Estimating pedestrian walking speed at street crossings using the YOLOv4 and deep SORT algorithms: Proof of principle.

There is evidence that existing standards for signal timing do not provide enough time for many pedestrians to safely cross intersections. Yet, current methods for studying this problem rely on inefficient manual observations. The objective of this work was to determine if the YOLOv4 and Deep SORT computer vision algorithms have the potential to be incorporated into automated measurement systems to measure and compare pedestrian walking speeds at one-stage and two-stage street crossings captured in birds-eye-view video. Walking speed was estimated for 1018 pedestrians at single-stage (591 pedestrians) and two-stage (427 pedestrians) street crossings. Pedestrians in the one-stage crossing were found to be significantly slower than pedestrians who crossed the two-stage crossing in one signal (1.19 ± 0.50 vs. 1.31 ± 0.49 m/s, p < 0.001). This proof of principle study demonstrated that the YOLOv4 and Deep SORT approaches are promising for estimating pedestrian walking speed.

Efficacy of Installation of Temporary Bathing Transfer Aids by Older Adults.

Grab bars facilitate bathing and reduce the risk of falls during bathing. Suction cup handholds and rim-mounted tub rails are an alternative to grab bars. The objective of this study was to determine whether older adults could install handholds and tub rails effectively to support bathing transfers. Participants installed rim-mounted tub rails and suction cup handholds in a simulated bathroom environment. Installation location and mechanical loading performance were evaluated. Participant perceptions during device installation and a bathing transfer were characterized. While 85% of suction cup handholds met loading requirements, more than half of participants installed the suction cup handhold in an unexpected location based on existing guidance documents. No rim-mounted tub rails were successfully installed. Participants were confident that the devices had been installed effectively. Suction cup handholds and rim mounted tub rails are easy to install, but clients may need additional guidance regarding where, and how to install them.

A comparison of minimum segment models for the estimation of centre of mass position and velocity for slip recovery during a bathtub transfer task.

BACKGROUND: Exploring the use of minimum marker sets is important for balancing the technical quality of motion capture with challenging data collection environments and protocols. While minimum marker sets have been demonstrated to be appropriate for evaluation of some motion patterns, there is limited evidence to support model choices for abrupt, asymmetrical, non-cyclic motion such as balance disturbance during a bathtub exit task. RESEARCH QUESTION: How effective are six models of reduced complexity for the estimation of centre of mass (COM) displacement and velocity, relative to a full-body model. METHODS: Eight participants completed a bathtub exit task. Participants received a balance perturbation as they crossed the bathtub rim, stepping from a soapy wet bathtub to a dry floor. Six reduced models were developed from the full, 72-marker, 12 segment 3D kinematic data set. Peak displacement and velocity of the body COM, and RMSE (relative to the full-body model) for displacement and velocity of the body COM were determined for each model. RESULTS: Main effects were observed for peak right, left, anterior, posterior, upwards and downwards motion, and peak left, anterior, posterior, upwards and downwards velocity. Time-varying (RMSE) was smaller for models including the thighs than models not containing the thighs. In contrast, inclusion of upper arm, forearm, and hand segments did not improve model performance. The model containing the sacrum marker only consistently performed the worst across peak and RMSE metrics. SIGNIFICANCE: Findings suggest a simplified centre of mass model may adequately capture abrupt, asymmetrical, non-cyclic tasks, such as balance disturbance recovery during obstacle crossing. A reduced kinematic model should include the thighs, trunk and pelvis segments, although models that are more complex are recommended, depending on the metrics of interest.

Biomechanical Demands and User Preference Associated with Wall-Mounted and Rim-Mounted Grab Bars.

Background. Grab bars are used to support bathing tasks. Sometimes, temporary rim-mounted grab bars may be preferred over permanent wall-mounted grab bars. Purpose. We compared postural requirements, applied loads, and user perceptions between two configurations of rim-mounted grab bars, a vertical wall-mounted grab bar, and a no-grab bar condition. Method. Ten adults entered and exited a simulated bathing environment. Trunk flexion was evaluated via 3D kinematics, while load cells mounted to the grab bars facilitated the evaluation of applied loads. Participants rated each condition on perceived safety, comfort, effectiveness, and ease of use. Findings. Rim-mounted grab bars resulted in greater trunk flexion and greater applied loads and were less favorably perceived. Implications. The rim-mounted grab bars included in this study may induce challenging postural demands and loading scenarios, and occupational therapists should consider whether they meet the needs of their clients.

Grab Bar Use Influences Fall Hazard During Bathtub Exit.

OBJECTIVE: This study evaluated the hazard (risk of unrecovered balance loss and hazardous fall) and strategies associated with grab bar use, compared to no grab bar use, during unexpected balance loss initiated whilst exiting a bathtub. BACKGROUND: While independent bathing is critical for maintaining self-sufficiency, injurious falls during bathing transfer tasks are common. Grab bars are recommended to support bathing tasks, but no evidence exists regarding fall prevention efficacy. METHOD: Sixty-three adults completed a hazardous bathtub transfer task, experiencing an unpredictable external balance perturbation while stepping from a slippery bathtub to a dry surface. Thirty-two were provided a grab bar, while 31 had no grab bar available. Slips and grab bar use were recorded via four video cameras. Slip occurrence and strategy were identified by two independent video coders. RESULTS: Participants who had a grab bar were 75.8% more likely to recover their balance during the task than those who did not have a grab bar. Successful grab bar grasp was associated with balance recovery in all cases. Attempts to stabilize using other environmental elements, or using internal strategies only, were less successful balance recovery strategies. Grab bar presence appeared to cue use of the environment for stability. Proactive grasp and other strategies modified grasping success. CONCLUSION: Grab bars appear to provide effective support for recovery from unexpected balance loss. Grab bar presence may instigate development of fall prevention strategies prior to loss of balance. APPLICATION: Bathroom designs with grab bars may reduce frequency of fall-related injuries during bathing transfer tasks.

Effect of Handrail Height and Age on Trunk and Shoulder Kinematics Following Perturbation-Evoked Grasping Reactions During Gait.

OBJECTIVE: To characterize the effect of handrail height and age on trunk and shoulder kinematics, and concomitant handrail forces, on balance recovery reactions during gait. BACKGROUND: Falls are the leading cause of unintentional injury in adults in North America. Handrails can significantly enhance balance recovery and help individuals to avoid falls, provided that their design allows users across the lifespan to reach and grasp the rail after balance loss, and control their trunk by applying hand-contact forces to the rail. However, the effect of handrail height and age on trunk and shoulder kinematics when recovering from perturbations during gait is unknown. METHOD: Fourteen younger and 13 older adults experienced balance loss (sudden platform translations) while walking beside a height-adjustable handrail. Handrail height was varied from 30 to 44 inches (76 to 112 cm). Trunk and shoulder kinematics were measured via 3D motion capture; applied handrail forces were collected from load cells mounted to the rail. RESULTS: As handrail height increased (up to 42 inches/107 cm), peak trunk angular displacement and velocity generally decreased, while shoulder elevation angles during reaching and peak handrail forces did not differ significantly between 36 and 42 inches (91 and 107 cm). Age was associated with reduced peak trunk angular displacements, but did not affect applied handrail forces. CONCLUSION: Higher handrails (up to 42 inches) may be advantageous for trunk control when recovering from destabilizations during gait. APPLICATION: Our results can inform building codes, workplace safety standards, and accessibility standards, for safer handrail design.

Effect of using of a lower-extremity exoskeleton on disability of people with multiple sclerosis.

BACKGROUND: Although ongoing exercise is known to reduce disability in people with multiple sclerosis (MS), participation in lower-extremity exercise programs can be limited by their existing mobility impairments. Lower-extremity exoskeletons could address this problem by facilitating home and community locomotion and enhancing exercise capability but little data is available on the potential of this technology for reducing disability of people with MS. METHODS: We evaluated the Keeogo™ exoskeleton for people with MS using an open-label randomised cross-over design. The trial design allowed us to quantify rehabilitation effects (tested without device) and training effects (tested with device) using functional outcomes: 6-minute walk test (6MWT), timed stair test (TST), and timed up-and-go (TUG). Baseline and post-study self-report instruments included Medical Outcomes Survey Short Form-36 (SF36), MS Walking Scale (MSWS), and others. Amount of home use was documented by daily activity log. Partial correlation analysis was used to explore the relationships between changes in functional outcomes and self-report disability, controlling for amount of home use of the device. RESULTS: Twenty-nine participants with MS completed the trial. Change scores for MSWS, SF36 physical function and SF36 emotional well-being correlated positively with changes in 6MWT which was explained by amount of home use. CONCLUSIONS: The benefits in physical functioning and emotional well-being from using the exoskeleton at home were linked to amount of device usage. Low-profile robotic exoskeletons could be used to deliver facilitated exercise while assisting with locomotor activities of daily living, such as walking and stair climbing in the home and community environment.IMPLICATIONS FOR REHABILITATIONExoskeletons for home use may have the potential to benefit people with MS in terms of physical functioning and emotional well-being.The benefits in physical functioning and emotional well-being appeared to be linked to amount of usage.Exoskeletons might be useful for delivering facilitated exercise while assisting with walking and stair climbing in the home.

Consumer perspectives on grab bars: A Canadian national survey of grab bar acceptability in homes.

Given the prevalence and severity of bathroom falls and injuries across age groups, there is growing interest in policy-level approaches to bathroom fall prevention. Grab bars reduce fall risk during bathing transfers and improve bathing accessibility for adults of all ages and abilities. However, they are frequently absent from bathing environments, even in the homes of individuals who have a specific need for a grab bar. While mandatory bathroom grab bar installation has been suggested, it is unclear whether this would be supported by Canadians. The purpose of this study was to characterize Canadian public perceptions on the installation and use of grab bars in home bathrooms. We surveyed 443 Canadians about whether they currently had a grab bar and their perspectives on grab bar policy. 65.4% of respondents did not have a grab bar. However, 88.5% of respondents would allow a grab bar to be installed in their bathroom at no cost to them, only 11.5% of respondents would object to grab bar installation becoming mandatory in new builds, and 85.6% of respondents would use a grab bar if it were installed in their bathroom. Responses were affected by age (in four groups: 18-39, 40-59, 60-79, and 80+ years), self-reported impairment, and home ownership status. Older adults, respondents who reported having impairments, and home owners were more likely to respond favorably toward grab bars. Based on these results, the majority of Canadians would respond positively to policy mandating bathroom grab bars in new homes.

Evaluation of safety and efficacy outcomes of direct oral anticoagulants versus warfarin in normal and extreme body weights for the treatment of atrial fibrillation or venous thromboembolism.

Despite evolving evidence, the use of direct oral anticoagulants (DOACs) in patients with extremes of body weight remains controversial. This study aimed to measure the impact of DOACs compared to warfarin on safety and efficacy outcomes in extreme body weight patients. This multi-center, health system, retrospective study examined the outcomes of patients with all body weights and extreme body weights prescribed a DOAC (rivaroxaban, apixaban, dabigatran, edoxaban) or warfarin for atrial fibrillation or venous thromboembolism over a 9-year period. The primary outcome was a composite of thromboembolism, symptomatic recurrent VTE, or severe bleeding; analyzed by pre-determined BMI cutoffs. A total of 19,697 patients were included in the study: 11,604 in the DOAC group and in the 8093 in the warfarin group. 295 patients were underweight and 9108 patients were pre-obese to obese class 3. After adjusting for potential confounders, warfarin patients had higher odds of experiencing the composite outcome compared to DOAC patients (OR 1.337, 95% CI 1.212-1.475). Additionally, obese patients were 24.6% more likely to experience the outcome compared to normal BMI patients. Adjusted modeling showed that warfarin patients experienced higher bleed rates compared to DOAC patients (OR 1.432, 95% CI 1.266-1.620). Obese patients were less likely to be diagnosed with a bleed (OR 0.749, 95% CI 0.658-0.854), and underweight patients were more likely to be diagnosed with a bleed (OR 1.522, 95% CI 1.095-2.115) compared to normal BMI patients. In conclusion, DOACs for atrial fibrillation or VTE in patients with extreme body weights appear safe and effective when compared to warfarin.

The Effect of Handrail Cross-Sectional Design and Age on the Speed and Quality of Reach-To-Grasp Reactions to Recover Balance.

OBJECTIVE: To determine the effect of handrail cross-section on the speed and quality of reach-to-grasp movements following balance loss in younger and older adults. BACKGROUND: Grasping a handrail is a common strategy for balance recovery. For handrails to be effective, the design must enable fast and accurate reactive grasping. Little is known about the effect of handrail cross-section on the timing or quality of the reach-to-grasp movement following balance loss. METHODS: Twenty-four younger and 16 older adults experienced incrementally increasing magnitudes of perturbations in the forward and backward direction until they were no longer able to recover balance. We analyzed the last trial where the participant could recover using only the handrail, without stepping or relying on the harness, the maximum withstood perturbation (MWP). Seven handrail cross-sections were tested. RESULTS: Handrail cross-section did not affect the speed or timing of the reach-to-grasp reaction for younger or older adults. However, handrail cross-section affected the MWP, the grip types used, and the likelihood of making an error or adjustment when grasping. The greatest MWP and fewest errors occurred with 1.5" round handrails. CONCLUSION: The absence of common strategies for accurately grasping complex shapes (reaching more slowly), combined with the higher frequency of errors with larger handrails, suggests that both older and younger adults prioritized quickly reaching the handrail over prehension during reach-to-grasp balance reactions. APPLICATION: This work provides new insights on the effect of age and handrail cross-sectional design on reach-to-grasp reactions to recover balance, which can inform safer handrail design standards.

Pharmacokinetic Evaluation of Cefazolin in the Cerebrospinal Fluid of Critically Ill Patients.

BACKGROUND: The relative distribution of cefazolin into the cerebrospinal fluid (CSF) remains debated. Determining the distribution of cefazolin into the CSF in noninfected adults may allow for further treatment applications of cefazolin. This prospective pharmacokinetic study aimed to determine the pharmacokinetic parameters of cefazolin in serum and CSF from external ventricular drains (EVDs) in neurologically injured adults. METHODS: Blood and CSF were collected, using a biologic waste protocol, for cefazolin quantification and trapezoidal rule-based pharmacokinetic analysis in a total of 15 critically ill adults receiving 2000 mg intravenously every 8 hours or the renal dose equivalent for EVD prophylaxis. RESULTS: A median (range) of 3 (2-4) blood and 3 (2-5) CSF samples were collected for each patient. The most common admitting diagnosis was subarachnoid hemorrhage (66.7%). The median calculated cefazolin CSF Cmax and Cmin values (interquartile range [IQR]) were 2.97 (1.76-8.56) mg/L and 1.59 (0.77-2.17) mg/L, respectively. The median (IQR) CSF to serum area under the curve ratio was 6.7% (3.7%-10.6%), with time-matched estimates providing a similar estimate (8.4%). Of those receiving cefazolin every 8 hours, the median and minimum directly measured CSF cefazolin concentration ≥4 hours following administration were 1.87 and 0.78 mg/L, respectively. CONCLUSIONS: Cefazolin dosed for EVD prophylaxis achieved CSF concentrations suggesting viability as a therapeutic option for patients with meningitis or ventriculitis due to susceptible bacteria such as methicillin-susceptible Staphylococcus aureus. Further clinical trials are required to confirm a role in therapy for cefazolin. Population-based pharmacokinetic-pharmacodynamic modeling may suggest an optimal cefazolin regimen for the treatment of central nervous system infections.

The effect of handrail cross-sectional design and age on applied handrail forces during reach-to-grasp balance reactions.

Handrails have been shown to reduce the likelihood of falls. Despite common use, little is known about how handrail shape and size affect the forces that people can apply after balance loss, and how these forces and the corresponding ability to recover balance depend on age. Following rapid platform translations, 16 older adults and 16 sex-matched younger adults recovered their balance using seven handrail cross-sections varying in shape and size. Younger adults were able to withstand higher perturbations, but did not apply higher forces, than older adults. However, younger adults achieved their peak resultant force more quickly, which may reflect slower rates of force generation with older adults. Considering handrail design, the 38 mm round handrails allowed participants to successfully recover from the largest perturbations and enabled the highest force generation. Conversely, tapered handrails had the poorest performance, resulting in the lowest force generation and withstood perturbation magnitudes. Our findings suggest that the handrail cross-sectional design affects the magnitude of force generation and may impact the success of recovery. Our findings can inform handrail design recommendations that support effective handrail use in demanding, balance recovery scenarios.

Increasing the contrast of tread edge highlighters improves stair descent safety in older adults with simulated visual impairment.

Falls during stair descent are dangerous and costly. Contrasting tread edge highlighters improve measures of stair safety, however the necessary contrast level of these interventions has not been investigated. Thirteen older adults (67.7 ± 5.5 years) completed stair descent trials under normal (300lx) and low (30lx) lighting conditions, blurred and normal vision, and four different contrast levels (0%, 30%, 50%, 70%) between the tread edge highlighter and the neighbouring tread surface. Cadence and heel clearance decreased for 0% contrast compared to 50% and 70% contrast conditions, but contrast had no effect on foot overhang. Blurred vision was observed to be a greater factor influencing biomechanical measures of fall risk than low ambient lighting. Results suggest higher contrast highlighters improve measures of safety, even more so during simulated vision impairment, and that at least 50% contrast difference provides adequate visual information for safer stair ambulation.

Does increased gait variability improve stability when faced with an expected balance perturbation during treadmill walking?

BACKGROUND: Currently, there is uncertainty as to whether movement variability is errorful or exploratory. RESEARCH QUESTION: This study aimed to determine if gait variability represents exploration to improve stability. We hypothesized that 1) spatiotemporal gait features will be more variable prior to an expected perturbation than during unperturbed walking, and 2) increased spatiotemporal gait variability pre-perturbation will correlate with improved stability post-perturbation. METHODS: Sixteen healthy young adults completed 15 treadmill walking trials within a motion simulator under two conditions: unperturbed and expecting a perturbation. Participants were instructed not to expect a perturbation for unperturbed trials, and to expect a single transient medio-lateral balance perturbation for perturbed trials. Kinematic data were collected during the trials. Twenty steps were recorded post-perturbation. Unperturbed and pre-perturbation gait variabilities were defined by the short- and long-term variabilities of step length, width, and time, using 100 steps from pre-perturbation and unperturbed trials. Paired t-tests identified between-condition differences in variabilities. Stability was defined as the number of steps to centre of mass restabilization post-perturbation. Multiple regression analyses determined the effect of pre-perturbation variability on stability. RESULTS: Long-term step width variability was significantly higher pre-perturbation compared to unperturbed walking (mean difference = 0.28 cm, p = 0.0073), with no significant differences between conditions for step length or time variabilities. There was no significant relationship between pre-perturbation variability and post-perturbation restabilization. SIGNIFICANCE: Increased pre-perturbation step width variability was neither beneficial nor detrimental to stability. However, the increased variability in medio-lateral foot placement suggests that participants adopted an exploratory strategy in anticipation of a perturbation.

A kinematic analysis of balance recovery following an unexpected forward balance loss during stair descent.

Falls during stair descent pose a major health concern. A stronger understanding of recovery from balance loss during stair descent is needed to guide fall prevention strategies and environmental design. We characterized balance recovery strategies, trunk and center-of-mass (COM) kinematics, and handrail use following unexpected forward balance loss during stair descent, and the effect of perturbation magnitude on these outcomes. Eighteen young adults experienced a rapid platform translation during stair descent to disrupt balance. Deception was used to reduce anticipation. All participants used compensatory stepping to recover balance, and most applied forces to the handrail in multiple directions. Higher perturbation magnitude resulted in higher COM velocity and handrail forces, more frequent incomplete steps, and quicker step contact time. Our findings provide a foundation for understanding balance recovery on stairs. The findings emphasize the importance of designing stairways that enable compensatory stepping, and handrails that permit adequate force generation in multiple directions to facilitate balance recovery on stairs.

Determining the effect of stair nosing shape on foot trajectory during stair ambulation in healthy and post-stroke individuals.

Stair design can influence the risk of stair falls. Stair nosings are intended to provide greater foot accommodation, although to date little is known about how the nosing shape can affect foot trajectory during stair ambulation. This study investigates the impact of different nosing shapes (round, square, tapered, and no nosing) on foot clearance and overhang measures during stair ascent and descent among healthy and post-stroke older adults. Slower cadence in ascent and descent, and greater foot overhang during descent highlighted the increased risk of stair falls for persons with chronic stroke. For both healthy and post-stroke participants, the tapered and round nosing shapes resulted in the largest horizontal foot clearance, and smallest foot overhang, respectively. However, given the greater step-to-step variability detected with round nosings, the tapered nosing presents as the safest choice among all evaluated designs. The results of this work can be used to inform architectural and accessible design standards for a safer built environment.

Azole-resistant Aspergillus and Echinocandin-resistant Candida - What are the treatment options?

PURPOSE OF REVIEW: This review summarizes current treatment options for echinocandin-resistant Candida spp. (ERC) and azole-resistant Aspergillus fumigatus (ARAF), emphasizing recent in vitro/in vivo data, clinical reports, and consensus statements. RECENT FINDINGS: Advances in ERC and ARAF treatment are limited to specific antifungal combinations and dose optimization but remain reliant on amphotericin products. Although novel antifungals may provide breakthroughs in the treatment of resistant fungi, these agents are not yet available. Early identification and appropriate treatment remain a paramount, albeit elusive, task. SUMMARY: When either ERC or ARAF are suspected or proven, amphotericin products remain the cornerstone of initial therapy. For ERC, azoles are de-escalation options for susceptible isolates in stable patients to avoid amphotericin toxicities. Although combination echinocandin with high-dose salvage posaconazole or isavuconazole may be attempted in ARAF, it requires careful consideration following patient stabilization. Future research defining optimal therapies and early identification of ERC and ARAF is of extreme importance.

Hand-rung forces after a ladder climbing perturbation.

The hands are believed to be important for arresting falls from ladders. Yet, there is a paucity of kinetic data for the hand-handhold interface during recovery from a ladder climbing perturbation. This study quantified the hand-rung forces utilized after ladder climbing perturbations and the factors (upper body strength, fall severity, reestablished foot placement) contributing to hand-rung force. A ladder rung was released under the foot of the participants to simulate a climbing misstep perturbation. Hand-rung forces after the perturbation were quantified from load cells connected to two ladder rungs. Mean peak hand-rung force magnitudes were found to range between 46% and 84% of the climber's body weight. These magnitudes approached and, in some cases, exceeded individuals' grasping capacity. Individual upper body strength was not found to consistently contribute to hand-rung force, but increased hand-rung force was clearly linked with greater fall severity after an ascending perturbation. Individuals that reestablished foot placement after an ascending perturbation utilized lower hand-rung forces. Therefore, this study suggests hand-rung force to be dependent on circumstances of the falling event (fall severity, reestablished foot placement) as opposed to the climber's capability of producing upper body force. This knowledge highlights the importance of handhold and ladder designs for arresting a falling event, and is critical to inform ladder fall interventions such as designing handholds that resist high forces and permitting steps that enable reestablished foot placement.

Characterizing the demands of backward balance loss and fall recovery during stair descent to prevent injury.

Understanding the demands of balance recovery on stairs is important for developing strategies to prevent falls on stairs. This study characterized recovery strategies and whole-body movement following unexpected backward balance loss during stair descent in twelve young adults. Following balance loss, peak downward COM velocity was approximately double that experienced during non-perturbation stair descent. Participants used several balance recovery strategies: harness reliance (n = 1), no grasping reaction (n = 3), and grasping some environmental feature (n = 8). Of the five participants who used the handrail, four demonstrated grasping errors. Peak resultant handrail forces ranged from 24.2N to 238.3N. The results highlight the challenge of balance recovery during stair descent, showing that some people will use any available surface to arrest a fall. Our findings serve as a benchmark to understand the impact of stair-related interventions on fall recovery.

Effect of handrail height and age on the timing and speed of reach-to-grasp balance reactions during slope descent.

We investigated the effect of handrail height on the timing and speed of reach-to-grasp balance reactions during slope descent, in fourteen younger and thirteen older adults. Participants walked along an 8° slope mounted to a robotic platform. Platform perturbations evoked reach-to-grasp reactions. Handrail height did not significantly affect handrail contact time (i.e., time from perturbation onset to handrail contact) or movement time (i.e., time from EMG latency to handrail contact). Participants appeared to compensate for the increased hand-handrail distance with higher rails via increased peak upward hand speed, and decreased vertical handrail overshoot. Aging was associated with slower EMG latency, reduced hand acceleration time, and increased hand deceleration time. Our findings suggest that participants were not disadvantaged by higher handrails from reach-to-grasp timing or speed perspectives, and that other metrics (e.g., center-of-mass control after grasping) may be more important when evaluating handrail designs for balance recovery.