School of Human Movement Studies Publications - UQ eSpace

Abdominal palpation haptic device for colonoscopy simulation using pneumatic control

2012-06-25T09:54:41Z

In this paper, we describe the development of a haptic device to be used in a simulator aiming to train the skills of gastroenterology assistants in abdominal palpation during colonoscopy, as well as to train team interaction skills for the colonoscopy team. To understand the haptic feedback forces to be simulated by the haptic device, we conducted an experiment with five participants of varying BMI. The applied forces and displacements were measured and hysteresis modeling was used to characterize the experimental data. These models were used to determine the haptic feedback forces required to simulate a BMI case in response to the real-time user interactions. The pneumatic haptic device consisted of a sphygmomanometer bladder as the haptic interface and a fuzzy controller to regulate the bladder pressure. The haptic device showed good steady state and dynamic response was adequate for simulating haptic interactions. Tracking accuracy averaged 94.2 percent within 300 ms of the reference input while the user was actively applying abdominal palpation and minor repositioning.

A best practice dietetic service for rural patients with cancer undergoing chemotherapy: A pilot of a pseudo-randomised controlled trial

2010-02-23T00:00:00Z

Ability as an exclusionary concept in youth sport

Hay, Peter J. — 2012-09-08T21:08:14Z

In this chapter I will offer a socially critical explanation of two key ways in which the concept or notion of ability can influence the engagement and progress of children and young people in sport. In the first instance I will focus on the exclusionary consequences of common and prevailing understandings of ability and their notable influence in numerous talent identification processes. Second, I will offer an alternative social construction conception of ability to demonstrate the arbitrary nature of ability and its potential for influencing the inclusion and exclusion of young people in a movement culture such as sport.

A birth-weight questionnaire indicated that life style modifies the birth weight and metabolic syndrome relationship at age 36

2009-04-02T00:00:00Z

Able athletes with disabilities: Issues and group work

Hanrahan, S.J. — 2007-08-14T00:00:00Z

Abnormal tenocyte morphology is more prevalent than collagen disruption in asymptomatic athletes' patellar tendons

2009-03-10T00:00:00Z

This study investigated the prevalence of each of the four features of patellar tendinosis in asymptomatic athletic subjects undergoing patellar tendon anterior cruciate ligament (ACL) reconstruction. Fifty subjects (39 males and 11 females) undergoing ACL reconstruction using a patellar tendon graft were screened for previous tendon symptoms, training and playing history and had their patellar tendons examined with ultrasound prior to surgery. During surgery, a small piece of proximal posterocentral tendon was harvested, fixed and examined under light microscopy. Histopathological changes were graded for severity. Results demonstrate that 18 tendons were abnormal on light microscopy and 32 were normal. There were no differences between subjects with and without pathology in respect of training, recovery after surgery and basic anthropometric measures. Three tendons were abnormal on ultrasound but only one had proximal and central changes. Tendons showed a consistent series of changes. Tenocyte changes were found in all but one of the abnormal tendons. In all but one of the tendons with increased ground substance there were tenocyte changes, and collagen separation was always associated with both tenocyte changes and increased ground substance. No tendons demonstrated neovascularization. It appears that cellular changes must be present if there is an increase in ground substance, or collagen and vascular changes. Further research is required to confirm these findings. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved

A brief educational intervention using acceptance and commitment therapy: Four injured athletes' experiences

Mahoney, John og Hanrahan, Stephanie J. — 2011-10-18T00:00:00Z

The purpose of this study was to research the experiences of four injured athletes during their rehabilitation from ACL injuries and to examine the potential usefulness of an adapted ACT intervention in addressing individuals' adherence to rehabilitation protocols and their general psychological well-being. We investigated the usefulness of a brief, 4-session ACT program adapted for educational purposes and presented data as case studies. The case studies suggested that (a) the injured athletes experienced a multitude of private events immediately following injury, throughout their recovery, and when approaching a full return to sport; (b) the injured athletes typically avoided these private events and engaged in emotion-driven behaviors; (c) an adapted ACT approach for educational purposes could be useful on at least a basic level to help injured athletes accept private events, commit to rehabilitation behaviors, and have some certainty about returning to sport; and (d) more could be done to address the needs of injured athletes beyond the structure of our 4-session educational intervention. We concluded that the ACT-based intervention, to a certain extent, educated injured athletes about how to meet the challenges of their recoveries and how to commit to their rehabilitations, as well as to exhibit behaviors that would potentially permit their successful reentries to sport.

A brief on school-linked mental health services

Lawson, H. — 2009-03-09T00:00:00Z

Absence of an increase in the soleus H-reflex with increasing voluntary drive during shortening contractions in man

Oya, T. og Cresswell, A — 2007-08-23T00:00:00Z

Absence of cross-limb transfer of performance gains following ballistic motor practice in older adults

2011-02-20T00:00:00Z

The phenomenon of crosslimb transfer, in which unilateral strength training can result in bilateral strength gains, has recently been tested for ballistic movements. Performance gains associated with repetitive motor practice, and the associated transfer, occur within a few minutes. In this study, young and older adults were trained to perform ballistic abductions of their dominant (right) index finger as quickly as possible. Performance was assessed bilaterally before, during, and after this training. Both groups exhibited large performance gains in the right hand as a result of training (P < 0.001; young 84% improvement, older 70% improvement), which were not significantly different between groups (P < 0.40). Transcranial magnetic stimulation revealed that the performance improvements were accompanied by increases in excitability, together with decreases in intracortical inhibition, of the projections to both the trained muscle and the homologous muscle in the contralateral limb (P < 0.05). The young group also exhibited performance improvements as a result of cross-limb transfer in the left (untrained) hand (P < 0.005), equivalent to 75% of the performance increase in the trained hand. In contrast, there were no significant performance gains in the left hand for the older group (P = 0.23). This was surprising given that the older group exhibited a significantly greater degree of mirror activity than the young group (P < 0.01) in the left first dorsal interosseus muscle (FDI) during right hand movements. Our findings suggest that older adults exhibit a reduced capacity for cross-limb transfer, which may have implications for motor rehabilitation programs after stroke. Copyright © 2011 the American Physiological Society.

Absorption and pharmacokinetics of bilirubin and biliverdin administration in the rat

2009-10-21T00:00:00Z

Abstract motor programming in prehension: Normal and pathological performance

Tresilian, J. R. — 2008-06-10T00:00:00Z

A carbohydrate-restricted diet during resistance training promotes more favorable changes in body composition and markers of health in obese women with and without insulin resistance

2011-09-25T00:00:00Z

A case for intervention? Physical activity behaviour in an urban sample of middle-to-high income Northeast Mexicans

Gilson, N. D. — 2009-02-19T00:00:00Z

Gilson evaluates the need for physical activity (PA) intervention in a select group of urban, middle-to-high income men and women from the Northeast of Mexico. This was undertaken by assessing the extent to which the sample fulfilled contemporary PA criteria. Results show that all subjects reported an income greater than 5 times the national minimum, classifying the sample within the middle-to-high socio-economic cohort of Mexico.

Accelerometer Data Reduction: A Comparison of Four Reduction Algorithms on Select Outcome Variables

2009-03-10T00:00:00Z

Purpose: Accelerometers are recognized as a valid and objective tool to assess free-living physical activity. Despite the widespread use of accelerometers, there is no standardized way to process and summarize data from them, which limits our ability to compare results across studies. This paper a) reviews decision rules researchers have used in the past, b) compares the impact of using different decision rules on a common data set, and c) identifies issues to consider for accelerometer data reduction. Methods: The methods sections of studies published in 2003 and 2004 were reviewed to determine what decision rules previous researchers have used to identify wearing period, minimal wear requirement for a valid day, spurious data, number of days used to calculate the outcome variables, and extract bouts of moderate to vigorous physical activity (MVPA). For this study, four data reduction algorithms that employ different decision rules were used to analyze the same data set. Results: The review showed that among studies that reported their decision rules, much variability was observed. Overall, the analyses suggested that using different algorithms impacted several important outcome variables. The most stringent algorithm yielded significantly lower wearing time, the lowest activity counts per minute and counts per day, and fewer minutes of MVPA per day. An exploratory sensitivity analysis revealed that the most stringent inclusion criterion had an impact on sample size and wearing time, which in turn affected many outcome variables. Conclusions: These findings suggest that the decision rules employed to process accelerometer data have a significant impact on important outcome variables. Until guidelines are developed, it will remain difficult to compare findings across studies.

Acceptance as a Process Variable in Relation to Catastrophizing in Multidisciplinary Pain Treatment

2013-01-08T15:34:53Z

Access to physical activity: The stories of six young women negotiating a physically active lifestyle

Hunt, K. B. og Lee, J. T. og Macdonald, D. — 2007-08-24T00:00:00Z

Accumulating Brisk Walking for Fitness, Cardiovascular Risk, and Psychological Health

2009-03-03T00:00:00Z

MURPHY, M., A. NEVILL, C. NEVILLE, S. BIDDLE, and A. HARDMAN. Accumulating brisk walking for fitness, cardiovascular risk, and psychological health. Med. Sci. Sports Exerc., Vol. 34, No. 9, pp. 1468–1474, 2002. Purpose: To compare the effects of different patterns of regular brisk walking on fitness, risk factors for cardiovascular disease, and psychological well-being in previously sedentary adults. Methods: Twenty-one subjects (14 women), aged 44.5 ± 6.1 yr (mean ± SD) were randomly assigned to two different, 6-wk programs of brisk walking in a cross-over design, with an interval of 2 wk. One program comprised one 30-min walk per day, 5 d·wk-1 (long bout) and the other three 10-min walks per day, also 5 d·wk-1 (short bouts). All walking was at 70–80% of predicted maximal heart rate. Maximal oxygen uptake ([latin capital V with dot above]O2max), body composition, resting arterial blood pressure, fasting plasma lipoprotein variables, and psychological parameters were assessed before and after each program. Results: Overall, subjects completed 88.2 ± 1.1% and 91.3 ± 4.1% of prescribed total walking time in the short- and long-bout programs, respectively. Both programs increased plasma concentrations of high-density lipoprotein cholesterol, and decreased concentrations of triacylglycerol and total cholesterol (all P < 0.05). There were no changes in body mass, but the sum of four skinfolds, waist circumference, and hip circumference were decreased after both walking programs (all P < 0.05). Predicted [latin capital V with dot above]O2max increased with both programs (P < 0.05), but this increase was greater with the program based on short bouts (P < 0.05). Both walking patterns resulted in similar decreases in tension/anxiety (P < 0.05). Conclusion: These findings suggest that three short bouts (10 min) of brisk walking accumulated throughout the day are at least as effective as one continuous bout of equal total duration in reducing cardiovascular risk and improving aspects of mood in previously sedentary individuals.

Accuracy of body mass index estimated from self-reported height and weight in mid-aged Australian women

2010-11-07T00:00:00Z

Accuracy of DXA scanning of the thoracic spine: cadaveric studies comparing BMC, areal BMD and geometric estimates of volumetric BMD against ash weight and CT measures of bone volume

2009-03-10T00:00:00Z

Biomechanical studies of the thoracic spine often scan cadaveric segments by dual energy X-ray absorptiometry (DXA) to obtain measures of bone mass. Only one study has reported the accuracy of lateral scans of thoracic vertebral bodies. The accuracy of DXA scans of thoracic spine segments and of anterior-posterior (AP) thoracic scans has not been investigated. We have examined the accuracy of AP and lateral thoracic DXA scans by comparison with ash weight, the gold-standard for measuring bone mineral content (BMC). We have also compared three methods of estimating volumetric bone mineral density (vBMD) with a novel standard–ash weight (g)/bone volume (cm3) as measured by computed tomography (CT). Twelve T5–T8 spine segments were scanned with DXA (AP and lateral) and CT. The T6 vertebrae were excised, the posterior elements removed and then the vertebral bodies were ashed in a muffle furnace. We proposed a new method of estimating vBMD and compared it with two previously published methods. BMC values from lateral DXA scans displayed the strongest correlation with ash weight (r=0.99) and were on average 12.8% higher (p<0.001). As expected, BMC (AP or lateral) was more strongly correlated with ash weight than areal bone mineral density (aBMD; AP: r=0.54, or lateral: r=0.71) or estimated vBMD. Estimates of vBMD with either of the three methods were strongly and similarly correlated with volumetric BMD calculated by dividing ash weight by CT-derived volume. These data suggest that readily available DXA scanning is an appropriate surrogate measure for thoracic spine bone mineral and that the lateral scan might be the scan method of choice.

Accuracy of pQCT for evaluating the aged human radius: an ashing, histomorphometry and failure load investigation

2009-03-13T00:00:00Z

Introduction: Quantifying the determinants of bone strength is essential to understanding if or how the structure will fail under load. Determining failure requires knowledge of material and geometric properties. However, characterizing the relative contributions of geometric parameters of bone to overall bone strength has been difficult to date because of limitations in imaging technology. Peripheral quantitative computed tomography (pQCT) uses digital images to derive estimates of bone strength in the peripheral skeleton and is a relatively safe technique to differentiate cortical from trabecular bone and assess bone geometry and density. However, in a compromised osteoporotic bone, thin cortices and low scan resolution can limit accurate analysis. Methods: Therefore, in this two-part investigation we scanned ten pairs (n=20) of fresh-frozen radial specimens [female, mean (SD) age 79(6) years] using pQCT (XCT 2000) at the 4 and 30% sites of the distal radius. We investigated the accuracy of four different acquisition resolutions (200, 300, 400, 500 μm) and several analysis modes and thresholds. We evaluated (1) the accuracy of the Norland/Stratec XCT 2000 pQCT in assessing low-density bones by comparing pQCT outcomes to ashing and histomorphometry and (2) the association of geometric parameters by pQCT and areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) to failure load at the distal radius. Results: Using histomorphometry and ashing as reference standards, we found that pQCT scans varied systematically and underestimated or overestimated total area and mineral content at the radial midshaft depending on the analysis algorithm and selected threshold. Overall, most pQCT analysis modes were accurate. In the mechanical testing studies, bone mineral content and cortical bone content at the midshaft were strongly associated with failure load. The pQCT parameters that best accounted for failure load were total content at the 4% site and cortical thickness at the 30% site and they accounted for up to 81% of the variance. The best DXA predictor of failure load was total density at the distal third site and it explained 75% of the variance. Conclusions: In summary, analysis mode, resolution and thresholding affected pQCT outputs at the radial midshaft. This study extends our understanding of pQCT analysis and provides important data regarding determinants of bone strength at the distal radius

Accuracy of self-reported body weight, height and waist circumference in a Dutch overweight working population

2010-04-01T00:00:00Z

Accuracy of SRM and power tap power monitoring systems for bicycling

2007-08-15T00:00:00Z

Purpose: Although manufacturers of bicycle power monitoring devices SRM and Power Tap (PT) claim accuracy to within 2.5%, there are limited scientific data available in support. The purpose of this investigation was to assess the accuracy of SRM and PT under different conditions. Methods: First, 19 SRM were calibrated, raced for 11 months, and retested using a dynamic CALRIG (50-1000 W at 100 rpm). Second, using the same procedure, five PT were repeat tested on alternate days. Third, the most accurate SRM and PT were tested for the influence of cadence (60, 80, 100, 120 rpm), temperature (8 and 21degreesC) and time (1 h at similar to300 W) on accuracy. Finally, the same SRM and PT were downloaded and compared after random cadence and gear surges using the CALRIG and on a training ride. Results: The mean error scores for SRM and PT factory calibration over a range of 50-1000 W were 2.3 +/- 4.9% and -2.5 +/- 0.5%, respectively. A second set of trials provided stable results for 15 calibrated SRM after 11 months (-0.8 +/- 1.7%), and follow-up testing of all PT units confirmed these findings (-2.7 +/- 0.1%). Accuracy for SRM and PT was not largely influenced by time and cadence; however. power output readings were noticeably influenced by temperature (5.2% for SRM and 8.4% for PT). During field trials, SRM average and max power were 4.8% and 7.3% lower, respectively, compared with PT. Conclusions: When operated according to manufacturers instructions, both SRM and PT offer the coach, athlete, and sport scientist the ability to accurately monitor power output in the lab and the field. Calibration procedures matching performance tests (duration, power, cadence, and temperature) are, however, advised as the error associated with each unit may vary.

Accuracy of weight status perception in contemporary Australian children and adolescents

2010-07-04T00:00:00Z

Achievement goal orientations, attributional style, and motivational climate as predictors of performance and persistance

Hanrahan, S.J. og Cerin, E. og Hartel, C. — 2007-08-24T00:00:00Z

Achievement Goal Profiles in School Physical Education: Differences in Self-determination, Sport Ability Beliefs, and Physical Activity

2009-02-27T00:00:00Z

Background: Physical activity is a major public health issue as trends show inadequate levels of physical activity for health and rising levels of obesity. Understanding motivation for physical activity in youth by assessing their motivational profiles associated with school physical education could inform future interventions. Aims: To investigate goal orientation and perceived competence profiles in young adolescents and to test the nature of differences between clusters on motivational and physical activity measures. Sample: Boys (N = 427) and girls (N = 391), aged 11-14 years, from two comprehensive schools in England. Method: Cross-sectional survey using cluster analysis. Results: Clusters reflecting 'highly', 'moderately', and 'lowly' motivated youth were found. Physical activity, incremental sport ability beliefs, and self-determined motivation were highest in the highly motivated cluster. Girls were under-represented in this cluster. Conclusions: High motivation towards physical activity is characterised by high task and high ego orientation, and high perceived competence. With only 38% of this group being girls, interventions are required to boost motivation for girls based on goal and self-determination approaches

Achieving salt restriction in chronic kidney disease

2013-02-12T12:20:32Z

There is consistent evidence linking excessive dietary sodium intake to risk factors for cardiovascular disease and chronic kidney disease (CKD) progression in CKD patients; however, additional research is needed. In research trials and clinical practice, implementing and monitoring sodium intake present significant challenges. Epidemiological studies have shown that sodium intake remains high, and intervention studies have reported varied success with participant adherence to a sodium-restricted diet. Examining barriers to sodium restriction, as well as factors that predict adherence to a low sodium diet, can aid researchers and clinicians in implementing a sodium-restricted diet. In this paper, we critically review methods for measuring sodium intake with a specific focus on CKD patients, appraise dietary adherence, and factors that have optimized sodium restriction in key research trials and discuss barriers to sodium restriction and factors that must be considered when recommending a sodium-restricted diet.

Achilles tendon disorders: Etiology and epidemiology

2010-03-23T00:00:00Z

The Achilles tendon is the strongest tendon in the human body. Because most Achilles tendon injuries take place in sports and there has been a general increase in popularity of sporting activities, the number and incidence of the Achilles tendon overuse injuries and complete, spontaneous ruptures has increased in the industrialized countries during the last decades. The most common clinical diagnosis of Achilles overuse injuries is tendinopathy. The basic etiology of the Achilles tendinopathy is known to be multi-factorial. Although histopathologic studies have shown that ruptured Achilles tendons have clear degenerative changes before the rupture, many Achilles tendon ruptures take place suddenly without any preceding signs or symptoms.

A circle is a wheel is a circle

Minniti, A. M. — 2008-06-10T00:00:00Z

A collaborative approach to cervical cancer screening

Brown, W.J. og Byles, J.E. — 2011-01-11T00:00:00Z

A colonoscopy competency framework derived from task analysis

2009-12-08T00:00:00Z

A colonoscopy competency framework derived from task analysis

2009-12-13T00:00:00Z

A community-based fitness and mobility exercise program for older adults with chronic stroke: A randomized, controlled trial

2009-03-10T00:00:00Z

A comparison of lactate kinetics, minute ventilation and acid-base balance as measures of the anaerobic threshold

2011-03-09T00:00:00Z

A comparison of maximal bioenergetic enzyme activities obtained with commonly used homogenization techniques

2011-03-09T00:00:00Z

A comparison of muscle damage and systematic inflammatory responses to submaximal versus maximal eccentric exercise

2007-08-23T00:00:00Z

A comparison of muscle damage and systemic inflammatory responses to submaximal versus maximal eccentric exercise

2007-08-23T00:00:00Z

A comparison of peak power in the shoulder press and shoulder throw

2007-08-14T00:00:00Z

The ability to generate peak power is central for performance in many sports. Currently two distinct resistance training methods are used to develop peak power, the heavy weight/slow velocity and light weight/fast velocity regimes. When using the light weight/fast velocity power training method it was proposed that peak power would be greater in a shoulder throw exercise compared with a normal shoulder press. Nine males performed three lifts in the shoulder press and shoulder throw at 30% and 40% of their one repetition maximum (1RM). These lifts were performed identically, except for the release of the bar in the throw condition. A potentiometer attached to the bar measured displacement and duration of the lifts. The time of bar release in the shoulder throw was determined with a pressure switch. ANOVA was used to examine statistically significant differences where the level of acceptance was set at p <0.05. Peak power was found to be significantly greater in the shoulder throw at 30% of 1 RM condition [F, (1, 23) =2.325 p <0.05) and at 40% of 1 RM [F, (1, 23) =2.905 p <0.05) compared to values recorded for the respective shoulder presses. Peak power was also greater in the 30% of 1 RM shoulder throw (510 +/- 103W) than in the 40% of 1 RM shoulder press (471 +/- 96W). Peak power was produced significantly later in the shoulder throw versus the shoulder press. This differing power reflected a greater bar velocity of the shoulder throw at both assigned weights compared with the shoulder press.

A comparison of physical activity context preferences between adults with psychological distress and those without

Burton, N. og Khan, A. og Brown, W. — 2013-03-03T11:41:57Z

A comparison of physiological and anthropometric characteristics among playing positions in junior rugby league players

Gabbett, T. J. — 2010-03-19T00:00:00Z

A comparison of physiological and anthropometric characteristics among playing positions in sub-elite rugby league players

Gabbett, Tim J. — 2010-03-22T00:00:00Z

This study compared the physiological and anthropometric characteristics of specific playing positions and positional playing groups in sub-elite rugby league players. Altogether, 415 sub-elite rugby league players underwent measurements of standard anthropometry (body mass, height, sum of four skinfolds), muscular power (vertical jump), speed (10-m, 20-m, and 40-m sprint), agility (“L” run), and estimated maximal aerobic power (multi-stage fitness test). Props were significantly heavier and had a greater skinfold thickness than all other playing positions. Centres, fullbacks, and hookers were faster than props over 40 m. When the data were analysed according to positional commonality, props were taller, heavier, had a greater skinfold thickness, were less agile, and were slower over 10 m than all other positional groups. The hookers/halves and outside backs positional groups were significantly faster over 40 m than the backrowers and props positional groups. In addition, the hookers/halves and outside backs positional groups had significantly greater estimated maximal aerobic power than the props positional group. The results of this study demonstrate that few physiological and anthropometric differences exist among individual playing positions in sub-elite rugby league players, although props are taller, heavier, have greater skinfold thickness, slower 10-m and 40-m speed, less agility, and lower estimated maximal aerobic power than other positional groups. These findings provide normative data for sub-elite rugby league players competing in specific individual positions and positional playing groups.

A comparison of posture and muscle activity during tablet computer, desktop computer and paper use by young children

2009-03-05T00:00:00Z

A comparison of the clinical, histopathologic, and ultrastructural phenotypes in carriers of X-linked and autosomal recessive Alport's syndrome

2011-03-09T00:00:00Z

Previous series that described phenotypes in carriers of Alport's syndrome did not distinguish genetically between carriers of X-linked and autosomal recessive disease. In this study, modes of inheritance in unselected families with Alport's syndrome associated with two city and two provincial hospitals were determined using microsatellite markers, and carriers of disease haplotypes were identified within these families. All 47 carriers (100%) from 18 families with X-linked Alport's syndrome had dysmorphic hematuria on phase-contrast microscopy, but few developed renal failure (3 of 40 carriers; 8%), clinical hearing loss (2 of 45 carriers; 4%), retinopathy (1 of 30 carriers; 3%), or lenticonus (0 of 30 carriers; 0%). Eleven of the 14 carriers (79%) from 2 families with autosomal recessive disease had dysmorphic hematuria, but none had renal failure, clinical hearing loss, retinopathy, or lenticonus. Urinary red blood cell counts in carriers of X-linked Alport's syndrome were greater than those in carriers of autosomal recessive disease (P < 0.0001), but the frequency of proteinuria and hypertension and levels of protelnuria were not different. There was more tubulointerstitial damage in carriers of X-linked disease (P = 0.012); however, carriers of autosomal recessive disease had more widespread and more uniform thinning of the glomerular basement membrane (P < 0.0001) and less lamellation (P < 0.04).

A comparison of the cycling performance of cyclists and triathletes

2007-08-15T00:00:00Z

The aim of this study was to compare the cycling performance of cyclists and triathletes. Each week for 3 weeks, and on different days, 25 highly trained male cyclists and 18 highly trained male triathletes performed: (1) an incremental exercise test on a cycle ergometer for the determination of peak oxygen consumption ((V) over dot O-2peak), peak power output and the first and second ventilatory thresholds, followed 15 min later by a sprint to volitional fatigue at 150% of peak power output; (2) a cycle to exhaustion test at the (V) over dot O-2peak power output; and (3) a 40-km cycle time-trial. There were no differences in (V) over dot O-2peak, peak power output, time to volitional fatigue at 150% of peak power output or time to exhaustion at (V) over dot O-2peak power output between the two groups. However, the cyclists had a significantly faster time to complete the 40-km time-trial (56:18 +/- 2:31 min:s; mean +/- s) than the triathletes (58:57 +/- 3:06 min:s; P < 0.01), which could be partially explained (r = 0.34-0.51; P < 0.05) by a significantly higher first (3.32 +/- 0.36 vs 3.08 +/- 0.36 l . min(-1)) and second ventilatory threshold (4.05 +/- 0.36 vs 3.81 +/- 0.29 l . min(-1); both P < 0.05) in the cyclists compared with the triathletes. In conclusion, cyclists may be able to perform better than triathletes in cycling time-trial events because they have higher first and second ventilatory thresholds.

A comparison of the effects of fatigue on subjective and objective assessment of situation awareness in cycling

Knez, Wade L. og Ham, Daniel J. — 2010-03-31T00:00:00Z

Maximal effort on a 30 km Time Trial (TT30) was examined to assess whether it would elicit changes in objective and subjective tests of the participants’ perception of the environment and their ability to anticipate future occurrences (situation awareness; SA) and to determine the effect of post-exercise recovery on SA. Nine experienced (5.22 ± 2.77 years) road cyclists had their objective and subjective levels of SA assessed prior to and at the completion of two TT30. The participants’ results were compared to measurements of maximal oxygen uptake (VO2max), peak power output (PPO), age and years of competitive cycle racing experience. Fatigue resulting from maximal effort on a TT30 produced significant changes in both the objective and subjective test of SA. Effect sizes of 0.93 and 0.99 indicated that the first and second TT30 were likely or almost certain to have a beneficial effect on the objective assessment of SA. However, the effect sizes of 0.97 and 0.95 relating to the subjective assessment of cognitive performance on the first and second TT30 showed that it was very likely the participants’ had an increased difficulty in maintaining SA. A recovery period of up to three minutes post TT30 had no effect on SA. Changes in SA had no relationship with measurements of VO2max, peak power output (PPO), age and years of competitive cycle racing experience. The findings suggest that within a laboratory environment, participants consistently underestimate their ability to make accurate assessments of their cycling environment compared to objective measures of their SA.

A comparison of the physiological demands of well-trained cyclists to field and laboratory mountain bike race simulation

2009-03-04T00:00:00Z

A comparison of two Hill-type skeletal muscle models on the construction of medial gastrocnemius length-tension curves in humans in vivo

2012-08-03T19:10:04Z

A comparison of two methods for the calculation of accumulated oxygen deficit

2007-08-15T00:00:00Z

The aim of this study was to compare accumulated oxygen deficit data derived using two different exercise protocols with the aim of producing a less time-consuming test specifically for use with athletes. Six road and four track male endurance cyclists performed two series of cycle ergometer tests. The first series involved five 10 min sub-maximal cycle exercise bouts, a (V) over dotO(2peak) test and a 115% (V) over dotO(2peak) test. Data from these tests were used to estimate the accumulated oxygen deficit according to the calculations of Medbo et al. (1988). In the second series of tests, participants performed a 15 min incremental cycle ergometer test followed, 2 min later, by a 2 min variable resistance test in which they completed as much work as possible while pedalling at a constant rate. Analysis revealed that the accumulated oxygen deficit calculated from the first series of tests was higher (P< 0.02) than that calculated from the second series: 52.3 +/- 11.7 and 43.9 +/- 6.4 ml . kg(-1), respectively (mean +/- s). Other significant differences between the two protocols were observed for (V) over dot O-2peak, total work and maximal heart rate; all were higher during the modified protocol (P<0.01 and P< 0.02, respectively). Oxygen kinetics were also significantly faster during the modified 2 min maximal test. We conclude that the difference in accumulated oxygen deficit between protocols was probably due to a reduced oxygen uptake, possibly caused by a slower oxygen on-response during the 115% (V) over dot O-2peak test in the first series, and (V) over dot O-2-power output regression differences caused by an elevated (V) over dot O-2 during the early stages of the second series.

A comparison of two prosthetic feet on the multi-joint and multi-plane kinetic gait compensations in individuals with a unilateral trans-tibial amputation

2011-09-11T00:00:00Z

A Complex Partnership to Optimize and Stabilize the Public Child Welfare Workforce

2009-03-06T00:00:00Z

This article introduces a complex partnership developed in a Northeastern state. Its aim is to optimize and stabilize the public child welfare workforce and thereby improve outcomes for clients as well as results for country and borough agencies. To achieve this aim, this partnership has implemented a comprehensive, multi‐faceted strategy. Intermediaries play pivotal roles in this partnership system. Originating with a focus on social work education, this partnership quickly focused on research. Participatory workforce research aimed at understanding turnover led to a hybrid, complex intervention involving team‐driven articipatory action research and learning in local agencies. These design teams, facilitated by social workers, connect professional development and organizational development to retention planning and ultimately, to workforce optimization initiatives. (Author abstract)