Inhalation of ultrafine and fine particulate matter disrupts systemic vascular function.

This study investigated the effects of particulate matter (PM) with aerodynamic diameter 0.02-1 microm (noted as PM1) inhalation during exercise on conduit artery and microvascular function. Inhalation of internal combustion-derived PM is associated with cardiovascular mortality and morbidity.

Modulation of the tibial nerve H-reflex by mechanical stimulation of afferents in the lumbar spine.

The purpose of this study was to describe the convergence of afferent discharges from the ligament-muscular system of the lumbar spine to the segmentally-related gastrocnemius muscle. The subjects were 32 healthy, young volunteers recruited from a college student population. Afferent discharges from the ligament-muscular system of the lumbar spine were evoked by manually moving the trunk into either flexion (n = 16) or left lateral bending (n = 16) using a multi-directional adjustable treatment table (Zenith Cox Flexion Table).

Responsiveness of the Bournemouth and Oswestry questionnaires: a prospective pilot study.

Background: The assessment of health-related quality-of-life outcome information has become an essential feature in the delivery of quality health care. Outcome assessment and increased clinical research capacity have been identified as recommended areas of priority for chiropractic research, chiropractic colleges, and the profession.

Objective: This article reports the results of a multisite pilot project utilizing New York Chiropractic College's 3 off-campus health centers.

Spinal reflex excitability changes after lumbar spine passive flexion mobilization.

Background: Flexion distraction has gained increased credibility as a therapeutic modality for treatment of low back pain. Although important work in the area has elucidated the intradiskal pressure profiles during flexion distraction, the accompanying neural responses have yet to be described.

Objective: The purpose of this pilot study was to assess neural reflex responses to motion with 3 degrees of freedom applied to the lumbar spine and to evaluate H-reflex responses of the soleus.

Endogenous opioid effects on motoneuron pool excitability: potential analgesic effect of acute exercise.

Background: Metabolic and thermal stresses of exercise mediate the release of endogenous opioids depressing motoneuron activation (MNA). Although exercise is routinely presented as a coequal treatment for management of acute and chronic low back pain (LBP), it is not clear that exercise-induced endogenous opioid release can play a role in the analgesic and treatment outcomes for patients with LBP. Furthermore, if opioid involvement is present, it is not clear what level of exercise might be beneficial in the suppression of MNA and possibly LBP.

The short golf backswing: effects on performance and spinal health implications.

Background: Full recoil golf swings have been implicated in back pain and injury in golfers. Evidence suggests that a restricted backswing may reduce the potential for injury without compromising performance.

Objective: To examine both golf swing performance and selected muscular actions of the trunk and shoulder during a full recoil swing as compared with a modified short backswing.

Comparison of effects of spinal manipulation and massage on motoneuron excitability.

The purpose of this study was to compare the magnitude and duration of motoneuron inhibition occurring as a sequel to spinal manipulation or paraspinal and limb massage. The physiologic mechanisms involved in spinal manipulative therapy and massage therapy are largely unknown. One possible hypothesis is based upon the theory that these two distinct and different modalities may attenuate the activity of alpha motoneurons.

Spinal reflex attenuation associated with spinal manipulation.

Study Design: This study evaluated the effect of lumbosacral spinal manipulation with thrust and spinal mobilization without thrust on the excitability of the alpha motoneuronal pool in human subjects without low back pain.

Objectives: To investigate the effect of high velocity, low amplitude thrust, or mobilization without thrust on the excitability of the alpha motoneuron pool, and to elucidate potential mechanisms in which manual procedures may affect back muscle activity.

Summary Of Background Data: The physiologic mechanisms of spinal manipulation are largely unknown.

The effect of activity history and current activity on static and dynamic postural balance in older adults.

The purpose of this study was to investigate the effects of former athleticism and current activity status on static and dynamic postural balance in older adults. Fifty-six subjects participated in four study groups including former athletes, currently active (AA; n = 15; 69.1+/-4.

Hemodynamic responses to the stroop and cold pressor tests after submaximal cycling exercise in normotensive males.

The effect of 30 min of cycling exercise at 60% VO2max on hemodynamic responses to the Stroop and cold pressor tests in 12 normotensive males was examined. Subjects were randomly assigned in a counterbalanced design to perform the stressors pre- and postexercise and served as their own controls. Cardiac output (CO), heart rate (HR), and stroke volume were measured continuously by impedance cardiography.

Comparison of anaerobic components of the Wingate and Critical Power tests in males and females.

The purpose of the study was to reexamine the relationship between the Wingate and Critical Power tests of anaerobic capacity (AC) and anaerobic reserve (AR), respectively. A second purpose was to observe gender differences. Both tests were administered to 16 female and 13 male subjects (N = 29) on a Monark cycle ergometer with six subjects repeating AR measurement.

Blood pressure responses to acute exercise in type A and B females and males.

Cardiovascular responses to moderate steady-state exercise were studied in Type A and Type B males and females. Eighteen men and 17 women, ages 20 to 40 years, were chosen for Type A (males = 10, females = 10) and Type B (males = 8, females = 7) groups by means of the Jenkins Activity Survey (JAS). Subjects exercised on a electronic cycle ergometer at 60% O2peak for 20 min.

The effect of sleep deprivation and exercise load on isokinetic leg strength and endurance.

Isokinetic leg strength and fatigue were measured in 24 male U.S. Marine Corps volunteers in a simulated sleep loss and unusually heavy work scenario.

The effects of strength training and centrifuge exposure on +Gz tolerance.

Weight training (WT) as a countermeasure to +Gz intolerance seems to be an accepted modality, but lacks convincing support in the research literature. This study examines factors associated with WT in an operational environment as a countermeasure to +Gz intolerance. Fourteen naval aviators were assigned to a WT group (n = 7) and a non-weight-trained control (NWT) group (n = 7).

Blood pressure responses to acute exercise in type A females.

Cardiovascular responses to moderate steady state exercise were studied in type A females. Twenty-one women, ages 18 to 43 years (mean 29.7 +/- 2.

Isokinetic strength and endurance during 30-day 6 degrees head-down bed rest with isotonic and isokinetic exercise training.

The purpose of our study was to determine if an intensive, intermittent, isokinetic, lower extremity exercise training program would attenuate or eliminate the decrease of muscular strength and endurance during prolonged bed rest (BR). The 19 male subjects (36 +/- 1 yr, 178 +/- 2 cm, 76.5 +/- 1.

Aerobic fitness and opioidergic inhibition of cardiovascular stress reactivity.

The role of endogenous opioids in aerobic fitness-induced decrements in cardiovascular stress reactivity was examined by comparing the effects of opioid antagonism with naltrexone on responses to stress in young adults with high versus low levels of aerobic fitness. Two hundred forty subjects were given an activity questionnaire and males with the highest (Fit) and lowest (Nonfit) aerobic activity profiles were recruited for maximal oxygen consumption (VO2max) treadmill testing and psychological stress testing (final sample N = 28). Heart rate and blood pressures were measured during performance on a computer-controlled arithmetic task after pretreatment with either naltrexone (Trexan, DuPont) or a placebo.

Effect of downhill running on motoneuron pool excitability.

The purpose of this study was to compare alterations in motoneuron pool excitability after eccentric-biased (ECC-B) downhill running exercise with non-biased (NO-B) level running exercise. Six male subjects (25-34 yr) participated in the study, which included ECC-B exercise (-10% grade) and NO-B exercise (0% grade) at 50% of maximal O2 uptake for 20 min. The control trial consisted of 20 min of quiet rest with all subjects participating in all conditions (repeated measures).

Exercise-training protocols for astronauts in microgravity.

The question of the composition of exercise protocols for use by astronauts in microgravity is unresolved. Based on our knowledge of physical working requirements for astronauts during intra- and extravehicular activity and on the findings from bed-rest studies that utilized exercise training as a countermeasure for the reduction of aerobic power, deterioration of muscular strength and endurance, decrements in mood and cognitive performance, and possibly for bone loss, two exercise protocols are proposed. One assumes that, during microgravity, astronaut exercise physiological functions should be maintained at 100% of ground-based levels; the other assumes that maximal aerobic power in flight can be reduced by 10% of the ground-based level.

Body composition in paraplegic male athletes.

The body composition and anthropometric characteristics of male paraplegic athletes (PARA, N = 22) were contrasted to an able-bodied ectomorphic (N = 22) and mesomorphic (N = 31) comparison group of moderately and highly trained male subjects. The validity of 12 body composition [density (Db)] prediction equations reported in the literature, 4 generalized, were determined (tested) on this special group of athletes (PARA). On the whole, the prediction equations over-predicted Db in PARA by 0.

Motor neuron excitability: the Hoffmann reflex following exercise of low and high intensity.

The current exercise literature lacks physiological evidence for a stress reduction induced by high intensity aerobic work. The purpose of this study was to investigate the effectiveness of high intensity aerobic work on stress reduction and to evaluate the currently tenable hypotheses in view of the data on the response to high intensity work. The subjects participated in a control trial and two 20-min treadmill exercise trials at low and high (40% and 75% VO2max) intensity.

Physical training and +Gz tolerance reevaluated.

The effect of physical training on +Gz tolerance is of vital interest in the aerospace community. The data on the effect of physical training on orthostatic tolerance or simulated air combat maneuvers is equivocal. The effects of aerobic and strength training programs is briefly reviewed.

Anaerobic contribution to distance running performance of trained cross-country athletes.

Recent reports have suggested that running economy (RE) defined as oxygen consumption at standardized treadmill speeds may be an important determinant for successful distance running performance. The purpose of this study was to examine the additional role, if any, played by anaerobic factors in distance running performance. Highly trained male cross-country runners (N = 12) were administered a battery of standardized aerobic and anaerobic laboratory evaluations.