Musculoskeletal System Commons^™

Direct Effects Of Capsaicin On Voltage-Dependent Calcium Channels Of Mammalian Skeletal Muscle, Dmytro Isaev, Tatiana Prytkova, Badarunnisa Mohamed, Mohamed Omar Mahgoub, Keun-Hang Susan Yang, Murat Oz

Pharmacy Faculty Articles and Research

Capsaicin, a naturally occurring polyphenol, is known to affect energy expenditure and muscle fatigue and modulate contractions in skeletal muscle. The L-type Ca²⁺ channels are known to be an important ion channel involved in the various muscle functions and the effect of capsaicin on the skeletal L-type Ca²⁺ channels is currently unknown. In this study, the effects of capsaicin and capsaicin analogs on depolarization-induced Ca²⁺ effluxes through L-type Ca²⁺ channels in transverse tubule membranes from rabbit skeletal muscle and L-type Ca²⁺ currents recorded using the whole-cell patch clamp technique in rat myotubes were examined. Capsaicin, …

Gray Matter Morphology And Pain-Related Disability In Young Adults With Low Back Pain, Jo Armour Smith, Rongwen Tain, Isaac Chrisman, Kelli G. Sharp, Laura M. Glynn, Linda R. Van Dillen, Jesse V. Jacobs, Steven C. Cramer

Physical Therapy Faculty Articles and Research

Structural neuroplasticity in the brain may contribute to the persistence of low back pain (LBP) symptoms and the disability associated with them. It is not known if structural adaptations are evident early in the lifespan in young adults with LBP. This study compared gray matter in cortical sensorimotor regions in young adults with and without persistent LBP and identified gray matter and clinical predictors of pain-related disability. Eighty-two individuals with and without a history of LBP participated. Peak and average gray matter density in cortical sensorimotor regions of interest was quantified using voxel-based morphometry. Pain-related disability, pain intensity, pain duration, …

Spatiotemporal Gait Parameter Consistency Across Two Days Of Treadmill Walking In Stroke Survivors, Alejandro Aguirre Ramirez, Samantha N. Jeffcoat, Natalia Sanchez, Andrian Kuch

Student Scholar Symposium Abstracts and Posters

Retraining impaired gait is essential in post-stroke recovery. This project aims to determine between day variability of spatiotemporal gait measures in treadmill walking post-stroke to differentiate between changes due to the intervention and measurement errors due to between day test-retest variability. Six individuals post-stroke performed a two-minute walk test at a self-selected speed (SSS) for two consecutive days. SSS was assessed through the six-minute walk test. Reflective markers were placed on anatomical landmarks (van den Bogert et al. 2013). The heel markers were used for step detection. We calculated spatiotemporal parameters: stride length, stride time, step length, stance time, and …

Do People With Low Back Pain Walk Differently? A Systematic Review And Meta-Analysis, Jo Armour Smith, Heidi Stabbert, Jennifer J. Bagwell, Hsiang-Ling Teng, Vernie Wade, Szu-Ping Lee

Physical Therapy Faculty Articles and Research

Background

The biomechanics of the trunk and lower limbs during walking and running gait are frequently assessed in individuals with low back pain (LBP). Despite substantial research, it is still unclear whether consistent and generalizable changes in walking or running gait occur in association with LBP. The purpose of this systematic review was to identify whether there are differences in biomechanics during walking and running gait in individuals with acute and persistent LBP compared with back-healthy controls.

Methods

A search was conducted in PubMed, CINAHL, SPORTDiscus, and PsycINFO in June 2019 and was repeated in December 2020. Studies were included …

Kinematic Assessment Of Turning And Walking Tasks Among Stroke Survivors By Employing Wearable Sensors And Pressure Platform, Masoud Abdollahi, Pranav Madhav Kuber, Christopher Hoang, Michael Shiraishi, Rahul Soangra, Ehsan Rashedi

Physical Therapy Faculty Articles and Research

Stroke survivors often experience reduced movement capabilities due to alterations in their neuromusculoskeletal systems. Modern sensor technologies and motion analyses can facilitate the determination of these changes. Our work aims to assess the potential of using wearable motion sensors to analyze the movement of stroke survivors and identifying the affected functions. We recruited 10 participants (5 stroke survivors, 5 healthy individuals) and conducted a controlled laboratory evaluation for two of the most common daily activities: turning and walking. Among the extracted kinematic parameters, range of trunk and sacrum lateral bending in turning were significantly larger in stroke survivors (p-value<0.02). However, no statistical difference in mean angular velocity and range of motion for trunk/sacrum/shank flexion-extension were obtained in the turning task. Our results also indicated that during walking, while there was no difference in swing time, double support portion of gait among the stroke group was significantly larger (p-value = 0.001). Outcomes of this investigation may help in designing new rehabilitation programs for stroke and other neurological disorders and/or in improving the efficacy of such programs.Clinical Relevance— This study may provide a better insight on the detailed functional differences between stroke survivors and healthy individuals which in turn could be used to develop a more efficient rehabilitation program for stroke community.

The Physiological Interaction Of Sleep Deprivation And Zoledronate On Distal Femur Trabecular Thickness Of Ovariectomized Rats, Erin Nolte, Frank Frisch, Oliver Lopez

Health Sciences and Kinesiology Faculty Articles

Osteoporosis, a disease resulting in an increased risk of fracture due to compromised bone, affects 1 in 3 postmenopausal women. Discontinuities in the microarchitecture of bone, such as trabeculae, are seen in postmenopausal osteoporosis. This study aimed to evaluate how sleep deprivation affects the distal femur trabecular thickness of estrogen-deficient rats treated with Zoledronate. 29 ovariectomized Wistar female rats were separated into 4 groups. The control group (C) was housed in standard housing with a 12-hour light/dark cycle and was given an intravenous injection of 0.45 mL of 0.9% saline. The Zoledronate group (Z) were also housed in standard conditions …

Lower Extremity Kinetics And Muscle Activation During Gait Are Significantly Different During And After Pregnancy Compared To Nulliparous Females, Jennifer J. Bagwell, Nicholas Reynolds, Michelle Walaszek, Hannah Runez, Kristina Lam, Jo Armour Smith, Dimitrios Katsavelis

Physical Therapy Faculty Articles and Research

Background

Low back, pelvic, and lower extremity pain are common during and after pregnancy. Understanding differences in mechanics between pregnant and non-pregnant females is a first step toward identifying potential pathological mechanisms. The primary purpose of this study was to compare joint kinetics and muscle activation during gait between females during and after pregnancy to nulliparous females.

Methods

Twenty pregnant females completed testing on three occasions (second trimester, third trimester, and post-partum), while 20 matched, nulliparous controls were tested once. Motion capture, force data, and surface electromyography were averaged across seven trials during gait. Lower extremity kinematics, lower extremity moments …

A Comparison Of Denoising Methods In Onset Determination In Medial Gastrocnemius Muscle Activations During Stance, Jian Zhang, Rahul Soangra, Thurmon Lockhart

Physical Therapy Faculty Articles and Research

One of the most basic pieces of information gained from dynamic electromyography is accurately defining muscle action and phase timing within the gait cycle. The human gait relies on selective timing and the intensity of appropriate muscle activations for stability, loading, and progression over the supporting foot during stance, and further to advance the limb in the swing phase. A common clinical practice is utilizing a low-pass filter to denoise integrated electromyogram (EMG) signals and to determine onset and cessation events using a predefined threshold. However, the accuracy of the defining period of significant muscle activations via EMG varies with …

Task-Invariance And Reliability Of Anticipatory Postural Adjustments In Healthy Young Adults, Jo Armour Smith, Niklas König Ignasiak, Jesse V. Jacobs

Physical Therapy Faculty Articles and Research

Background

Anticipatory postural adjustments (APAs) occur in the trunk during tasks such as rapid limb movement and are impaired in individuals with musculoskeletal and neurological dysfunction. To understand APA impairment, it is important to first determine if APAs can be measured reliably and which characteristics of APAs are task-invariant.

Research question

What is the test-retest reliability of latency, amplitude and muscle activation patterns (synergies) of trunk APAs during arm-raise and leg-raise tasks, and to what extent are these APA characteristics invariant across tasks at the individual and group levels?

Methods

15 young adults (mean age: 23.7 (±3.2) years) performed six …

Glucocorticoids Rapidly Activate Camp Production Via GΑs To Initiate Non-Genomic Signaling That Contributes To One-Third Of Their Canonical Genomic Effects, Francisco J. Nuñez, Timothy B. Johnstone, Maia L. Corpuz, Austin G. Kazarian, Nicole N. Mohajer, Omar Tliba, Reynold A. Pannettieri Jr., Cynthia J. Koziol-White, Moom Roosan, Rennolds S. Ostrom

Pharmacy Faculty Articles and Research

Glucocorticoids are widely used for the suppression of inflammation, but evidence is growing that they can have rapid, non-genomic actions that have been unappreciated. Diverse cell signaling effects have been reported for glucocorticoids, leading us to hypothesize that glucocorticoids alone can swiftly increase the 3′,5′-cyclic adenosine monophosphate (cAMP) production. We found that prednisone, fluticasone, budesonide, and progesterone each increased cAMP levels within 3 minutes without phosphodiesterase inhibitors by measuring real-time cAMP dynamics using the cAMP difference detector in situ assay in a variety of immortalized cell lines and primary human airway smooth muscle (HASM) cells. A membrane- impermeable glucocorticoid showed …

Evaluation Of Tumor Necrosis Factor Alpha In Sleep-Deprived Menopausal- Induced Rats And The Impact On Bone Health, Nicole Ellsworth, Dwight Curry Iii, Cj Deleon, Frank Frisch

Student Scholar Symposium Abstracts and Posters

Post-menopausal osteoporosis as a consequence of estrogen depletion is a growing concern for women in the United States. As more women take on executive positions and experience sleep deprivation, there is the potential for up regulation of pro-inflammatory cytokines, such as tumor necrosis factor alpha. It follows that the homeostatic imbalance of osteoclastic and osteoblastic activity leads to a greater risk of disease. Bisphosphonates generally, and Zolendronate specifically works by decreasing the number of osteoclasts. This current study investigated the impact of Zolendronate on the concentrations of tumor necrosis factor alpha-type (TNFɑ) in 32 ovariectomized Wistar rats. Throughout a five …

Bone Strength And Distal Femur Trabecular Thickness In Sleep Deprived Ovariectomized Rats Treated With Zoledronate, Erin Nolte, Frank Frisch

Student Scholar Symposium Abstracts and Posters

Osteoporosis is a disease that causes the density and quality of bone to be decreased, which can increase the risk of fracture by 40%. 1 in 3 women over the age of 50 will be affected by osteoporosis. This study aimed to show how bone strength and distal femur trabecular thickness might be affected by Zoledronate and sleep-deprivation in estrogen-deficient rats. Wistar female rats were ovariectomized to contrive postmenopausal estrogen-deficiency. The rats were separated into 4 groups. The control group (C, n=4) was given an intraperitoneal (IP) injection of 0.45 mL of 0.9% saline, were housed in standard conditions permitting …

Individuals With Recurrent Low Back Pain Exhibit Significant Changes In Paraspinal Muscle Strength After Intramuscular Fine Wire Electrode Insertion, Szu-Ping Lee, Vincent Dinglasan, Anthony Duong, Russell Totten, Jo Armour Smith

Physical Therapy Faculty Articles and Research

Objective

To examine how insertion and presence of intramuscular fine‐wire electromyography electrodes (IFWE) in lumbar multifidus affect paraspinal muscle strength, endurance, and activation in persons with and without recurrent lower back pain (RLBP) during activities that require high levels of muscle contraction.

Design

Case‐control with randomization of conditions.

Setting

Clinical Research Laboratory.

Participants

Forty participants age 18‐40 were recruited (18 female; mean age = 25.5 yr); 20 with a history of RLBP were compared to a matching control group of 20 without RLBP.

Interventions

Each participant was tested under three conditions over three sessions. On Session 1, the baseline condition, …

Effects Of Obesity And Fall Risk On Gait And Posture Of Community-Dwelling Older Adults, Thurmon E. Lockhart, Christopher W. Frames, Rahul Soangra, Abraham Lieberman

Physical Therapy Faculty Articles and Research

Epidemiological studies link increased fall risk to obesity in older adults, but the mechanism through which obesity increases falls and fall risks is unknown. This study investigates if obesity (Body Mass Index: BMI>30 kg/m2) influenced gait and standing postural characteristics of community dwelling older adults leading to increased risk of falls. One hundred healthy older adults (age 74.0±7.6 years, range of 56-90 years) living independently in a community participated in this study. Participants’ history of falls over the previous two years was recorded, with emphasis on frequency and characteristics of falls. Participants with at least two falls in the …

A Method To Concatenate Multiple Short Time Series For Evaluating Dynamic Behaviour During Walking, Niklas König Ignasiak

Physical Therapy Faculty Articles and Research

Gait variability is a sensitive metric for assessing functional deficits in individuals with mobility impairments. To correctly represent the temporal evolution of gait kinematics, nonlinear measures require extended and uninterrupted time series. In this study, we present and validate a novel algorithm for concatenating multiple time-series in order to allow the nonlinear analysis of gait data from standard and unrestricted overground walking protocols. The fullbody gait patterns of twenty healthy subjects were captured during five walking trials (at least 5 minutes) on a treadmill under different weight perturbation conditions. The collected time series were cut into multiple shorter time series …

Does Variability Of Footfall Kinematics Correlate With Dynamic Stability Of The Centre Of Mass During Walking?, Niklas König Ignasiak

Physical Therapy Faculty Articles and Research

A stable walking pattern is presumably essential to avoid falls. Stability of walking is most accurately determined by the short-term local dynamic stability (maximum Lyapunov exponent) of the body centre of mass. In many studies related to fall risk, however, variability of step width is considered to be indicative of the stability of the centre of mass during walking. However, other footfall parameters, in particular variability of stride time, have also been associated with increased risk for falling. Therefore, the aim of this study was to investigate the association between short-term local dynamic stability of the body centre of mass …

Anticipatory Postural Adjustments And Spatial Organization Of Motor Cortex: Evidence Of Adaptive Compensations In Healthy Older Adults, Jo Armour Smith, Beth E. Fisher

Physical Therapy Faculty Articles and Research

During anticipated postural perturbations induced by limb movement, the central nervous system generates anticipatory postural adjustments (APAs) in the trunk and hip musculature to minimize disturbances to equilibrium. Age-related changes in functional organization of the nervous system may contribute to changes in APAs in healthy older adults. Here we examined if altered APAs of trunk/hip musculature in older adults are accompanied by changes in the representation of these muscles in motor cortex. Twelve healthy older adults, 5 with a history of falls and 7 nonfallers, were compared with 13 young adults. APAs were assessed during a mediolateral arm raise task …

The Chapman Bone Algorithm: A Diagnostic Alternative For The Evaluation Of Osteoporosis, Elise Levesque, Anton Ketterer, Wajiha Memon, Cameron James, Noah Barrett, Cyril Rakovski, Frank Frisch

Mathematics, Physics, and Computer Science Faculty Articles and Research

Osteoporosis is the most common metabolic bone disease and goes largely undiagnosed throughout the world, due to the inaccessibility of DXA machines. Multivariate analyses of serum bone turnover markers were evaluated in 226 Orange County, California, residents with the intent to determine if serum osteocalcin and serum pyridinoline cross-links could be used to detect the onset of osteoporosis as effectively as a DXA scan. Descriptive analyses of the demographic and lab characteristics of the participants were performed through frequency, means and standard deviation estimations. We implemented logistic regression modeling to find the best classification algorithm for osteoporosis. All calculations and …

Insertion And Presence Of Fine-Wire Intramuscular Electrodes To The Lumbar Paraspinal Muscles Do Not Affect Muscle Performance And Activation During Highexertion Spinal Extension Activities, Szu-Ping Lee, Jo Armour Smith, Matthew Kimber, Kelsey Houk

Physical Therapy Faculty Articles and Research

Background

Low back pain (LBP) is commonly associated with paraspinal muscle dysfunctions. A method to study deep lumbar paraspinal (i.e. multifidus) muscle function and neuromuscular activation pattern is intramuscular electromyography (EMG). Previous studies have shown that the procedure does not significantly impact muscle function during activities involving low-level muscle contractions. However, it is currently unknown how muscular function and activation are affected during high-exertion contractions.

Objective

To examine the effects of insertion and presence of fine-wire EMG electrodes in the lumbar multifidus on muscle strength, endurance, and activation profiles during high-exertion spinal extension muscle contractions.

Design

Single-blinded, repeated measures intervention …

Effects Of Load Carriage And Surface Inclination On Linear And Non-Linear Postural Variability, Rahul Soangra, Hema Bhatt, Ehsan Rashedi

Physical Therapy Faculty Articles and Research

Understanding of inclined-work-related risk of falls and developing novel practical engineering controls for reducing this risk of falls among hilly working population remains in high demand. Standing on sloped surfaces provides a unique environment for examining the biomechanics and neural control of standing. The present investigation examined the variability of postural signals when standing on inclined surfaces and with load carriages by linear and nonlinear analysis. The purpose of this study was to determine if the sloped surface deteriorated in postural stability among healthy individuals with two distinctive kinds of load carriage methods head versus posterior load carriage. We also …

Changes In The Utilization Of Osteoporosis Drugs After The 2010 Fda Bisphosphonate Drug Safety Communication, Bander Balkhi, Enrique Seoane-Vazquez, Rosa Rodriguez-Monguio

Pharmacy Faculty Articles and Research

Introduction

In October 2010, the US Food and Drug Administration (FDA) issued a safety communication regarding the risks of atypical fractures of the femur, with bisphosphonates drugs. This study evaluated the impact of the bisphosphonates FDA safety communication on the utilization of osteoporosis medications in Medicaid programs.

Methods

Osteoporosis drugs utilization data from the July 2006 to June 2014 were extracted from the national Summary Files from the Medicaid State Drug Utilization Data maintained by the Centers for Medicare & Medicaid Services (CMS). We performed an interrupted time series analyses to evaluate trends in utilization of osteoporosis drugs before and …

Cortical Contribution To Linear, Non-Linear And Frequency Components Of Motor Variability Control During Standing, Niklas König Ignasiak

Physical Therapy Faculty Articles and Research

Motor variability is an inherent feature of all human movements and reflects the quality of functional task performance. Depending on the requirements of the motor task, the human sensory-motor system is thought to be able to flexibly govern the appropriate level of variability. However, it remains unclear which neurophysiological structures are responsible for the control of motor variability. In this study, we tested the contribution of cortical cognitive resources on the control of motor variability (in this case postural sway) using a dual-task paradigm and furthermore observed potential changes in control strategy by evaluating Ia-afferent integration (H-reflex). Twenty healthy subjects …

Suppression Of Chrn Endocytosis By Carbonic Anhydrase Car3 In The Pathogenesis Of Myasthenia Gravis, Ailian Du, Shiqian Huang, Xiaonan Zhao, Kuan Fang, Shuangyan Zhang, Jiefang Huang, Xiang Miao, Fulvio Baggi, Rennolds S. Ostrom, Yanyun Zhang, Xiangjun Chen, Congfeng Xu

Pharmacy Faculty Articles and Research

Myasthenia gravis is an autoimmune disorder of the neuromuscular junction manifested as fatigable muscle weakness, which is typically caused by pathogenic autoantibodies against postsynaptic CHRN/ AChR (cholinergic receptor nicotinic) in the endplate of skeletal muscle. Our previous studies have identified CA3 (carbonic anhydrase 3) as a specific protein insufficient in skeletal muscle from myasthenia gravis patients. In this study, we investigated the underlying mechanism of how CA3 insufficiency might contribute to myasthenia gravis. Using an experimental autoimmune myasthenia gravis animal model and the skeletal muscle cell C2C12, we find that inhibition of CAR3 (the mouse homolog of CA3) promotes CHRN …

Bilabial Substitution Patterns During Consonant Production In A Case Of Congenital Aglossia, Betty Mcmicken, Frederico Salles, Shelley Von Berg, Margaret Vento-Wilson, Kelly Rogers, Asterios Toutios, Shrikanth S. Narayanan

Communication Sciences and Disorders Faculty Articles and Research

Purpose: Congenital aglossia is a rare syndrome in which an individual is born without a tongue. The present paper examines articulatory details of the production of multiple consonants by an aglossic speaker.

Method: Real-time magnetic resonance imaging data of the upper airway were collected from the aglossic speaker. Air-tissue boundaries were determined from the video sequences using a segmentation algorithm, and dynamics of vocal-tract constrictions and cross-dimensions were calculated.

Results: The aglossic speaker produced the consonants /t, d, th, l ,r, f ,v, s, sh/ with a bilabial closure instead of a normal lingua-alveolar closure; however, in …

Wine Flavor Perception In A Person With Isolated Congenital Aglossia, Naïve Wine Taster, And Sommelier, Kristin Mahood, Long Wang, Betty Mcmicken, Cheryl Rock

Communication Sciences and Disorders Faculty Articles and Research

Objective: This study aimed to augment previous research that investigated flavor perception in isolated congenital aglossia by a whole food/beverage approach. Isolated congenital aglossia is the rare condition of absence of a tongue at birth without the presence of other symptoms. Previous studies confirmed taste perception in isolated congenital aglossia using single taste solutions including sour, salty, sweet, bitter, and umami.

Methods: The current randomized, double-blinded study age- and sex-matched a naïve wine taster and sommelier to the 46 year-old female with isolated congenital aglossia. A Nose and Palate Survey with 54 variables created based on the Court …

Antimicrobial Hydroxyapatite-Gelatin-Silica Composite Pastes With Tunable Setting Properties, Vuk Uskoković, Shreya Ghosh, Victoria M. Wu

Pharmacy Faculty Articles and Research

Bone grafting is one of the commonest surgical procedures, yet all bone substitutes developed so far suffer from specific weaknesses and the search for a bone graft material with ideal physical and biological properties is still ongoing. Calcium phosphate pastes are the most frequently used synthetic bone grafts, yet they (a) often take an impractically long time to set, (b) release the drug content too fast, and (c) do not form pores large enough to accommodate host cells and foster osseointegration. To make up for these deficiencies, we introduced gelatin and silica to pastes composed of 5–15 nm sized hydroxyapatite …

The Motor Cortical Representation Of A Muscle Is Not Homogeneous In Brain Connectivity, Jo Armour Smith, Alaa Albishi, Sarine Babikian, Skulpan Asavasopon, Beth E. Fisher, Jason Kutch

Physical Therapy Faculty Articles and Research

Functional connectivity patterns of the motor cortical representational area of single muscles have not been extensively mapped in humans, particularly for the axial musculature. Functional connectivity may provide a neural substrate for adaptation of muscle activity in axial muscles that have both voluntary and postural functions. The purpose of this study was to combine brain stimulation and neuroimaging to both map the cortical representation of the external oblique (EO) in primary motor cortex (M1) and supplementary motor area (SMA), and to establish the resting-state functional connectivity associated with this representation. Motor evoked potentials were elicited from the EO muscle in …

Compartmentalized Camp Responses To Prostaglandin Ep2 Receptor Activation In Human Airway Smooth Muscle Cells, Shailesh R. Agarwal, Kathryn Miyashiro, Htun Latt, Rennolds S. Ostrom, Robert D. Harvey

Pharmacy Faculty Articles and Research

Background and Purpose

Previous studies indicate that prostaglandin EP2 receptors (EP2Rs) selectively couple to adenylyl cyclase type 2 (AC2) in non-lipid raft domains of airway smooth muscle (ASM) cells, where they regulate specific cAMP-dependent responses. The goal of the present study was to identify the cellular microdomains where EP2Rs stimulate cAMP production.

Experimental Approach

FRET-based cAMP biosensors were targeted to different subcellular locations of primary human ASM cells. The Epac2-camps biosensor, which expresses throughout the cell, was used to measure bulk cytoplasmic responses. Epac2-MyrPalm and Epac2-CAAX were used to measure responses associated with lipid raft and non-raft regions of the …

Efficacy Of Electromyography And The Dead Bug Exercise, Taylor M. Scavo, Rachel C. Cooklin, Erika N. Faria, Madeline L. Johnson, Eric Sternlicht

Student Scholar Symposium Abstracts and Posters

The Dead Bug exercise is performed in physical therapy clinics to restore lumbar spine stability and core strength in patients with lower back pain (LBP). The aim of this study was to evaluate the efficacy of using electromyography (EMG) feedback to enhance proper mechanics during the Dead Bug exercise. Sixteen healthy, college age students volunteered as subjects for the study. Subjects performed the Dead Bug (Fig. 1a.) with and without visual EMG cues and were given instructions on how to execute the exercise. Data was recorded using a BTS FREEEMG Analyzer and signal processed and data analyzed using the BTS …

What Is The Contribution Of Ia-Afference For Regulating Motor Output Variability During Standing?, Niklas König Ignasiak

Physical Therapy Faculty Articles and Research

Motor variability is an inherent feature of all human movements, and describes the system‘s stability and rigidity during the performance of functional motor tasks such as balancing. In order to ensure successful task execution, the nervous system is thought to be able to flexibly select the appropriate level of variability. However, it remains unknown which neurophysiological pathways are utilized for the control of motor output variability. In responding to natural variability (in this example sway), it is plausible that the neuro-physiological response to muscular elongation contributes to restoring a balanced upright posture. In this study, the postural sway of 18 …