Spatiotemporal Measures Research Articles

Dual-task treadmill walking at self-paced versus fixed speeds.

Investigating cognitive-motor interference on the treadmill allows for better examination of motor adaptation to the dual-task challenges through the information of continuous strides. However, one of the major critiques for conducting dual-task investigation on a treadmill is the use of a constant, fixed walking speed, constraining the natural fluctuations of the speed of human walking, which could be addressed by using the self-paced feature of a feedback-controlled treadmill. Do people use different adaptation and task prioritization strategies during the dual-task treadmill walking at self-paced versus fixed speeds? Eighteen healthy younger participants walked on an instrumented treadmill (1) under two speed conditions: self-paced and fixed-speed, and (2) with and without each of the four different cognitive tasks. Dynamic margins of stability (MOS), step spatiotemporal measures, kinematic variability, and local dynamic stability were computed for each trial. Participants had significantly more local instability during self-paced than fixed-speed treadmill walking. The often-reported response of reducing stride time variability during dual-task, fixed-speed walking was not observed during dual-task, self-paced walking. In addition, there were significantly greater dual-task interference effects on stride time variability and local dynamic stability as well as the Paced Auditory Serial Addition Test performance during self-paced walking. Reduced variability in the lower-extremity joint angles, trunk motion and position, and MOS measures were observed both in dual-task, self-paced and fixed-speed walking. Healthy younger adults had different task prioritization and greater dual-task effects on gait stability and cognitive performance during self-paced versus fixed-speed walking. However, similar adaptation strategies, in terms of gait adjustments, were used for the two walking conditions. The results suggest that self-paced treadmill walking is more challenging than the fixed-speed walking and can serve as a better alternative to the overground walking than the fixed-speed walking for the dual-task investigation.

27. Achievement of minimum clinically important differences in patient reported outcomes does not imply outright improvements in objective functional outcome measures for surgical treatment of adult spinal deformities

27. Achievement of minimum clinically important differences in patient reported outcomes does not imply outright improvements in objective functional outcome measures for surgical treatment of adult spinal deformities

P80. The effect of scoliosis support orthosis bracing on adult spinal deformity patients: Evaluation of gait and dynamic balance

<h3>BACKGROUND CONTEXT</h3> Non-operative treatment is regarded as the first-line of therapy for patients with adult spinal deformity (ASD) without neurologic deficits or significant impairment. While there is high-level evidence supporting the use of rigid bracing in adolescent idiopathic scoliosis, there is a paucity of literature pertaining to the use of scoliosis support orthosis (SSO) in ASD patients. <h3>PURPOSE</h3> To investigate the impact of an SSO on pain, gait parameters, and functional balance measures in symptomatic ASD patients. <h3>STUDY DESIGN/SETTING</h3> Prospective cohort study. <h3>PATIENT SAMPLE</h3> Thirty ASD patients (26 Females, Age: 72.7, Cobb Angle: 47.1°) <h3>OUTCOME MEASURES</h3> Six-minute walk test, Time Up and Go test, 3D Gait analysis, Cone of Economy analysis, VAS, ODI, SRS22r, Fear Avoidance Beliefs Questionnaire (FABQ) [32], and Tampa Scale for Kinesiophobia (TSK). <h3>METHODS</h3> Thirty ASD patients were evaluated on 3 different occasions: first day of bracing: baseline (Pre), and 45-min post fitting (Post45m), and after 8-weeks of bracing for 4 hours a day (Post8w). Each patient performed a 6-minute walk (over-ground gait), a dynamic balance test, and completed VAS, ODI, and SRS22r. <h3>RESULTS</h3> Significant short- and long-term improvements using SSO were found in the 6-minute walk (Pre: 278.6; Post45m: 322.2; Post8w: 338.8 m, p<0.001), walking speed (Pre: 0.88; Post45m: 0.97; Post8w: 0.97 m/s, p<0.001), head total sway distance during the balance test (Pre: 81.33; Post45m: 68.63; Post8w: 60.72 cm, p=0.048), low-back pain (VAS: Pre: 5.5; Post45m: 3.5; Post8w: 3.3, p<0.001), and for the ODI (Pre: 41.9; Post45m: 32.9; Post8w: 30.1, p=0.005). <h3>CONCLUSIONS</h3> This study demonstrated clinically significant improvements in PROMs, spatiotemporal gait parameters and functional balance measures with the use of a SSO for patients with ASD. Some improvements were established immediately following brace fitting and many improvements were observed after wearing SSO for 8 weeks. In addition, this is the first SSO study for ASD to examine gait parameters and functional balance measures in order to understand the benefits of non-operative treatment from a functional and activity of daily living perspective. Based on the results of this study, it is reasonable to consider custom fitted SSO as a treatment option to provide a measurable degree of pain relief and improvement of function for patients with ASD, if the goals of treatment match the measured benefits demonstrated in our paper. Future studies are warranted to investigate if the observed benefits can be maintained over longer periods, possibly with reduced wear times for patients with ASD. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

P4. Minimum clinically important differences in degenerative lumbar patient-reported outcomes are not indicative of widespread improvements in objective functional outcome measures

<h3>BACKGROUND CONTEXT</h3> Patient reported outcome measures (PROMs) benchmarked by the minimum clinically important difference (MCID) are often used to indicate patient functional status before and after surgery for degenerative lumbar pathology (DLP). Prior research has shown that not all spine PROMs directly relate to objective functional improvements in activities like walking and standing. Currently it is unclear whether achieving PROMs MCID should be considered outrightly indicative of improved functional outcomes measures (FOMs). <h3>PURPOSE</h3> Determine if achievement of PROMs MCID relates to significant changes in objective gait and balance FOMs among surgical DLP patients. <h3>STUDY DESIGN/SETTING</h3> Non-randomized, retrospective review of DLP patient pre- and postoperative PROM and FOM data. <h3>PATIENT SAMPLE</h3> There were 99 patients treated with decompression or single-level fusion for DLP. <h3>OUTCOME MEASURES</h3> Visual analog scales (VAS) for low-back and leg pain, Oswestry Disability Index (ODI), spatiotemporal and kinematic gait measures, and postural balance measures (range-of-sway: ROS, total-sway distance: TSD). <h3>METHODS</h3> Surgical DLP patients completed PROMs and functional evaluations one week before surgery (P0) and at three- and 12-month postoperative follow-ups (P3 and P12). Functional evaluations included walking and balance tests using three-dimensional motion tracking. FOMs showing significant P0-P3-P12 univariate improvements were compared between achieved MCID (aMCID) and not achieved MCID (nMCID) for each PROM at P0-P3 and P0-P12. <h3>RESULTS</h3> All PROMs showed significant univariate improvements (P0, P3, P12 respectively): VAS low-back (4.2±3.7, 1.7±1.7, 2.5±2.9, p=0.002), VAS-leg (5.8±3, 1.4±1.9, 1.6±2.6, p<0.001), ODI (43.4±13.6, 23.9±15.8,22.9±17.1, p<0.001). Two of 14 gait FOMs showed significant univariate improvements: increased step length (0.54±0.05m, 0.56±0.04m, 0.57±0.04m, p=0.043) and reduced single-support time (0.45±0.07s,0.44±0.06s, 0.42±0.04s, p=0.040). Three of six balance FOMs showed significant univariate improvements: reduced coronal ROS (2.95±2.19cm, 1.88±0.9cm, 1.9±0.73cm, p=0.025), reduced sagittal ROS (6.58±2.58cm, 5.5±1.72cm, 5.16±1.56cm, p=0.025), and reduced TSD (71±45.4cm, 50.3±19cm, 48±14.2cm, p=0.014) for the head. MCID achievement was as follows: VAS low-back: 67%@P3, 46%@P12; VAS leg: 73%@P3, 75% @P12; ODI: 58%@P3, 72%@P12. aMCID yielded significantly greater improvements in the following FOMs (aMCID/nMCID respectively): @P3: longer step length for VAS leg (0.03±0.03m/-0.01±0.05m, p=0.021), less coronal head ROS for VAS low-back (-1.59±3.19cm/-0.09±1.67cm, p=0.016) and VAS leg (-1.54±3.07cm/0.07±1.75cm, p<0.001), less sagittal head ROS for VAS leg (-1.94±4.1cm/-0.9±3.43cm, p=0.003), and less head TSD for VAS leg (-26.17±53.17cm/-8.54±32.57cm, p=0.002); @P12: less sagittal head ROS for ODI (-1.63±4.44cm/-0.71±2.38cm, p=0.046). Although significant, relative numeric improvements were minimal for head ROS. <h3>CONCLUSIONS</h3> Select statistically significant differences in FOMs were found however, numerical differences were low and widespread improvements across all FOMs were not found, even with significant univariate improvements. Achieving MCID for VAS leg pain may be related to improved step length and dynamic balance, but there is little evidence to suggest that it should be considered indicative of overall functional improvement of DLP surgery patients. PROMs and FOMs may be measuring different yet equally important aspects of DLP patient function. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Use of wearable sensors to identify biomechanical alterations in runners with Exercise-Related lower leg pain

Exercise-related lower leg pain (ERLLP) is one of the most prevalent running-related injuries, however little is known about injured runners’ mechanics during outdoor running. Establishing biomechanical alterations among ERLLP runners would help guide clinical interventions. Therefore, we sought to a) identify defining biomechanical features among ERLLP runners compared to healthy runners during outdoor running, and b) identify biomechanical thresholds to generate objective gait-training recommendations. Thirty-two ERLLP (13 M, age: 21 ± 5 years, BMI: 22.69 ± 2.25 kg/m2) and 32 healthy runners (13 M, age: 23 ± 6 years, BMI: 22.33 ± 3.20 kg/m2) were assessed using wearable sensors during one week of typical outdoor training. Step-by-step data were extracted to assess kinetic, kinematic, and spatiotemporal measures. Preliminary feature extraction analyses were conducted to determine key biomechanical differences between healthy and ERLLP groups. Analyses of covariance (ANCOVA) and variability assessments were used compare groups on the identified features. Participants were split into 3 pace bands, and mean differences across groups were calculated to establish biomechanical thresholds. Contact time was the key differentiating feature for ERRLP runners. ANCOVA assessments reflected that the ERLLP group had increased contact time (Mean Difference [95% Confidence Interval] = 8 ms [6.9,9.1], p < .001), and approximate entropy analyses reflected greater contact time variability. Contact time differences were dependent upon running pace, with larger between-group differences being exhibited at faster paces. In all, ERLLP runners demonstrated longer contact time than healthy runners during outdoor training. Clinicians should consider contact time when assessing and treating these ERLLP runner patients.

Computerized Dual-Task Testing of Gait Visuomotor and Cognitive Functions in Parkinson's Disease: Test-Retest Reliability and Validity.

BackgroundMobility and cognitive impairments in Parkinson’s disease (PD) often coexist and are prognostic of adverse health events. Consequently, assessment and training that simultaneously address both gait function and cognition are important to consider in rehabilitation and promotion of healthy aging. For this purpose, a computer game-based rehabilitation treadmill platform (GRP) was developed for dual-task (DT) assessment and training.ObjectiveThe first objective was to establish the test-retest reliability of the GRP assessment protocol for DT gait, visuomotor and executive cognitive function in PD patients. The second objective was to examine the effect of task condition [single task (ST) vs. DT] and disease severity (stage 2 vs. stage 3) on gait, visuomotor and cognitive function.MethodsThirty individuals aged 55 to 70 years, diagnosed with PD; 15 each at Hoehn and Yahr scale stage 2 (PD-2) and 3 (PD-3) performed a series of computerized visuomotor and cognitive game tasks while sitting (ST) and during treadmill walking (DT). A treadmill instrumented with a pressure mat was used to record center of foot pressure and compute the average and coefficient of variation (COV) of step time, step length, and drift during 1-min, speed-controlled intervals. Visuomotor and cognitive game performance measures were quantified using custom software. Testing was conducted on two occasions, 1 week apart.ResultsWith few exceptions, the assessment protocol showed moderate to high intraclass correlation coefficient (ICC) values under both ST and DT conditions for the spatio-temporal gait measures (average and COV), as well as the visuomotor tracking and cognitive game performance measures. A significant decline in gait, visuomotor, and cognitive game performance measures was observed during DT compared to ST conditions, and in the PD-3 compared to PD-2 groups.ConclusionThe high to moderate ICC values along with the lack of systematic errors in the measures indicate that this tool has the ability to repeatedly record reliable DT interference (DTI) effects over time. The use of interactive digital media provides a flexible method to produce and evaluate DTI for a wide range of executive cognitive activities. This also proves to be a sensitive tool for tracking disease progression.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier NCT03232996.

Sampling rate influences the regularity analysis of temporal domain measures of walking more than spatial domain measures.

The spatiotemporal dynamics of stepping can provide useful information about walking performance. Most often, the identification of gait motion is performed using 3-D cinematography. The sampling rate of motion capture systems may influence the accuracy of these measures albeit in varying degrees for measures within the spatial versus temporal domain. What are the effects of sampling frequency on common analysis methods of measures within the spatial and temporal domain? Specifically, mean, variability (i.e. standard deviation), and regularity (i.e. sample entropy) of step length (i.e. spatial domain) and step time (i.e. temporal domain) measures were assessed following ten minutes of preferred-speed treadmill walking in eleven young adults. The spatiotemporal mean measures were not affected by changing sampling frequencies. Frequencies ≥120 Hz showed consistent results for spatial variability measures, while temporal variability increased due to decreased resolution in capturing variability when data was sampled at 120 Hz or less. In assessing regularity, poor temporal resolution at lower sampling rates led to "binning", limiting the variety of vector patterns. As a result, more vectors were classified as similar, leading to a signal appearing more periodic. For the spatial domain, sample entropy was not affected, indicating the greater sensitivity of step time to sampling rate compared to step length. Sampling rate influenced recognition of gait events. By reducing the sampling rate, the time intervals were increased and reduced the resolution leading to less accurate gait event detection in the temporal domain. The sampling rate of 120 Hz is the minimum sampling rate that should be used to calculate spatiotemporal data for variability and sample entropy.

The effect of scoliosis support orthosis bracing on adult spinal deformity patients: evaluation of gait and dynamic balance.

Non-operative treatment is regarded as the first-line therapy for patients with adult spinal deformity (ASD) without neurologic deficits or significant impairment. While there is high-level evidence supporting the use of rigid bracing in adolescent idiopathic scoliosis, there is a paucity of literature pertaining to the use of scoliosis support orthosis (SSO) in ASD patients. To investigate the impact of an SSO on pain, gait parameters, and functional balance measures in symptomatic ASD patients. Thirty ASD patients (26 Females, Age: 72.7, Cobb Angle: 47.1°) were evaluated on 3 different occasions: first day of bracing: baseline (Pre), and 45-min post fitting (Post45m), and after 8-weeks of bracing for 4 hours a day (Post8w). Each patient performed a 6-minute walk (over-ground gait), a dynamic balance test, and completed VAS, ODI, and SRS22r. Significant short- and long-term improvements using SSO were found in the 6-minute walk (Pre: 278.6; Post45m: 322.2; Post8w: 338.8 m, p<0.001), walking speed (Pre: 0.88; Post45m: 0.97; Post8w: 0.97 m/s, p<0.001), head total sway distance during the balance test (Pre: 81.33; Post45m: 68.63; Post8w: 60.72 cm, p=0.048), low-back pain (VAS: Pre: 5.5; Post45m: 3.5; Post8w: 3.3, p<0.001), and for the ODI (Pre: 41.9; Post45m: 32.9; Post8w: 30.1, p=0.005).This study demonstrated clinically significant improvements in PROMs, spatiotemporal gait measures, and functional balance measures after continuous use of a SSO. These improvements were observed immediately following brace-fitting and maintained at an 8-week follow-up. Given these results, it is reasonable to consider a SSO for conservative management of patients with mild symptoms of pain and deformity, and who have not yet progressed to meet surgical indications.

Assessment of Spatiotemporal Peak Shift of Intra-Urban Transportation Taking a Case in Bangkok, Thailand

Reducing congestion has been one of the critical targets of transportation policies, particularly in cities in developing countries suffering severe and chronic traffic congestions. Several traditional measures have been in place but seem not very successful. This paper applies the agent-based transportation model MATSim for a transportation analysis in Bangkok to assess the impact of spatiotemporal transportation demand management measures. We collect required data for the simulation from various data sources and apply maximum likelihood estimation with the limited data available. We investigate two demand management scenarios, peak time shift, and decentralization. As a result, we found that these spatiotemporal peak shift measures are effective for road transport to alleviate congestion and reduce travel time. However, the effect of those measures on public transport is not uniform but depends on the users’ circumstances. On average, the simulated results indicate that those measures increase the average travel time and distance. These results suggest that demand management policies require considerations of more detailed conditions to improve usability. The study also confirms that microsimulation can be a tool for transport demand management assessment in developing countries.

Comparing Household and Individual Measures of Access through a Food Environment Lens: What Household Food Opportunities Are Missed When Measuring Access to Food Retail at the Individual Level?

Geographers and public health researchers have long been interested in social, spatial, and economic factors that drive access and exposure to food retail. A growing body of evidence draws on mobility data to capture locations accessed by individuals beyond the home address. Given that food-related activities are shared by household members and often gendered, taking an individual-level approach might limit researchers’ ability to accurately describe access to food retail. Using data that includes Global Positioning System trajectories of forty-six adults from twenty-one households in Toronto, this study compares access to food retailers at the individual and household levels and evaluates measurement issues that arise when relying on one household member. Spatial and spatiotemporal measures of access were derived from individual and total household activity spaces. Differences in access were tested for men and women and moderating effects of neighborhood, shopping responsibility, car access, and employment status were investigated. Supermarket density was greater for women when compared with men in the household, as well as their total household measure. Additionally, within-household differences in counts of supermarkets were moderated by neighborhood. Future research should consider the role of place and the contributions of household members when measuring access to food at the individual level.

An assessment of physical and spatiotemporal behaviour during different phases of match play in professional Australian football

ABSTRACT Despite advancements in the scale of data available for quantifying the physical and spatiotemporal characteristics of match play, there is an absence of research combining these aspects in professional sport. This study sought to differentiate between phases of play in professional Australian football using novel physical and spatiotemporal metrics. Data was obtained from Australian Football League games to provide new insight into the specific characteristics of each phase of play. A retrospective cross-sectional design was utilised with team’s physical and spatiotemporal variables, measured via global navigation satellite system devices. A multinomial logistic regression was conducted to determine which physical and spatiotemporal measures were associated with each phase of play (contested play, defence, offence, set shot, goal reset, umpire stoppage). The addition of the predictors to a model that contained only the intercept significantly improved the fit between the model and data, with the logistic model correctly predicting the phase of play for 63.7% of the cases. This was the first study to concurrently examine differences in physical and spatiotemporal characteristics with respect to phase of play in an Australian football context. Differences in duration, physical and spatiotemporal properties were observed, providing new insight for coaches and subsequently providing direction for conditioning and practice design.

Bouncing behavior of sub-four minute milers

Elite middle distance runners present as a unique population in which to explore biomechanical phenomena in relation to running speed, as their training and racing spans a broad spectrum of paces. However, there have been no comprehensive investigations of running mechanics across speeds within this population. Here, we used the spring-mass model of running to explore global mechanical behavior across speeds in these runners. Ten elite-level 1500 m and mile runners (mean 1500 m best: 3:37.3 ± 3.6 s; mile: 3:54.6 ± 3.9 s) and ten highly trained 1500 m and mile runners (mean 1500 m best: 4:07.6 ± 3.7 s; mile: 4:27.4 ± 4.1 s) ran on a treadmill at 10 speeds where temporal measures were recorded. Spatiotemporal and spring-mass characteristics and their corresponding variation were calculated within and across speeds. All spatiotemporal measures changed with speed in both groups, but the changes were less substantial in the elites. The elite runners ran with greater approximated vertical forces (+ 0.16 BW) and steeper impact angles (+ 3.1°) across speeds. Moreover, the elites ran with greater leg and vertical stiffnesses (+ 2.1 kN/m and + 3.6 kN/m) across speeds. Neither group changed leg stiffness with increasing speeds, but both groups increased vertical stiffness (1.6 kN/m per km/h), and the elite runners more so (further + 0.4 kN/m per km/h). The elite runners also demonstrated lower variability in their spatiotemporal behavior across speeds. Together, these findings suggested that elite middle distance runners may have distinct global mechanical patterns across running speeds, where they behave as stiffer, less variable spring-mass systems compared to highly trained, but sub-elite counterparts.

Changes in Spatiotemporal Measures and Variability During User-Driven Treadmill, Fixed-Speed Treadmill, and Overground Walking in Young Adults: A Pilot Study.

Walking is an integral indicator of human health commonly investigated while walking overground and with the use of a treadmill. Unlike fixed-speed treadmills, overground walking is dependent on the preferred walking speed under the individuals' control. Thus, user-driven treadmills may have the ability to better simulate the characteristics of overground walking. This pilot study is the first investigation to compare a user-driven treadmill, a fixed-speed treadmill, and overground walking to understand differences in variability and mean spatiotemporal measures across walking environments. Participants walked fastest overground compared to both fixed and user-driven treadmill conditions. However, gait cycle speed variability in the fixed-speed treadmill condition was significantly lower than the user-driven and overground conditions, with no significant differences present between overground and user-driven treadmill walking. The lack of differences in variability between the user-driven treadmill and overground walking may indicate that the user-driven treadmill can better simulate the variability of overground walking, potentially leading to more natural adaptation and motor control patterns of walking.

Fisher behavior matters: Harnessing spatio-temporal fishing effort information to support China's fisheries management

Fisher behavior has been widely considered important for fisheries management, but is often overlooked in China's fisheries management. The current management scheme creates few incentives to survey fishers, leading to limited behavioral information that further hinders decision-makers from accounting for human-nature interactions in management. To resolve this deadlock, we collected data on temporal and spatial variations in fishing effort from a pilot survey in Haizhou Bay, China, and incorporated this behavioral information in a fishery simulator to evaluate its impacts on the effectiveness of management measures. We selected the commercially important small yellow croaker (Larimichthys polyactis) as the targeted species in this study. Spatiotemporal management measures imposed on the stock were evaluated. Despite the large temporal and spatial scale of China's fisheries closure, our results indicate that the effectiveness of management measures can be reliant on the interaction between fisher behavior and fish population dynamics. In particular, we found that pulse fishing after the seasonal closure could create positive effects on fish biomass and catch because of the unique biology and seasonal migration patterns of the target species as well as its spatiotemporal relationship with fishing activities, which differs from the previous concern when not accounting for such interactions. Additionally, we observed that spatial movement of fishing vessels tended to pose more impacts on biomass and catch of our targeted species compared to pulse fishing, indicating the importance of understanding fleet spatial dynamics in future research and management. To promote the incorporation of behavioral information into China's fisheries management scheme, we advocate extending the current ecology-oriented monitoring programs to include social dimensions, collecting spatiotemporal behavioral data from well-designed fisher monitoring programs, and developing new strategies to cope with uncertainty in fleet dynamics in the upcoming fisheries management reforms.

The Biomechanical Characteristics of the Strongman Yoke Walk.

The yoke walk is a popular strongman exercise where athletes carry a heavily loaded frame balanced across the back of their shoulders over a set distance as quickly as possible. The aim of this study was to use ecologically realistic training loads and carry distances to (1) establish the preliminary biomechanical characteristics of the yoke walk; (2) identify any biomechanical differences between male and female athletes performing the yoke walk; and (3) determine spatiotemporal and kinematic differences between stages (intervals) of the yoke walk. Kinematic and spatiotemporal measures of hip and knee joint angle, and mean velocity, stride length, stride rate and stance duration of each 5 m interval were taken whilst 19 strongman athletes performed three sets of a 20 m yoke walk at 85% of their pre-determined 20 m yoke walk one repetition maximum. The yoke walk was characterised by flexion of the hip and slight to neutral flexion of the knee at heel strike, slight to neutral extension of the hip and flexion of the knee at toe-off and moderate hip and knee range of motion (ROM), with high stride rate and stance duration, and short stride length. Between-interval comparisons revealed increased stride length, stride rate and lower limb ROM, and decreased stance duration at greater velocity. Although no main between-sex differences were observed, two-way interactions revealed female athletes exhibited greater knee extension at toe-off and reduced hip ROM during the initial (0–5 m) when compared with the final three intervals (5–20 m), and covered a greater distance before reaching maximal normalised stride length than males. The findings from this study may better inform strongman coaches, athletes and strength and conditioning coaches with the biomechanical knowledge to: provide athletes with recommendation on how to perform the yoke walk based on the technique used by experienced strongman athletes; better prescribe exercises to target training adaptations required for improved yoke walk performance; and better coach the yoke walk as a training tool for non-strongman athletes.

Changes in prefrontal cortical activity and turning in response to dopaminergic and cholinergic therapy in Parkinson's disease: A randomized cross-over trial

IntroductionCholinergic dysfunction contributes to mobility deficits in Parkinson's disease (PD). People with PD rely on limited prefrontal executive-attentional resources for the control of locomotion, including turning. Cortical and behavioral responses to cholinergic augmentation during turning remains unclear. We examined prefrontal cortex (PFC) activity while turning-in-place and spatiotemporal measures of turns in response to usual dopaminergic medication and adjunct cholinergic augmentation. MethodsThis study consisted of a single-site, randomized, double-blind crossover trial. Twenty PD participants were assessed in the levodopa-off state and then randomized to either levodopa + donepezil (5 mg) or levodopa + placebo treatments for two weeks followed by a 2-week washout before crossover. The primary outcome was change from off state in PFC activity while turning-in-place (assessed with functional near-infrared spectroscopy). Secondary outcomes were changes in spatiotemporal turning measures (assessed with body-worn inertial measurement units) and accuracy in the secondary task. ResultsNineteen participants completed the trial. While levodopa + placebo had no effect on PFC activity when turning-in-place with a dual-task, levodopa + donepezil led to a large reduction in PFC activity (effect size, −0.82). Spatiotemporal measures of turning improved with both treatments, with slightly greater effect sizes observed for levodopa + donepezil. Additionally, the accuracy in the concurrent cognitive task improved only with levodopa + donepezil (effect size, 0.63). ConclusionThe addition of cholinergic therapy with donepezil (5 mg/day for 2 weeks) to standard dopaminergic therapy reduced the burden on prefrontal executive-attentional resources while turning with a dual-task and improved secondary task accuracy and turning.

Inertial-Based Human Motion Capture: A Technical Summary of Current Processing Methodologies for Spatiotemporal and Kinematic Measures.

Inertial-based motion capture (IMC) has been suggested to overcome many of the limitations of traditional motion capture systems. The validity of IMC is, however, suggested to be dependent on the methodologies used to process the raw data collected by the inertial device. The aim of this technical summary is to provide researchers and developers with a starting point from which to further develop the current IMC data processing methodologies used to estimate human spatiotemporal and kinematic measures. The main workflow pertaining to the estimation of spatiotemporal and kinematic measures was presented, and a general overview of previous methodologies used for each stage of data processing was provided. For the estimation of spatiotemporal measures, which includes stride length, stride rate, and stance/swing duration, measurement thresholding and zero-velocity update approaches were discussed as the most common methodologies used to estimate such measures. The methodologies used for the estimation of joint kinematics were found to be broad, with the combination of Kalman filtering or complimentary filtering and various sensor to segment alignment techniques including anatomical alignment, static calibration, and functional calibration methods identified as being most common. The effect of soft tissue artefacts, device placement, biomechanical modelling methods, and ferromagnetic interference within the environment, on the accuracy and validity of IMC, was also discussed. Where a range of methods have previously been used to estimate human spatiotemporal and kinematic measures, further development is required to reduce estimation errors, improve the validity of spatiotemporal and kinematic estimations, and standardize data processing practices. It is anticipated that this technical summary will reduce the time researchers and developers require to establish the fundamental methodological components of IMC prior to commencing further development of IMC methodologies, thus increasing the rate of development and utilisation of IMC.

Effect of transfemoral prosthetic socket interface design on gait, balance, mobility, and preference: A randomized clinical trial.

There are alternative transfemoral (TF) socket interface designs that have not been compared with the standard of care, ischial ramus containment (IRC). The interface directly affects performance. To compare 3 TF interface designs, IRC, dynamic socket (DS), and subischial (Sub-I), regarding gait, balance, mobility, and preference. The authors hypothesized that these more active users may experience gait, mobility, and preference benefits from the less intrusive DS and Sub-I interface designs. Single-blind, repeated-measures, 3-period randomized controlled crossover clinical trial. People with unilateral TF amputation with 1 year or longer prosthesis use experience, independent community ambulatory status, 18 to 60 years of age, of any race or ethnicity, with a body mass of 45 to 125 kg, and with a self-reported ability to walk for 20 minutes continuously were included in the study. Each participant was fit in all 3 interface designs. Thirteen participants completed the clinical trial. Velocity, cadence, mobility, and balance were not statistically different between the 3 socket conditions. The DS demonstrated significantly greater symmetry in swing, stance, single support percentage, and toe angle compared with IRC and Sub-I. Sixty days after study completion, 7 participants changed interfaces, trending away from IRC. Large differences were not observed. Small differences in spatiotemporal gait measures combined with patient preference may make a meaningful difference to individual patients and should be considered.

The Kickstart Walk Assist System for improving balance and walking function in stroke survivors: a feasibility study

BackgroundCompared with traditional physical therapy for stroke patients, lower extremity exoskeletons can provide patients with greater endurance and more repeatable and controllable training, which can reduce the therapeutic burden of the therapist. However, most exoskeletons are expensive, heavy or require active power to be operated. Therefore, a lighter, easy to wear, easy to operate, low-cost technology for stroke rehabilitation would be a welcome opportunity for stroke survivors, caregivers and clinicians. One such device is the Kickstart Walk Assist system and the purpose of this study was to determine feasibility of using this unpowered exoskeleton device in a sample of stroke survivors.MethodsThirty stroke survivors were enrolled in the study and experienced walking with the Kickstart exoskeleton device that provided spring-loaded assistance during gait. After 5 days of wearing the exoskeleton, participants were evaluated in the two states of wearing and not wearing the exoskeleton. Outcome measures included: (a) spatio-temporal gait measures, (b) balance measures and (c) exoskeleton-use feedback questionnaire.ResultsIn comparison to not wearing the device, when participants wore the Kickstart walking system, weight bearing asymmetry was reduced. The time spent on the 10-m walk test was also reduced, but there was no difference in the timed-up-and-go test (TUGT). Gait analysis data showed reduction in step time and double support time. Stroke survivors were positive about the Kickstart walking system’s ability to improve their balance, speed and gait. In addition, their confidence level and willingness to use the device was also positive.ConclusionsThese findings show the feasibility of using the Kickstart walking system for improving walking performance in stroke survivors. Our future goal is to perform a longer duration study with more comprehensive pre- and post-testing in a larger sample of stroke survivors.Trial registration Chinese Clinical Trial Registry, ChiCTR2000032665. Registered 5 May 2020—Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=53288

Reliability of inertial sensor based spatiotemporal gait parameters for short walking bouts in community dwelling older adults

BackgroundWhen performing quantitative analysis of gait in older adults we need to strike a balance between capturing sufficient data for reliable measurement and avoiding issues such as fatigue. The optimal bout duration is that which contains sufficient gait cycles to enable a reliable and representative estimate of gait performance. Research questionHow does the number of gait cycles in a walking bout influence reliability of spatiotemporal gait parameters measured using body-worn inertial sensors in a cohort of community dwelling older adults? MethodsOne hundred and fifteen (115) community dwelling older adults executed three 30-metre walk trials in a single measurement session. Bilateral gait data were collected using two inertial sensors attached to each participant’s right and left shank, and gait events detected from the medio-lateral angular velocity signal. The number of gait cycles selected from each walking trial was varied from 3 to 16. Intraclass correlation coefficients (ICC(2,k)) were calculated to evaluate the reliability of each spatiotemporal gait parameter according to the number of gait cycles included in the analysis. ResultsThe specified algorithm and the clipping procedure for extracting short bouts of gait data seem appropriate for assessing older adults, providing reliable spatiotemporal measures from three gait cycles (three strides per leg) and good reliability for most parameters describing gait variability and gait asymmetry after six gait cycles (six strides per leg). SignificanceA combination of using bilateral sensor data and adaptive thresholds for gait event detection enable reliable measures of spatiotemporal gait parameters over short walking bouts (minimum six gait cycles) in community dwelling older adults. This opens new possibilities in the use of wearable sensors in gait assessment based on short walking tasks. We recommend the number of gait cycles should be reported along with the calculated measures as reference values.