmill walking modified lower limb kinematics during the early adaptation period. Modifications in the adaptive process in response to vibration would suggest that the sensory-motor system had been unsuccessful in down weighting the disruptive proprioceptive input resulting from vibration. Ten participants experienced split-belt walking, with and without vibration, while gait kinematics were obtained with a 12-camera collection system. Bilateral hip, knee, and ankle joint angles were calculated and the first five strides after the split were averaged for each subject to create joint angle waveforms for each of the assessed joints, for each experimental condition. The intralimb variables of stride length, percent stance time, and relative timing between various combinations of peak joint angles were assessed using repeated measures MANOVA. Results indicate that vibration had very little impact on the split-belt walking adaptive process, although quadriceps vibration did significantly reduce percent stance time by 1.78% relative to the no vibration condition. The data suggest that the perceptual-motor system was able to down weight the disrupted proprioceptive input such that the locomotor body schema was able to effectively manage the lower limb patterns of motion necessary to adapt to the changing belt speed. Complementary explanations for the current findings are also discussed.

This report is the first systematic evaluation of the effects of prolonged weightlessness on the bipedal postural control processes during self-generated perturbations produced by voluntary upper limb movements. Spaceflight impacts humans in a variety of ways, one of which is compromised postflight postural control. We examined the neuromuscular activation characteristics and center of pressure (COP) motion associated with arm movement of eight subjects who experienced long-duration spaceflight (3–6 mo) aboard the Mir space station. Surface electromyography, arm acceleration, and COP motion were collected while astronauts performed rapid unilateral shoulder flexions before and after spaceflight. Subjects generally displayed compromised postural control after flight, as evidenced by modified COP peak-to-peak anterior-posterior and mediolateral excursion, and pathlength relative to preflight values. These changes were associated with disrupted neuromuscular activation characteristics, particularly after the completion of arm acceleration (i.e., when subjects were attempting to maintain upright posture in response to self-generated perturbations). These findings suggest that, although the subjects were able to assemble coordination modes that enabled them to generate rapid arm movements, the subtle control necessary to maintain bipedal equilibrium evident in their preflight performance is compromised after long-duration spaceflight.

The purpose of this study was to determine whether applying foot pressure to unrestrained subjects during space flight could enhance the neuromuscular activation associated with rapid arm movements. Four men performed unilateral arm raises while wearing--or not wearing--specially designed boots during a 81- or 115-day space flight. Arm acceleration and surface EMG were obtained from selected lower limb and trunk muscles. Pearson r coefficients were used to evaluate similarity in phasic patterns between the two in-flight conditions. In-flight data also were magnitude normalized to the mean voltage value of the muscle activation waveforms obtained during the no-foot-pressure condition to facilitate comparison of activation amplitude between the two in-flight conditions. Foot pressure enhanced neuromuscular activation and somewhat modified the phasic features of the neuromuscular activation during the arm raises.

The use of continuous low frequency vibration has been shown to improve perception of limb motion under certain conditions. The purpose of this study was to determine whether practice combined with continuous low frequency vibration could be used to enhance learning and subsequent transfer of a knee joint positioning task. Absolute and constant error were compared between a Control group, that did not receive vibration during practice and an Experimental group, that received 15Hz vibration on the quadriceps tendon during each practice trial. Both groups were able to reduce absolute and constant error with practice but vibration had no impact on learning or transfer. These findings indicate that subjects effectively ignore the vibration induced input instead of using it in a beneficial way to augment the sensory input associated with limb motion. This suggests that the vibration induced haptic input may be down weighted by the sensory motor system such that ongoing movement was not disrupted. It is possible that vibration may only be useful when the haptic input generated by vibration is meaningfully related to the task.

Understanding the context in which vibration of musculature about the ankle joints elicits postural sway is important if it is to be utilized as a means of manipulating postural control for therapeutic or training purposes. The purpose of this study was to observe if the postural response associated with the vibration of the tibialis anterior (TA) muscles would remain intact despite multiple exposures during a series of forward and backward translating perturbations. Twenty young healthy adults (18-35 years old) were asked to maintain an upright erect posture on a forceplate with their eyes closed during two separate trials of quiet stance both without (preNV) and with (preVib) TA muscle vibration being applied. Subjects were then exposed to 60 bouts of forward and backwards translating perturbations of various amplitudes with TA vibration being applied during 30 of the perturbations, after which another trial of quiet stance with TA vibration (postVib) was taken. Anterior-posterior center of pressure (COP) and shear force measurements were used to calculate root-mean-square (RMS) of the sway, mean power frequency (MPF), shift from zero, and strategy score percentages as dependent variables. Of interest here are the postural responses obtained during the quiet stance conditions. A one-way ANOVA with Tukey's HSD post-hoc tests were used to compare means of the three quiet stance conditions for each of the dependent variables. Non-significant MPF results revealed no change in sway frequency oscillations due to vibration throughout the study. RMS sway was significantly greater for preVib and postVib trials than preNV, and strategy scores were significantly lower for preVib and postVib than preNV, indicating greater shear forces with the vibration conditions. No significant differences between preVib and postVib means were observed in any of the COP measures. This indicates that adaptation to the TA muscle vibration response did not occur and suggests that the distorted input associated with vibration was not fully down weighted by the sensory motor system during quiet upright stance, despite repeated exposure to vibration throughout the testing protocol.