Jan M. Hondzinski

Louisiana State University | LSU · School of Kinesiology

Objective To investigate the effect of a 16-week Tai Chi practice on strength, tactile sensation, kinesthesia, and static postural control among older adults of different age groups. Methods This is a quasi-experimental study. Thirteen participants aged 60–69 years (60–69yr), 11 aged 70–79 years (70–79yr), and 13 aged 80–89 years (80–89yr) complet...

Gaze direction and use of visual feedback can affect illusory influences over perceptions and manual length size estimates of the vertical−horizontal (V−H) illusion, in which the vertical, bisecting segment of an inverted T (IT) appears longer than the horizontal, bisected segment. We questioned whether V−H illusory influences would also exist for...

Background To date, no medication has slowed the progression of Parkinson’s disease (PD). Preclinical, epidemiological, and experimental data on humans all support many benefits of endurance exercise among persons with PD. The key question is whether there is a definitive additional benefit of exercising at high intensity, in terms of slowing disea...

Introduction: Visual feedback of hand and target location can influence strategies for visuomotor adaptation. Contributions of the hand and eyes during visuomotor adaptation are unknown yet would provide insights into adaptive control strategies used. Purpose: In this study we aimed to assess the effects of a visual feedback manipulation on movem...

Abstract Studies showed fast muscle fibers have a greater constant b value of Hill's equation than that of slow muscle fibers, and the changing ratio of b/Vmax indicates the altered characteristics of muscles under certain conditions such as static stretching. This study was to investigate the effect of acute passive static stretching on the curvat...

Visually guided reaching precision and accuracy depend on the level of coupling between movements of the eyes and hand. In the present study, participants performed central fixations and either saccadic or smooth pursuit eye movements during fast and accurate reaching tasks involving eye–hand coupling and decoupling to better understand type of eye...

We investigated whether visually guided reaching differs for sitting and standing postures while the eyes and hand are coupled to move in the same direction or decoupled to move in opposite directions. We also investigated how coupled and decoupled reaching tasks influenced standing postural control. Eighteen healthy young adults (M = 21 years) mov...

Results from previous research reveal that people perform eye-hand coupling tasks faster and/or with greater accuracy compared to eye-hand decoupling tasks whether sitting and or standing. However, it is not known whether changes in body posture influence both tasks equally or whether the eye-hand coordination tasks alter sway during stance. With t...

Presentation link: https://www.youtube.com/watch?v=9AHp-9wOUtc

We examined potentially deceptive influences of the vertical-horizontal (V-H) illusion on manual length estimations. When viewing V-H illusory configurations, people perceive that the bisecting segment length exceeds the bisected segment length when segments are actually equal. Participants used downward or rightward pointing movements to manually...

Eye-hand decoupling (EHD) studies using direct (i.e. move eyes and hand together) and decoupled (i.e. move eyes and hand in opposite directions) tasks showed performance differences between healthy and neurologic populations. Subjects were instructed to move a cursor using finger movements in both tasks as quickly and accurately as possible. In thi...

Muscular fatigue, which reduces force output and position sense, often leads to increased sway and potential balance impairments. In contrast, visually-guided saccadic eye movements (saccades) can attenuate sway more than fixating gaze on an external target. The goals of this study were to determine whether the use of saccades could reduce the incr...

Background: An exoskeleton may assist performance of basic work-related tasks. Its application should not alter user kinematics, which compromise user safety. Objective: This case study was used to assess whether people wearing a lower-body K-SRD™ exoskeleton could complete common work tasks without altering kinematics that may increase injury risk...

Background of Study: Although exercise has many benefits, older African American (AA) women are less active than older Caucasian women and older AA men. Balance and muscle-strengthening activities are typically recommended for decreased falls, whereas the role of aerobic training alone on falls prevention is controversial. Objective: This was a mix...

Despite the exercise benefits, disparities among diverse older adults continue to exist where African American women have the lowest percentage of any population group in meeting national recommended activity guidelines. Drawing on the philosophical tradition of phronesis (practical reasoning) introduced by Aristotle, we studied perceptions of the...

Upright people making goal-directed movements in dark environments often vertically undershoot remembered target locations when compared to performances in illuminated environments. In this study, we wanted to determine whether influences of the gravitational pull and/or type of muscle activation could explain differences in vertical endpoint preci...

Despite the proliferation of theory-based behavior-change programs to promote physical activity, obesity and diabetes rates continue to rise. Given the notable ineffective interventions, it is important to examine why these efforts have been largely unsuccessful and to consider potential alternatives. The purpose of this article is to consider the...

Performances of many activities of daily living rely on the proper integration of different sensory and motor systems. In neurologically healthy people the CNS integrates sensory cues into task commands to control performances. Use of visual inputs from central and peripheral visual fields can facilitate the online control of movement and form spat...

People with Parkinson's disease (PD) possess motor symptoms that influence several kinematic and kinetic aspects of gait. These deficits present particular problems as they place the person with PD at risk for falls and contribute to their perception of quality of life and disability. Although gait disturbances can occur during straight line walkin...

LI, L. and J.M. HONDZINSKI. Select exercise modalities may reverse movement dysfunction because of peripheral neuropathy. Exerc. Sport Sci. Rev., Vol. 40, No. 3, pp. 133-137, 2012. Peripheral neuropathy (PN) is a highly prevalent and potentially debilitating disease linked to mobility and postural control impairments and movement dysfunction in goa...

The purpose of this study was to describe the between day reliability of measurements for quick yaw head movements toward and away from visual stimuli placed at different eccentricities in the horizontal hemi-field. Results showed that primary measures of reaction time of yaw head rotation and reaction time of sternocleidomastoid muscle (SCM) activ...

Rhythmic auditory stimulation (RAS) can influence movement during straight line walking and direction transition in individuals with Parkinson disease (PD). The authors studied whether multidirectional step training with RAS would generalize to functional gait conditions used in daily activities and balance. In a matched-pairs design, 8 patients pr...

We examined the effects of aging and lower limb sensory deficits (LLSD) on whole body control. Performances of a reaching task involving a step were measured in subjects with LLSD and young and older controls. Having LLSD was accompanied with greater reach errors and variability in lateral step deviations. Aging effects explained the smaller step d...

The purposes of this study were to determine whether gaze direction provides a control signal for movement direction for a pointing task requiring a step and to gain insight into why discrepancies previously identified in the literature for endpoint accuracy with gaze directed eccentrically exist. Straight arm pointing movements were performed to r...

The aim of this investigation was to gain further insight into control strategies used for whole body reaching tasks. Subjects were requested to step and reach to remembered target locations in normal room lighting (LIGHT) and complete darkness (DARK) with their gaze directed toward or eccentric to the remembered target location. Targets were locat...

Many people viewing a small distant object report the use of a dominant eye, which may change when viewing the same object in right or left viewing fields. This study was designed to determine if the accuracy in left and right gaze recordings from a video-based binocular eye tracking system with eye-head integration would change when observers look...

The effects of gaze and step direction on a step and reach task were studied to gain insight to possible motor control strategies used in goal-directed whole-body movements. Head, foot and arm positions were monitored while subjects reached to nine targets in space. In dim light, subjects looked at and reached to actual targets or remembered target...

autonomic modulation of the heart, as measured by heart rate variability, is directly associated with cardiorespiratory fitness and inversely associated with all-cause mortality. The extent to which cardiorespiratory fitness and heart rate variability are related in older adults is difficult to ascertain due to difficulties in assessing physical fi...

Complex movements are generally thought to consist of a series of simpler elements. If this is so, how does the sensorimotor system assemble the pieces? This study recorded and evaluated sequences of arm movements to various targets placed in three-dimensional (3D) space. Subjects performed sequences consisting of single, double, or triple segments...

Previous studies have perturbed the association between motor commands and arm movements by applying forces to the arm during two-dimensional movements. These studies have revealed that, when the normal hand path is perturbed, subjects gradually adapt their motor commands to return to this path. The present study used the spin of a gyroscope to cre...

Experiments were designed to examine the visual contributions to performance of back aerial double somersaults by collegiate acrobats. Somersaults were performed on a trampoline under three visual conditions: (a) NORMAL acuity; (b) REDUCED acuity (subjects wore special contacts that blocked light reflected onto the central retina); and (c) NO VISIO...

What strategies are used in learning to control new movements? The present investigation sought to understand this process by analyzing the changes in whole-body kinematics that occurred when subjects attempted to learn an unusual kicking movement. Five novices were taught a capoeira kick that involved both the upper and lower body for balance and...

The effects of varying gaze direction on perceptions of the upper limb kinesthetic coordinate system axes and of the median plane location were studied in nine subjects with no history of neuromuscular disorders. In two experiments, six subjects aligned the unseen forearm to the trunk-fixed anterior-posterior (a/p) axis and earth-fixed vertical whi...

The effects of varying gaze direction on perceptions of the upper limb kinesthetic coordinate system axes and of the median plane location were studied in nine subjects with no history of neuromuscular disorders. In two experiments, six subjects aligned the unseen forearm to the trunk-fixed anterior-posterior (a/p) axis and earth-fixed vertical whi...

The major purpose of this research was to determine whether kinesthetic/proprioceptive perceptions of the earth-fixed vertical axis are more accurate than perceptions of intrinsic axes. In one experiment, accuracy of alignment of the forearm to earth-fixed vertical and head- and trunk-longitudinal axes by seven blindfolded subjects was compared in...

The purpose of these experiments was to investigate whether visual perceptions of the earth-fixed vertical axis are more accurate than those of intrinsic body-fixed axes. In one experiment, nine neurologically normal young adult subjects' abilities to position a luminescent rod vertically or parallel to the longitudinal axis of the head or trunk we...

Samenvatting Een-trampoline is een veelvuldig gebruikt hulpmiddel voor oefening en revalidatie en wordt aangeprezen als zeer nuttig om spanningen in de onderste extremiteit te verminderen. Het vervormbare oppervlak van de mini-trampoline kan een andere mechanica in het subtalare gewricht bewerkstelligen, dat potentieel kan leiden tot een atypische...

The jogging minitrampoline is a common tool for exercise and rehabilitation that is lauded as helpful in reducing lower extremity stresses. The deformable bed of the minitrampoline may result in altered jogging mechanics of the subtalar joint, potentially leading to uncharacteristic mechanics of the lower extremity. The purpose of this study was to...

Thesis (Ph. D.)--University of Iowa, 1998. Includes bibliographical references (leaves 229-239). Microfiche. s