Tolerance to morphine-induced increases in [14C]catecholamine synthesis in mouse brain.

Morphine sulfate increased the incorporation of carbon-14-labeled tyrosine into labeled catecholamines in the mouse brain. Tolerance was manifested by a shift to the right in the dose-response curve for morphine after mice were treated repeatedly with morphine. Naloxone, a specific morphine antagonist, also shifted the dose-response curve for morphine to the right.

Limitations of kinematics in the assessment of wheelchair propulsion in adults and children with spinal cord injury.

BACKGROUND AND PURPOSE: Recently, there has been a trend for designers to reduce the weight of wheelchairs. Wheelchair performance is frequently evaluated in clinical as well as laboratory settings by kinematic motion analysis. The purpose of this study was to examine the effect of weight on the kinematics of wheelchair propulsion in nonathletic adults and children with spinal cord injury. SUBJECTS AND METHODS: The weight of identical new low-weight test chairs (9.3 kg) was manipulated by adding weight (5 and 10 kg) in two matched groups (n = 10) of adults and children with spinal cord injury. The three-dimensional coordinates of reflective markers were obtained as the subjects performed level wheeling at a speed of 2 m/s. RESULTS: The pediatric group was found to have significantly lower wheeling speeds than the adult group. The addition of weight, however, did not alter the wheeling speeds in either group. Neither the proportions of the wheeling cycle spent in propulsion (24%) nor the angular (shoulder flexion-extension, elbow flexion-extension, shoulder abduction, and trunk flexion-extension) kinematics of wheeling changed with additions of weight in either group. The angular kinematics of the pediatric group, however, were different than those of the adult group. CONCLUSION AND DISCUSSION: These results indicate that adding weight in the range of 5 to 10 kg did not affect wheeling style under the level-wheeling, low-speed conditions of the study. It is possible that performance in wheelchair propulsion may be more appropriately determined by kinetic and energetic outcome measures than by kinematic measures.

Comparison of functional and medical assessment in the classification of persons with spinal cord injury.

For many reasons, persons with spinal cord injury (SCI) are classified according to a set of guidelines in which the term classification refers to a numeric value based on some selection of motor, sensory, and/or functional tests. The resulting classification is used as a means of quantifying the extent of neurological injury. Scales that focus on neurological injury (in the acute phase) differ from those that focus on functional ability (in the chronic phase). The relationship among these scales in grouping persons with SCI has not been ascertained. The purpose of the present study was to compare several classification systems within the same group of spinal cord injured subjects. Thirty subjects with traumatic SCI were classified by the same examiner and grouped according to three classification systems: 1) the American Spinal Injury Association (ASIA) Scale; 2) the Bracken Scale; and, 3) the wheelchair basketball (BB) Sports Test. Calculation of Spearman's Rho correlation coefficients showed positive associations between the ASIA Scale and BB Sports Test (0.81). The Bracken Scale showed a negative correlation with the ASIA system (-0.66) and the BB Sports Test (-0.48). Of the three classification systems, the ASIA Scale showed the greatest discrimination in grouping subjects with SCI in both mixed (complete and incomplete), as well as incomplete injuries. It was clear that these three systems could result in different patterns of subject grouping and thus might affect the outcome of the clinical research studies.

Kinematics of wheelchair propulsion in adults and children with spinal cord injury.

This study examined the kinematic features of wheelchair propulsion in two neurologically matched groups of adults and children with uncomplicated spinal cord injury. The average mass and age of the pediatric group was much smaller than the adult group (37.4kg and 11.3 years vs 68.5kg and 33.5 years). Each subject propelled his/her own chairs and new, low-mass wheelchairs at a steady, nominal speed of 2 m/sec across a level surface. Three dimensional video analysis determined the movement of upper body angles (elbow, shoulder, trunk, and shoulder abduction) based on reflective markers placed on the subjects' shoulder, elbow, wrist, and hip joints. Analysis of the temporal factors showed that although the average group overground velocities of the adult group (2.4m/sec) were significantly greater than the pediatric group (2.3 m/sec), the two groups spent comparable proportions of the wheeling cycle in propulsion (24%). Analysis of the angular kinematics (elbow, shoulder, and shoulder abduction angular changes over a time normalized wheeling cycle) showed that whereas the pediatric group did show significant absolute angular differences from the adult group, the angular changes over time were the same in both groups. The implications of this work are that, for the first time, it can be said that children propel their wheelchairs in the same manner as adults. In addition, these data were similar to those previously reported in athletic adult populations. We conclude that published data from adult wheelchair users may be applied to pediatric wheelchair users, thus providing a basis for pediatric wheelchair prescription.(ABSTRACT TRUNCATED AT 250 WORDS)

Development and clinical evaluation of a computerized limb volume measurement system (CLEMS).

Limb edema is a common problem in both rehabilitation and acute care settings. In the past, attempts to determine an optimal management strategy for limb edema have been limited by the lack of accurate, noninvasive, rapid, clinical tools for quantifying limb volumes. The water displacement method is slow and difficult to use in the clinical setting. Furthermore, water displacement requires that the limb be in a dependent position. The tape measure method is unreliable because it is difficult to position the tape measure on a swollen limb. The development and evaluation of a new tool called the computerized limb volume measurement system (CLEMS) is described. The shape and volume of a limb or limb segment can be rapidly measured by CLEMS, independent of limb position. The limb volumes generated by CLEMS were compared to volumes determined by water displacement and by a tape measure. Volumes of eighteen legs (plaster, nonedematous and edematous) were measured using CLEMS, water displacement, and the tape measure. In all cases, the CLEMS and water displacement methods showed close agreement. CLEMS was found to be a reliable and valid new method of determining limb volume; whereas, the tape measure method was found to be invalid. This new tool allows clinicians to measure the efficacy of different treatment strategies in the management of limb edema.