ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We proposed that there are significant correlations between muscle strength and bone mineral density in premenopausal women and that these correlations are site-specific. To test this hypothesis, we examined the relationships among site-specific bone mineral density, physical activity, and muscle strength in a group of 96 healthy premenopausal Caucasian women. Bone mineral density was measured at the lumbar spine and at three sites in the proximal femur (trochanter, femoral neck, and Ward's triangle) with dual-energy x-ray absorptiometry and at the mid-radius with single-photon absorptiometry. The muscle strength of hip and spinal muscle groups was determined with a strain gauge isodynamometer, and grip strength was measured with the JAMAR dynamometer. The strength of shoulder girdle muscle groups was evaluated with the use of free weights. Physical activity was determined by surveying the subjects and by using a standardized scale. Data analysis revealed significant linear correlations of muscle strength with bone mineral density at the mid-radius (r= 0.31;P= 0.002) and at the hip (r= 0.26;P= 0.01). Grip strength was significantly correlated with bone mineral density of both the spine and the femur (r= 0.24,r= 0.34;P< 0.05 for both). Back extensor strength correlated with bone mineral density of the hip (Ward's triangle;r= 0.23;P= 0.023). However, there was no significant positive correlation between the strength of the spinal flexor or extensor muscles and the site-related bone mass (lumbar spine). Only one of the three components of the physical activity score (job) positively correlated with vertebral bone mineral density (r= 0.21;P= 0.04). Physical activity negatively correlated with age (r= 0.24;P= 0.02). We conclude that in premenopausal women, the effect of muscle strength on bone mass is more systemic than site-specific. A positive correlation between vertebral bone mass and components of physical activity demonstrates that even job-related physical activity is an important factor in maintaining adequate bone mass.

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

摘要:

The relationship between muscle strength and bone density is well known, but only a limited number of studies relating muscle strength to bone mineral density of a site-specific limb have been performed. The main purposes of this study were as follows: (1) to assess the relationship between the strength of hip muscles and bone mineral density of the proximal femur in 100 postmenopausal women; (2) to compare strength values of three subgroups, which were formed on the basis of the femoral neck Z-scores. By using an isokinetic dynamometer (Cybex 350), muscle strength tests were performed for hip muscles and bone mineral density measurements were obtained by dual energy x-ray absorptiometry. Statistical analysis demonstrated a moderately positive correlation between bone mineral density of the femoral neck and hip muscle strength (with abductors:r= 0.267,P= 0.008; with adductors:r= 0.276,P= 0.007). A moderate correlation was also found between bone mineral density of Ward's triangle and hip adductors (r= 0.327;P= 0.001). When muscle strength mean values of subgroups were compared with each other, there was no statistically significant differences. These data may suggest that the isokinetic strength of hip muscles may not contribute to the bone mineral density of the proximal femur.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Fibrillation potentials have been reported to decline in amplitude with time after denervation. The use of maximum fibrillation potential amplitude to determine the relative acuity of axonal loss ("old"v"new/recurrent") has been advocated but with conflicting endorsements as to the appropriate benchmark amplitude, i.e., 100 μV compared with 250 μV. This investigation uses computer simulations to examine the rate of fibrillation potential amplitude decline expected given known values for muscle fiber size atrophy and conduction velocity slowing over time after denervation. Factors that affect the amplitude and potentially lead to erroneous interpretations in the clinical scenario of partially denervated muscle tissue are discussed. The use of fibrillation potential maximum amplitude criteria to determine the age of lesion onset in both totally and partially denervated muscle is fraught with technical and pathophysiological hazards of interpretation and must be considered cautiously, if at all, in clinical practice.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Unlike the well-examined cardiovascular changes during movement stimuli, changes of cerebral hemodynamics and cerebral metabolism in physical exercises have, as yet, rarely been studied. Our objective was to investigate whether there are changes in cerebral hemodynamics and cerebral metabolism caused by active and passive movement stimuli. Response to repetitive active and passive movement stimuli was studied in 14 volunteers (8 females, 6 males; mean age, 35.2 ± 8 yr). Each volunteer was subjected to four measurement series while performing a defined active and passive exercise program of the right upper or right lower limb. Measurement series were designed according to Aaslid's "evoked flow test"; exercises were performed for 20 s, followed by a rest of 20 s. This sequence was repeated 10 times in each series. As a measure of cerebral hemodynamics mean and peak blood flow velocity of the middle cerebral artery were recorded by transcranial Doppler sonography (Multidop-X-DWL). In addition, cerebral metabolism was quantified in a subsample by means of oxygenic cytochrome aa3 (respiratory chain enzyme), cerebral oxygen saturation using near infrared spectroscopy (Critikon). As well, noninvasive blood pressure (Penaz method) and expiratory pCO2were measured. Compared with resting measures, an increase in mean cerebral blood flow velocity of the middle cerebral artery of 3.8% (P= 0.003, pairedttest) was observed after active exercises of the right lower limb and 3.5% after active exercises of the right upper limb. Respective changes were 3.4% (P= 0.004) for passive exercises of the lower limb and 4.6% (P= 0.007) for passive exercises of the right upper limb. Peak cerebral blood flow velocity of the middle cerebral artery showed an even more pronounced increase during passive and active exercises in all cases, with values of between 12.2% (P< 0.001) and 13.6% (P< 0.001). Significant increases (1.5-3%) of cytochrome aa3 and cerebral oxygen saturation were observed during active and passive exercises. These studies show that active as well as passive exercises are followed by an increase of cerebral blood flow velocity. We attribute the increase of cerebral hemodynamic and cerebral metabolism to cerebral activation and autoregulative mechanisms.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We report on a 13-year-old female with idiopathic acute sensory neuronopathy mimicking a sensory form of Guillain-Barré syndrome, which was identified by using electrodiagnosis and spine magnetic resonance imaging. Motor conduction results were normal, but no sensory nerve action potentials were seen in the four limbs. On magnetic resonance imaging of the whole spine, the diffuse gadolinium enhancement of the dorsal roots in the spinal canal was detected, without evidence of intramedullary lesions. The clinical symptoms and electrodiagnostic findings had persisted for more than 18 months of follow-up.

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

摘要:

The purpose of the study contained herein was to determine the usefulness of electrical impedance for measurement of bladder volume in spinal cord-injured patients, with an assessment of the relationship between electrical impedance and bladder volume exclusively. The study was performed during urodynamic studies to match the exact bladder volume. Thirteen patients with complete spinal cord injuries were recruited. We used silver-silver chloride compound electrodes composed of one pair of current and amplitude electrodes to minimize the influence of superficial skin impedance. Each compound electrode was attached on the lower abdomen bilaterally after skin cleansing. Constant current (60 kHz-1.0 mA), converted from 9 V of direct current, was applied, and corresponding electrical impedance (Ω) was measured at "pre" (before urodynamic empty bladder), "full" (with a urodynamic filled bladder), and "post" (after urodynamic empty bladder) status. Electrical impedance at the full status was definitely lower than that at the pre and post statuses in all subjects, with a statistically significant difference (P< 0.001). The correlation between electrical impedance and bladder volume was negative (r= −0.7988), and the fact of how much the variation in electrical impedance could be explained by variation in bladder volume was estimated (r2= 0.6381). From these findings, we have determined that the electrical impedance analysis technique can be an alternative measure of bladder volume indirectly.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The objective of this case series study was reautomatization of gait after limb-saving surgery for tumors at a laboratory of gait analysis. Twelve patients (9 males and 3 females; mean age, 38 years) who underwent limb-saving surgery of the lower limb at least 1 year previously and ten normal subjects (3 males and 7 females; mean age, 37.5 years) were studied. The main outcome measures were walking speed and stride time duration under normal walking conditions as well as the use of different types of constraints. Patients walked with a lower preferred walking speed than the normal subjects. Patients showed a higher coefficient of variation of stride time in normal walking as well as complex walking compared with normal subjects. During walking with constraints, a significant decrease in stride time was found in patients but not in normal subjects. Although restoration of gait after limb-saving surgery is impressive, it is not complete (lower walking speed) and can break down under conditions of visual and cognitive load. Hence, the application of complex tasks reveals that gait reautomatization is not complete in these patients during a period of 2 to 5 years after surgery.

ISSN:0894-9115    

出版商:OVID    

年代:1998

数据来源: OVID