Assessment of Exercise Stroke Volume and Its Prediction From Oxygen Pulse in Paralympic Athletes With Locomotor Impairments: Cardiac Long-Term Adaptations Are Possible.

The determinants of cardiac output (CO) during exercise, i.e., stroke volume (SV) and heart rate (HR), could differ in Paralympic athletes (PAthl) with spinal cord injury (SCI) with respect to PAthl with locomotor impairments caused by different health conditions (HCs).

Pre-frontal Cortex Oxygenation Changes During Aerobic Exercise in Elite Athletes Experiencing Sport-Related Concussion.

: Recent research suggests that aerobic exercise can be performed safely within the first week following a concussion injury and that early initiation of exercise may speed recovery. To better understand the physiological changes during a concussion, we tested the hypothesis that mild-to-intense exercise testing can be performed within days immediately following injury, and can be used to discern differences between the concussed and normal healthy state. Thus, the purpose was to observe the cerebral hemodynamic responses to incremental exercise testing performed acutely post-concussion in high-performance athletes.

Genetic Effects on Sensorineural Hearing Loss and Evidence-based Treatment for Sensorineural Hearing Loss.

In this article, the mechanism of inheritance behind inherited hearing loss and genetic susceptibility in noise-induced hearing loss are reviewed. Conventional treatments for sensorineural hearing loss (SNHL), i.e.

Reliability and reactivity of the prefrontal hemodynamic responses in essential hypertension: a functional near infrared spectroscopy study.

Prefrontal (PFC) cerebral vasoreactivity may be altered in hypertension but has not been studied during postural change and carbon dioxide (CO2) rebreathing. In this study, a dual procedure of 5% CO2 rebreathing with positional change (standing to supine and reverse) was performed on normotensive (N = 24) and essential hypertensive males (N = 16) (18-55 years) to assess reliability of PFC responses using functional near infrared spectroscopy. The groups (matched on age levels, N = 13) were also compared on their hemodynamic reactivity (change of oxyhemoglobin or total hemoglobin as a function of change in end tidal CO2).

Hemodynamic changes in the prefrontal cortex during working memory in essential hypertension.

Behavioral performance and hemodynamic changes in the prefrontal cortex (PFC) represent cerebrovascular reserve and may indicate functional deficits related to essential hypertension. Fifteen stage 1 hypertensive and normotensive males (19-55 years) were compared on four tests of working memory (digit span and auditory consonant trigrams), and accompanying hemodynamic changes measured by functional near infrared spectroscopy (fNIRS). With participants blindfolded, the four tests were randomized while fNIRS was used to monitor bilateral PFC changes in oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), total hemoglobin (tHb), and hemoglobin difference.

Electromyographic, cerebral, and muscle hemodynamic responses during intermittent, isometric contractions of the biceps brachii at three submaximal intensities.

This study examined the electromyographic, cerebral and muscle hemodynamic responses during intermittent isometric contractions of biceps brachii at 20, 40, and 60% of maximal voluntary contraction (MVC). Eleven volunteers completed 2 min of intermittent isometric contractions (12/min) at an elbow angle of 90° interspersed with 3 min rest between intensities in systematic order. Surface electromyography (EMG) was recorded from the right biceps brachii and near infrared spectroscopy (NIRS) was used to simultaneously measure left prefrontal and right biceps brachii oxyhemoglobin (HbO2), deoxyhemoglobin (HHb), and total hemoglobin (Hbtot).

Serial monitoring of CO2 reactivity following sport concussion using hypocapnia and hypercapnia.

Primary Objective: This study examined the effects of mild traumatic brain injury (mTBI) on cerebrovascular reactivity (CVR).

Research Design: A repeated measures design was used to examine serial changes in CVR.

Methods And Procedures: Twenty subjects who recently suffered a mTBI were subjected to a respiratory challenge consisting of repeated 20 s breath-holds (BH) and hyperventilations (HV).

Does whole-body vibration acutely improve power performance via increased short latency stretch reflex response?

Objectives: It remains unclear whether an increased intrafusal mechanical sensitivity is related to the vibration-induced performance improvement. This investigation aimed to determine the residual acute effect of whole-body vibration and its duration on pre-activation levels, short-latency stretch reflex and performance during drop jumps.

Design: Repeated measures.

Does vibration counteract the static stretch-induced deficit on muscle force development?

Objectives: To determine the residual acute vibration-stretching effect on preactivation levels, short-latency stretch reflex, and performance during execution of drop jumps.

Design: Repeated measures.

Methods: Eleven male recreational athletes performed a set of three 45cm drop jumps before and immediately after a 30s static stretching exercise with and without simultaneously imposed muscle vibration (45Hz, 5mm).

Effects of hypoxia on cerebral and muscle haemodynamics during knee extensions in healthy subjects.

A hypoxic model was used to investigate changes in localized cerebral and muscle haemodynamics during knee extension (KE) in healthy individuals. Thirty-one young healthy volunteers performed one set of KE until failure under hypoxia (14 % O(2)) or normoxia (21 % O(2)) at 50, 75 or 100 % of 1 repetition maximum, in random order, on three occasions. Prefrontal cerebral and vastus lateralis muscle oxygenation and blood volume (Cox, Mox, Cbv and Mbv, respectively) were recorded simultaneously by near-infrared spectroscopy.

Acute l-arginine supplementation increases muscle blood volume but not strength performance.

l-Arginine (L-arg) is an amino acid precursor to nitric oxide (NO). Dietary supplements containing L-arg have been marketed with the purpose of increasing vasodilation, thereby elevating blood flow to the exercising muscle and enhancing the metabolic response to exercise. Our goal was to identify the acute effect of L-arg supplementation on biceps strength performance, indicators of NO production (nitrite and nitrate - NOx), and muscle blood volume (Mbv) and oxygenation (Mox) during recovery from 3 sets of resistance exercise.

Physiologic responses of competitive Canadian cross-country skiers with disabilities.

Objective: To examine the acute cardiorespiratory and metabolic responses in competitive cross-country skiers with disabilities.

Design: Cross-sectional comparisons using a select group of Canadian athletes training for the Vancouver 2010 Paralympic Winter Games.

Setting: Canmore Nordic Centre Provincial Park, Canmore, Alberta.

Cerebrovascular reactivity impairment after sport-induced concussion.

Purpose: This study evaluated cerebrovascular reactivity (CVR) after a sport-induced concussion, also called mild traumatic brain injury (mTBI), by monitoring middle cerebral artery blood velocity (vMCA) with transcranial Doppler ultrasonography and simultaneous end-tidal carbon dioxide (PETCO(2)) measurements.

Methods: Thirty-one athletes (16-25 yr old) participated in this study. The participants were divided into two groups-healthy (n = 21) and mTBI (n = 10).

Comparison of a double poling ergometer and field test for elite cross country sit skiers.

Background: Sport specific ergometers are important for laboratory testing (i.e. peak oxygen consumption (VO(2))) and out of season training.

L-Arginine as a potential ergogenic aid in healthy subjects.

Dietary supplements containing L-arginine, a semi-essential amino acid, are one of the latest ergogenic aids intended to enhance strength, power and muscle recovery associated with both aerobic and resistance exercise. L-arginine is claimed to promote vasodilation by increasing nitric oxide (NO) production in the active muscle during exercise, improving strength, power and muscular recovery through increased substrate utilization and metabolite removal, such as lactate and ammonia. Research on L-arginine has recently tested this hypothesis, under the assumption that it may be the active compound associated with the vasodilator effects of NO.

Cerebral and muscle oxygenation changes during static and dynamic knee extensions to voluntary fatigue in healthy men and women: a near infrared spectroscopy study.

The aim of the study was to examine the changes in cerebral and muscle blood volume (Cbv, Mbv) and oxygenation (Cox, Mox) during static and dynamic knee extensions to fatigue in men (N=10; 29±9 years) and women (N=14; 27±8 years). After assessment of 1 repetition maximum (1RM) during unilateral knee extensions with the dominant limb, each subject exercised at 50%, 75% and 100% of 1 RM in random order on separate occasions. Simultaneous changes in Cbv, Cox, Mbv and Mox from the contralateral prefrontal lobe and the dominant limb were measured by near infrared spectroscopy.

Boosting in athletes with high-level spinal cord injury: knowledge, incidence and attitudes of athletes in paralympic sport.

Unlabelled: Autonomic dysreflexia (AD) is unique to individuals with spinal injuries (SCI) at T6 or above and can be voluntarily induced. Although AD improves wheelchair racing performance in some athletes, it also elicits exaggerated blood pressure, which could be dangerous. The International Paralympic Committee considers AD doping and banned its use.

Rehabilitation in bariatrics: opportunities for practice and research.

Purpose: Obesity is associated with a wide range of chronic illnesses and disabilities familiar to rehabilitation researchers and practitioners. Obesity discourse in the area of rehabilitation science and practice is limited.

Method: A meeting of rehabilitation researchers, practitioners, industry and decision makers was held for the purpose of identifying research and practice priorities in the area of bariatric rehabilitation.

Effect of opioid administration on cardiorespiratory and muscle oxygenation during lifting in chronic back pain patients.

The objectives of this study were to examine the effects of opioid administration on the acute cardiorespiratory and muscle oxygenation responses during a repetitive lifting and lowering test (RLL) to voluntary fatigue in participants with chronic low back pain (LBP). Written informed consent was obtained from 27 LBP participants (mean age 50.9 +/- 16.

Field evaluation of paralympic athletes in selected sports: implications for training.

Purpose: The purpose of this study was 1) to describe the acute cardiorespiratory and metabolic responses of Paralympic athletes participating in the following five sports: Nordic sit skiing (NS, n = 5), wheelchair distance racing (WR, n = 6), wheelchair basketball (WB, n = 13), wheelchair fencing (WF, n = 6), and wheelchair tennis (WT, n = 4); and 2) to examine the relationship between field test performance and laboratory measures of aerobic fitness of these Paralympic athletes.

Methods: Each athlete completed an incremental arm cranking exercise test to determine ventilatory threshold (VT) and peak oxygen uptake (VO2peak). Subsequently, field assessments were carried out using a telemetric system to measure the cardiorespiratory responses in their respective sport.

Acute effects of sustained isometric knee extension on cerebral and muscle oxygenation responses.

Cerebral contra-lateral frontal lobe and the dominant vastus lateralis muscle oxygenation (Cox, Mox) and blood volume (Cbv, Mbv) were recorded simultaneously using near infrared spectroscopy (NIRS) in 12 healthy volunteers (37.4 +/- 9.9 years; 72.

Opioid prescriptions in canadian workers' compensation claimants: prescription trends and associations between early prescription and future recovery.

Study Design: Historical cohort study.

Objective: We investigated the prescription of opioids in injured Canadian workers to determine recent trends in use and the association between early prescription and future recovery.

Summary Of Background Data: Opioid analgesia is effective for reducing chronic nonmalignant pain, and opioid prescriptions for musculoskeletal pain seem to have increased over the past years.

Microvascularity of the lumbar erector spinae muscle during sustained prone trunk extension test.

This study evaluated the reliability of oxygenation and blood volume responses, from the right erector spinae in twenty two healthy men and women, during static prone trunk extension on two separate days. Near-infrared spectroscopy (NIRS)-derived physiological change for oxygenation was calculated as the difference between the 'baseline' before the start of the trunk extension and 'minimum' at the point of volitional exhaustion. The physiological change for blood volume was calculated as the difference between the 'baseline' value and 'maximum' at the point of volitional exhaustion.

Acute opioid administration improves work-related exercise performance in patients with chronic back pain.

Unlabelled: We studied the impact of acute opioid administration on work-related exercise performance in patients with chronic back pain. A double-blinded, random-order, placebo-controlled, crossover trial was conducted. Subjects were predominantly men (63%), with a mean age of 49 years.

Functional changes in cerebral and paraspinal muscle physiology of healthy women during exposure to whole-body vibration.

The objective of this study was to investigate the effects of whole-body vibration on multiple tissues simultaneously in fourteen healthy women. On three separate days, participants were exposed to frequencies, 3, 4.5, or 6 Hz (at 0.