Rats and genetically manipulated mouse models have played an important role in the exploration of molecular causes of cardiovascular diseases. However, it has not been fully investigated whether mice or rats and humans manifest similar patterns of ventricular wall motion. Although similarities in anatomy and myofiber architecture suggest that fundamental patterns of ventricular wall motion may be similar, the considerable differences in heart size, heart rate, and sarcomeric protein isoforms may yield quantitative differences in ventricular wall mechanics. To further our understanding of the basic mechanisms of myofiber contractile performance, we quantified regional and global indexes of ventricular wall motion in mice, rats, and men using magnetic resonance (MR) imaging. Both regular cine and tagged MR images at apical, midventricular, and basal levels were acquired from six male volunteers, six Fischer 344 rats, and seven C57BL/6 mice. Morphological parameters and ejection fraction were computed directly from cine images. Myocardial twist (rotation angle), torsion (net twist per unit length), circumferential strain, and normalized radial shortening were calculated by homogeneous strain analysis from tagged images. Our data show that ventricular twist was conserved among the three species, leading to a significantly smaller torsion, measured as net twist per unit length, in men. However, both circumferential strain and normalized radial shortening were the largest in male subjects. Although other parameters, such as circumferential-longitudinal shear strain, need to be evaluated, and the causes of these differences in contractile mechanics remain to be elucidated, the preservation of twist appears fundamental to cardiac function and should be considered in studies that extrapolate data from animals to humans.

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This study deals with the quantitation of axial rotation at the knee. Passive rotation of the knee was measured at various degrees of flexion on 17 subjects with normal knees and 19 patients with unilateral anterolateral rotatory instability. Normal subjects were found to have bilateral symmetric rotational knee motion at each angle of flexion tested. When the knee is in a position of flexion between 30 and 90 degrees, there are approximately 45 degrees external and 25 degrees internal rotation. Rotatory motion decreases with further extension and, at 5 degrees of flexion, the knee has 23 degrees external and 10 degrees internal rotation. The knee with a torn anterior cruciate ligament and anterolateral rotatory instability was found to have an arc of rotation similar to the contralateral knee and to the control knees between 30 and 90 degrees flexion. At 15 degrees of flexion, a slightly greater arc of rotation was measured compared to normal knees. At 5 degrees of flexion, a significantly greater range of external (to 41 degrees) as well as internal (to 14 degrees) rotation was measured.

Background and Purpose. Standardized pediatric assessment tools such as the Pediatric Evaluation of Disability Inventory (PEDI) numerically quantify changes during rehabilitation through test scores, but they are unable to provide client-specific information regarding important changes in function. The purpose of this study was to identify the smallest change in PEDI scores during inpatient rehabilitation that was considered to be a minimal clinically important difference (MCID) by physical therapists and other clinicians. Subjects and Methods. A retrospective review was done of the medical charts of 53 children and youth (1–19 years of age) discharged from an inpatient rehabilitation hospital. Fifteen clinicians (5 physical therapists, 6 occupational therapists, and 4 speech and language pathologists) who were masked to the PEDI scores provided ratings of the magnitude of functional changes during inpatient rehabilitation using a Likert scale and a visual analog scale (VAS). Ratings by clinicians were reduced to 4 categories, including the MCID, and compared with PEDI change scores. Results. The MCIDs ranged from 6 to 15 points (X̄=11.5, 95% confidence interval=±2.8) for all PEDI scales. Likert scale and VAS ratings were correlated (τ=.73–.80). Discussion and Conclusion. Across all scales, PEDI change scores on the order of about 11% (0–100 scale) appear to be meaningful to clinicians during a child's or adolescent's inpatient rehabilitation. These data can serve as a starting point for interpreting group and individual changes on the PEDI during physical therapy intervention in inpatient rehabilitation.