Reducing the immediate availability of red blood cells in cardiac surgery, a single-centre experience.

BACKGROUND: In our institution, we have redefined our criteria for direct availability of red blood cell (RBC) units in the operation room. In this study, we sought to evaluate the safety of applying this new logistical policy of blood transfusion in the first preliminary group of patients. METHODS: In March 2010, we started a new policy concerning the elective availability of RBC units in the operation room. This policy was called: No Elective Red Cells (NERC) program. The program was applied for patients undergoing primary isolated coronary artery bypass grafting (CABG) or single valve surgery. No elective RBC units were preoperatively ordered for these patients. In case of urgent need, blood was delivered to the operating room within 20 min. The present study includes the first 500 patients who were managed according to this policy. Logistic regression analyses were performed to investigate the impact of biomedical variables on fulfilling this NERC program. RESULTS: The majority of patients (n = 409, 81 %) did not receive any RBCs during the hospital stay. In patients who did receive RBCs (n = 91, 19 %), 11 patients (2.2 %) received RBCs after 24 h postoperatively. Female gender, left ventricular ejection fraction (LVEF) and EuroSCORE were significant predictors for the need of blood transfusion (OR = 3.12; 2.79; 1.17 respectively). CONCLUSION: In a selected group of patients, it is safe to perform cardiac surgery without the immediate availability of RBCs in the operating room. Transfusion was avoided in 81 % of these patients. Female gender, LVEF and EuroSCORE were associated with blood transfusion.

Avian Aspergillus fumigatus strains resistant to both itraconazole and voriconazole.

The in vitro susceptibilities of 59 avian Aspergillus fumigatus strains to amphotericin B, itraconazole, and voriconazole were determined using the standard microdilution broth method (CLSI M38-A2). Four isolates showed acquired resistance to itraconazole and voriconazole, harboring implications for the treatment of aspergillosis in both birds and humans.

Trichome dynamics and artemisinin accumulation during development and senescence of Artemisia annua leaves.

Artemisinin is a sesquiterpene lactone endoperoxide and an important antimalarial drug produced in Artemisia annua. To unravel the diverse processes determining artemisinin yield in A. annua crops, artemisinin accumulation during the development of individual leaves was studied in two field experiments. During the life cycle of a leaf, artemisinin was always present. Quantities were low at leaf appearance and increased steadily. In leaves studied until after senescence, maximum quantities and concentrations were achieved after the leaf had turned brown. The total quantity of possible artemisinin precursors per leaf (dihydroartemisinic acid and other upstream precursors) was highest early in the leaf cycle when the leaf was still expanding. Dihydroartemisinic acid was more abundant than the other compounds and its quantity declined during leaf development whereas that of artemisinin increased. Dihydroartemisinic acid was not converted directly into artemisinin, because on a per leaf basis the decline in molar quantity of precursors in the earliest formed leaves was not compensated for by a simultaneous increase in artemisinin. Our results suggest that a (putative) intermediate such as dihydroartemisinic acid hydroperoxide temporarily may have accumulated in considerable quantities. The number of mature, capitate trichomes on the adaxial leaf side increased after leaf appearance until the end of leaf expansion, and then decreased, probably due to collapse of trichomes. Artemisinin production thus (also) occurred when trichomes were collapsing. Later formed leaves achieved higher concentrations of artemisinin than earlier formed leaves, because of a higher trichome density and a higher capacity per trichome.

Identification of intermediates and enzymes involved in the early steps of artemisinin biosynthesis in Artemisia annua.

An important group of antimalarial drugs consists of the endoperoxide sesquiterpene lactone artemisinin and its derivatives. Only little is known about the biosynthesis of artemisinin in Artemisia annua L., particularly about the early enzymatic steps between amorpha-4,11-diene and dihydroartemisinic acid. Analyses of the terpenoids from A. annua leaves and gland secretory cells revealed the presence of the oxygenated amorpha-4,11-diene derivatives artemisinic alcohol, dihydroartemisinic alcohol, artemisinic aldehyde, dihydroartemisinic aldehyde and dihydroartemisinic acid. We also demonstrated the presence of a number of biosynthetic enzymes such as the amorpha-4,11-diene synthase and the--so far unknown--amorpha-4,11-diene hydroxylase as well as artemisinic alcohol and dihydroartemisinic aldehyde dehydrogenase activities in both leaves and glandular trichomes. From these results, we hypothesise that the early steps in artemisinin biosynthesis involve amorpha-4,11-diene hydroxylation to artemisinic alcohol, followed by oxidation to artemisinic aldehyde, reduction of the C11-C13 double bond to dihydroartemisinic aldehyde and oxidation to dihydroartemisinic acid.

Effects of stage duration in incremental running tests on physiological variables.

To study the effect of stage duration on some physiological variables in an incremental running test, 8 well-trained runners underwent 3 running tests, with stage durations of 1, 3 and 6 min. To study maximal lactate steady state (maxLASS) and its corresponding speed, every subject underwent a 4th test with three 15-min stages at three speeds, based on the running speed at 4 mmol/l blood lactate (V4) in the 6 min per stage protocol. The first load in the 15 min per stage test was V4 - 0.5 km/h, the second at V4, and the third V4 + 0.5 km/h. To compare the maxLASS speed with outdoor performance, the subjects also ran 5 km at this speed on an outdoor track. Mean maximal running speed (V (max)) in the incremental test was significantly lower in the 6-min (15.1 km/h) and 3-min stage protocol (17.1 km/h), compared with the 1-min stage protocol (18.3 km/h). Mean peak VO (2) and mean peak heart rate were not different between the protocols with different stage duration. The mean V4 was significantly lower in the 6 min per stage protocol compared with the 3 min per stage protocol (12.9 vs. 14.4 km/h). Mean ventilatory threshold was not different between the 1, 3 and 6 min per stage protocols. No threshold behaviour was found in respiratory rate. MaxLASS can be estimated from V4 in the 6 min per stage protocol, and verified by three 15-min intensities being V4 - 0.5 km/h, at V4, and V4 + 0.5 km/h. The mean blood lactate concentration at the maxLASS speed was not different between treadmill running and outdoor running on a track. In conclusion, for measuring peak values of physiological variables in an incremental running test, the duration per stage is of less importance, however, when measuring blood lactate concentration as a function of running speed, the duration per stage should be at least 6 min.

Role of cucurbitacin C in resistance to spider mite (Tetranychus urticae) in cucumber (Cucumis sativus L.).

Cucurbitacins are bitter triterpenoid compounds that are toxic to most organisms and occur widely in wild and cultivated Cucurbitaceae. The only cucurbitacin identified in Cucumis sativus is cucurbitacin C. The bitter taste of cucumber has been correlated with resistance to the spider mite Tetranychus urticae, but a quantitative relationship has not been established. We determined the spider mite resistance and cucurbitacin C content in the dihaploid progeny derived from the F1 generation of a cross between a bitter, spider-mite-resistant cucumber line and a bitter-free, spider-mite-susceptible line. The ratio of the number of bitter to bitter-free dihaploids conformed to the expected 1:1 ratio, based on a monogenic segregation pattern. Genetic analysis ascribed 69% of the variance of the difference in spider mite survival rate to the bitterness locus. Within the group of bitter dihaploids, cucurbitacin C content was significantly correlated with spider mite resistance. Thus, a quantitative relationship between cucurbitacin C content and spider mite resistance could be established.

Plasma chemistry reference values in ostriches.

Reference values for 18 plasma chemical variables in blue neck ostriches (Struthio camelus australis, n = 60, age 24-36 mo) were established for use in veterinary clinical practice using nonparametric statistics. The following values were established for the percentiles P2.5 and P97.5: sodium 147-157 mmol/L, calcium 2.4-4.8 mmol/L, inorganic phosphate 1.3-2.3 mmol/L, chloride 94-105 mmol/L, glucose 10.3-13.7 mmol/L, urea 0.5-0.8 mmol/L, uric acid 351-649 mumol/L, bile acids 8-33 mumol/L, total protein 39-56 g/L, albumin-globulin ratio 0.45-0.59, osmolality 304-330 mOsm/kg, alkaline phosphate 69-217 IU/L, aspartate aminotransferase 243-418 IU/L, gamma-glutamyltransferase 0-1 IU/L, creatine kinase 1648-4894 IU/L, glutamate dehydrogenase 8-17 IU/L, and lactate dehydrogenase 860-2236 IU/L. The plasma calcium concentration was significantly (P < 0.001; r = 0.74) related to the total protein concentration and an adjustment-formula for calcium was derived: adjusted Ca (mmol/L) = Ca (mmol/L)--0.09 TP (g/L) + 4.4. The influence of blood sample treatment on the plasma potassium concentration as seen in other avian species was demonstrated in a separate experiment, emphasizing the need to separate plasma and cells immediately after collection in avian blood samples.

Body composition and cardiorespiratory fitness indicators in prepubescent boys and girls.

Abstract. Relations between frequently used indicators of cardiorespiratory fitness, sex and body composition were studied in a birth-cohort based sample of young prepubescent children (age range: 6.8 - 8.2 years). The Bruce treadmill test was used to assess submaximal heart rate, endurance time (ET), calculated total work (W(total)) and maximal power output (P(max)) in 100 children (50 boys, 50 girls). Body composition was determined by skinfold measurements. In 17 children, maximal oxygen consumption was measured. Percent body fat was negatively associated with ET and relative oxygen uptake (ml x min(-1) x kg(-1)) and was positively related to submaximal heart rate at 6 minutes exercise (HR6). Fat-free mass was positively related to W(total), P(max) and absolute oxygen uptake (ml x min(-1)). Relative oxygen uptake (ml x min(-1) x kg(-1)) was related to ET. Absolute oxygen uptake (ml x min(-1)) was related to W(total) and P(max). The observed differences in indicators of cardiorespiratory fitness between boys and girls were largely attributable to a difference in body composition. The results further demonstrate that when oxygen uptake measurement is not feasible, W(total) or P(max) (expressed per kilogram fat-free mass) seem to provide better indicators of aerobic power than endurance time.

Effect of exercise training on physical activity and substrate utilization in the elderly.

This study examined the effect of training on physical activity and substrate utilization in the elderly. Before the start, in week 6 and week 12 (T0, T6 and T12) data on physical fitness, physical activity and substrate utilization were collected in the exercise (11 males, 11 females; 63 +/- 8yrs) and control group (6 males, 5 females; 59 +/- 4yrs). Physical activity was registered with a tri-axial accelerometer and substrate utilization was calculated from resting respiratory exchange ratio (RER) by indirect calorimetry. At T6 physical activity on training days was significantly higher than on non-training days (33.4 +/- 10.3 vs. 26.5 +/- 7.8 counts x min(-1); p<0.001). At T12, after adjusting for training activity, physical activity on training days was significantly lower than on non-training days (23.7 +/- 8.4 vs. 28.2 +/- 9.3 counts x min(-1); p<0.01). RER decreased significantly (0.02 +/- 0.03; p <0.05), indicating a relatively larger fat oxidation. Changes in RER were negatively correlated with pre-training RER. In conclusion, in elderly an increase in structured training (exercise) is compensated for by a corresponding decrease in non-training physical activity. Training increased relative fat utilization in elderly with a high pre-training RER, whereas elderly with a low pre-training RER decreased their relative fat utilization.

Spider mite-induced (3S)-(E)-nerolidol synthase activity in cucumber and lima bean. The first dedicated step in acyclic C11-homoterpene biosynthesis.

Many plant species respond to herbivory with de novo production of a mixture of volatiles that attracts carnivorous enemies of the herbivores. One of the major components in the blend of volatiles produced by many different plant species in response to herbivory by insects and spider mites is the homoterpene 4,8-dimethyl-1,3(E), 7-nonatriene. One study (J. Donath, W. Boland [1995] Phytochemistry 39: 785-790) demonstrated that a number of plant species can convert the acyclic sesquiterpene alcohol (3S)-(E)-nerolidol to this homoterpene. Cucumber (Cucumis sativus L.) and lima bean (Phaseolus lunatus L.) both produce 4,8-dimethyl-1,3(E),7-nonatriene in response to herbivory. We report the presence in cucumber and lima bean of a sesquiterpene synthase catalyzing the formation of (3S)-(E)-nerolidol from farnesyl diphosphate. The enzyme is inactive in uninfested cucumber leaves, slightly active in uninfested lima bean leaves, and strongly induced by feeding of the two-spotted spider mite (Tetranychus urticae Koch) on both plant species, but not by mechanical wounding. The activities of the (3S)-(E)-nerolidol synthase correlated well with the levels of release of 4, 8-dimethyl-1,3(E),7-nonatriene from the leaves of the different treatments. Thus, (3S)-(E)-nerolidol synthase is a good candidate for a regulatory role in the release of the important signaling molecule 4,8-dimethyl-1,3(E),7-nonatriene.

Effect of exercise training on total daily physical activity in elderly humans.

This study examined the effect of 12 weeks of exercise training on daily physical activity in elderly humans. Training consisted of a weekly group session and an individual session with cardio- and weight-stack machines. A group of 15 subjects served as the exercise group [EXER mean age 59 (SD 4) years], and 7 subjects as the controls [CONT mean age 57 (SD 3) years]. Physical activity and physical fitness were measured before the start of training (T), at week 6 and week 12 (T0, T6, T12 respectively) in EXER, and at T0 and T12 in CONT. Physical activity over 14 days was measured using a tri-axial accelerometer and physical fitness was measured during an incremental exercise test. At T12, mean maximal power output had significantly increased in EXER compared to CONT 8 (SD 12) vs -5 (SD 9) W; P < 0.02] and mean submaximal heart rate (at 100 W) had reduced [-10 (SD 7) vs -2 (SD 6) beats x min(-1); P < 0.05]. No differences or changes in physical activity were observed between EXER and CONT. At T6, physical activity on training days was significantly higher than on non-training days (P < 0.001). When the accelerometer output of the training session was subtracted from the accelerometer output on training days, at T12 non-training physical activity was significantly lower than on non-training days (P < 0.004). Accelerometer output of the individual training session at T12 had significantly increased compared to T6 (P < 0.05), whereas, accelerometer output of the group training session had remained unchanged. In conclusion, in elderly subjects an exercise training programme of moderate intensity resulted in an improved physical fitness but had no effect on total daily physical activity. Training activity was compensated for by a decrease in non-training physical activity.

Isokinetic aerobic power output testing of the quadriceps muscle.

A stepwise increasing exercise protocol to measure the maximal aerobic power output of the quadriceps muscle is proposed for use in rehabilitation medicine. Sixteen healthy volunteers performed isokinetic knee extension/flexion exercises at an angular velocity of 180 degrees x s(-1). The protocol consisted of stages of 200 knee movements from 100 flexion to full extension, starting at 10% peak torque (PT) and increasing by 10% PT each following stage until exhaustion. Quadriceps work, oxygen uptake, heart rate, plasma lactate concentration and surface electromyography were monitored. Quadriceps power output (Pext) was highly related (r = 0.95) to the extension torque at which the subjects were instructed to exercise. The test-retest (r = 0.82) and left to right (r = 0.94) correlations of maximum quadriceps power output (Pmax) were high. Both sexes (males 43+/-9W, females 36+/-8W) achieved their Pmax at 47% PT. At submaximal power output stages oxygen uptake (r = 0.85) and EMG-amplitude (r = 0.88) were linearly related to Pext. Mechanical efficiency (optimum at 60% Pmax) showed a large variation between power output stages and between subjects. The relationship between relative oxygen uptake and heart rate or plasma lactate concentration was similar to that of whole body exercise, e.g. running. We conclude that the proposed test is reliable for assessing the maximal aerobic power output of the quadriceps muscle. This parameter of the muscle function may add useful information for assessing the rehabilitation process after knee immobilization.

Physical fitness and sports skills in relation to sports injuries. A four-year prospective investigation of sports injuries among physical education students.

In order to study the relationship between physical fitness/sport-specific skills and sports injuries 136 physical education students were studied during their 4-years of training in a prospective investigation. Physical fitness was measured every year using a battery of fitness tests, and the performance marks of a number of sports scored at the exams of the academy were used as parameters for the sport-specific skills. Sports injuries were recorded every 3 weeks on standard forms. Relative risk ratios were calculated between the tertile groups good, average and poor for all variables of physical fitness and sport-specific skills. Injury-proneness was defined for all and for acute and chronic injuries separately near the median number of injuries sustained. In only 6 out of 126 computed relative risks was a significant difference found. Discriminant analysis revealed an explanation of 16%, 14% and 11% of the variance for respectively all, acute and chronic injuries, at which 5 or 6 variables in varying combination were included. From our findings it may be concluded that physical fitness and sport-specific skills have little impact on sports injuries for the following two main reasons. Firstly, subjects at risk for sports injuries participate per definition in sports activities and have consequently developed their fitness and skills compared to the sedentary population. Thus, the range in physical fitness or sports skills in the population at risk is relatively small (physical education students belong to the 7th-10th decile in fitness test scores within a general college student population) and therefore an effect is hard to show. Secondly, the total number of sports injuries is very small and moreover, it should be distributed over several categories for analysis. The favourable advantages of using physical education students to study intrinsic risk factors (comparable and varied sports program, excellent compliance) appeared to be insufficient to compensate for drawbacks of selection.

Physical characteristics as risk factors for sports injuries: a four year prospective study.

A variety of physical characteristics of athletes has been proposed to be related to the risk to sustain a sports injury. The aim of the present study was to determine the influence of flexibility, anthropometric characteristics and malalignment of the lower extremities on the risk to sustain a sports injury, using a prospective study design and subjects exposed to rather equal extrinsic risk factors. Physical education students (N = 136) were followed during their four-year education. Sixteen flexibility indices, four anthropometric characteristics and five malalignment indices of the lower extremities were assessed at the start of the study and all sports injuries sustained in that four-year period were recorded. No influence of flexibility or anthropometric variables on the total number of injuries or the number of several specific injuries (ankle sprain, muscle rupture, dislocation, shin splints, backache) could be established. Malalignments of the lower extremities (average prevalence 18% and only minor deviations) did show some but inconsistent relations with the number of (specific) injuries. For pelvic obliquity it was positive as predicted, but for malalignment of the rearfoot and a deviant footprint it appeared to be negative. Leg length inequality and malalignment of the knees were not related to injuries. The most likely explanation for these (poor) findings is the relatively low number and great variety of sports injuries recorded. Further, the homogeneity in physical characteristics of the population under study makes it difficult to find significant relationships. A study design that meets both the criterium of similar extrinsic risk factors and that of a wide range of physical characteristics in a representative sporting population, however, is not practicable.

Effect of an 18-wk weight-training program on energy expenditure and physical activity.

The purpose of this study was to examine the effect of an 18-wk weight-training program on average daily metabolic rate (ADMR). Before the intervention and in weeks 8 and 18 (T0, T8, and T18, respectively) data on body composition, sleeping metabolic rate (SMR), food intake, energy cost of the weight-training program (EEex), and nontraining physical activity (accelerometer) were collected in the exercise group (EXER, n = 18 males). ADMR was determined in a subgroup (EX12, n = 12) by using doubly labeled water. At T0 and T18, data (except ADMR) were also collected in a control group (Con, n = 8). Body mass did not change in EXER or Con. Fat-free mass increased only in EXER with 2.1 +/- 1.2 kg, whereas fat mass decreased in EXER as well as Con (2.0 +/- 1.8 and 1.4 +/- 1.0 kg, respectively). Initial ADMR (12.4 +/- 1.2 MJ/day) increased at T8 (13.5 +/- 1.3 MJ/day, P < 0.001) with no further increase at T18 (13.5 +/- 1.9 MJ/day). SMR did not change in EXER (4.8 +/- 0.5, 4.9 +/- 0.5, 4.8 +/- 0.5 kJ/min) or Con (4.7 +/- 0.4, 4.8 +/- 0.4 kJ/min). Energy intake did not change in EXER (10.1 +/- 1.8, 9.7 +/- 1.8, 9.2 +/- 1.9 MJ/day) or Con (10.2 +/- 2.6, 9.4 +/- 1.8, 10.1 +/- 1.5 MJ/day) and was systematically underreported in EX12 (-21 +/- 14, -28 +/- 18, -34 +/- 14%, P < 0.001). EEex (0.47 +/- 0.20, 0.50 +/- 0.18 MJ/day) could only explain 40% of the increase in ADMR. Nontraining physical activity did not change in both groups. In conclusion, although of modest energy cost, weight-training induces a significant increase in ADMR.

Is prevention of sports injuries a realistic goal? A four-year prospective investigation of sports injuries among physical education students.

To assess the reliability of injury registration and to determine the incidence of injury in intramural (program of the institution) and extramural (leisure time) sports activities, we prospectively recorded information on sports injuries for 4 years in a group of 136 physical education students. Registration forms were completed every 3 weeks, and data on medical consultations were recorded. During the last year, we asked 59 students to recall all injuries sustained to establish the reliability of retrospective injury registration. In the prospective study, 525 sports injuries were recorded: 58% during intramural activities and 42% during extramural. The incident rate per 1000 hours of intramural activities (1.26) was significantly lower than that for extramural activities (1.77). A gradual decline in response rate from 98.4% the 1st year to 87.7% in the final year indicated a decreasing compliance during the study period. Eighteen percent of all injuries with recorded medical consultations were not reported by the students. At the retrospective injury registration in the final year of the study, students had forgotten 54% of the recorded injuries and 50 injuries (20% of all recorded injuries) were mentioned that had not been recorded during the previous years. We conclude that, even in a well-supervised population, prospective injury registration is not complete, and the reliability of retrospective injury registration is even poorer.

Effect of weight-training on energy expenditure and substrate utilization during sleep.

This study was performed to investigate the effect of weight-training (12 wk; 21 male subjects) on energy expenditure and substrate utilization during sleep. Sleeping metabolic rate (SMR) as measured in a respiration chamber was calculated according to three procedures: the lowest mean energy expenditure of a shiftable 3-h interval between 0:00 and 6:00 (SMR3) and SMR over predetermined intervals from 3:00 to 6:00 (SMR3-6) and from 0:00 to 6:00 (SMR0-6). In analogy with SMR the corresponding respiratory quotients were expressed as RQ3, RQ3-6, and RQ0-6. Changes in body composition were assessed from changes in body weight, body volume (densitometry), and total body water (deuterium dilution). Weight-training induced an increase in fat-free mass (+1.1 +/- 1.3 kg; P < 0.001) and a decrease in fat mass (-2.3 +/- 1.5 kg; P < 0.001) and body weight (-1.1 +/- 2.1 kg; P < 0.05). There was no significant change in SMR, irrespective of the way SMR was expressed. Only RQ3 decreased significantly (from 0.82 +/- 0.04 to 0.79 +/- 0.02; P < 0.05). Remarkably RQ3, RQ3-6, and RQ0-6 were highly negative correlated with the pre-training RQ (r = -0.93, -0.91, and -0.90, respectively: P < 0.001) resulting in a diminished variation in post-training RQ (P < 0.001). These results suggest that weight-training has no effect on SMR but increases relative fat utilization in low fat oxidizers and vice versa for individuals displaying high pre-training lipid oxidation.

Exercise systolic arterial blood pressure in middle-aged women with normal and elevated arterial blood pressure.

Considerable interindividual variation in the response of blood pressure to exercise has been found. Factors independently contributing to this variation are insufficiently evaluated. This is especially true for women and older age groups. Reference values of progressive maximal exercise testing in middle-aged, active subjects, especially in women, are scarce. In this study, the response of systolic arterial blood pressure during a progressive maximal cycle ergometer test was investigated in 871 physically active female subjects aged 40 years or older with normal, borderline elevated and elevated blood pressure. The influence of 14 different subject characteristics on this response was studied: 63% of variation in exercise systolic blood pressure (eSBP) could be explained by work load, pre-eSBP, age and exercise heart rate. No difference in eSBP with increasing work load was found between the three groups. Subjects with higher exercise heart rates had higher systolic blood pressures at the same work load compared to subjects with lower exercise heart rates. Maximal working capacity (Wmax) was significantly lower in the elevated blood pressure group although maximal heart rate and lactate were similar. Wmax was age-dependent. Other subject variables were not significantly associated with eSBP. Values of eSBP for reference purposes are presented.

Effects of cast-bracing of the knee on physical performance in healthy subjects.

Effects of application of a hinged cast-brace on thigh muscle strength and physical performance tests were studied in eight healthy volunteers. The cast-brace was applied to one leg for four weeks. The subjects were free to move around. The extra loading by the cast-brace was determined in a progressive uphill walk test on a treadmill with measurements of oxygen uptake, heart rate and plasma lactate concentration. Submaximal oxygen uptake in the uphill walk test was raised significantly (average 9%) on the day after application. After four weeks of cast-brace wearing the submaximal oxygen uptake in the uphill walk test had decreased, but remained elevated (average 4%) even one day after removal. Heart rate was significantly higher (average 7%) during cast application and after removal. Plasma lactate concentration, however, was not influenced. To investigate the effect of four weeks cast-bracing various performance tests to judge the thigh muscle function were taken before application and after removal. No significant changes in peak torque of knee flexion and extension, in physiologic variables at submaximal running pace during treadmill exercise, maximal running speed, 60 m dash, or in jump height were found. In conclusion, cast-bracing of a healthy knee for four weeks has no significant effects on physical performance after removal.