ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Patients with infantile spinal muscular atrophy develop pectus excavatum along with a severe restrictive syndrome as a result of failure to expand the upper chest wall and lungs because of intercostal muscle weakness. By using an automatic motion analyzer to provide three-dimensional computer analyses of images sampled at 25 Hz, 9 spinal muscular atrophy Type II patients and 13 controls underwent kinematic analysis of thoracoabdominal movements partitioned into the upper thorax, lower thorax, and abdominal volume compartment. The analyses were performed during spontaneous breathing for the controls and during spontaneous breathing and while using mechanically assisted ventilation for the patients. Vital capacity, maximum inspiratory pressures, and nocturnal oxyhemoglobin saturation and transcutaneous carbon dioxide tensions were also measured for the patients. The kinematic data demonstrated a paradoxical ventilatory pattern for the spontaneously breathing SMA patients with the following inspiratory volume changes: upper thorax, −6.4 ± 9.6%; lower thorax, 7.3 ± 15.8%; abdominal, 99.1 ± 21.3%. During mechanical ventilation, the compartmental volume changes were as follows: upper thorax, 13.5 ± 6%; lower thorax, 13.7 ± 7.9%; abdominal, 72.7 ± 9.3%. This kinematic pattern is comparable with that seen in spontaneously breathing normal subjects. We conclude that mechanical ventilation can normalize kinematic volume changes during alveolar ventilation and that this might help deter loss of thoracic compliance caused by the chronic hypoventilation of the upper thoracic compartments. Kinematic analysis may be helpful for choosing the ventilation parameters to optimize therapeutic benefits.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The objective of this study was to investigate effectiveness of force application, the ratio power output/energy expenditure, and timing parameters of wheelchair propulsion in persons with tetraplegia (TP,n= 17) and paraplegia (PP,n= 12), at two different intensity conditions. All subjects performed a maximal exercise test on a wheelchair ergometer. Exercise bouts with an intensity of 30 to 50% and 60 to 80% of the maximal power output were analyzed. Effectiveness of force application, defined as the ratio of the effective force and the total force, was considerably lower in TP, compared with PP. Effectiveness of force application in the plane of the wheel was comparable between TP and PP. TP showed a significantly lower effectiveness of force application in the frontal plane and applied the forces in a more lateromedial direction to the hand rim. The ratio power output/energy expenditure, calculated as an indication of gross mechanical efficiency, was considerably lower in TP and was associated with the effectiveness of force application (r= 0.64;P< 0.01). Timing parameters showed that TP positioned their hands in a more backward position on the hand rim. Comparing the different intensity conditions revealed that force was applied more effectively, and the ratio power output/energy expenditure was higher at the higher intensity condition. Push time, relative to cycle time, increased, and beginning angle showed a forward shift with a higher load. TP tended to decrease, whereas PP showed a tendency for an increase in stroke angle with a higher load. The low effectiveness and different pattern of force application in TP should be taken into account when developing other wheelchair propelling mechanisms and training programs for this population.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Wheelchair sports and daily manual wheelchair propulsion are dominated by frequent short-term power demands. The purpose of the current cross-sectional study was to determine the variation in propulsion technique in association with sprint power production among elite wheelchair athletes. Therefore, 67 wheelchair athletes (different impairments; 17 female and 50 male athletes; age, 29.1 ± 7 yr; body weight, 60.7 ± 11.8 kg; training hours, 12.9 ± 6.4 h · wk−1; VO2 peak, 1.7 ± 0.7 liter · min−1; aerobic power output, 72.2 ± 36.7 W) were studied during the World Championships and Games for the Disabled in Assen (1990) on propulsion technique and anaerobic work capacity in a 30-s sprint test on a computer controlled wheelchair ergometer. Mean power output (P30) (97 ± 45.8 W; range, 8.3-195.3 W) and heart rate (158.6 ± 23.6 b · min−1) were highly variable and seemed associated with impairment level: track athletes, classified in four different functional classes, showed a class-related P30 of 23, 68, 100, and 138 W for the male athletes (n= 38). Sprint power relative to body weight varied between 0.36 W · kg BW−1± 0.04 and 1.85 W · kg BW−1± 0.43 for the different subject groups. Propulsion technique in terms of forces applied to the rim and timing showed significant differences between subject groups for the majority of parameters studied. Apart from the mediolateral force and the negative dip at the start of the push phase, the technique parameters were significantly related to power production. Fraction effective force, the ratio between the total force vector and the effective force applied to the hand rim, appeared low on average (especially for subjects with cerebral palsy and those with a high spinal lesion) but showed a significant correlation with power output (r= 0.5). In general, propulsion technique parameters were related to both performance and functionality. The number of training hours showed a small but significant relation with peak power (r= 0.31), peak torque (r= 0.4), the amount of work per push (r= 0.41) and the total force vector (r= 0.31), stressing the role of training status, next to disability, as important mediating factor in both propulsion technique as well as performance capacity. No association between training hours and fraction effective force was seen. It can be concluded that propulsion technique and performance parameters are highly variable among wheelchair athletes. Also, propulsion technique is strongly associated with functionality and training hours and does clearly relate to performance. The current results on technique and performance and their possible causal relationship, but also with impairment and sports discipline, must be further substantiated in a longitudinal study design.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

This study explores the "higher order" cognitive abilities of conceptual reasoning, problem solving, mental flexibility, and efficiency in 36 adolescents with spina bifida. The subjects, age 10 to 23 years, were assessed on a set of neuropsychological measures, and an individual profile analysis was conducted. All subjects, regardless of intelligence quotient, evidenced significant impairments of mental flexibility, efficiency of processing, conceptualization, or problem-solving ability. Separate data analysis was carried out for subjects with an average intelligence quotient. Results indicated a high degree of variability within profiles with at least one area of dysfunction (as determined by performance less than the 15th percentile) for each subject. This study demonstrates the need for individual analysis of "higher order" cognitive functions including conceptual reasoning, problem solving, mental flexibility, and efficiency of thinking for children who have spina bifida, regardless of level of lesion or general intelligence level. It is argued that neuropsychological deficits underlie the "motivational" and academic difficulties observed often among this population, especially for those with an average intelligence quotient. These data support the need to assess conceptual abilities in children with spina bifida and to provide consultation and early intervention services.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID