Testing a Biobehavioral Model of Chronic Stress and Weight Gain in Young Children (Family Stress Study): Protocol and Baseline Demographics for a Prospective Observational Study.

BACKGROUND: Chronic stress is an important risk factor in the development of obesity. While research suggests chronic stress is linked to excess weight gain in children, the biological or behavioral mechanisms are poorly understood. OBJECTIVE: The objectives of the Family Stress Study are to examine behavioral and biological pathways through which chronic stress exposure (including stress from COVID-19) may be associated with adiposity in young children, and to determine if factors such as child sex, caregiver-child relationship quality, caregiver education, and caregiver self-regulation moderate the association between chronic stress and child adiposity. METHODS: The Family Stress Study is a prospective cohort study of families recruited from 2 Canadian sites: the University of Guelph in Guelph, Ontario, and McMaster University in Hamilton, Ontario. Participants will be observed for 2 years and were eligible to participate if they had at least one child (aged 2-6 years) and no plans to move from the area within the next 3 years. Study questionnaires and measures were completed remotely at baseline and will be assessed using the same methods at 1- and 2-year follow-ups. At each time point, caregivers measure and report their child's height, weight, and waist circumference, collect a hair sample for cortisol analysis, and fit their child with an activity monitor to assess the child's physical activity and sleep. Caregivers also complete a web-based health and behaviors survey with questions about family demographics, family stress, their own weight-related behaviors, and their child's mental health, as well as a 1-day dietary assessment for their child. RESULTS: Enrollment for this study was completed in December 2021. The final second-year follow-up was completed in April 2024. This study's sample includes 359 families (359 children, 359 female caregivers, and 179 male caregivers). The children's mean (SD) age is 3.9 years (1.2 years) and 51% (n=182) are female. Approximately 74% (n=263) of children and 80% (n=431) of caregivers identify as White. Approximately 34% (n=184) of caregivers have a college diploma or less and nearly 93% (n=499) are married or cohabiting with a partner. Nearly half (n=172, 47%) of the families have an annual household income ≥CAD $100,000 (an average exchange rate of 1 CAD=0.737626 USD applies). Data cleaning and analysis are ongoing as of manuscript publication. CONCLUSIONS: Despite public health restrictions from COVID-19, the Family Stress Study was successful in recruiting and using remote data collection to successfully engage families in this study. The results from this study will help identify the direction and relative contributions of the biological and behavioral pathways linking chronic stress and adiposity. These findings will aid in the development of effective interventions designed to modify these pathways and reduce obesity risk in children. TRIAL REGISTRATION: ClinicalTrials.gov NCT05534711; https://clinicaltrials.gov/study/NCT05534711. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48549.

Compliance with the 24-hour movement behavior guidelines and the impact of sleep methods among toddler, preschool, and school-aged children enrolled in the Guelph Family Health Study.

Canadian movement guidelines focused on physical activity (PA), sleep, and screen time support childhood development and reduce the risk of chronic disease. Accelerometers are often used to capture these behaviors; however, they are limited in their ability to record daytime sleep due to potential misclassification. OBJECTIVES: The objectives of this study were to 1) determine the prevalence of children enrolled in the Guelph Family Health Study who met the guidelines and to 2) compare the impact of different sleep measurement methods. DESIGN/METHODS: Toddlers (1.5-<3 years; n = 128; valid data for all movement behaviors, n = 70), preschoolers (3-<5 years; n = 143; valid data for all movement behaviors, n = 104), and school-aged (5-<6 years; n = 49; valid data for all movement behaviors, n = 31) children were included. Screen time and sleep habits were obtained through parental report and published normative data. PA and sleep were recorded using accelerometers (wGT3X-BT ActiGraph; right hip). RESULTS: It was found that 66 % of toddler, 44 % of preschool, and 63 % of school-aged children met the screen time guidelines. Further, 63 % of toddler, 98 % of preschooler, and 80 % of school-aged children met PA guidelines. Sleep guideline compliance ranged from 3 % to 83 % in toddler, 27 % to 92 % in preschooler, and 32 % to 90 % in school-aged children. These proportions were found to be significantly different (Cochran's Q and McNemar's tests). CONCLUSIONS: Nearly all children met PA guidelines. In contrast, less than half to two-thirds met screen time guidelines. Compliance with sleep guidelines varied substantially with measurement method, highlighting the need for standardization.

Visual cue spatial context affects performance of anticipatory postural adjustments.

Past research indicates that anticipatory postural adjustment (APA) errors may be due to the incorrect selection of responses to visual stimuli. In the current study we used the Simon task as a methodological tool to challenge the response selection stage of processing by presenting visual cues with conflicting spatial context; in this case generating a step response to a left pointing arrow which appears to the participant's right side or vice versa. We expected greater mediolateral APA errors, delayed APA and step onset times, and greater lateral CoP displacement prior to stepping for visual cues with incongruent spatial contexts compared to cues with congruent. Thirteen healthy young adults completed step initiation trials (n = 40) from a force platform while whole-body kinematic motion was tracked. Participants were presented with arrows pointing to the left or right, indicating to step with the left or right limb, respectively. These arrows were presented on the same side as the desired step direction (congruent) or the opposite side (incongruent). Results revealed that incongruent trials resulted in significantly more incidences of mediolateral APA errors and greater mediolateral CoP deviations during the APA compared to congruent visual cue context trials. No effects were observed for the temporal outcomes, suggesting that young adults can maintain temporal execution of steps despite these motor control errors. This study demonstrates that the spatial context of visual information significantly impacts the success of response selection processes during step initiation, furthering our knowledge of how humans integrate visual information to initiate whole body movement.

What Is the Role of Sustained Visual Attention in the Maintenance of Postural Control in Young Adults?

Dual tasks requiring sustained visual attention and upright stance are common, yet their impact on standing balance is not well understood. We investigated the role of visual attention in the maintenance of postural control, using the multiple-object tracking (MOT) task. Healthy young adults (n = 12) performed the MOT task at three object movement speeds while seated or standing. MOT performance was assessed using tracking capacity (k). Metrics calculated to assess mediolateral (ML) and anterior-posterior (AP) postural control included: maximum difference between CoM and CoP position (CoM-CoP Max), root mean square distance for center of pressure and center of mass position (CoP and CoM RMS distance), and correlation between CoM and CoP time series signals (CoM/CoP correlation). As predicted, k decreased significantly as object movement speed increased for both standing and seated conditions. Object movement speed also significantly affected AP CoM-CoP Max in seated conditions (p = .021) and AP CoM/CoP correlation for standing conditions (p = .002). The results demonstrate utility of the MOT task in understanding the role of visual attention in postural control, even though healthy young adults were able to compensate for the addition of a sustained visual attention task, with minimal deficits to postural control.

Enabling the ActiGraph GT9X Link's Idle Sleep Mode and Inertial Measurement Unit Settings Directly Impacts Data Acquisition.

The ActiGraph GT9X has been implemented in clinical trials to track physical activity and sleep. Given recent incidental findings from our laboratory, the overall aim of this study was to notify academic and clinical researchers of the idle sleep mode (ISM) and inertial measurement unit (IMU)'s interaction, as well as their subsequent effect on data acquisition. Investigations were undertaken using a hexapod robot to test the X, Y and Z sensing axes of the accelerometers. Seven GT9X were tested at frequencies ranging from 0.5 to 2 Hz. Testing was performed for three sets of setting parameters: Setting Parameter 1 (ISMONIMUON), Setting Parameter 2 (ISMOFFIMUON), Setting Parameter 3 (ISMONIMUOFF). The minimum, maximum and range of outputs were compared between the settings and frequencies. Findings indicated that Setting Parameters 1 and 2 were not significantly different, but both were significantly different from Setting Parameter 3. Upon inspection, it was discovered that the ISM was only active during Setting Parameter 3 testing, despite it being enabled in Setting Parameter 1. Researchers should be aware of this when conducting future research using the GT9X.

Physiological and clinical responses to cycling 7850 km over 85 days in a physically active middle-aged man with idiopathic Parkinson's disease.

This case characterizes the clinical motor, perceived fatigue, gait and balance, cardiovascular, neuromuscular, and cardiopulmonary responses after cycling 7850 km over 85 days in a physically active 57-year-old male with idiopathic Parkinson's disease (PD). The participant cycled 73/85 days (86%); averaging 107.5 ± 48.9 km/day over 255.4 ± 108.8 min. Average cycling heart rate was 117 ± 11 bpm. The Unified Parkinson Disease Rating Scale (UPDRS) Part III motor score decreased from 46 to 26 (-44%), while the mean Parkinson Fatigue Scale (PFS-16) score decreased from 3.4 to 2.3 (-32%). Peak power output on a maximal aerobic exercise test increased from 326 to 357 W (+10%), while peak isotonic power of single-leg knee extension increased from 312 to 350 W (+12%). Maximal oxygen uptake following the trip was 53.1 mL/min/kg or 151% of predicted. Resting heart rate increased from 48 to 71 bpm (+48%). The systolic and diastolic blood pressure responses to a 2-min submaximal static handgrip exercise were near absent at baseline (∆2/∆2 mm Hg) but appeared normal post-trip (∆17/∆9 mm Hg). Gait and static balance measures were unchanged. This case report demonstrates the capacity for physiological and clinical adaptations to a high-volume, high-intensity cycling regiment in a physically active middle-aged male with PD.

The Role of Cognition When Executing an Online, Visually Evoked Adjustment to an Obstacle Circumvention Strategy.

We know that performing simultaneous cognitive tasks during locomotion results in reduced performance on either or both tasks, however the role of the cognitive system in the execution of last-minute changes to ongoing adaptive locomotor tasks is not fully understood. Nineteen participants were initially cued to circumvent to left, right, or step over an obstacle while an auditory cognitive task was simultaneously presented. In half of the trials, no change in avoidance strategy was required; in the remaining trials, participants were visually cued two steps in advance to execute a new circumvention strategy. Participants decreased gait velocity and increased cognitive task response times when executing changes in strategy, highlighting the important role the cognitive system plays in these complex tasks.

The association between visual attention and body movement-controlled video games, balance and mobility in older adults.

BACKGROUND: Body movement-controlled video games involving physical motion and visual attention may have the potential to train both abilities simultaneously. Our purpose was to determine the associations between performance in these games and visual attention, balance and mobility in a group of older adults. The long-term goal is to identify the optimal type of interactive games with regards to training potential. METHODS: Fifty healthy adults aged 65+ years participated in this cross-sectional study. Visual attention was measured with static and dynamic versions of a useful field of view (UFV) and a multiple object tracking (MOT) test. Balance was measured with a force plate in bi-pedal quiet stance test (QST) and one-legged stance (OLST). Gait variability and walking speed were assessed with the Five Meter Walk Test (5MWT). Four Microsoft™ Xbox® 360 Kinect™ interactive video games were chosen based on the apparent levels of visual attention demand. RESULTS: Visual attention (UFV and MOT) was significantly associated with performance in Xbox® Kinect™ games that appeared to have a high visual attention demand (p < 0.05), while there was minimal or no significant association with games with apparent low visual attention demand. Balance and mobility show correlations with visual attention, and with Xbox games. CONCLUSION: The results suggest that there are relationships between visual attention, balance, mobility and Xbox® Kinect™ game performance. Since different Xbox® games were associated with different balance, mobility and visual attention scores, a variety of such games, rather than a single game, may be most effective for training for falls prevention.

Performance during reactive handrail grasping during forward walking by young and older adults with and without prior knowledge of the direction of movement is correlated with grip strength.

It has been suggested that the most frequent cause of falls in assisted-living facilities is due to incorrect weight shifting. Lateral instability and weakness have also been linked to falls risk. The objective of this study was to evaluate balance responses to weight shifting during walking and to investigate age-related changes in movement and strength. Thirty-two participants (16 young, 16 older) completed 12 straight walking trials and 6 trials in each condition where a weight shift was required to grasp a handrail. Instructions were to walk down the pathway and, if cued, grasp the handrail as quickly as possible. Conditions included left and right grasping trials, with and without prior knowledge about the movement direction. Kinematic data were recorded and center of mass (COM) was calculated to examine whole body movements. A clinical balance test, strength, and body composition measures were captured to facilitate exploration into the relationship of these measures with reactive movements used during weight transfers. Young adults had quicker lateral COM velocities and reached peak velocity earlier. Males completed the task quicker than females and, for everyone, having knowledge about direction enabled quicker responses. Grip strength was correlated to most performance metrics in this study; more-so than body composition. Slower reactive movements might reflect a more cautious strategy in the older adults or it may highlight changes that occur with increased age and strength changes.

Exploring the cognitive demands required for young adults to adjust online obstacle avoidance strategies.

Humans integrate visual information about their surrounding environment to properly adapt their locomotion to step over or around obstacles in their path. We know that cognition aids in the execution of locomotion and in complex maneuvers such as obstacle avoidance. However, the role of the cognitive system in performing online adjustments to an obstacle avoidance strategy during locomotion has not yet been elucidated. Nineteen young adults instrumented with kinematic markers were asked to step over or circumvent an obstacle to the left or right. In half of these trials, participants were required to adjust this strategy when cued by LED lights two steps prior to obstacle crossing. In 75% of trials, a cognitive task was simultaneously presented (incongruent or congruent auditory Stroop cue, or neutral cue). Center of mass position and velocity was estimated and gait metrics (eg. step length) were calculated to quantify how individuals performed this last-minute direction change and determine how these responses changed when simultaneously performing a cognitive task. Results showed statistically shorter crossing steps, where the trailing limb was placed further from the leading edge and the lead limb was placed closer to the trailing edge when responding to the auditory Stroop task. Performing these avoidance strategy changes also decreased cognitive task performance. Our findings suggest that visually integrating a new stepping pattern to cross an obstacle is a complex locomotor maneuver, and requires the aid of the cognitive system to be performed effectively in a young adult population.

Examining the effects of applying ActiGraph low-frequency extension feature to analyze the sleeping behaviours of preschool-aged children.

This study compares sleep outcome measures obtained using normal- and low-frequency extension (LFE) settings (Actilife). Forty-two children (aged 3-6 years) were instructed to wear an ActiGraph GT3X+ accelerometer on their hip for 7 days, 24 h/day. Total sleep time (min), sleep efficiency (%), and number and cumulative length (min) of awakening were used to compare the settings. Results suggest that the LFE setting results in significant but relatively small reductions in the sleep metrics of children. Trial registration no.: clincialtrials.gov (ID no. NCT02223234) Novelty LFE setting, available through ActiGraph, estimates a significantly reduced total sleep time and efficiency.

Modelling the dynamic margins of stability for use in evaluations of balance following a support-surface perturbation.

The dynamic margin of stability provides a method that captures the center of mass (CoM) state (position-velocity) in relation to the base of support (BoS). However, the model upon which this concept was derived does not consider how the inertial characteristics of forced support-surface perturbations would influence balance control. Within the current article, the inverted pendulum model was restructured to account for fixed, piecewise accelerations of the BoS. From this logic, two variations of the adjusted margin of stability, each maintaining a similar definition of extrapolated CoM, are proposed; one ignoring horizontal ground contact and inertial forces applied to the BoS, the other incorporating these forces. Unique within the proposed models is the time-variant BoS boundaries that depend on the perturbation applied. Verification of the solution for each model is provided, along with a comparison of obtained values to previous methods of defining CoM position-velocity stability metrics using a computational model and optimal control. For the simpler model variation (ignoring forces), we also assessed how CoM position and perturbation parameter selection over/underestimate the predicted maximal permissible velocity. The results of these analyses suggest that factors which increase the acceleration impulse decrease the difference between the two models; the opposite was observed for factors increasing displacements between the CoM and BoS boundary. Lastly, use of the proposed adjusted margin of stability within an experimental data set highlights the ability of our model to predict instability (stepping strategies; negative margin of stability) relative to the use of the extrapolated CoM alone.

Can older adults' balance and mobility improve with visual attention training?

PURPOSE: We hypothesize that training older adults with a structured visual attention task will result in improved balance and mobility, potentially reducing their risk for falls. METHODS: Healthy older adults aged 70 + took part in the study (mean age 80.3 ± 6 years). In this randomised control trial (NCT02030743), 15 participants were randomly assigned to a visual attention training group and 15 to a control group. Visual attention training was undertaken twice a week (45 min sessions) for 3 weeks (= six sessions) using versions of a selective attention useful field of view test and attended field of view test. The outcome measures were postural sway using a force plate, the Mini-Balance Evaluation Systems Test, the One-Legged Stance test, the 5 Meter Walking test, the Sit to Stand test, the Timed Up and Go test without and with a concurrent cognitive task. RESULTS: There was a greater improvement in visual attention after training in the intervention group compared to the control group (p < 0.01). However, a mixed ANOVA (2× groups, 2× visit) showed no main effect of visit or group or any interaction for any of the force plate parameters. T tests of the changes over time between the intervention group and the control groups for the other balance and mobility assessment tools showed no improvement after the visual attention training. CONCLUSION: It was found that there was no improvement in either mobility or balance after the visual attention training and no difference between the intervention and the control groups.

Repeated Exposure to Forward Support-Surface Perturbation During Overground Walking Alters Upper-Body Kinematics and Step Parameters.

Locomotion requires both proactive and reactive control strategies to maintain balance. The current study aimed to: (i) ascertain upper body postural responses following first exposure to a forward (slip) support-surface perturbation; (ii) investigate effects of repeated perturbation exposure; (iii) establish relationships between arms and other response components (trunk; center of mass control). Young adults (N = 11) completed 14 walking trials on a robotic platform; six elicited a slip response. Kinematic analyses were focused on extrapolated center of mass position (xCoM), bilateral upper- and forearm elevation velocity, trunk angular velocity, and step parameters. Results demonstrated that postural responses evoked in the first slip exposure were the largest in magnitude (e.g., reduced backward stability, altered reactive stepping, etc.) and preceded by anticipatory anterior adjustments of xCoM. In relation to the perturbed leg, the large contra- and ipsilateral arm responses observed (in first exposure) were characteristically asymmetric and scaled to the degree of peak trunk extension. With repeated exposure, xCoM anticipatory adjustments were altered and in turn, reduced posterior xCoM motion occurred following a slip (changes plateaued at second exposure). The few components of the slip response that persisted across multiple exposures did so at a lesser magnitude (e.g., step length and arms).

Age-related alterations in reactive stepping following unexpected mediolateral perturbations during gait initiation.

BACKGROUND: A common technique to regain stability following an unexpected perturbation is reactive stepping, aimed to control the accelerated center of mass (COM). Many older adults (OA) struggle to execute the fast, coordinated stepping strategy required to arrest COM movement within the base of support (BOS) during these unexpected events, likely due to age-related physiological declines. Recent ecological data also suggests that many falls in OA occur due to errors in transferring or shifting body weight during activities of daily living. The present study utilized gait initiation, which requires a coordinated transition from quiet stance to dynamic gait, as an example of one of these difficult transitional movements. RESEARCH QUESTION: Our goal was to combine this inherently unstable task, gait initiation, with an unexpected mediolateral (ML) perturbation of the support surface to examine age-related changes in reactive stepping patterns during a novel transitional gait task. METHODS: A total of 18 young adults (YA) and 16 OA (>65 years) performed 35 trials containing 10 unexpected ML perturbations of the support surface. To quantify age-related differences, we calculated step width, length, time and COM velocity in the first two steps following the perturbation. RESULTS: We observed that, in general, OA walked slower and took shorter, faster steps (reducing time in single support) compared to YA. Following the perturbation, OA altered their stepping patterns by reducing their BOS (more narrow step width compared to YA), and required more than the two steps used by YA to complete the goal-directed task. SIGNIFICANCE: These age-related changes are concerning as a multi-step recovery strategy has been previously associated with an elevated risk of falls in OA.

Do perturbation-evoked responses result in higher reaction time costs depending on the direction and magnitude of perturbation?

To date, little work has focused on whether cognitive-task interference during postural response execution is influenced by the direction and/or magnitude of the perturbation applied. Hypothetically, the increased difficulty associated with a backward loss of balance could necessitate increased allocation of cognitive resources to counteract destabilizing forces. The current study investigated these relationships using a paradigm in which individuals performed a cognitive task (auditory Stroop task during quiet stance; baseline condition). In certain trials, a translation of the support surface was concurrently evoked (magnitude: small or large; direction: forward or backward) which required a postural response to maintain balance. Ten healthy young adults completed four blocks of these experimental trials (26 randomized trials/block). Postural stability during balance recovery was evaluated using the margin of stability (MoS), while Stroop task performance was based on reaction time cost (RTC) and differences between experimental conditions. Results showed no effect of perturbation direction on RTC, but there was an observed MoS increase at peak extrapolated center of mass excursion following a small perturbation evoked concurrently with the cognitive task. No effect of cognitive-task performance was detected for MoS during stepping strategies (followed large perturbations). Instead, increased RTC were observed relative to the fixed base of support responses. In general, young adults adopted a "posture-first" strategy, regardless of perturbation direction, reinforcing the importance of cognition in the maintenance of upright balance.

Modeling margin of stability with feet in place following a postural perturbation: Effect of altered anthropometric models for estimated extrapolated centre of mass.

BACKGROUND: Maintaining the centre of mass (CoM) of the body within the base of support is a critical component of upright balance; the ability to accurately quantify balance recovery mechanisms is critical for many research teams. RESEARCH QUESTION: The purpose of this study was to investigate how exclusion of specific body segments in an anthropometric CoM model influenced a dynamic measure of postural stability, the margin of stability (MoS), following a support-surface perturbation. METHODS: Healthy young adults (n = 10) were instrumented with kinematic markers and a safety harness. Sixteen support-surface translations, scaled to ensure responses did not involve a change in base of support, were then issued (backwards, forwards, left, or right). Whole-body CoM was estimated using four variations of a 13-segment anthropometric model: i) the full-model (WFM), and three simplified models, ii) excluding upper limbs (NAr); iii) excluding upper and lower limbs (HTP); iv) pelvis CoM (CoMp). The CoM calculated for each variant was then used to estimate extrapolated CoM (xCoM) position and the resulting MoS within the plane of postural disturbance. RESULTS: Comparisons of simplified models to the full model revealed significant differences (p < 0.05) in MoS for all models in each perturbation condition; however, the largest differences were following sagittal plane based perturbations. Poor estimates of WFM MoS were most evident for HTP and CoMp models; these were associated with the greatest values of RMS/maximum error, poorest correlations, etc. The simplified models provided low-error approximates for frontal plane perturbations. SIGNIFICANCE: Findings suggest that simplified calculations of CoM can be used by researchers without reducing MoS measurement accuracy; however, the degree of simplification should be context-dependent. For example, CoMp models may be appropriate for questions pertaining to frontal plane MoS; sagittal plane MoS necessitates inclusion of lower limb and HTP segments to prevent underestimation of postural stability.

Slip and Trip Perturbations During an Object Transport Task Requiring a Lateral Change in Support.

The ability to counteract destabilizing external forces while simultaneously executing a complex task presents a novel way to ascertain one's ability to generate adaptive postural control responses to avoid a potential fall. In this study, participants performed an upper limb object transport task requiring a lateral change in support on a robotic platform that could remain fixed in space or translated (mimicking a slip or trip perturbation). No significant stability differences were observed at initial recovery step between slip and trip perturbations. Variability measures were greatest during the trip perturbations; though stability was at its greatest level preceding these perturbations. These results will aid in the design of future studies that will investigate adaptive postural control responses generated by older adults when executing similar, ongoing complex upper body tasks interrupted by a destabilizing support surface perturbation.

Examining Transfer Effects of Dual-Task Training Protocols for a Complex Locomotor Task.

Training protocols designed to improve dual-task performance of an obstacle crossing and auditory Stroop task (OBS+Stroop) were tested. In Experiment  1 , following baseline collection of OBS+Stroop trials, proximally related walking training was performed, and participants were then retested on the OBS+Stroop test. After training, participants adopted a more cautious obstacle crossing strategy, indicating a potentially safer navigation strategy. Transfer effects from distally related training were then examined (Experiment  2 ); a computer game training paradigm was examined using the same testing protocol as Experiment  1 . Computer training demonstrated improved dual-task performance on some measures, but did not induce a more cautious stepping strategy. Results indicate that dual-task training needs to be similar to targeted tasks to yield reliable, positive training outcomes.

Older adults exhibit altered motor coordination during an upper limb object transport task requiring a lateral change in support.

Investigating an ecologically relevant upper limb task, such as manually transporting an object with a concurrent lateral change in support (sidestepping alongside a kitchen counter), may provide greater insight into potential deficits in postural stability, variability and motor coordination in older adults. Nine healthy young and eleven older, community dwelling adults executed an upper limb object transport task requiring a lateral change in support in two directions at two self-selected speeds, self-paced and fast-paced. Dynamic postural stability and movement variability was quantified via whole-body center of mass motion. The onset of lead lower limb movement in relation to object movement onset was quantified as a measure of motor coordination. Older adults demonstrated similar levels of stability and variability as their younger counterparts, but at slower peak movement velocity and increased task duration. Furthermore, older adults demonstrated asymmetrical motor coordination between left and right task directions, while younger adults remained consistent regardless of task direction. Thus, older adults significantly modulated movement speed and motor coordination to maintain similar levels of stability and variability compared to their younger counterparts.