Duration and frequency of every day activities in total hip patients.

Little knowledge about frequency and duration of daily activities in patients after total hip arthroplasty is available. Such information is required for the definition of realistic load collectives for pre-clinical testing of prostheses. It could also be helpful for the quantitative evaluation of surgery outcome with different prosthesis types. The purpose of this study was to develop and apply a system for the determination of frequency and duration of patient activities in their habitual environment and to compare the results to a clinical outcome score (Harris hip score).A portable activity monitoring system (weight 1.6 kg including batteries) was designed using a Palm top computer, 2 inclination sensors for the thigh and calf and one goniometer positioned at the knee joint. An algorithm was developed to identify frequency and duration of the activities lying, sitting, standing, walking and stair climbing from the signals of the 3 sensors. 42 patients participated in the study and were equipped with the system in the morning at their home. Datasets of 31 patients (age 62.5+/-11.5 y) covered more than 6h (9.8 +/- 1.6 h) and were included in the analysis. Prosthesis specific data as well as the Harris hip score were collected.The most frequent patient activity was sitting (44.3% of the time), followed by standing (24.5%), walking (10.2%), lying (5.8%) and stair climbing (0.4%). The median number of steps/stairs was 6048/164. The number of step cycles representing one year in vivo use should, consequently, be increased to 1.1 million. The Harris hip score (91.4 +/- 9.8) correlated significantly with the number of stairs (r(2) = 0.26, p = 0.003) and showed a positive tendency with the number of steps per day. No differences in activity levels between prosthesis specific factors were found.     

Physiological analysis of running performance: revision of the hyperbolic model

1 This paper presents a physiological model for the analysis of the "running curve" (i.e. the relationship between running time and power output) (Table I and Fig. 1). This model is derived from the basic hyperbolic model (Eq. 2: Fig. 2 a) modified in order to take into account the slow adjustment of oxygen utilization and of glycolysis at the onset of exercise (Eq. 7) and the progressive reduction of average aerobic power sustained with increasing running time for races lasting longer than 7 min (Eq. 10; Fig. 2 b, 2 d). 2 This model provides a satisfactory smoothing of the running curve from 200 m to marathon. Average errors (in absolute value) between actual and estimated power output are 0.9 +/- 0.2% (+/- SE) and 1.3 +/- 0.4% for male and female world records respectively (Table II). The basic hyperbolic model (Ptc = A/tc + B) provides a satisfactory smoothing of the running curve on comparatively narrow ranges of events (Table III). 3 Estimations of anaerobic energy stores and of VO2 max made for male and female from world records (1,219 J.kg-1 and 76.4 ml.kg-1.min-1; 1,118 J.kg-1 and 67.8 ml.kg-1.min-1 respectively) are in reasonable agreement with expected values in elite runners (Table IV). 4 The model allows the computation of an objective measure of endurance, i.e. the so-called "ability to sustain a high percentage of VO2 max for a long period of time".(ABSTRACT TRUNCATED AT 250 WORDS)     

Maximal exercise capacity and oxygen consumption of lambs with an aortopulmonary left-to-right shunt

We determined maximal exercise capacity and measured hemodynamics in 10 6-wk-old lambs with an aortopulmonary left-to-right shunt [S, 57 +/- 11%, (SD)] and in 9 control lambs (C) during a graded treadmill test 8 days after surgery. Maximal exercise capacity (3.7 +/- 0.2 km/h and 10 +/- 5% inclination vs. 4.0 +/- 0.9 km/h and 15 +/- 0% inclination, P less than 0.02) and peak oxygen consumption (25 +/- 7 vs. 34 +/- 8 ml O2.min-1.kg-1, P less than 0.02) were both lower in the shunt than in the control lambs. This was due to a lower maximal systemic blood flow in the shunt lambs (271 +/- 38 vs. 359 +/- 71 ml.min-1.kg-1, P less than 0.01). Despite their high maximal left ventricular output, which was higher than in the control lambs (448 +/- 87 vs. 359 +/- 71 ml.min-1.kg-1, P less than 0.05), the left-to-right shunt could not be compensated for during maximal exercise because of a decreased reserve in heart rate (S: 183 +/- 22 to 277 +/- 38 beats/min; C: 136 +/- 25 to 287 +/- 29 beats/min) and in left ventricular stroke volume (S: 1.8 +/- 0.3 to 1.6 +/- 0.4 ml/kg; C: 1.0 +/- 0.3 to 1.3 +/- 0.2 ml/kg). We conclude that exercise capacity of shunt lambs is lower than that of control lambs, despite a good left ventricular performance, because a part of the reserves for increasing the left ventricular output is already utilized at rest.     

Musculo-skeletal loading conditions at the hip during walking and stair climbing.

Musculo-skeletal loading plays an important role in the primary stability of joint replacements and in the biological processes involved in fracture healing. However, current knowledge of musculo-skeletal loading is still limited. In the past, a number of musculo-skeletal models have been developed to estimate loading conditions at the hip. So far, a cycle-to-cycle validation of predicted musculo-skeletal loading by in vivo measurements has not been possible. The aim of this study was to determine the musculo-skeletal loading conditions during walking and climbing stairs for a number of patients and compare these findings to in vivo data.Following total hip arthroplasty, four patients underwent gait analysis during walking and stair climbing. An instrumented femoral prosthesis enabled simultaneous measurement of in vivo hip contact forces. On the basis of CT and X-ray data, individual musculo-skeletal models of the lower extremity were developed for each patient. Muscle and joint contact forces were calculated using an optimization algorithm. The calculated peak hip contact forces both over- and under-estimated the measured forces. They differed by a mean of 12% during walking and 14% during stair climbing.For the first time, a cycle-to-cycle validation of predicted musculo-skeletal loading was possible for walking and climbing stairs in several patients. In all cases, the comparison of in vivo measured and calculated hip contact forces showed good agreement.Thus, the authors consider the presented approach as a useful means to determine valid conditions for the analysis of prosthesis loading, bone modeling or remodeling processes around implants and fracture stability following internal fixation.     

Physiological factors associated with the lower maximal oxygen consumption of master runners

We examined the hemodynamic factors associated with the lower maximal O2 consumption (VO2max) in older formerly elite distance runners. Heart rate and VO2 were measured during submaximal and maximal treadmill exercise in 11 master [66 +/- 8 (SD) yr] and 11 young (32 +/- 5 yr) male runners. Cardiac output was determined using acetylene rebreathing at 30, 50, 70, and 85% VO2max. Maximal cardiac output was estimated using submaximal stroke volume and maximal heart rate. VO2max was 36% lower in master runners (45.0 +/- 6.9 vs. 70.4 +/- 8.0 ml.kg-1.min-1, P less than or equal to 0.05), because of both a lower maximal cardiac output (18.2 +/- 3.5 vs. 25.4 +/- 1.7 l.min-1) and arteriovenous O2 difference (16.6 +/- 1.6 vs. 18.7 +/- 1.4 ml O2.100 ml blood-1, P less than or equal to 0.05). Reduced maximal heart rate (154.4 +/- 17.4 vs. 185 +/- 5.8 beats.min-1) and stroke volume (117.1 +/- 16.1 vs. 137.2 +/- 8.7 ml.beat-1) contributed to the lower cardiac output in the older athletes (P less than or equal 0.05). These data indicate that VO2max is lower in master runners because of a diminished capacity to deliver and extract O2 during exercise.     

Validation of two running tests as estimates of maximal aerobic power in children

In order to validate the "Maximal Multistage 20 Meter Shuttle Run Test" by Leger and Lambert (1982) (20-MST) as an estimate of maximal aerobic power (VO2max) and to compare the results of this test with the results of a 6 min endurance run, 82 subjects (41 boys and 41 girls) aged 12-14 performed the 20-MST and the 6 min endurance run, and had their VO2max directly measured during maximal treadmill running. The 20-MST is a maximal running test starting at a running speed of 8.0 km X h-1, which is increased every minute and in which the pace is set by an audio signal. Performing the test, one runs a 20-meter course back and forth. The test result is expressed as "palier" (one palier is approximately one minute). The mean results of the 20-MST were, for boys, 8.0 palier (+/- 1.7) and for girls, 6.4 palier (+/- 1.5). The mean results of the 6 min endurance run were for boys, 1264.4 meters (+/- 160.8), and for girls, 1103.9 meters (+/- 144.7). The mean VO2max for boys was 53.2 ml X kg-1 X min-1 (+/- 5.4) and for girls, 44.1 (+/- 4.8) ml X kg-1 X min-1. The correlation coefficient between VO2max and the 20-MST was found to be 0.68 (+/- 3.9) for boys, 0.69 (+/- 3.4) for girls and 0.76 (+/- 4.4) for both sexes, and that of VO2max with the 6 min endurance run was 0.51 (+/- 4.6) for boys, 0.45 (+/- 4.3) for girls and 0.63 (+/- 5.3) for both sexes. The conclusion is that the 20-MST is a suitable tool for the evaluation of maximal aerobic power. Although the differences in validity between the 20-MST and the 6 minutes endurance run were statistically not significant (p greater than 0.05), for reasons of practicability the 20-MST should be preferred to the 6 minutes endurance run when used in physical education classes.     

The Energy Expenditure of Stair Climbing One Step and Two Steps at a Time: Estimations from Measures of Heart Rate

Stairway climbing provides a ubiquitous and inconspicuous method of burning calories. While typically two strategies are employed for climbing stairs, climbing one stair step per stride or two steps per stride, research to date has not clarified if there are any differences in energy expenditure between them. Fourteen participants took part in two stair climbing trials whereby measures of heart rate were used to estimate energy expenditure during stairway ascent at speeds chosen by the participants. The relationship between rate of oxygen consumption () and heart rate was calibrated for each participant using an inclined treadmill. The trials involved climbing up and down a 14.05 m high stairway, either ascending one step per stride or ascending two stair steps per stride. Single-step climbing used 8.5±0.1 kcal min⁻¹, whereas double step climbing used 9.2±0.1 kcal min⁻¹. These estimations are similar to equivalent measures in all previous studies, which have all directly measured The present study findings indicate that (1) treadmill-calibrated heart rate recordings can be used as a valid alternative to respirometry to ascertain rate of energy expenditure during stair climbing; (2) two step climbing invokes a higher rate of energy expenditure; however, one step climbing is energetically more expensive in total over the entirety of a stairway. Therefore to expend the maximum number of calories when climbing a set of stairs the single-step strategy is better.     

In vivo knee moments and shear after total knee arthroplasty

Tibiofemoral loading is very important in cartilage degeneration as well as in component survivorship after total knee arthroplasty. We have previously reported the axial knee forces in vivo. In this study, a second-generation force-sensing device that measured all six components of tibial forces was implanted in a 74-kg, 83-year-old male. Video motion analysis, ground reaction forces, and knee forces were measured during walking, stair climbing, chair-rise, and squat activities. Peak total force was 2.3 times body weight (BW) during walking, 2.5 x BW during chair rise, 3.0 x BW during stair climbing, and 2.1 x BW during squatting. Peak anterior shear force at the tibial tray was 0.30 x BW during walking, 0.17 x BW during chair rise, 0.26 x BW during stair climbing, and 0.15 x BW during squatting. Peak flexion moment at the tray was 1.9% BW x Ht (percentage of body weight multiplied by height) for chair-rise activity and 1.7% BW x Ht for squat activity. Peak adduction moment at the tray was -1.1% BW x Ht during chair-rise, -1.3% BW x Ht during squatting. External knee flexion and adduction moments were substantially greater than flexion and adduction moments at the tray. The axial component of forces predominated especially during the stance phase of walking. Shear forces and moments at the tray were very modest compared to total knee forces. These findings indicate that the soft tissues around the knee absorbed most of the external shear forces. Our results highlight the importance of direct measurements of knee forces.     

Evidence for altered alpha-adrenoreceptor responsiveness after a single bout of maximal exercise.

We studied hemodynamic responses to alpha- and beta-receptor agonists in eight men to test the hypothesis that adrenoreceptor responsiveness is altered within 24 h of the performance of maximal exercise. Adrenoreceptor responsiveness was tested under two experimental conditions (with and without maximal exercise). Adrenoreceptor tests were performed 24 h after each subject performed graded upright cycle ergometry to volitional exhaustion. The 2 test days (experimental conditions) were separated by at least 1 wk, and the order of exercise and no-exercise conditions was counterbalanced. Steady-state graded infusions of phenylephrine (PE) and isoproterenol (Iso) were used to assess alpha- and beta-adrenoreceptor responsiveness, respectively. Slopes calculated from linear regressions between Iso and PE doses and changes in heart rate, blood pressure, and leg vascular resistance for each subject were used as an index of alpha- and beta-adrenoreceptor responsiveness. The slope of the relationship between heart rate and Iso with maximal exercise was 1773 +/- 164 beats x microm-1x kg-1x min-1 compared with 1987 +/- 142 beats x microg-1x kg-1x min-1 without exercise (P = 0.158), whereas the slopes of the relationship between vascular resistance to Iso were -438 +/- 123 peripheral resistance units (PRU) x microg-1x kg-1x min-1 with maximal exercise and -429 +/- 105 x microg-1x kg-1 x min-1 without exercise (P = 0.904). Maximal exercise was associated with greater (P < 0.05) vascular resistance (15.1 +/- 2.8 PRU x microg-1 kg-1x min-1) and mean arterial blood pressure (15.8 +/- 2.1 mmHg. microg-1x kg-1x min-1) responses to PE infusion compared with no exercise (9.0 +/- 2.0 PRU x microg-1 kg-1 x min-1 and 10.9 +/- 2.0 mmHg. microg-1x kg-1x min-1, respectively). These results provide evidence that a single bout of maximal exercise increases alpha1-adrenoreceptor responsiveness within 24 h without affecting beta-cardiac and vascular adrenoreceptor responses.     

In vitro fatigue failure of cemented acetabular replacements: a hip simulator study

Although hip simulators for in vitro wear testing of prosthetic materials used in total hip arthroplasty (THA) have been available for a number of years, similar equipment has yet to appear for endurance testing of fixation in cemented THA, despite considerable evidence of late aseptic loosening as one of the most significant failure mechanisms in this type of replacements. An in vitro study of fatigue behavior in cemented acetabular replacements has been carried out, utilizing a newly developed hip simulator. The machine was designed to simulate the direction and the magnitude of the hip contact force under typical physiological loading conditions, including normal walking and stair climbing, as reported by Bergmann et al. (2001, Hip 98, Freie Universitaet, Berlin). A 3D finite element analysis has been carried out to validate the function of the hip simulator and to evaluate the effects of boundary conditions and geometry of the specimen on the stress distribution in the cement mantle. Bovine pelvic bones were implanted with a Charnley cup, using standard manual cementing techniques. Experiments were carried out under normal walking and descending stairs loading conditions with selected load levels from a body weight of 75-125 kg. Periodically, the samples were removed from the test rigs to allow CT scanning for the purpose of monitoring damage development in the cement fixation. The hip simulator was found to be satisfactory in reproducing the hip contact force during normal walking and stair climbing, as reported by Bergmann et al. Finite element analysis shows that the stress distributions in the cement mantle and at the bone-cement interface are largely unaffected by the geometry and the boundary conditions of the model. Three samples were tested up to 17 x 10(6) cycles and sectioned post-testing for microscopic studies. Debonding at the bone-cement interface of various degrees in the posterior-superior quadrant was revealed in these samples, and the location of the failures corresponds to the highest stressed region from the finite-element analysis. Preliminary experimental results from a newly developed hip simulator seem to suggest that debonding at the bone-cement interface is the main failure mechanism in cemented acetabular replacements, and descending stairs seem to be more detrimental than normal walking or ascending stairs with regard to fatigue integrity of cement fixation.     

Peak oxygen uptake during arm cranking for men and women

To determine upper body peak O2 uptake (VO2) in a group of young females and to obtain information on possible sex differences, 40 subjects, 20 females and 20 males, mean age 26 +/- 4 (SD) and 31 +/- 6 yr, respectively, were studied during maximal arm-cranking exercise. Peak values for power output, VO2, minute ventilation (VE), and heart rate (HR) were determined for each subject. In addition, arm-shoulder volume (A-SV) was measured before exercise. Significant differences between males and females (P less than 0.05) were found for peak power output (134 +/- 18 vs. 86 +/- 13 W), peak VO2 expressed in liters per minute (2.55 +/- 0.45 vs. 1.81 +/- 0.36) and milliliters per kilogram per minute (34.2 +/- 5.3 vs. 29.2 +/- 4.9), peak VE (95.4 +/- 14.5 vs. 70.1 +/- 19.2 1 X min-1), and A-SV (3,126 +/- 550 vs. 2,234 +/- 349 ml), whereas peak HR was not significantly different between the two groups (174 +/- 14 vs. 174 +/- 36 beats X min-1). However, when peak VO2 was corrected for arm and shoulder size there was no significant difference between the groups (0.82 +/- 0.13 vs. 0.78 +/- 0.13 ml X ml A-SV-1 X min-1). These results suggest that the observed differences between men and women for peak VO2 elicited during arm cranking when expressed in traditional terms (1 X min-1 and ml X kg-1 X min-1) are a function of the size of the contracting muscle mass and are not due to sex-related differences in either O2 delivery or the O2 utilization capacity of the muscle itself.     

Maximal mechanical power output and capacity of cyclists and young adults

The maximal average power output (Wmax) has been examined in 10 male students, 22 pursuit and 12 sprint cyclists. In 24 of these subjects (8 students, 10 pursuit and 6 sprint cyclists), estimates of the maximal capacity (Wcap) of the short-term anaerobic energy yielding processes were made. The results show that the sprinters had a higher absolute Wmax (1241 +/- 266 W) and Wcap (16.7 +/- 4.9 kJ) than either the students (1019 +/- 183 W, 14.7 +/- 2.8 kJ) or the pursuit cyclists (962 +/- 206 W, 14.0 +/- 2.9 kJ). However, the differences were removed when the values were standardised for muscle size. In the sprinters the Wmax was attained at an optimal pedal frequency Vopt of 132 +/- 3 min-1 and the estimated maximal velocity of pedalling (V0) was 262 +/- 8 min-1. The comparable figures in the students and pursuit cyclists were 118 +/- 8 min-1, 235 +/- 17 min-1 and 122 +/- 6 min-1, 242 +/- 12 min-1 respectively. The coefficient of variation of duplicate measurements of Wcap was found to be +/- 9%. Using data of Wilkie (1968) for muscle phosphagen and glycolytic stores (27 mmol.kg-1), it was estimated that the probable efficiency of the anaerobic processes during maximal cycling was 0.22. It was concluded that Wmax and Wcap are largely determined by body size and muscularity. The efficiency of anaerobiosis appears to be of the same order of magnitude as found for oxidative work.     

Hip contact forces and gait patterns from routine activities.

In vivo loads acting at the hip joint have so far only been measured in few patients and without detailed documentation of gait data. Such information is required to test and improve wear, strength and fixation stability of hip implants. Measurements of hip contact forces with instrumented implants and synchronous analyses of gait patterns and ground reaction forces were performed in four patients during the most frequent activities of daily living. From the individual data sets an average was calculated. The paper focuses on the loading of the femoral implant component but complete data are additionally stored on an associated compact disc. It contains complete gait and hip contact force data as well as calculated muscle activities during walking and stair climbing and the frequencies of daily activities observed in hip patients. The mechanical loading and function of the hip joint and proximal femur is thereby completely documented. The average patient loaded his hip joint with 238% BW (percent of body weight) when walking at about 4 km/h and with slightly less when standing on one leg. This is below the levels previously reported for two other patients (Bergmann et al., Clinical Biomechanics 26 (1993) 969-990). When climbing upstairs the joint contact force is 251% BW which is less than 260% BW when going downstairs. Inwards torsion of the implant is probably critical for the stem fixation. On average it is 23% larger when going upstairs than during normal level walking. The inter- and intra-individual variations during stair climbing are large and the highest torque values are 83% larger than during normal walking. Because the hip joint loading during all other common activities of most hip patients are comparably small (except during stumbling), implants should mainly be tested with loading conditions that mimic walking and stair climbing.     

Stair climbing is more critical than walking in pre-clinical assessment of primary stability in cementless THA in vitro

Pre-clinical testing of hip endoprostheses is a mandatory requirement before clinical release. Inadequate loading conditions may lead to lower elastic and plastic interface movements than those occurring post-operatively in vivo. This study investigated the influence of patient activity on the primary stability of cementless prostheses with a special emphasis on active simulation of muscle forces. A loading setup, based on validated musculo-skeletal analyses, was used to generate the hip contact force during walking and stair climbing by transmitting muscle forces through the femur. In addition, a loading configuration which only generated the hip contact force occurring during stair climbing at the prosthesis head was simulated. CLS prostheses were implanted in 18 composite femora and subjected to cyclical loading. The relative micro-movements at the bone-prosthesis interface were determined and appeared to be extremely sensitive to the specific patient activity. Compared to walking, stair climbing generated higher micro-movements, with pronounced axial and rotational components. Stair climbing with the femur loaded by the resultant hip contact force only exhibited a characteristic valgus tilt of the stem with significantly lower interface micro-movements than under active simulation of muscle forces. The analyses suggest that stair climbing induced the highest mechanical instability at the bone-prosthesis interface, a level which may compromise the necessary osseointegration process. Active simulation of muscle forces considerably affects the primary stability of cementless hip endoprostheses. Pre-clinical in vitro tests should therefore simulate stair climbing and include muscle activity in the assessment of initial implant stability, otherwise micro-movements may be underestimated and the primary stability overestimated.     

Biomechanics of the ankle-foot system during stair ambulation: implications for design of advanced ankle-foot prostheses

Unilateral lower limb prosthesis users display temporal, kinematic, and kinetic asymmetries between limbs while ascending and descending stairs. These asymmetries are due, in part, to the inability of current prosthetic devices to effectively mimic normal ankle function. The purpose of this study was to provide a comprehensive set of biomechanical data for able-bodied and unilateral transtibial amputee (TTA) ankle-foot systems for level-ground (LG), stair ascent (SA), and stair descent (SD), and to characterize deviations from normal performance associated with prosthesis use. Ankle joint kinematics, kinetics, torque-angle curves, and effective shapes were calculated for twelve able-bodied individuals and twelve individuals with TTA. The data from this study demonstrated the prosthetic limb can more effectively mimic the range of motion and power output of a normal ankle-foot during LG compared to SA and SD. There were larger differences between the prosthetic and able-bodied limbs during SA and SD, most evident in the torque-angle curves and effective shapes. These data can be used by persons designing ankle-foot prostheses and provide comparative data for assessment of future ankle-foot prosthesis designs.     

Force-velocity properties of two avian hindlimb muscles

Recent work has provided measurements of power output in avian skeletal muscles during running and flying, but little is known about the contractile properties of avian skeletal muscle. We used an in situ preparation to characterize the force-velocity properties of two hind limb muscles, the lateral gastrocnemius (LG) and peroneus longus (PL), in Wild Turkeys (Meleagris gallopavo). A servomotor measured shortening velocity for at least six different loads over the plateau region of the length-tension curve. The Hill equation was fit to the data to determine maximum shortening velocity and peak instantaneous power. Maximum unloaded shortening velocity was 13.0+/-1.6 L s(-1) for the LG muscle and 14.8+/-1.0 L s(-1) for the PL muscle (mean+/-S.E.M.). These velocities are within the range of values published for reptilian and mammalian muscles. Values recorded for maximum isometric force per cross-sectional area, 271+/-28 kPa for the LG and 257+/-30.5 kPa for the PL, and peak instantaneous power output, 341.7+/-36.4 W kg(-1) for the LG and 319.4+/-42.5 W kg(-1) for the PL, were also within the range of published values for vertebrate muscle. The force-velocity properties of turkey LG and PL muscle do not reveal any extreme differences in the mechanical potential between avian and other vertebrate muscle.     

The physiological cost of carrying light and heavy loads

Nine subjects walked on a treadmill with load weights equal to 10% and 40% of body weight carried on the back. Although the speed of the treadmill was selected so that the measured oxygen consumption (VO2) was the same for both load conditions, the heavier load placed an extra strain on the cardiopulmonary system and was perceived by all subjects as harder work than the lighter load. When the subjects worked at their own pace, walking on a level road or climbing stairs with load weights equal to 10% and 40% of body weight, they compensated for the heavier load by decreasing walking speed or climbing rate. Although the energy costs calculated from walking speed, body and load weight for self-paced walking and the external work of stair climbing were the same for both load conditions, the heavier load was again perceived as harder work. These findings are discussed as they relate to the definition of acceptable load weights.     

Reproducibility of power production during sprint arm ergometry

Sprint tests are frequently used to evaluate between-subject differences and can provide a valuable insight into performance capacity. The present study determined the reproducibility of peak and mean power output during upper-body sprints. After familiarization 25 men (mean [+/- SD] age 29 [6] years, body mass 82.8 [12.7] kg and height 1.76 [0.05] m) completed 2 20-second upper-body sprint tests using an adapted cycle ergometer. Mean (+/- SD) values of all power (uncorrected and corrected) measurements achieved during the 2 tests were checked for systematic bias using separate paired t-tests. Test-retest reproducibility was examined using coefficients of variation and single-measure intraclass correlation coefficients, as well as an assessment of the typical (random) error and the 95% limits of agreement. The value of corrected peak power (628 [167] W) was higher (p < 0.05) compared with the uncorrected value (509 [109] W). Values of corrected (465 [95] W) and uncorrected (444 [87] W) mean power were similar (p > 0.05). The mean bias value for all power parameters equated to less than +/-1% of the absolute values of power measured. Intraclass correlation coefficients for all data sets ranged from 0.97 to 0.98. Coefficients of variation for uncorrected and corrected values of peak power were 2.8 and 4.5%, while corresponding values for mean power were 2.9 and 3.2%, respectively. The reproducibility of all power indices was below 5%. The results of this study indicate that both uncorrected and corrected measurements of peak power output and mean power output can be used to assess performance during sprint arm ergometry.