Publications by authors named "CROMWELL R"

Epiploic appendagitis (EA) is an uncommon intraabdominal pathology resulting in transient, localized pain. The condition is caused by ischemia of one of the epiploic appendages, which are distributed axially along the length of the colon. EA is often mistaken for other more common etiologies of an acute abdomen.

View Article and Find Full Text PDF

Scapular dyskinesis, the impairment of optimal scapular position and motion, is common in association with shoulder injury. A comprehensive evaluation process can show the causative factors and lead to effective treatment protocols. The complexity of scapular motion and the integrated relationship between the scapula, humerus, trunk, and legs suggest a need to develop rehabilitation programs that involve all segments working as a unit rather than isolated components.

View Article and Find Full Text PDF

During spaceflight, astronauts are exposed to a variety of unique hazards, including altered gravity fields, long periods of isolation and confinement, living in a closed environment at increasing distances from Earth, and exposure to higher levels of hazardous ionizing radiation. Preserving human health and performance in the face of these relentless hazards becomes progressively more difficult as missions increase in length and extend beyond low Earth orbit. Finding solutions is a significant challenge that is further complicated by logistical issues associated with studying these unique hazards.

View Article and Find Full Text PDF

Purpose: The purpose of this article was to provide an overview of the National Aeronautics and Space Administration (NASA) 70-day Bed Rest Study. The integrated complement of investigations and the standardized bed rest environment that served as the platform for this study complement are described. Outcomes of the studies will not be presented here but will be reported in separate publications.

View Article and Find Full Text PDF

Introduction: We evaluated ophthalmic changes in healthy individuals who underwent integrated resistance and aerobic training (iRAT) during 70-d 6° head-down tilt (HDT) bed rest (BR).

Methods: Participants were selected using NASA standard screening procedures. Standardized NASA BR conditions were implemented.

View Article and Find Full Text PDF

Purpose: To compare ocular outcomes in healthy subjects undergoing 14- and/or 70-day head-down-tilt (HDT) bed rest (BR).

Methods: Participants were selected by using NASA standard screening procedures. Standardized NASA BR conditions were implemented.

View Article and Find Full Text PDF

Sex and gender differences have long been a research topic of interest, yet few studies have explored the specific differences in neurological responses between men and women during and after spaceflight. Knowledge in this field is limited due to the significant disproportion of sexes enrolled in the astronaut corps. Research indicates that general neurological and sensory differences exist between the sexes, such as those in laterality of amygdala activity, sensitivity and discrimination in vision processing, and neuronal cell death (apoptosis) pathways.

View Article and Find Full Text PDF

Introduction: We evaluated ocular outcomes in a 14-d head-down tilt (HDT) bed rest (BR) study designed to simulate the effects of microgravity on the human body.

Methods: Healthy subjects were selected using NASA standard screening procedures. Standardized NASA BR conditions were implemented (e.

View Article and Find Full Text PDF

Introduction: We report ocular changes occurring in a healthy human subject enrolled in a bed rest (BR) study designed to replicate the effects of a low-gravity environment.

Case Report: A 25-yr-old Caucasian man spent 30 consecutive days in a 6 degrees head-down tilt (HDT) position at the NASA Flight Analogs Research Unit. Comprehensive ophthalmologic exams, optic disc stereo-photography, standard automated perimetry (SAP), and optic disc Spectralis OCT scans were performed at baseline, immediately post-BR (BR+0), and 6 mo post-BR.

View Article and Find Full Text PDF

Ocular structural and functional changes, including optic disk edema and reduction of near visual acuity, have been recently described in some astronauts returning from long-duration space travels. It is hypothesized that ocular changes related to spaceflight may occur, in predisposed individuals, as a result of cephalad shift of body fluids, possibly leading to elevated intracranial pressure (ICP). Results from head-down bed-rest studies (used to simulate the effects of microgravity) and from parabolic flight experiments (used to produce transient periods of microgravity) indicate that ocular blood flow and intraocular pressure (IOP) may undergo changes in a low-gravity environment.

View Article and Find Full Text PDF

The goal of this study was to determine if exposure to sensorimotor adaptation training improved head stabilization in older adults. Sixteen participants, age 66-81 yr, were assigned at random to the control group (n = 8) or the experimental group (n = 8). Both groups first completed 6 trials of walking a foam pathway consisting of a moveable platform that induced a lateral perturbation during walking.

View Article and Find Full Text PDF

Background: The purpose of the present study was to develop an objective outcome measure to assess the performance of head-down bed rest subjects. The rationale behind the development was that the current outcome measure is subjective and dependent upon how much the clinical psychologist knows about subject behaviors during the study to rate them accurately.

Methods: The behaviorally anchored rating scales (BARS) were developed through the use of the critical incident technique, along with traditional BARS development procedures, and the use of focus groups.

View Article and Find Full Text PDF

Sequenced physiologic muscle activations in the upper and lower extremity result in an integrated biomechanical task. This sequencing is known as the kinetic chain, and, in upper extremity dominant tasks, the energy development and output follows a proximal to distal sequencing. Impairment of one or more kinetic chain links can create dysfunctional biomechanical output leading to pain and/or injury.

View Article and Find Full Text PDF

The goal of this study was to determine if prolonged exposure to perceptual-motor mismatch increased adaptability and retention of balance in older adults. Sixteen adults, aged 66 to 81 years, were randomized to one of two groups: either the control group (n=8) or the experimental group (n=8). Both groups first completed six trials of walking an obstacle course.

View Article and Find Full Text PDF

The addition of inertia to exercising astronauts could increase ground reaction forces and potentially provide a greater health benefit. However, conflicting results have been reported regarding the adaptations to additional mass (inertia) without additional net weight (gravitational force) during locomotion. We examined the effect of increasing inertia while maintaining net gravitational force on vertical ground reaction forces and temporal kinematics during walking and running.

View Article and Find Full Text PDF

The study proposed to identify balance strategies used by younger and older adults during gait under proprioceptive, visual, and simultaneous proprioceptive-visual challenges. Participants ambulated under 4 conditions: consistent, noncompliant surface; inconsistent, compliant surface (C); consistent, noncompliant surface with vision obscured (NCVO); and inconsistent, compliant surface with vision obscured (CVO). Balance adaptations were measured as changes in gait velocity, cadence, and gait-stability ratio (GSR).

View Article and Find Full Text PDF

Background: Age-related declines in balance and walking ability are major risk factors for falls. Older adults reduce the dynamic components of walking in an effort to achieve a more stable walking pattern. Tae Kwon Do is an exercise that trains dynamic components of balance and walking that diminish with age.

View Article and Find Full Text PDF

Gait speed, commonly modified to adapt to the balance and stability challenges of aging, is related to measures of balance and mobility. This study investigated associations between age, Berg Balance Scale, Activities-Specific Balance Confidence (ABC) Scale, One Question Fear of Falling (1QFOF), and gait speed in adults using regression analysis. Results suggested an interaction between 1QFOF and ABC scores.

View Article and Find Full Text PDF

The purpose of this study was to determine adaptations in head stability resulting from altered gaze control and vision during over-ground walking. Using over-ground walking permitted adaptations in walking velocity and cadence that are otherwise not possible during treadmill walking or walking-in-place. Gaze control and vision were manipulated by having 20 young adult subjects 1) walk naturally, 2) view a distant, earth-fixed target to enhance the vestibulo-ocular reflex (VOR), 3) view a head-fixed target to suppress the VOR, and 4) walk in darkness.

View Article and Find Full Text PDF

Age-related adaptations during walking create a more stable walking pattern, which is less effective for forward progression and might be related to balance deficiencies. This study determined the relationship between walking stability and measures of balance in older adults. Seventeen older and 20 young adults performed the Berg Balance Test (BBT) and walked 10 m.

View Article and Find Full Text PDF

Background And Purpose: Head stability is the dynamic process of maintaining an equilibrium position of the head-in-space. Individuals with vestibular deficits restrict head movements during dynamic activities in an effort to adapt to vestibular loss. However, this strategy does not provide them with a successful means for adaptation during dynamic tasks where head movements are required.

View Article and Find Full Text PDF

Changes in body orientation with respect to space during incline walking can alter vestibular information requiring a different solution to the problem of head stabilization. Eleven young adults walked along a level walkway, and ascended and descended an inclined surface. Head, neck and trunk angular positions in space were collected.

View Article and Find Full Text PDF

A great deal of interest has developed regarding the impact of cognitive deficits on the everyday functioning of people with schizophrenia. This study examined the relationships between cognitive functioning and the performance of a specific independent living skill (grocery shopping) in a sample of 73 individuals with schizophrenia or schizoaffective disorder. Cognitive variables included tests of verbal memory, executive functioning, verbal fluency, sustained attention and visual motor skill.

View Article and Find Full Text PDF