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PubMed1982

Perceived exertion during patient lifts. An evaluation of the importance of various factors for the subjective strain during lifting and carrying of patients. A study at a geriatric hospital.

Model experiments and practical studies of patient lifts were carried out with the aim of finding a method for assessing perceived exertion during various types of patient lifts. In the model experiments perceived exertion was rated on the RPE (Borg) scale under standardized conditions with variation of the subject's working posture and the load to be lifted. A strong correlation was found between increased perceived exertion and an un-optimal posture and heavy load respectively. In the practical study of patient lifts the following eight variables were rated: posture, acceleration, the patient's weight, time needed for the lift, the load, patient cooperation, the moment about the fulcrum and the possibilities of getting a good hold. The subjects were asked to rate the perceived exertion on the RPE scale. Six common types of patient lifts were studied. By multiple regression analysis the different variables were analysed in relation to perceived exertion. Strong correlations were found between different variables and perceived exertion, with some variation between the different types of patient lifts. The perceived exertion in various types of patient lifts can therefore be characterized by a small number of variables (the most strongly correlated). By choosing the most characteristic variables for each patient lift, the method can be utilized to study changes in the perceived exertion for different types of patient lifts when the external conditions during the lift are changed.

Adult↗
PubMed2002

PVC tracheal tubes exert forces and pressures seven to ten times higher than silicone or armoured tracheal tubes--an in vitro study.

PURPOSE: Many types of tracheal tubes (TT) including silicone, polyvinylchloride (PVC) and armoured have been used for blind tracheal intubation (TI) via the intubating laryngeal mask airway (ILMA) and may cause trauma to the airway. We examined the maximal in vitro forces and pressures exerted by the tip of various TT as it exits the ILMA. METHODS: Silicone, PVC and armoured TT were studied. A #5 ILMA was secured on a wooden platform. With the use of a Harvard pump, force was applied to push the TT through the ILMA at 0.34 cm*sec(-1). Forces exerted to push the TT and forces exerted by the TT tips on distal objects were calculated using proximal and distal pressure manometres. The areas of contact between the distal TT tips and the distal objects were measured by planimetry of an imprint. The final pressures exerted by the TT tips on a fixed distal object were calculated by dividing the forces exerted by the areas of contact. RESULTS: When compared to silicone and armoured TT, PVC TT exerted seven to ten times higher forces and pressures on distal objects. (P < 0.05). Heating PVC TT and inserting PVC TT with reverse curvature to the ILMA did not decrease the forces and pressures exerted by the distal tip. CONCLUSION: The high forces and pressures exerted by PVC TT may theoretically contribute to increased morbidity to patients' airway and esophagus. Caution should be exercised before attempting blind TI via the ILMA with a PVC TT.

Intubation, Intratracheal↗
PubMed2000

Hemiplegic migraine induced by exertion.

BACKGROUND: It is known that exertion can aggravate migraine headache. However, the relationship between exertion and migraine aura is unknown. OBJECTIVE: To study the relationship between exertion and migraine aura. DESIGN: Case report. SETTING: Tertiary care hospital. PATIENT: A 67-year-old man presented with recurrent attacks of exertion-induced hemiplegic migraine. Since the hemiparetic attacks were exertion induced, they were initially ascribed to recurrent transient ischemic attacks. However, the clinical picture, normal findings on cerebral angiography and neuroimaging (during the period of hemiparesis), lack of response to treatment with antiplatelets and anticoagulants, and successful treatment with verapamil suggested that the hemiparesis was not due to ischemia, but was indeed a migraine aura. We suggest that exertion induced the aura of hemiparesis by lowering the threshold for the development of cortical spreading depression. Even though our patient had no family history of hemiplegic migraine, a mutation in an ion channel gene (eg, the CACNA1A gene on chromosome 19) might account for his episodic attacks. CONCLUSION: Migraine aura should be included in the differential diagnosis of exertion-induced focal neurologic deficit.

Aged↗
PubMed2004

Physical activity, self-efficacy, and perceived exertion among adolescents.

The relationship of self-efficacy, a sense of confidence in personal physical activity (PA) skills, to perceived exertion during activity was explored among 168 African American and European American boys and girls between 9 and 17 years of age. Participants walked/ran on a treadmill at a speed equivalent to 60% of their peak VO2 for 20 minutes and provided ratings of exertion every 4 minutes. Pre-activity self-efficacy predicted perceived exertion for boys only. Girls were lower than boys in pre-activity self-efficacy and subsequently reported greater perceived exertion. For both genders, lower perceived exertion during PA resulted in higher post-activity self-efficacy. Uncomfortable perceptions of exertion during initial efforts to increase PA are likely to discourage future activity. Interventions that can lower perceptions of exertion may enhance self-efficacy and promote a sense of competence in PA skills.

Adolescent↗
PubMed2003

The effect of passive heating and face cooling on perceived exertion during exercise in the heat.

Increased body temperature is thought to be an important component of the higher perception of exertion that is a feature of fatigue during exercise in the heat but a causal relationship has yet to be demonstrated. We have investigated the effect of passive heating on the perception of exertion during a standard bout of exercise and also assessed the effect of cooling the head on compensating for the increased body temperature on the feelings of exertion. Ten male subjects performed a 14-min cycling exercise [average power approximately 63% of maximum power output ( W(max))] at an ambient temperature of 35 degrees C at resting rectal temperature [mean (SD): 37.49 (0.27) degrees C; control (CON) trial] on one occasion, and after sitting in a sauna to raise rectal temperature [mean (SD): 38.95(0.13) degrees C; sauna (SAU) trial]. During the exercise, subjects reported their ratings of overall perceived exertion (RPE), perceived exertion of the legs (RPE(legs)) and thermal comfort (TC). A blood sample was collected by the end of the exercise for determination of plasma glucose, lactate and prolactin and haematocrit. RPE values were significantly elevated after passive heating [mean (SE): 14.5 (0.7) units in CON and 17.2 (0.5) units in SAU, at the end of exercise; P<0.001] as were the RPE(legs) ( P<0.01), while ratings of TC were similar in CON and SAU trials. Passive heating increased blood glucose ( P<0.05) but had no effect on lactate at the end of the exercise. Plasma prolactin was markedly elevated as a result of the sauna exposure [mean (SE): 1598 (152) versus 225 (31) mU l(-1) in SAU and CON trials, respectively; P<0.001]. Six of the subjects repeated the two trials but with the face cooled during exercise (trials CON(FAN) and SAU(FAN)) that was achieved by combining face fanning and spraying the face with a mist of cooled water. Face cooling decreased RPE values after sauna to a point that no differences between the two conditions existed. RPE(legs) scores and heart rate, however, remained higher in SAU(FAN) compared with CON(FAN) ( P<0.05). We conclude that hyperthermia is a causative element of the increased perception of exertion during submaximal exercise in the heat and that the effect of increased core temperature on the feelings of exertion is modulated by face cooling.

Adult↗
PubMed2001

The effects of voluntary contraction intensity and gender on perceived exertion during isokinetic quadriceps exercise.

The objectives of the present study were to: (1) examine perceived exertion across different target voluntary contraction intensities, (2) compare perceived exertion ratings with actual target intensities, and (3) compare perceived exertion ratings between males and females. The subjects for this study included 30 healthy, college-aged male (n = 15) and female (n = 15) volunteers. All subjects were free of orthopedic, cardiopulmonary, systemic and neurological disease. Each subject completed five maximal isokinetic, concentric quadriceps contractions in a seated position at 60 degrees.s-1 to determine their single, highest peak torque. All subjects then completed, in a random order, 3-5 submaximal isokinetic contractions at 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% of their single, highest peak torque. Each relative contraction level (i.e., percentage) was achieved by having the subjects attempt to match the peak of their torque curve to a horizontal line on a computer monitor. Perceived exertion was measured by asking the subjects to provide a number that corresponded to the feelings in their quadriceps during exercise by viewing a modified category-ratio (CR-10) scale. The results of a two-factor (gender x intensity) analysis of variance revealed a significant, intensity main effect (F8,232 = 92.19, P < 0.001, eta 2 = 0.77, 1 - beta = 0.99) and no significant gender main effect (F8,232 = 2.66, P = 0.11, eta 2 = 0.09, 1 - beta = 0.35) or interactions (F8,232 = 1.01, P = 0.43, eta 2 = 0.04, 1 - beta = 0.46). The findings of this study demonstrate that perceived exertion is significantly (P < 0.05) different from the specific target values on the CR-10 scale at 10%, and 50-90% maximum voluntary contraction. The results revealed that the increase in perceived exertion across the contraction intensities could be fit to both linear (F1,29 = 205.41, P < 0.001, eta 2 = 0.88, 1 - beta = 0.99) and quadratic (F1,29 = 10.05, P = 0.004, eta 2 = 0.26, 1 - beta = 0.87) trends. These findings suggest that perceived exertion is underestimated during submaximal isokinetic exercise, and is not different between males and females.

Adult↗
PubMed1988

Efficiency under record performance demands: exertion control--an individual difference variable?

Semiprofessional players ran basketball circuits under either normal or record performance demands. Lactate concentration and heart rate were measured as indexes of exertion. Number of dribbling errors, attempted shots, hits, and hit rate served as measures of performance and efficiency. Several individual difference measures were taken in order to identify those athletes who were capable of moderating the extent of exertion and of preserving their performance from impairment. The indexes of exertion rose sharply from normal to record trials. Correspondingly, the numbers of dribbling errors and of shots increased while the hit rate declined. However, there were considerable individual differences in restraining exertion and preserving efficiency--both indexes of exertion control. Neither achievement motive scores nor questionnaire items that ask for self-knowledge about exertion control could account for these differences. However, individuals capable of exertion control could be discriminated by an action-control scale that asks about postdecisional implementation of action steps (Kuhl, 1985).

Achievement↗
PubMed1990

Influence of simultaneous bilateral exertion on muscle strength during voluntary submaximal isometric contraction.

The influence of simultaneous bilateral exertion on muscle strength was tested under the conditions in which the same or different levels of strength were exerted by the right and left arm (or hand). Isometric muscle strength of elbow flexion, elbow extension and hand grip was studied. Subjects voluntarily exerted 25%, 50%, and 75% of maximal strength based on their subjective judgement without the feedback of the strength actually exerted. Involuntary decrements of muscle strength were caused by the bilateral exertion. Muscle strength of both sides decreased under the condition where the same level of strength was exerted by the right and the left arm (or hand). When different levels of strength were exerted by each arm (or hand), the strength of the weaker side considerably decreased, while the strength of the stronger side did not decrease.

Adolescent↗
PubMed2002

Work-time profile, blood lactate concentration and rating of perceived exertion in the 1998 Greco-Roman Wrestling World Championship.

The aim of this study was to examine work-time profiles, blood lactate concentrations and perceived exertion among Greco-Roman wrestlers in the 1998 World Championship. Forty-two senior wrestlers from nine nations were studied in 94 matches. Each match was recorded with a video camera (Panasonic AG 455, film rate: 25 Hz) and analysed for duration of work (wrestling) and rest (interrupt) periods. Blood lactate concentration was determined with an electrochemical device (Analox P-LM5) and a rating of perceived exertion scale (Borg) was used to estimate general exertion and exertion in the extremity and trunk muscles. The mean duration of the matches was 427 s (range 324-535 s), with mean durations of work and rest of 317 and 110 s, respectively. The mean periods of work and rest were 37.2 and 13.8 s, respectively. Mean blood lactate concentration was 14.8 mmol x 1(-1) (range 6.9-20.6). The difference in mean blood lactate concentration between the first- and final-round matches was not significant (P > 0.05). Blood lactate concentration was significantly higher (P < 0.04) in matches of long duration than in those of short duration. The mean general rating of perceived exertion for all matches was 13.8 according to the scale used. Most of the wrestlers (53.3%) perceived exertion to be highest in the flexors of the forearm, followed by the deltoids (17.4%) and the biceps brachii muscles (12.0%). In addition to a relatively high rating of perceived exertion in the arm muscles, this indicates a high specific load on the flexor muscles of the forearm.

Adult↗
PubMed1994

Perception of pain and exertion during exercise on a cycle ergometer in chronic pain patients.

HYPOTHESIS: Chronic pain patients (CPP) are generally thought to present with reduced fitness in relation with pain enhancement during exercise. A distortion of exertion perception may coexist, which could lead CPP to reduce physical activities. DESIGN: Case-control study, with a nonrandomized consecutive sample that was age matched. SETTING: A Chronic Pain Unit in a Multidisciplinary Pain Center of a university hospital in a city of > 1,000,000 inhabitants. SUBJECTS: 42 CPP referred for evaluation and 34 controls (staff members and relatives). OUTCOME MEASURES: Fitness index and exertion perception index was obtained by a cycle ergometer test. Trend analysis was performed on pain scores reported on a visual analogue scale during exertion. RESULTS: Male CPP mean fitness index was found to be significantly reduced. No difference in exertion perception was found between groups. Trend analysis of reported pain revealed that 49% of CPP showed a positive trend, 5% a negative trend, and 46% showed no significant trend as exercise intensity increased. There was no significant relation between type of trend and fitness nor exertion perception index. CONCLUSIONS: Only male CPP have a reduced work capacity. Exertion perception seems normal among CPP. The possible distortion of exertion perception as a causal factor in the reduced fitness of CPP has to be rejected. Lack of significant correlation between type of trend of pain while exercising on a cycle ergometer and fitness index shows that one should be careful in proposing that reduced fitness is only related to pain enhancement during exercise in CPP.

Adult↗
PubMedDate not supplied

Self-efficacy and perceived exertion of girls during exercise.

BACKGROUND: An important national goal in Healthy People 2010 is to reduce the high prevalence of sedentary lifestyles and resultant overweight and obesity among girls. OBJECTIVES: The purpose of the present study was threefold: (a) to determine if pre-exercise self-efficacy predicted girls' perceptions of exertion during exercise, (b) to determine if these perceptions, in turn, influenced postexercise self-efficacy, and (c) to assess if exercise self-efficacy increased following completion of an exercise task. METHODS: A sample of 103 girls, 8 to 17 years of age, pedaled 20 minutes on a cycle ergometer at 60% of their predetermined peak VO2 in a climatic chamber (90 degrees F, 50% relative humidity). Ratings of perceived exertion were obtained every 4 minutes. Exercise self-efficacy was assessed before and after the exercise session. RESULTS: Controlling for peak VO2 and percent body fat, pre-exercise efficacy exerted an independent effect on perception of exertion during exercise with girls high on pre-exercise self-efficacy reporting lower perceived exertion during exercise, than girls low on self-efficacy. Both pre-exercise efficacy and perceived exertion explained postexercise efficacy. Exercise self-efficacy increased significantly from pre- to postexercise. CONCLUSIONS: Pre-exercise efficacy is an important factor influencing girls' perceptions of exertion during exercise and their postexercise efficacy. Increased exercise self-efficacy of girls following successful completion of an exercise challenge suggests possible strategies to increase physical activity.

Adolescent↗
PubMed1993

Consistency of sincere and feigned grip exertions with repeated testing.

Our purpose was to test the hypothesis that feigned exertions would show greater variability in both force and electromyograms than would sincere exertions over repeated testing sessions. Eleven normal subjects made sincere and feigned exertions while performing the five-handle position Jamar grip test. The subjects were tested 6 times in a 3- to 5-week period. Contrary to the hypothesis, feigned exertions did not show greater variability than sincere exertions. Both sincere and feigned exertions were highly consistent over the six sessions. However, the sincere and feigned exertions did differ in the patterns of force and electromyogram on the five-handle position test. These results and those of previous studies suggest that clinicians should use more than one type of test when testing suspected malingerers.

Adult↗
PubMed1990

Renal and systemic hemodynamic responses to sustained submaximal exertion in horses.

We investigated the effects of 1 h of sustained submaximal exertion on the renal and systemic hemodynamics of six horses. The horses ran on a treadmill at a speed that produced heart rates of 55-60% of each horse's maximum heart rate. Exertion produced heart rates of 121 +/- 6.6 and 126 +/- 6.1 (SE) beats/min after 15 and 60 min, respectively. Cardiac output increased significantly (P less than 0.05) from 70.1 +/- 3.1 to 246.2 +/- 4.7 ml.min-1.kg body wt-1 after 15 min of exertion and thereafter did not change. There was no significant change from rest in p-aminohippuric acid and creatinine clearances, filtration fraction, or renal blood flow during exertion. Plasma total solid concentration and hematocrit increased by 3.8 and 8.6%, respectively, between 20 and 60 min of exertion. Pulmonary artery temperature increased significantly from 37.6 degrees C at rest to 38.6 degrees C at 60 min of exertion. This study demonstrates the ability of the horse to maintain renal hemodynamics similar to resting values and systemic hemodynamics at steady-state values despite hemoconcentration and increased body temperature during sustained submaximal exertion.

Animals↗
PubMed1991

Movement and time: exertion and perceived duration.

This study examined differences in consciousness indexes (perceived duration of time) at different levels of physical exertion within the framework of Newman's model of health and with emphasis on Prigogine's theory of dissipative structures. The sample consisted of 100 volunteers participating in regular aerobic exercise. Instruments included 817E Monarch Stationary Bicycles, 1800 Dynamap Automatic Blood Pressure/Pulse Monitors, the production method of time estimation, and the Perceived Exertion Scale. Repeated measures ANOVA revealed significant differences in consciousness indexes during exertion (p less than .00001). Paired t-tests yielded significant differences between the resting consciousness index and consciousness indexes at preferred, increased, and decreased exertion levels (p = .000). Results indicate that the consciousness index decreased with physical exertion regardless of actual exertion level. In addition, changes in perceived exertion and in physiological parameters suggest a pattern of expanding consciousness that is consistent with the theoretical framework.

Adolescent↗
PubMed2003

Knee flexor torque and perceived exertion: a gender and reliability analysis.

PURPOSE: The objectives of the present study were to examine gender differences and between-day variability of isometric hamstring muscle peak torque and perceived exertion. METHODS: Subjects included 20 healthy, college-aged male (N = 10) and female (N = 10) volunteers. Each subject completed five maximal voluntary isometric hamstring muscle contractions (MVC), in a prone position, with their knee at 30 degrees flexion. Subjects then completed, in random order, isometric contractions at 10, 20, 30, 40, 50, 60, 70, 80, and 90% of their three highest averaged MVC. Perceived exertion was measured with a modified Borg CR-10 scale after each contraction. Ten randomly chosen subjects were asked to return approximately 1 wk after the initial evaluation to repeat the same procedure. Peak hamstring muscle torque was examined in absolute (N.m), relative (N.m.kg-1), and allometric-scaled (N.m.kg-n) units. Perceived exertion across the contraction intensities was modeled to a power function in order to determine the exponent and proportionality constant. RESULTS: Males generated significantly greater hamstring muscle torque than females in absolute, relative, and allometric-scaled units (P < 0.05). No significant differences in perceived exertion occurred across the submaximal contraction intensities between females and males, nor for the derived exponents and proportionality constants. Perceived exertion ratings were observed to be significantly lower (P < 0.05) across the contraction intensity range on the second day. CONCLUSIONS: The major findings demonstrated that perceived exertion did not differ between healthy young female and male adults, despite males generating significantly more hamstring muscle torque, and perceived exertion ratings decreased at similar relative contraction intensity levels across testing days.

Adult↗
PubMed1982

Regional coronary anatomy in rest angina. Comparison of patients with rest and exertional angina using quantitative coronary angiography.

To determine if patients with rest angina have more severe regional ischemia than patients with exertional angina, we compared the severity of left coronary artery (LCA) stenosis in 29 patients with transient anterior ischemic ST-T changes at rest, and 30 patients with anterior ST changes only during exertion. The percentage diameter stenosis was measured with Vernier calipers as (2 x lesion diameter x 100 percent)/(prestenotic + poststenotic diameter). There was no difference between the two groups in the mean diameter stenosis of unoccluded LCA vessels either when all vessels were compared (rest: 69 +/- 12 percent; exertional: 70 +/- 13 percent [p = NS]) or when only the maximal stenosis in each patient was compared (rest: 74 +/- 10 percent; exertional: 75 +/- 12 percent [p = NS]). Total occlusion of at least one major vessel of the LCA also occurred with similar frequency in patients with rest (6/29) and exertional (12/30) angina (p = NS). However, collateral development distal to 76-100 percent LCA lesions was significantly less frequent in rest angina (4/21 vessels [19 percent]) than in exertional angina (21/30 vessels [70 percent]), (p less than .03). We conclude that patients with rest angina do not have more severe coronary stenosis than patients with exertional angina, but frequently may have more severe regional ischemia due to reduced collaterization of jeopardized myocardium.

Aged↗
PubMed2000

Ability to coordinate exertion of force by the dominant hand: comparisons among university students and 65- to 78-year-old men and women.

The purposes of this study were to examine the characteristics of ability to coordinate exertion of force in 60 healthy older people (30 men, 30 women) from the viewpoint of sex differences and to compare their performance with those of 60 healthy university students (30 men, 30 women). The test of ability to coordinate exertion of force was conducted by having the subject fit the exertion value of grip strength to a changing demand value appearing on the display of a personal computer (using a bar chart-description form). The changes in the demand value were tracked. The variable estimating ability to coordinate exertion of force was the total sum of the differences between demand and the produced grip strength induced by time lapses. The ability to coordinate exertion of force in the older subjects was inferior to that of the younger subjects, and large individual differences were observed. Unlike the younger subjects, the means of the ability to coordinate exertion of force of the older subjects significantly decreased between trials. The ability to coordinate exertion of force of the older women was significantly inferior to that of the older men, but the means of the measurements among three trials shows a similar tendency to decrease in both sexes.

Adolescent↗
PubMed2004

Perceived exertion during resistance exercise by children.

This pilot study examined the validity of a new scale of perceived exertion during acute bouts of resistance exercise in young children. The researchers developed an 11-point numerical scale with five pictures representing youths at various levels of exertion while lifting weights. 26 children (M age 10.1 +/- 1.2 yr.) performed one set of 10 repetitions at 35%, 55%, and 75% of their one-repetition maximum on the chest press and leg press exercises using child-size weight training machines. Scaling procedures for the perceptual anchors on the perceived exertion scale were based on one repetition maximum testing. Children could use this scale to translate into numbers their perceptions of physical exertion during upper and lower body resistance exercise. Perceived exertion distributed as a positive linear function of the percent of one repetition maximum on the chest press and leg press exercises (rs = .70 to .77), and perceived exertion increased significantly across all three exercise intensities on both exercises. These preliminary findings provide partial evidence for validation when this scale was used during resistance exercise with children. Additional validation regarding perceived exertion during resistance exercise with children is warranted.

Child↗