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OBJECTIVE: Although the role of reputation in determining the relative standings in the U.S. News & World Report (USNWR) annual rankings of the top 50 hospitals has received analytical attention, the role of reputation in the best children's hospitals pediatric specialty rankings has not been quantified. Our goal was to quantify the role of reputation in determining the relative standings of the top-ranked pediatric specialties and their associated hospitals in the 2008–2010 editions of the USNWR best children's hospital rankings. METHODS: A cross-sectional study of USNWR data collected from the top 30 hospitals in each of 6 (and later 10) specialties was performed. The main outcome measures were rankings based on total USNWR scores and subjective reputation scores. RESULTS: On average, rankings based on reputation scores alone correlated with USNWR overall rankings; correlation coefficients ranged from 0.80 to 0.98 (Spearman Correlation; mean P < .001). This relationship was consistent over all 3 survey years. CONCLUSIONS: The relative standings of the top 30 pediatric hospitals in each of 10 specialties are largely explained by the compelling correlation between subjective reputation scores and ranking scores.

In this study, we assessed how ungraded jogging and graded walking at the same rating of perceived exertion (RPE) affect heart rate and oxygen consumption ([Vdot]O(2)). Twenty untrained participants completed a treadmill test to determine peak [Vdot]O(2) (mean = 40.3 +/- 6.3 ml . kg(-1) . min(-1)). Participants completed separate 30-min trials of moderate exercise (RPE of 13 on the Borg 6-20 scale) in random order on the treadmill: graded walking and ungraded jogging. Treadmill speed or grade was adjusted throughout the trial by the experimenter based on participant responses to maintain an RPE of 13. The jogging trial produced a significantly higher heart rate (161 +/- 18 vs. 142 +/- 24 beats . min(-1)) and [Vdot]O(2) (7.4 +/- 1.8 vs. 5.8 +/- 1.5 METs) (P0.01) than the walking trial. Treadmill grade decreased significantly during the walking trial (11.1 +/- 2.3% to 10.0 +/- 2.2%; P0.01), but treadmill speed did not change significantly during the jogging trial (5.2 +/- 1.0 miles . h(-1) to 5.0 +/- 0.9 miles . h(-1)) (P0.05), in an effort to maintain constant RPE. These findings provide evidence that similar perceptions of effort during graded walking and ungraded jogging do not produce similar cardiovascular and metabolic responses. The results indicate that, for a given prescribed perceived effort, jogging provides a greater stimulus for fitness benefits and caloric expenditure.

The purpose of this study is to assess cardiovascular responses to lower body positive pressure (LBPP) and to examine the effects of LBPP unloading on gait mechanics during treadmill ambulation. We hypothesized that LBPP allows comfortable unloading of the body with minimal impact on the cardiovascular system and gait parameters. Fifteen healthy male and female subjects (22–55 yr) volunteered for the study. Nine underwent noninvasive cardiovascular studies while standing and ambulating upright in LBPP, and six completed a gait analysis protocol. During stance, heart rate decreased significantly from 83 ± 3 beats/min in ambient pressure to 73 ± 3 beats/min at 50 mmHg LBPP ( P < 0.05). During ambulation in LBPP at 3 mph (1.34 m/s), heart rate decreased significantly from 99 ± 4 beats/min in ambient pressure to 84 ± 2 beats/min at 50 mmHg LBPP ( P < 0.009). Blood pressure, brain oxygenation, blood flow velocity through the middle cerebral artery, and head skin microvascular blood flow did not change significantly with LBPP. As allowed by LBPP, ambulating at 60 and 20% body weight decreased ground reaction force ( P < 0.05), whereas knee and ankle sagittal ranges of motion remained unaffected. In conclusion, ambulating in LBPP has no adverse impact on the systemic and head cardiovascular parameters while producing significant unweighting and minimal alterations in gait kinematics. Therefore, ambulating within LBPP is potentially a new and safe rehabilitation tool for patients to reduce loads on lower body musculoskeletal structures while preserving gait mechanics.

Although metaphyseal radiolucent changes are often seen in patients with Legg-Calvé-Perthes disease, the pathogenesis of these changes remains controversial. The purpose of the present study was to determine the prevalence and histopathological characteristics of these metaphyseal radiolucent changes in a piglet model of ischemic necrosis of the capital femoral epiphysis.Ischemic necrosis of the right femoral head was produced in fifty piglets by surgically placing a ligature tightly around the femoral neck. The contralateral, left hip of each animal was used as a control. Radiographs and histological sections of the femoral heads were examined at two, four, and eight weeks. The radiographs were used to measure the femoral neck length in order to assess growth disturbance.Thirteen of the fifty animals were found to have radiolucent changes in the proximal femoral metaphysis on the side of the infarcted femoral head. These changes were observed in none of the twelve animals that were evaluated at two weeks, in one of the fourteen animals that were evaluated at four weeks, and in twelve of the twenty-four animals that were evaluated at eight weeks. The radiolucent changes ranged from a focal cystic lesion to a diffuse area of radiolucency around the proximal femoral physis. Three distinct types of histological changes were observed in the metaphysis. Type-I changes were characterized by focal thickening of the physeal cartilage extending down into the metaphysis. Some of these lesions demonstrated cystic degeneration of the thickened cartilage. Type-II changes were characterized by central disruption of the physis and resorption and replacement of the metaphyseal bone in the region by fibrovascular tissue. Type-III changes were characterized by diffuse resorption of the physeal cartilage and resorption of the adjacent metaphyseal and epiphyseal bone. The mean femoral neck length on the infarcted side in animals with metaphyseal radiolucent changes was significantly shorter than that in animals without metaphyseal radiolucent changes (p = 0.02).Metaphyseal radiolucent changes frequently were observed in this piglet model at eight weeks after the induction of ischemia. The metaphyseal radiolucent changes were associated with histopathological lesions of the physis. The present study suggests that the presence of metaphyseal lesions can result in a greater growth disturbance of the proximal femoral physis than is seen in the absence of metaphyseal lesions.The present study supports the clinical observation that the presence of diffuse metaphyseal radiolucent changes may be associated with substantial growth disturbance of the proximal part of the femur in patients with Legg-Calvé-Perthes disease. The study provides a histopathological basis for proximal femoral physeal growth disturbance that has not been clearly demonstrated in the past. These findings also may provide a histopathological basis for the fluidfilled metaphyseal cysts that sometimes are observed on the magnetic resonance imaging scans of these patients.

This study investigated the mechanical effects that cycling has on running style which may explain the discomfort associated with the transition from cycling to running. The joint angles, angular velocities, reaction forces, and reaction moments of the left and right hip, knee, and ankle joints as well as stance time, flight time, stride length, and maximum vertical displacement of the center of gravity were measured using high-speed video and ground reaction force data. Data were collected from 11 competitive biathletes and triathletes. Each subject's running mechanics were determined from 10 trials for each of three conditions: (a) unfatigued, (b) immediately following 30 min of running, and (c) immediately following 30 min of bicycling. The results indicate that a person's running mechanics, as described by the variables above, are virtually unchanged between each of the three conditions. Therefore, awkwardness of the bicycle-to-run transition may not be related to a change in running mechanics.