Oxygen consumption, heart rate, and rating of perceived exertion in young adult women during backward walking at different speeds.

Backward walking has gained popularity as an adjunct to treatment for patients undergoing rehabilitation for patellofemoral pain syndrome and anterior cruciate ligament injuries. Researchers have suggested that backward walking decreases the compressive forces at the patellofemoral joint while also preventing overstretching of the anterior cruciate ligament. Prior to this study, precise prescription of backward walking speeds for women was not possible. The purpose of this study was to determine the relationship between heart rate, oxygen consumption, and backward walking speeds. Twenty-five healthy, adult female volunteers participated in this study. Subjects were tested at speeds of 0.96, 1.20, 1.43, 1.67, and 1.91 m/sec. Subjects also performed a graded exercise stress test. Analysis revealed curvilinear relationships between oxygen consumption and speed as well as between heart rate and speed. With these results, clinicians may now prescribe specific speeds of backward walking for women to elicit a desired cardiopulmonary response.

Phonophoretic delivery of 10% hydrocortisone through the epidermis of humans as determined by serum cortisol concentrations.

BACKGROUND AND PURPOSE: The purpose of this investigation was to determine whether application of hydrocortisone phonophoresis enhances transcutaneous delivery of topically applied hydrocortisone in humans, as determined by blood cortisol levels. SUBJECTS: The subjects were 16 men and women, between the ages of 18 and 33 years (X = 25, SD = 2.74), without symptoms of any ongoing inflammatory condition. METHODS: A gel coupling medium containing 10% hydrocortisone acetate was used. Ultrasound was delivered over a 50-cm2 area for 5 minutes at an intensity of 1.0 W/cm2 and a frequency of 1.0 MHz. Each subject received a control treatment (ultrasound alone) and an experimental treatment (hydrocortisone phonophoresis) on the volar aspect of the forearm 1 week apart. Blood was drawn, under both control and experimental conditions, from a cubital vein just proximal to the treatment site prior to each treatment and 0,5, and 15 minutes posttreatment. Serum cortisol concentrations were measured using a fluorescence polarization immunoassay. RESULTS: No rise in serum cortisol concentrations following hydrocortisone phonophoresis was detected. CONCLUSION AND DISCUSSION: These findings suggest that there was no penetration of hydrocortisone through the epidermis and into the underlying vasculature. Clinical implications regarding hydrocortisone levels within the subcutaneous tissues are discussed, and further research is suggested.

Effects of exercise training modality on glucose tolerance in men with abnormal glucose regulation.

To determine the effects of exercise training modality on glucose tolerance in men with untreated abnormal glucose regulation, 26 untrained men (age 54 +/- 9 years; mean +/- SD) with either non-insulin-dependent diabetes mellitus (N = 8), impaired glucose tolerance (IGT) (N = 12) or hyperinsulinemia with normal glucose tolerance (N = 6) were studied before and after 20 wk of either strength training (ST) (N = 8), aerobic (treadmill walk/jog) training (AT) (N = 8), or no exercise (control group; N = 10). Plasma concentrations of glucose and insulin were measured after a 12-14 hr fast and during a standard oral glucose tolerance test (OGTT) before and after training. The ST program significantly reduced total plasma glucose area (mmol.l-1.120 min-1) under the OGTT curve (1348 +/- 251 vs 1190 +/- 329, p < 0.05), and plasma glucose levels (mmol.l-1) at 60 min (p < 0.05), 90 min (P < 0.05), and 120 min (p < 0.05) after glucose ingestion. Strength training also lowered the total plasma insulin area (pmol.l-1.120 min-1) under the OGTT curve (60082 +/- 25467 vs 46727 +/- 11273, p < 0.05) as well as plasma insulin levels (pmol.l-1) at fasting (p < 0.05) and at 90 min (p < 0.01) and 120 min (p < 0.05) after glucose ingestion. All men with IGT (four in each training group) normalized their glucose tolerance following the training. There were no significant differences in OGTT results between ST and AT and no changes were observed in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of cardiopulmonary responses to forward and backward walking and running.

Backward running has long been used in sports conditioning programs and has recently been incorporated into rehabilitative settings as a method of increasing quadriceps strength while decreasing the joint compressive forces about the knee. Although backward locomotion has been studied kinetically, the metabolic cost of backward walking and/or running has not to our knowledge been previously characterized. Oxygen consumption and other cardiopulmonary variables were measured under constant speed exercise during backward and forward walking at 107.2 m.min-1 and during backward and forward running at 160.8 m.min-1. Peak oxygen consumption (VO2peak) was also measured during maximal incremental backward and forward running. VO2, HR, and blood lactate were significantly higher (P < 0.001) during backward walking and running than during forward walking and running. During backward walking and backward running, subjects exercised at 60% and 84% of their forward VO2peak, respectively. In conclusion, for a given speed, backward locomotion elicits a greater metabolic demand and cardiopulmonary response than forward locomotion. In general, these data suggest that while undergoing rehabilitation, an injured athlete may continue to exercise using backward walking/running at an intensity sufficient enough to maintain cardiovascular fitness levels.

Aerobic versus strength training for risk factor intervention in middle-aged men at high risk for coronary heart disease.

To compare the effects of strength training (ST) to those of aerobic training (AT) for coronary heart disease (CHD) risk factor intervention, we studied 37 previously untrained males (aged 50 +/- 9 years, mean +/- SD) before and after 20 weeks of either ST (N = 14), AT (walk/jog, N = 13), or no exercise (inactive controls, N = 10). Lipoprotein and lipid profiles, blood pressure, and glucose and insulin responses to an oral glucose tolerance test (OGTT) were assessed before and after the training period in all three groups. The ST program produced significant reductions in plasma glucose levels at 60, 90, and 120 minutes (P < .05) after glucose ingestion, whereas the AT program resulted in significant reductions only at 90 and 120 minutes (P < .05). ST also decreased insulin levels during fasting (P < .05) and at 90 and 120 minutes (P < .01) after glucose ingestion. AT decreased insulin levels at 90 and 120 minutes (P < .01) after glucose ingestion. Both training programs reduced the total area under the glucose tolerance curve for glucose (both P < .05) and insulin (both P < .05), but there were no significant differences in these changes between the two groups. None of the glucose or insulin values were significantly altered in the control group. There were no significant changes in lipoprotein and lipid profiles or blood pressure in any of the three groups. These results suggest that ST and AT have comparable effects on risk factors for CHD.(ABSTRACT TRUNCATED AT 250 WORDS)

Strength training does not improve lipoprotein-lipid profiles in men at risk for CHD.

Sixteen untrained males, age 46 +/- 11 yr (mean +/- SD), were studied to determine the effects of 20 wk of strength training on lipoprotein-lipid profiles and post-heparin lipase activities. All subjects had abnormal lipoprotein-lipid profiles and at least two other risk factors for coronary heart disease (CHD). To control for day-to-day variations in blood lipoprotein levels, baseline values were established by taking at least two blood samples on separate days from the training and control groups. The training program resulted in a 50% increase in upper body strength (P less than 0.001) and a 37% increase in lower body strength (P less than 0.001) as measured by the one repetition maximum test (1-RM). No changes in the 1-RM test were observed in the control group. There were no significant changes in VO2max (34.5 +/- 6.4 vs 36.2 +/- 7.4 ml.kg-1.min-1 or percent fat (25.4 +/- 4.2 vs 24.9 +/- 4.1%) with training. There were also no significant changes in plasma concentrations of triglyceride (193 +/- 96 vs 171 +/- 101 mg.dl-1), total cholesterol (231 +/- 22 vs 210 +/- 22 mg.dl-1), and HDL-C (35 +/- 6 vs 36 +/- 8 mg.dl-1), or LDL-C (139 +/- 16 vs 139 +/- 21 mg.dl-1). Furthermore, the activities of post-heparin lipoprotein lipase (9 +/- 4 vs 13 +/- 5 moles.ml-1.h-1) and hepatic lipase (35 +/- 10 vs 35 +/- 9 moles.ml-1.h-1) did not change with training.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of unilateral brain damage on contralateral and ipsilateral upper extremity function in hemiplegia.

This article describes the long-term effects of unilateral penetrating hemispheric lesions on contralateral and ipsilateral upper extremity motor performance and functional outcome. Activities-of-daily-living skill and gross motor performance contralateral to the lesions were compared among 32 left-sided and 19 right-sided hemiplegic subjects using analysis of variance and chi-square techniques. Ipsilateral to the damaged hemisphere, fine motor tasks of simple visual motor reaction time, grip and pinch strength, finger tapping, and Purdue Pegboard performance were tested. Analysis of covariance compared each ipsilateral task to performance in the corresponding hand of 70 matched controls. Results indicate similar long-term functional ADL outcome in right and left hemisphere-damaged subjects, despite more severe contralateral functional motor deficits following lesions of the left hemisphere. Right hemisphere lesions led to ipsilateral decrements in reaction time, and lesions of either hemisphere diminished grip or pinch strength, finger tapping, and pegboard performance ipsilaterally. These results demonstrate that unilateral brain damage involving the motor areas of either hemisphere has detrimental effects on ipsilateral upper extremity motor function. Findings are discussed and related to the concept that the left hemisphere is specialized or has greater neuronal representation for bilateral motor processes. Physical therapists involved in the treatment of patients with hemiplegia should be aware that motor functions of the ipsilateral, nonparetic upper extremity may also be affected adversely by unilateral brain lesions.

Intellectual function following penetrating head injury in Vietnam veterans.

The extent to which intellectual processes are preserved as a function of preinjury 'intelligence' and of size and location of the brain lesions was evaluated in Vietnam war veterans who survived penetrating missile wounds. With regard to an overall postinjury intelligence test score, preinjury intelligence was most predictive, size of lesion was next most predictive and lesion location was least important. For subtest scores from the same intelligence test, lesion location assumed much greater predictive value. Specifically, left temporal and occipital lesions impaired performance on subtests assessing vocabulary and object-function matching ability.

Clinical and radiological correlates of somatosensory evoked potentials in the late phase of head injury: a study of 500 Vietnam veterans.

Somatosensory evoked potentials were obtained after median nerve stimulation in 500 Vietnam veterans surviving penetrating head wounds 12-16 years earlier and 76 age-matched, uninjured controls. The results were studied in relation to neurologic history and findings, anatomical data provided by CT scan, and information derived from electroencephalograms. Thirty-five percent of head-injured individuals had abnormal SEPs and 76% of SEP abnormalities consisted of absence of N20 or N20/P25 complex. SEP abnormality correlated (P greater than 0.001) with the extent of total brain volume loss, sensory deficits (especially position and cortical discriminatory modalities), hemiparesis, organic mental disorder, CT evidence of parietal or thalamic injury, and centro-parietal EEG abnormalities. Recovery from hemiparesis was correlative with patients who subsequently had normal SEPs.

Site of penetrating brain lesions causing chronic acquired stuttering.

Ten subjects exhibited acquired stuttering that had persisted for 10 to 15 years following penetrating missile wounds sustained during the Vietnam War. None had a history of developmental or chronic adult stuttering. In comparison with other head-injured subjects and normal control subjects, the subjects with acquired stuttering had significant deficits in skilled rapid hand movements and oral and speech movements, suggesting a motor control disorder. The identified brain lesions of the acquired stuttering group were on the right in 5 subjects, on the left in 4, and bilateral in 1. The internal and external capsules, the frontal white matter, and the striatum were more frequently involved in the acquired stuttering group than in other head-injured subjects (p less than or equal to 0.05). This speech rhythm and rate disorder was not associated with evident cortical lesions in either hemisphere but with predominantly unilateral lesions of the subcortical pyramidal and extrapyramidal systems.

Clinical and radiological correlates of EEG in the late phase of head injury: a study of 515 Vietnam veterans.

Electroencephalograms were obtained in 515 Vietnam veterans 12-16 years after penetrating head injury, and the results were correlated with a variety of clinical and radiological parameters. Forty-two percent of EEGs were abnormal; 9% disclosed epileptiform findings (EF). EF correlated highly (P = 0.0001) with the extent of brain volume loss (defined by CT), posttraumatic epilepsy, and organic mental disorder. 'Seizure persistence' was higher and duration of posttraumatic epilepsy was longer in patients with 'prominent EF.' All patients with anterior temporal or central spike foci experienced posttraumatic seizures. Focal slowing correlated significantly with focal neurologic deficits such as hemisensory deficit or hemiparesis and Broca's aphasia as well as with seizures and residual organic mental disorder. Total or near total recovery from original hemiparesis was noted in 70% of the patients with normal EEG and 32% of the patients with focally slow tracings.

Effects of left-hand preference on postinjury measures of distal motor ability.

The relationship of preinjury left-hand dominance for motor performance to postinjury distal motor skills following penetrating brain wounds in patients without overt hemiplegia was examined. We studied 13 controls, 13 right-hemisphere brain-damaged patients, and 11 left-hemisphere brain-damaged patients on motor tasks measuring reaction time, strength, and coordination. Our results indicated that no persistent deficits were seen on distal motor tasks in left-handed adults who suffered a penetrating brain wound. These findings are compatible with the relative sparing of persistent neuropsychological deficits in left-handers following brain damage.

Vietnam head injury study. Preliminary analysis of the functional and anatomical sequelae of penetrating head trauma.

An overview is presented of the multidisciplinary design, specific methods of motor and functional assessment, and selected preliminary data trends from the Vietnam Head Injury Study. This longitudinal study combines analyses of retrospective records with current, comprehensive inpatient examinations and investigates the anatomical and functional sequelae of penetrating head trauma in 700 Vietnam Veterans at an average of 14 years after injury. Preliminary data analysis of results from the first 160 subjects demonstrates good functional recovery despite large brain lesions. Motor abnormalities have persisted in 28 percent of the sample and are correlated with lesions involving the frontoparietal area of the cortex and the deep midline brain structures. Design concepts and long-term outcome trends will be useful to therapists in neurological rehabilitation. The study provides a model for health-team members interested in designs for longitudinal collection of outcome data.

Exercise intensity: subjective regulation by perceived exertion.

The primary purpose of this investigation was to determine if a safe and effective physical conditioning heart rate (HR) could prescribed by perception of exertion. Ratings of perceived exertion (RPE) were requested from 10 normal adult men during treadmill exercise trials at 4.7, 6.5, 9.7, 11.3, and 12.9km/hr (T1). Subjects were then requested to subjectively regulate their own treadmill speed during 2 separate trials (T2 and T3) at the RPE reported for each speed during T1. Speed and HR at equivalent RPE were compared during T1, T2, and T3. Regression analyses revealed that there was no difference in speed across all RPE between the 3 trials; however, HR was seen to become progressively higher during T2 and T3 than during T1 as speed and RPE decreased. HR reliability was significant (p < 0.05) during running but not significant (p > 0.05) during walking. It is concluded that prescription of exercise by RPE can produce safe, effective, and reliable conditioning HR above 150bpm (80% HRmax) and running speeds above 9km/hr. Use of RPE for exercise prescription below these levels can result in inaccurate and unreliable conditioning heart rates. This method of exercise prescription has limitations and could result in dangerously high HR is used in cardiac rehabilitation programs, in which strict adherence to target HR is essential.