Biology subjects

Rosenblum, U.

Publications and source records attributed to Rosenblum, U..

5 recordsLinked to original sources

bioRxiv2024

Anxiety-related attentional changes and their relation to freezing of gait in people with Parkinson's: a cross validation of the Adapted Gait Specific Attentional Profile (G-SAPa)

BACKGROUNDAnxiety often exacerbates freezing of gait (FOG) in people with Parkinsons (PwP). Research shows that anxiety-related attentional processes and associated processing inefficiencies, such as conscious movement processing (CMP) and ruminations, can substantially impact movement control. However, the impact of these attentional characteristics on FOG remains largely unexplored. OBJECTIVESTo (i) validate an adapted 10-item (1-5 Likert scale) Gait-Specific Attentional Profile in PwP (G-SAP-PD), and (ii) assess if G-SAP-PD-subscales (Physiological Arousal, CMP, Rumination, and Processing Inefficiencies) are associated with self-reported FOG frequency. METHODSWe recruited 440 PwP (Mage=65.5{+/-}8.7; 5.8{+/-}5.0 years since diagnosis) across the UK. Participants completed the G-SAP-PD, and questions on demographics, medical background, and FOG frequency (scale of 0: "never freeze" to 4: "every day"). We assessed G-SAP-PDs internal consistency (alpha), structural validity (confirmatory factor analysis), and subscale scores associations with FOG frequency (ordinal regression). RESULTSThe G-SAP-PDs showed high internal consistency (>0.61) and acceptable/good model fit (comparative fit index=0.976). Physiological Arousal and CMP subscale scores were less strongly correlated for PwP with FOG (PwP+FOG, r=.52, p=0.001) compared to (PwP-FOG, r=.79; p=0.001). Higher Rumination (OR: 1.323, 95%CI: [1.214-1.440]) and Physiological Arousal (OR: 1.195, 95%CI: [1.037-1.377]) were significantly associated with higher FOG frequency, when controlling for age, time since diagnosis and balance/gait problems. CONCLUSIONSThe G-SAP-PD is a reliable and convenient tool to measure and identifying potentially maladaptive anxiety-related attentional processes that might impact FOG. Our data suggests a relative inability of PwP+FOG to engage in compensatory goal-directed attentional focus. Further study is warranted. Plain Language SummaryAnxiety can worsen freezing of gait in people with Parkinsons. It often leads to worrisome thoughts, and influences how people pay attention to their walking. We think that these changes in attention can substantially influence peoples movement - for better or worse. However, there is a lack of research on this topic, and reliable assessment tools are missing. Therefore, we tested if we could assess changes in the thoughts and attention of people with Parkinsons, using a questionnaire (Gait-Specific Attentional Profile (G-SAP-PD)), previously used in older adults without Parkinsons. This questionnaire aims to measure peoples perception of their physiological arousal (how anxious they feel), conscious movement (attention they direct to walking), rumination (worrisome thoughts), and thinking efficiency (the ability to focus on different tasks). We also investigated if people who experience freezing show different attentional characteristics compared to people who do not experience freezing. Four-hundred and forty people with Parkinsons filled the G-SAP-PD questionnaire. We confirmed the questionnaires reliability, and found that people who indicated to have more worrisome thoughts and greater physiological arousal also experienced freezing more often. Our findings suggest that people with Parkinsons who experience freezing were less able to consciously direct attention to the task at hand (taking a step) when experiencing high physiological arousal. The G-SAP-PD represents a short and convenient tool for identifying potentially negative attentional and thinking processes that may increase freezing frequency. With further research it could be used as a predictive tool and provide possible novel treatments to reduce freezing frequency.

neuroscience↗

bioRxiv2023

The Effect of Arm Restriction on Dynamic Stability and Upper Body Responses to Lateral Loss of Balance During Walking: An Observational Study

When losing balance, upper-body movements serve as mechanical aids to regain stability. However, it remains unclear how these movements contribute to dynamic stability during recovery from a lateral loss of balance while walking with arm restriction. We aimed to 1) quantify the effect of arm restriction on gait stability and upper-body velocities, and 2) characterize upper-body kinematic strategies in response to lateral surface translations under different arm restriction conditions. Healthy adults were exposed to lateral surface translations while walking on a computerized treadmill under three conditions: free arms, 1-arm restricted and, 2-arms restricted. Dynamic stability and upper-body velocities for the first step after perturbation onset were extracted. We found decreased dynamic stability in the sagittal plane and increased trunk velocity in the 2-arm restricted condition compared to the free arms condition. Head and trunk movements in the mediolateral plane were in opposite directions in 44.31% of responses. Additionally, significant trunk velocities were observed in the opposite direction to the perturbation-induced loss of balance. Our results support the contribution of increased upper-body velocities to balance responses following arm-restricted walking perturbations and suggest that the 2-arm restricted condition may be utilized as a perturbation-based balance training, focusing on head and trunk responses.

neuroscience↗

bioRxiv2022

Age and cognitive load affect muscle activation profiles in response to physical perturbations while walking

To maintain balance during walking, the central nervous system must adjust the base of support (i.e., modulation of step length and step width) to the center of mass displacement in every step. We aimed to explore age and concurrent cognitive attention-demanding task effects on lower limb muscle fiber type recruitment in response to unexpected loss of balance during walking i.e., perturbation. Twenty young (YA) and 18 older adults (OA), (27.00{+/-}2.79 and 70.13{+/-}3.95 years old, respectively) were exposed to unexpected perturbations, while walking on a treadmill, in virtual reality environment. Surface electromyography (sEMG) total spectral power for frequency bands associated with muscle fibers type I (40-60Hz), type IIa (60-150Hz) and type IIb (150-250Hz), from tibialis-anterior and vastus-lateralis muscles were analyzed. Four Generalized Estimating Equations models assessed age and cognitive attention-demanding tasks load association with lower-limb muscle activation patterns resulting from perturbation in single- and double-support phases of the gait cycle. Results show that OA employ a muscle fiber type IIa dominant increase strategy while YA show muscle fiber type IIb dominant increase in muscle fiber type recruitment in response to unexpected perturbations during walking. This suggests that the ability to recruit fast-twitch muscle fibers is deteriorated with age and thus may be related to insufficient balance recovery response.

neuroscience↗

bioRxiv2021

Muscle Activation Profile While Walking with Perturbations

During an unexpected loss of balance, avoiding a fall requires people to readjust their footing rapidly and effectively. We investigated the activation patterns of the ankle and knee muscles, and muscle fiber type recruitment resulting from unannounced, medio-lateral (i.e., right/left) horizontal-surface walking perturbations in twenty healthy adults (27.00{+/-}2.79 years, 10 females). Surface electromyography (sEMG) total spectral power for specific frequency bands (40-60Hz, 60-150Hz, 150-250Hz, 250-400Hz and 400-1000Hz), from tibialis anterior (TA) and vastus lateralis (VL) muscles were analyzed. Compared to non-perturbed walking, we found a significant increase in the total spectral power of lower-extremity muscles during the first 3 seconds after perturbation. When two feet were on the ground in time of perturbation we found a different muscle fiber type recruitment pattern between VL and TA muscles. This was not significant for perturbations implemented when one foot was on the ground. Our findings suggest that muscle operating frequency is modulated in real time to fit body state and somatosensory input in the context of functional goal requirements such as a rapid change of footing in response to unexpected loss of balance in single and double-support phases of gait. New & NoteworthyTo study muscle spectral profiles in response to loss of balance, we investigated the dynamics of muscle spectral power changes, across different frequency bands after unannounced mechanical perturbations during walking. We showed increased activation of high-frequency motor units of the lower-limb muscles, subside 3 seconds after perturbation. Differences in power increase of specific frequency bands suggest that muscle activation is modulated in real time to fit body state in the context of functional goal requirements.

physiology↗

bioRxiv2019

Novel methodology for assessing total recovery time in response to unexpected perturbations while walking

Walking stability is achieved by adjusting the medio-lateral and anterior-posterior dimensions of the base of support (step length and step width, respectively) to contain an extrapolated center of mass. We aimed to calculate total recovery time after different types of perturbations during walking, and use it to compare young and older adults following different types of perturbations. Walking trials were performed in 12 young (age 26.92 {+/-} 3.40 years) and 12 older (age 66.83 {+/-} 1.60 years) adults. Perturbations were introduced at different phases of the gait cycle, on both legs and in anterior-posterior or medio-lateral directions, in random order. A novel algorithm was developed to determine total recovery time values for regaining stable step length and step width parameters following the different perturbations and compared between the two participant groups under low and high cognitive load conditions, using principal component analysis (PCA). We analyzed 829 perturbations each for step length and step width. The algorithm successfully estimated total recovery time in 91.07% of the runs. PCA and statistical comparisons showed significant differences in step length and step width recovery times between anterior-posterior and medio-lateral perturbations, but no age-related differences. Initial analyses demonstrated the feasibility of comparisons based on total recovery time calculated using our algorithm.

neuroscience↗