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Articles 1 - 24 of 24
Full-Text Articles in Biomechanics
Age Induced Modifications In The Persistency Of Voluntary Sway When Actively Tracking The Complex Motion Of A Visual Target, Haralampos Sotirakis, Nick Stergiou, Dimitrios A. Patikas, Vassilia Hatzitaki
Age Induced Modifications In The Persistency Of Voluntary Sway When Actively Tracking The Complex Motion Of A Visual Target, Haralampos Sotirakis, Nick Stergiou, Dimitrios A. Patikas, Vassilia Hatzitaki
Journal Articles
Movement persistency, reflected in systematic cycle to cycle fluctuations of a rhythmical task such as walking or voluntary sway, is compromised with increasing age, making older adults more susceptible to falls. In the present study, we tested whether it is possible to improve rhythmic voluntary sway persistency in old age by actively tracking the complex (i.e. persistent) motion of a visual target. Twenty healthy young and 20 older adults performed 132 cycles of anterior-posterior sway under two conditions: a) self-paced sway and b) sway while tracking the vertical motion of a complex visual target. The persistency of sway cycle amplitude …
The Unique Demands Of Playing Posture On Youth Violinists And Violists, Liam Carroll
The Unique Demands Of Playing Posture On Youth Violinists And Violists, Liam Carroll
Honors Theses
The high prevalence of performing arts injuries is an acknowledged challenge facing the performing arts medicine community. The injuries seem to affect string players the most among orchestral musicians, specifically violinists and violists. The asymmetrical posture, head and neck displacement, and spinal displacement required by the posture to play violin and viola can lead to discomfort or injury in the performer. Performance related musculoskeletal disorders (PRMDs) can have an adverse impact on the life of a musician, preventing them from performing or making it uncomfortable. While there is a large body of research on PRMDs relating to adult musicians, there …
Swaying To The Complex Motion Of A Visual Target Affects Postural Sway Variability, Haralampos Sotirakis, Dimitrios A. Patikas, Nicholas Stergiou, Vassilia Hatzitaki
Swaying To The Complex Motion Of A Visual Target Affects Postural Sway Variability, Haralampos Sotirakis, Dimitrios A. Patikas, Nicholas Stergiou, Vassilia Hatzitaki
Journal Articles
Background
Voluntary shifting body weight in the anteroposterior direction is an important element of daily life activities, such as rising from a chair or initiating a step. In order to accommodate the daily-life challenges of such tasks, voluntary postural sway needs to be flexible and variable.
Research question
In this study we asked how whole-body tracking of a complex visual target motion with the concurrent provision of feedback modulates the variability of voluntary sway.
Methods
Twenty young adults (age: 27.10 ± 9.15years, height: 170.73 ± 9.40 cm, mass: 62.84 ± 11.48 kg) performed 132 cycles of voluntary antero-posterior sway, on …
Effects Of A Postural Restoration Focused Intervention On Muscle Activation During Deadlifts, Caleb Richardson
Effects Of A Postural Restoration Focused Intervention On Muscle Activation During Deadlifts, Caleb Richardson
Human Movement Sciences Theses & Dissertations
The purpose of this study was to determine the efficacy of implementing two Postural Restoration exercises and relating principles on deadlifts using a hexagonal barbell. Specifically, we aimed to examine the effects of the intervention on muscle activation and the location of the ground reaction force (GRF) center of pressure. Sixteen subjects (age 18-35 yrs.; male (n=14); female (n=2)), with at least 1 year of deadlifting experience, were randomly assigned into a control and intervention group (both n=8). Both groups performed two sets of three repetitions of deadlifts at 50% and at 80% of their estimated one repetition maximum (1-RM). …
Orderliness Of Visual Stimulus Motion Mediates Sensorimotor Coordination, Joshua L. Haworth, Nicholas Stergiou
Orderliness Of Visual Stimulus Motion Mediates Sensorimotor Coordination, Joshua L. Haworth, Nicholas Stergiou
Journal Articles
We explored the coupling of gaze and postural sway to the motion of a visual stimulus, to further understand sensorimotor coordination. Visual stimuli consisted of a horizontally oscillating red dot, moving with periodic (sine), chaotic, or aperiodic (brown noise) temporal structure. Cross Recurrence Quantification Analysis (cRQA) was used to investigate the coupling between each measured signal with the time series of the visual stimulus position. The cRQA parameter of percent determinism indicated similar strength of coupling of gaze with either periodic or chaotic motion structures, yet weaker coupling to aperiodic stimulus motion. The cRQA parameter of Maxline indicated a particular …
Infant Sitting Postural Control Appears Robust Across Changes In Surface Context, Elena Kokkoni, Joshua Haworth, Regina T. Harbourne, Nicholas Stergiou, Anastasia Kyvelidou
Infant Sitting Postural Control Appears Robust Across Changes In Surface Context, Elena Kokkoni, Joshua Haworth, Regina T. Harbourne, Nicholas Stergiou, Anastasia Kyvelidou
Journal Articles
Aim of the study: Independent sitting requires the control of the involved body segments over the base of support using information obtained from the three sensory systems (visual, vestibular, and somatosensory). The contribution of somatosensory information in infant sitting has not been explored. To address this gap, we altered the context of the sitting support surface and examined the infants’ immediate postural responses.
Materials and methods: Ten 7-month-old typically developing infants sat on compliant and firm surfaces in one session. Spatial, frequency, and temporal measures of postural control were obtained using center of pressure data.
Results Our results suggest that …
Children With Moderate To Severe Cerebral Palsy May Not Benefit From Stochastic Vibration When Developing Independent Sitting, Anastasia Kyvelidou, Regina T. Harbourne, Joshua L. Haworth, Kendra K. Schmid, Nicholas Stergiou
Children With Moderate To Severe Cerebral Palsy May Not Benefit From Stochastic Vibration When Developing Independent Sitting, Anastasia Kyvelidou, Regina T. Harbourne, Joshua L. Haworth, Kendra K. Schmid, Nicholas Stergiou
Journal Articles
Purpose: Determine sitting postural control changes for children with cerebral palsy (CP), using a perceptual-motor intervention and the same intervention plus stochastic vibration through the sitting surface. Methods: Two groups of children with moderate or severe CP participated in the 12 week interventions. The primary outcome measure was center of pressure data from which linear and nonlinear variables were extracted and the gross motor function measure (GMFM). Results: There were no significant main effects of intervention or time or an interaction. Both treatment groups increased the Lyapunov exponent values in the medial–lateral direction three months after the …
Comparison Of Lumbo-Pelvic Kinematics During Trunk Forward Bending And Backward Return Between Patients With Acute Low Back Pain And Asymptomatic Controls, Iman Shojaei, Elizabeth G. Salt, Quenten L. Hooker, Linda R. Van Dillen, Babak Bazrgari
Comparison Of Lumbo-Pelvic Kinematics During Trunk Forward Bending And Backward Return Between Patients With Acute Low Back Pain And Asymptomatic Controls, Iman Shojaei, Elizabeth G. Salt, Quenten L. Hooker, Linda R. Van Dillen, Babak Bazrgari
Biomedical Engineering Faculty Publications
Background—Prior studies have reported differences in lumbo-pelvic kinematics during a trunk forward bending and backward return task between individuals with and without chronic low back pain; yet, the literature on lumbo-pelvic kinematics of patients with acute low back pain is scant. Therefore, the purpose of this study was set to investigate lumbo-pelvic kinematics in this cohort.
Methods—A case-control study was conducted to investigate the differences in pelvic and thoracic rotation along with lumbar flexion as well as their first and second time derivatives between females with and without acute low back pain. Participants in each group completed one …
Dynamic Perception Of Dynamic Affordances: Walking On A Ship At Sea, Hannah Walter, Jeffrey B. Wagman, Nicholas Stergiou, Nurtekin Erkmen, Thomas A. Stoffregen
Dynamic Perception Of Dynamic Affordances: Walking On A Ship At Sea, Hannah Walter, Jeffrey B. Wagman, Nicholas Stergiou, Nurtekin Erkmen, Thomas A. Stoffregen
Journal Articles
Motion of the surface of the sea (waves, and swell) causes oscillatory motion of ships at sea. Generally, ships are longer than they are wide. One consequence of this structural difference is that oscillatory ship motion typically will be greater in roll (i.e., the ship rolling from side to side) than in pitch (i.e., the bow and stern rising and falling). For persons on ships at sea, affordances for walking on the open deck should be differentially influenced by ship motion in roll and pitch. Specifically, the minimum width of a walkable path should be greater when walking along the …
Aging Affects Postural Tracking Of Complex Visual Motion Cues, Haralampos Sotirakis, Anastasia Kyvelidou, L. Mademli, Nicholas Stergiou, Vassilia Hatzitaki
Aging Affects Postural Tracking Of Complex Visual Motion Cues, Haralampos Sotirakis, Anastasia Kyvelidou, L. Mademli, Nicholas Stergiou, Vassilia Hatzitaki
Journal Articles
Postural tracking of visual motion cues improves perception–action coupling in aging, yet the nature of the visual cues to be tracked is critical for the efficacy of such a paradigm. We investigated how well healthy older (72.45 ± 4.72 years) and young (22.98 ± 2.9 years) adults can follow with their gaze and posture horizontally moving visual target cues of different degree of complexity. Participants tracked continuously for 120 s the motion of a visual target (dot) that oscillated in three different patterns: a simple periodic (simulated by a sine), a more complex (simulated by the Lorenz attractor that is …
Mastoid Vibration Affects Dynamic Postural Control During Gait, Jung Chien, Mukul Mukherjee, Nicholas Stergiou
Mastoid Vibration Affects Dynamic Postural Control During Gait, Jung Chien, Mukul Mukherjee, Nicholas Stergiou
Journal Articles
Our objective was to investigate how manipulating sensory input through mastoid vibration (MV) could affect dynamic postural control during walking, with and without simultaneous manipulation of the visual and the somatosensory systems. We used three levels of MV (none, unilateral, and bilateral) via vibrating elements placed on the mastoid processes. We combined this with the six conditions of the Locomotor Sensory Organization Test (LSOT) paradigm to challenge the visual and somatosensory systems. We hypothesized that MV would affect both amount and temporal structure measures of sway variability during walking and that, in combination with manipulations of the visual and the …
Locomotor Sensory Organization Test: How Sensory Conflict Affects The Temporal Structure Of Sway Variability During Gait, Jung Hung Chien, Mukul Mukherjee, Ka-Chun Siu, Nikolaos Stergiou
Locomotor Sensory Organization Test: How Sensory Conflict Affects The Temporal Structure Of Sway Variability During Gait, Jung Hung Chien, Mukul Mukherjee, Ka-Chun Siu, Nikolaos Stergiou
Journal Articles
When maintaining postural stability temporally under increased sensory conflict, a more rigid response is used where the available degrees of freedom are essentially frozen. The current study investigated if such a strategy is also utilized during more dynamic situations of postural control as is the case with walking. This study attempted to answer this question by using the Locomotor Sensory Organization Test (LSOT). This apparatus incorporates SOT inspired perturbations of the visual and the somatosensory system. Ten healthy young adults performed the six conditions of the traditional SOT and the corresponding six conditions on the LSOT. The temporal structure of …
Plantar Pressure, Cutaneous Sensation And Stochastic Resonance: An Examination Of Factors Influencing The Control And Perception Of Posture, Michael A. Busa
Plantar Pressure, Cutaneous Sensation And Stochastic Resonance: An Examination Of Factors Influencing The Control And Perception Of Posture, Michael A. Busa
Doctoral Dissertations
The goal of this dissertation was to understand how people control posture in the context of sensory loss. To do so we explored three potential influences on the detection of external information and how they relate to the control of posture and perception of body orientation: 1) does changing posture alter the forces under the foot, and do these changes impact the ability to detect external vibrations? 2) Does decreasing the temperature of the foot influence the ability to detect external vibrations, the perception of body orientation, and the control of posture? And 3) does stochastic resonance (SR) improve the …
Locomotor Sensory Organization Test: A Novel Paradigm For The Assessment Of Sensory Contributions In Gait, Jung Hung Chien, Diderik-Jan Eikema, Mukul Mukherjee, Nicholas Stergiou
Locomotor Sensory Organization Test: A Novel Paradigm For The Assessment Of Sensory Contributions In Gait, Jung Hung Chien, Diderik-Jan Eikema, Mukul Mukherjee, Nicholas Stergiou
Journal Articles
Feedback based balance control requires the integration of visual, proprioceptive and vestibular input to detect the body’s movement within the environment. When the accuracy of sensory signals is compromised, the system reorganizes the relative contributions through a process of sensory recalibration, for upright postural stability to be maintained. Whereas this process has been studied extensively in standing using the Sensory Organization Test (SOT), less is known about these processes in more dynamic tasks such as locomotion. In the present study, ten healthy young adults performed the six conditions of the traditional SOT to quantify standing postural control when exposed to …
Evaluating The Similarity In Postures Between Forklift Operators In Virtual Reality And The Workplace, Youngmin Jun
Evaluating The Similarity In Postures Between Forklift Operators In Virtual Reality And The Workplace, Youngmin Jun
Electronic Thesis and Dissertation Repository
Forklift operators must adopt awkward postures in order to gain appropriate lines of sight; these postures are associated with musculoskeletal injuries and disorders such as low back pain and neck pain. The purpose of this thesis was to evaluate the similarity in postures between forklift operators in virtual reality simulation of forklift loading and unloading operations and a corresponding real world workplace. This evaluation will help determine whether the virtual reality system is a useful tool for performing controlled laboratory-based investigations of ergonomics issues in heavy mobile machinery. One certified forklift operator and one uncertified individual performed two cycles of …
Center Of Pressure And The Projection Of The Time-Course Of Sitting Skill Acquisition, Joshua L. Haworth, Regina T. Harbourne, Srikant Vallabhajosula, Nikolaos Stergiou
Center Of Pressure And The Projection Of The Time-Course Of Sitting Skill Acquisition, Joshua L. Haworth, Regina T. Harbourne, Srikant Vallabhajosula, Nikolaos Stergiou
Journal Articles
A normal time-course for the acquisition of sitting is essential. A delay in sitting may affect other developmental milestones, resulting in deficiencies in overall skill. Therefore, our aim was to identify variables whose measures at the very beginning of sitting would allow for the projection of the evolution of the sitting skill. Center of pressure data were collected from the postural sway of twenty-six typically developing infants while sitting on a force platform with a beginning ability to sit upright. Spatial, temporal and frequency variables of postural sway were obtained from both the medial/lateral and anterior/posterior directions of sway. Discriminant …
Early Complexity Supports Development Of Motor Behaviors In The First Months Of Life, Stacey C. Dusing, Leroy R. Thacker, Nikolaos Stergiou, James C. Galloway
Early Complexity Supports Development Of Motor Behaviors In The First Months Of Life, Stacey C. Dusing, Leroy R. Thacker, Nikolaos Stergiou, James C. Galloway
Journal Articles
Complexity in motor behavior is a hallmark of healthy systems. The purpose of this study was to investigate postural complexity during development of early motor behaviors and under two conditions. Twenty-two infants participated from 1 to 6 months of age. Linear and nonlinear measures of displacement of the center of pressure at the base of support were used to quantify magnitude and temporal structure of postural control. Behavioral coding was used to quantify the emergence of midline head control and early reaching. Results suggest that infants have complexity in postural control strategies early in development. This complexity decreases as infants …
A Perspective On Human Movement Variability With Applications In Infancy Motor Development, Nikolaos Stergiou, Yawen Yu, Anastasia Kyvelidou
A Perspective On Human Movement Variability With Applications In Infancy Motor Development, Nikolaos Stergiou, Yawen Yu, Anastasia Kyvelidou
Journal Articles
Movement variability is considered essential to typical motor development. However, multiple theoretical perspectives and measurement tools have limited interpretation of the importance of movement variability in biological systems. The complementary use of linear and nonlinear measures have recently allowed for the evaluation of not only the magnitude of variability but also the temporal structure of variability. As a result, the theoretical model of optimal movement variability was introduced. The model suggests that the development of healthy and highly adaptable systems relies on the achievement of an optimal state of variability. Alternatively, abnormal development may be characterized by a narrow range …
Postural Control Strategy During Standing Is Altered In Patients With Multiple Sclerosis, Jessie M. Huisinga, Jenna M. Yentes, Mary Filipi, Nikolaos Stergiou
Postural Control Strategy During Standing Is Altered In Patients With Multiple Sclerosis, Jessie M. Huisinga, Jenna M. Yentes, Mary Filipi, Nikolaos Stergiou
Journal Articles
Disturbances in balance are one of the first reported symptoms of Multiple Sclerosis (MS), yet limited research has been performed to classify the postural control deficits in this population. This study investigated the variability present in the sway patterns during quiet standing in patients with MS (PwMS) and healthy controls. Subjects were assessed (eyes open, closed) standing on a force platform. Variability of the sway patterns was quantified using a measure of amount of variability (root mean square; RMS) and two measures of temporal structure of variability (Lyapunov Exponent – LyE; Approximate Entropy – ApEn). RMS results revealed significantly higher …
Anterior-Posterior And Medial-Lateral Control Of Sway In Infants During Sitting Acquisition Does Not Become Adult-Like, Fabien Cignetti, Anastasia Kyvelidou, Regina T. Harbourne, Nikolaos Stergiou
Anterior-Posterior And Medial-Lateral Control Of Sway In Infants During Sitting Acquisition Does Not Become Adult-Like, Fabien Cignetti, Anastasia Kyvelidou, Regina T. Harbourne, Nikolaos Stergiou
Journal Articles
We examined (1) how sitting postural control in infants develops in the anterior–posterior (A/P) and medial–lateral (M/L) directions of sway, and (2) whether this control is already adult-like during the late phase of infant's sitting acquisition. COP data were acquired from 14 healthy infants (from the onset of sitting until independent sitting) and 21 healthy adults while sitting on a force platform. Attractor dimensionality (CoD: correlation dimension), attractor predictability (LyE: largest Lyapunov exponent), and sway variability (RMS: root-mean square) were calculated from the COP data to evaluate postural control. In the A/P direction, sitting was mastered by the infants by …
Reliability Of Center Of Pressure Measures For Assessing The Development Of Sitting Postural Control, Anastasia Kyvelidou, Regina T. Harbourne, Wayne A. Stuberg, Junfeng Sun, Nikolaos Stergiou
Reliability Of Center Of Pressure Measures For Assessing The Development Of Sitting Postural Control, Anastasia Kyvelidou, Regina T. Harbourne, Wayne A. Stuberg, Junfeng Sun, Nikolaos Stergiou
Journal Articles
Objectives: To determine the reliability of linear and nonlinear tools, including intrasession and intersession reliability, when used to analyze the center of pressure (COP) time series during the development of infant sitting postural control.
Design: Longitudinal study.
Setting: University hospital laboratory.
Participants: Typically developing infants (N33; mean SD age at entry in the study, 152.417.6d).
Interventions: Not applicable.
Main Outcome Measures: Infants were tested twice in 1 week at each of the 4 months of the study. Sitting COP data were recorded for 3 trials at each session (2 each month within 1 week). …
Differences In Upper Body Posture And Postural Muscle Activation In Females With Larger Breast Sizes, Mindy Bennett
Differences In Upper Body Posture And Postural Muscle Activation In Females With Larger Breast Sizes, Mindy Bennett
Boise State University Theses and Dissertations
Breast hypertrophy is a common medical condition whose morbidity has increased over recent decades. Symptoms of breast hypertrophy often include musculoskeletal pain in the neck, back and shoulders, and numerous psychosocial health burdens. To date, reduction mammaplasty (RM) is the only treatment shown to significantly reduce the severity of the symptoms associated with breast hypertrophy. However, due to a lack of scientific evidence in the medical literature justifying the medical necessity of RM, insurance companies often deny requests for coverage of this procedure. Therefore, the purpose of this study is to investigate biomechanical differences in the upper body of women …
Factors Affecting Functional Reach Scores In Youth With Typical Development, Kathleen G. Volkman, Nikolaos Stergiou, Wayne A. Stuberg, Regina T. Harbourne, Daniel Blanke, Julie Stoner
Factors Affecting Functional Reach Scores In Youth With Typical Development, Kathleen G. Volkman, Nikolaos Stergiou, Wayne A. Stuberg, Regina T. Harbourne, Daniel Blanke, Julie Stoner
Journal Articles
Purpose: Functional Reach Test scores were examined for the effects of traditional and alternate methods and subject characteristics.
Methods: Eighty subjects aged 7 to 16 years were tested. Effects of measurement method (from finger-to-finger or from toe-to-finger) and style of reach (1 or 2 arms) were investigated. Five subject variables were analyzed for interactions among the methods and groups defined by subject characteristics.
Results: Measurement method and style of reach showed a significant interaction. Interaction of method with subject characteristics was significant for age, height, and base of support only. Height groups by quartile were significantly different and scores increased …
Approximate Entropy Detects The Effect Of A Secondary Cognitive Task On Postural Control In Healthy Young Adults: A Methodological Report, James T. Cavanaugh, Vicki S. Mercer, Nikolaos Stergiou
Approximate Entropy Detects The Effect Of A Secondary Cognitive Task On Postural Control In Healthy Young Adults: A Methodological Report, James T. Cavanaugh, Vicki S. Mercer, Nikolaos Stergiou
Journal Articles
Background: Biomechanical measures of postural stability, while generally useful in neuroscience and physical rehabilitation research, may be limited in their ability to detect more subtle influences of attention on postural control. Approximate entropy (ApEn), a regularity statistic from nonlinear dynamics, recently has demonstrated relatively good measurement precision and shown promise for detecting subtle change in postural control after cerebral concussion. Our purpose was to further explore the responsiveness of ApEn by using it to evaluate the immediate, short-term effect of secondary cognitive task performance on postural control in healthy, young adults.
Methods: Thirty healthy, young adults performed a modified version …