Biology subjects

Fino, P. C.

Publications and source records attributed to Fino, P. C..

12 recordsLinked to original sources

bioRxiv2026

Altering sensory cues for spatial navigation does not impose a dual-task effect on gait and balance

Walking is an attentionally demanding process that draws from a limited pool of attentional resources. Dual-task assessments, where individuals perform a cognitive task while walking, often reveal changes in gait and balance due to competing attentional demands. As cognitive task difficulty increases, the attentional resources necessary to complete the task also increase, leading to greater interference with gait and balance. However, these interactions are typically examined using contrived lab-based tasks, leaving it unclear how the cognitive processes engaged during real-world movement impact walking. In the present study, we investigated whether increasing the attentional demand of spatial navigation, a cognitive process intrinsically linked to movement, interferes with gait and balance. Healthy adults completed an ambulatory virtual reality homing task in which they walked through a virtual environment and navigated to previously visited locations while wearing ankle and lumbar trackers. We increased the attentional demand of navigation by removing sensory cues during this homing phase: full cues, visual cues only, or self-motion cues only. Navigation performance declined as sensory cues were removed, but we observed no corresponding changes in their spatiotemporal gait and balance metrics. These results show that, in healthy adults, increasing the attentional demand of spatial navigation does not interfere with gait and balance during real-world movement. This finding suggests that locomotor control may be robust to navigation-related cognitive demands. Further research is needed to determine why navigation did not interfere with mobility and to clarify the relationship between these two interconnected processes.

physiology↗

bioRxiv2026

Effects of one night of sleep deprivation on single- and dual-task gait

Sleep deprivation impairs cognitive control, which may affect movements that rely on these processes, such as walking. To test whether gait changes after one night of sleep deprivation reflect reduced cognitive capacity, we compared its effects with those of dual-task walking (i.e., walking while performing a simultaneous cognitive task). We hypothesize that sleep deprivation will produce gait changes similar to those under dual-task conditions. Eighteen healthy adults (9 female, 9 male; 22.2 (2.3) yrs) were tested the morning after a sleep deprivation (SDEP) and a control night. Participants completed two 2-min trials: single-task walking and walking with a concurrent 2-back working memory task (DT, dual-task). Using lateral foot and pelvis marker trajectories, we calculated spatiotemporal parameters, foot placement error in antero-posterior (FPEAP) and mediolateral (FPEML) directions, and mediolateral margin of stability (MoSML). SDEP increased average step time (p<0.001) and step length (p=0.001), and DT reduced spatiotemporal variability. Both SDEP (p=0.001) and DT (p<0.001) reduced FPEAP, but only DT reduced FPEML (p<0.001). Additionally, mean MoSML decreased only in SDEP (p=0.011). Overall, these findings suggest that while sleep deprivation and dual-tasking both affect gait, the effects of sleep deprivation on gait cannot be fully explained by reduced cognitive resources.

neuroscience↗

bioRxiv2025

Misalignment between perceived and actual ability on a balance beam walking task

Effective dynamic balance control is necessary to maintain stability, but it is an individuals self-perceived ability that ultimately determines movement selection. Accurate self-estimation of balance ability is therefore essential to ensure that movement choices align with true capability. This study examined individuals perception of their ability on a clinically standardized Narrowing Beam Walking Task (NBWT) to examine 1) the initial perception of balance ability before attempting the task, and 2) how experience completing the task improves the accuracy of self-perceived balance. Collegiate athletes provided self-estimates of performance at baseline (before any trials with the task), early-training (after completing two trials), and post-training (after a further 8 trials). Actual task performance was quantified using the final 8 trials. At baseline, athletes poorly estimated their ability: individuals with poorer task performance tended to overestimate their ability while higher-performing individuals tended to underestimate their ability. With practice, absolute estimation error significantly decreased, indicating that task-specific exposure facilitated recalibration to bring self-estimates of performance in closer alignment to actual performance. These effects were consistent across all tested sporting disciplines. These findings show that effective balance control and frequent engagement in similar, but unrelated balance tasks, does not facilitate accurate self-perception of performance on the NBWT. Instead, brief task-specific exposure was required to refine balance estimates. These findings have implications for balance testing and rehabilitation that seeks to improve mobility in populations whose misjudgments of balance ability are often associated with negative outcomes, such as falls.

physiology↗

bioRxiv2025

Continuous Monitoring of Head Turns: Compliance, Kinematics, and Reliability of Wearable Sensing

Wearable devices offer objective mobility metrics for continuous monitoring but often focus on traditional measures like step count or gait speed. Other quantitative metrics such as head kinematics may provide valuable insights into mobility, balance, and sensory integration, given the heads central role in coordinating vestibular, ocular, and postural control. Yet, basic knowledge about capturing daily living head turns, including participant compliance, algorithms, normative data, and reliability, is not yet established. This study aimed to resolve this knowledge gap by capturing head and trunk movement kinematics over a 7-day period and to establish normative data in healthy adults. Participants (n = 24) wore head-mounted sensors for an average of 16.38 hours per day (SD = 4.43), completing 5,163 (SD = 1,466) head turns daily, with 72% occurring independently of trunk motion. Head turn amplitude (M = 58.18{degrees}, SD = 4.26{degrees}) was comparable to lumbar turns, while peak velocity was higher for head turns (M = 104.49{degrees}/s, SD = 12.08{degrees}/s). By the second day, all head turn metrics achieved excellent reliability (ICC > 0.9), supporting the feasibility of multi-day monitoring. Additionally, we examined the relationship between head motion and other mobility metrics and established recommendations for implementing similar protocols for capturing future studies, including the minimum number of days required for reliable data collection. Findings from this study provide a foundation for future multi-day continuous monitoring of head kinematics in both healthy and clinical populations.

bioengineering↗

bioRxiv2025

Effects of Unexpected Underfoot Perturbations During Turning on Measures of Mediolateral Stability and Corresponding Recovery Strategies

Humans regularly walk across uneven terrain, which demands the use of reactive control strategies to maintain forward progress and stability. While reactive control during walking has been well described during straight gait, it is unclear how reactive control differs during turning gait. Because turning is asymmetrical, perturbations to the inside and outside limbs may elicit different reactive adjustments. This study investigates how unexpected underfoot perturbations alter stability measures during turning and how individuals alter their foot placement to maintain stability after such perturbations. Seven healthy adults completed walking trials around a circular track while wearing mechanized shoes that pseudo-randomly delivered underfoot perturbations to either the inside or outside limb. We calculated mediolateral margin of stability corrected for centripetal acceleration (ML MoSC), step width, and step length from kinematic data. Linear mixed effects models compared the effects of perturbation type (inversion vs eversion), perturbation limb (inside vs outside), and their interaction for each outcome measure. ML MoSC was affected by both perturbation type and perturbation limb, with larger changes observed during eversion, and outside, perturbations. Changes to step width and step time during two recovery steps after each perturbation were primarily influenced by the perturbation limb - outside perturbations elicited consistent changes during two recovery steps compared to one altered step after inside perturbations. Perturbations to the outside limb during turning disrupt gait longer than perturbations to the inside limb. This difference across perturbation limb may indicate that outside steps are more important to maintaining and recovering stability than inside ones during turning.

bioengineering↗

bioRxiv2024

Behavioral risk models explain locomotor and balance changes when walking at virtual heights

Walking in daily life requires humans to adapt to environments that can influence ones fear of falling and anxiety about a potential fall. In such environments, individuals may adopt compensatory locomotor and balance changes to maintain a constant expected risk function equal to the product of the probability of some event (e.g., a fall) and the cost of that event (e.g., injury or death). Here, we tested whether locomotor behaviors broadly align with this risk model in two experiments with height-related threats in immersive virtual reality. In Experiment 1, we examined how individuals change their locomotor trajectory while walking along a straight high-elevation walkway. In Experiment 2, we examined how individuals change trajectory and balance control during curved walking where the location of high elevation threat varied. Participants adopted two behaviors that decreased their probability of falling off the edge and aligned with the risk-based model: participants altered their proximity to perceived threats that pose high costs (e.g., a high-elevation ledge), and decreased mediolateral center of mass velocity when that was not possible. Taken together, our results suggest that individuals alter locomotor behavior to change the probability of falling based on the perceived cost of that fall.

neuroscience↗

bioRxiv2024

Bases for the selection of alternate foot placement during straight- and turning-gait

Humans typically plan foot placement strategy multiple steps in advance when walking across complex terrain. Planning steps in advance is beneficial for both upright stability and forward progress, but one drawback is that new obstacles can make planned foot placement location unsafe between planning and execution, necessitating a rapid shift to foot placement that impacts stability and progress. This study investigates the bases for selection of alternate foot placement during both straight- and turning-gait. Thirteen healthy young adults walked along a virtually projected walkway with precision footholds oriented in either a straight line or with a single 60{degrees}, 90{degrees}, or 120{degrees} turn to the right. On a subset of trials, participants were required to rapidly avoid stepping on select footholds. We found stereotyped alternate foot placement strategies across turn angles that differed by turn strategy. Alternate foot placement for step turns supported the walkers instantaneous kinematics but not the planned change in trajectory; whereas foot placement for disrupted spin turns supported the walkers anticipated change in trajectory. We conclude that when humans are forced to rapidly alter previously developed motor plans for foot placement, they utilize a rapid stereotyped behavior that changes based on the demand of the turn.

bioengineering↗

bioRxiv2023

Walking (and talking) the plank: Dual-task performance costs in a virtual balance-threatening environment

We evaluated the effects of engaging in extemporaneous speech while walking in virtual environments meant to elicit low or high levels of mobility-related anxiety. We expected that mobility-related anxiety imposed by a simulated balance threat (i.e. virtual high elevation) would impair walking behavior and lead to greater dual-task costs. Altogether, 15 adults (age = 25.6 {+/-} 4.7 yrs, 7 women) walked at their self-selected speed within low (ground) and high elevation (15 meters) VR settings while speaking extemporaneously (dual-task) or not speaking (single-task). Likert-scale ratings of cognitive and somatic anxiety, confidence, and mental effort were evaluated after experiencing each condition, and gait speed, step length, and step width, and the variability of each, was calculated for each trial using the position of trackers attached to participants ankles. Silent speech pauses (>150ms) were determined from audio recordings to infer the cognitive costs of extemporaneous speech planning at low and high virtual elevation. The presence of a balance threat and the inclusion of a concurrent speech task both perturbed gait kinematics, but only the virtual height illusion increased anxiety and mental effort while decreasing confidence. Extemporaneous speech pauses were longer on average when walking, but no effects of virtual elevation were reported. Trends toward interaction effects arose in self-reported responses, participants reported more comfort walking at virtual heights if they engaged in extemporaneous speech. Walking at virtual elevation and walking while talking have independent and significant effects on gait; both effects were robust and did not support an interaction when combined (i.e., walking and talking at virtual heights). Rather than additive cognitive-motor demands, the nature of extemporaneous speech may have distracted participants from the detrimental effects of walking in anxiety-inducing settings.

bioengineering↗

bioRxiv2022

The Choice of Reference Frame Alters Interpretations of Non-Linear Gait

IntroductionHumans regularly follow non-linear trajectories, such as turning, during everyday ambulation. However, globally-defined and locally-defined reference frames fall out of alignment during non- linear locomotion, which complicates spatiotemporal and biomechanical analyses of gait. Thus, the choice of the locally-defined reference frame is an important methodological consideration. This study investigated how different definitions of reference frame change the results and interpretations of common gait measures. MethodsNine healthy adults completed two walking trials around a circular track. Kinematic data were collected via motion capture and used to calculate step length, step width, anteroposterior margin of stability, and mediolateral margin of stability using three different locally-defined reference frames: walkway-fixed, body-fixed, and trajectory-fixed. Linear-mixed effects models compared the effect of reference frame on each gait measure, and the effect of reference frame on conclusions about a known effect of turning gait - asymmetrical stepping patterns. ResultsAll four gait measures differed significantly across the three reference frames. A significant interaction of reference frame and step type (i.e. inside vs outside step) on all four gait measures (p < 0.001) indicated conclusions about asymmetry differed based on the choice of reference frame. ConclusionThe choice of reference frame will change the calculated gait measures and may alter the conclusions of studies investigating non-linear gait. Care should be taken when comparing studies that used different reference frames, as results cannot be easily harmonized. Future studies of non-linear gait need to justify and detail their choice of reference frame.

bioengineering↗

bioRxiv2022

The effects of physical and temporal certainty on locomotion with discrete underfoot perturbations

BackgroundAmbulation over complex terrain requires active control of foot placement to maintain a normal kinematic relationship between the center of mass and base of support. Recent investigations have suggested that foot placement location may be selected to anticipate shifts to the underfoot center of pressure. However, it is unclear whether temporal affordance and physical certainty contribute to the selection of a perturbation-specific anticipatory strategy. This study investigates anticipatory and reactive locomotor strategies for repeated underfoot perturbations with varying levels of temporal certainty, temporal affordance, and physical certainty. MethodsThirteen healthy adults walked with random underfoot perturbations from a mechanized shoe. Temporal certainty was challenged by presenting the perturbations with or without warning. Temporal affordance was challenged by adjusting the timing of a warning tone before the perturbation. Physical certainty was challenged with conditions that included only eversion perturbations, only inversion perturbations, or both eversion and inversion perturbations. Linear-mixed effects models assessed the effect of each condition on the percent change of margin of stability and step width, respectively. ResultsFor temporally uncertain perturbations and perturbations with one stride or less of affordance, we observed few changes to step width or margin of stability. As affordance increased to two strides, participants adopted a wider step width in anticipation of the perturbation (p = 0.001). Physical certainty had little effect on gait for the step of the perturbation, but participants recovered normal gait sooner when the physical nature of the perturbation was predictable (p < 0.001). DiscussionDespite having information about the timing and magnitude of upcoming perturbations, individuals do not develop perturbation specific feedforward strategies but instead rely on feedback control to recover normal gait after a perturbation. However, physical certainty appears to improve the efficiency of the feedback controller and allows individuals to recover normal gait sooner.

neuroscience↗

bioRxiv2019

Head Stabilization During Standing in People with Persisting Symptoms after Mild Traumatic Brain Injury

Increased postural sway is often observed in people with mild traumatic brain injury (mTBI), but our understanding of how individuals with mTBI control their head during stance is limited. The purpose of this study was to determine if people with mTBI exhibit increased sway at the head compared with healthy controls. People with persisting symptoms after mTBI (n = 59, 41 women) and control participants (n = 63, 38 women) stood quietly for one minute in four conditions: eyes open on a firm surface (EO-firm), eyes closed on a firm surface (EC-firm), eyes open on a foam pad (EO-foam), and eyes closed on foam (EC-foam). Inertial sensors at the head, sternum, and lumbar region collected tri-axial accelerations. Root-mean-square (RMS) accelerations in anteroposterior (AP) and mediolateral (ML) directions. Sway ratios between the head and sternum, head and lumbar, and sternum and lumbar region, were compared between groups. Temporal coupling of anti-phase motion between the upper and lower body angular accelerations was assessed with magnitude squared coherence and cross-spectral phase angles. People with mTBI demonstrated greater sway than controls across conditions and directions. During foam-surface conditions, the control group, but not the mTBI group, reduced ML sway at their head and trunk relative to their lumbar by increasing the expression of an anti-phase hip strategy within the frontal plane. These results are consistent with suggestions of inflexible or inappropriate postural control in people with mTBI.

neuroscience↗

bioRxiv2019

Estimating The Lateral Margin Of Stability During Walking And Turning Using Inertial Sensors

There is growing interest in using inertial sensors to continuously monitor gait during free-living mobility. Inertial sensors can provide many gait measures, but they struggle to capture the spatial stability of the center-of-mass due to limitations estimating sensor-to-sensor distance. While the margin of stability (MoS) is an established outcome describing the instantaneous mechanical stability of gait relating to fall-risk, methods to estimate the MoS from inertial sensors have been lacking. Here, we developed and tested a framework, based on centripetal acceleration, to determine a correlate for the lateral MoS using inertial sensors during walking with or without turning. Using three synchronized sensors located bilaterally on the feet and lumbar spine, the average centripetal acceleration over the subsequent step can be used as a correlate for lateral MoS. Relying only on a single sensor on the lumbar spine yielded similar results if the stance foot can be determined from other means. Additionally, the centripetal acceleration correlate of lateral MoS demonstrates clear differences between walking and turning, inside and outside turning limbs, and speed. While limitations and assumptions need to be considered when implemented in practice, this method presents a novel correlate for the lateral MoS during walking and turning using inertial sensors, although further validation is required for other activities and populations.

bioengineering↗