摘要:

The median frequency of the myoelectric signal of the cervical paraspinal muscles was studied in 28 normal subjects in prone and sitting positions. Median frequency parameters (initial median frequency and slope of the median frequency) of the myoelectric spectrum were monitored during sustained isometric neck extensions at 20%, 50%, 80%, and 100% of maximum voluntary contractions. Force output of 100% maximum voluntary contractions was also measured in the prone and sitting positions. Reliability of the median frequency parameters for repeated trials at various force levels was computed. There were significant differences (P< 0.05) in the median frequency parameters between the prone and sitting positions, and there was significantly higher 100% maximum voluntary contractions force production in the prone position than in the sitting position (P< 0.05). There were also high reliability estimates for the median frequency parameters in both test positions. The cervical paraspinal muscles may use different strategies of recruiting motor units during force production in various postures of the neck. It therefore is necessary to standardize the testing procedures before the median frequency parameters can be considered objectively to measure the. muscle function in the neck.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The purpose of this study is to elucidate anatomically the, atlantoaxial transarticular screw fixation described by Magerl in 1979 and compare it biomechanically with Gallie wiring. Five human C1-C2 specimens were tested in flexion/extension and rotation intact, then after wiring and screw fixation. Mean screw length was 39 mm, 25 mm in the C2 lamina and 14 mm in the lateral mass. Angular displacement of screwed specimens was significantly less than control or wired groups. Stiffness at 0–0.5 Nm loads was significantly greater for screwed specimens than for wired or controls (101 ± 49 Nm, 10.3 ± 9.2 Nm, and 1.96 ± 0.18 Nm, respectively). All specimens withstood 5 Nm in flexion and extension without failure. Screw fixation provides stability comparable to Gallie wiring and is stiffer at low-range forces and rotational angles.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Epidural empyema is a rare complication of elective spinal surgery. Four such cases are described. The clinical features of this postoperative complication were surprisingly vague and misleading. Fever was uncommon. Local inflammatory signs or rapid neurologic deterioration were absent. Computerized tomography proved useful in diagnosis and follow-up. Unlike spontaneous spinal epidural abscess, postoperative spinal epidural empyema had a benign course. Causative bacteria were miscellaneous. Surgical evacuation of the purulent collection and appropriate antibiotic therapy resulted in cure in all cases.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Fifty-three adult idiopathic scoliosis patients whose fusions ended caudally between L2 and S1 were reviewed relative to criteria for selection of the lowest fused vertebra and their outcome. The Harrington stable zone, central sacral line, and the presence of rotary subluxation, arthritis, spondylolisthesis, vertebral body and disc space wedging were studied. Preoperative and postoperative pain, quality of life, and decisions for surgery were surveyed with a 94% response. Results showed the older the patient, the lower the fusion. The Harrington stable zone was useful, whereas the central sacral line frequently indicated longer fusions by as much as three segments. The presence of pathoanatomic features also dictated lower fusions. Patients in whom the lowest level of fusion was consistent with selection criteria had reduced frequency and intensity of low-back pain.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Forty-seven patients were treated with spinal fusion and Cotrel-Dubousset instrumentation and were followed for an average of 28 months. Spinal procedures included: 1) posterior spinal fusion for idiopathic scoliosis (26 patients); 2) posterior pseudarthrosis repair (5 patients); 3) combined anterior/posterior fusion to the sacrum (6 patients); and 4) combined anterior/posterior osteotomies (10 patients). Group 1: Partial derotational correction was achieved for adolescent idiopathic scoliosis. Group 2: Successful pseudarthrosis repair was achieved in four patients. Group 3: A solid arthrodesis was obtained in two patients, whereas the other three patients underwent revision of sacral screw fixation for pseudarthrosis. One patient died postoperatively. Group 4: Pain relief and a balanced correction was achieved in all patients. The Cotrel-Dubousset system appears to be a versatile system and provides a wide range of possibilities for a variety of spinal problems.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In an effort to improve the cost-effectiveness of primary care for low-back pain, we developed, implemented, and evaluated a physician education intervention. The program was designed to provide family physicians with specific information, tools, and techniques that our previous studies and the literature suggested should be associated with more satisfying and cost-effective care for low-back pain. The in-clinic educational intervention included feedback of the findings of our previous studies of care for back pain (comparing family physicians and chiropractors), an up-to-date summary of scientific knowledge relevant to the management of back pain in primary care, a videotape contrasting ineffective and effective patient encounters, and a clinical assessment form for low-back pain. The back pain-related beliefs, attitudes, and behaviors of 15 primary care providers in a large health maintenance organization clinic and of 14 family physicians in six group practices were assessed before and after the intervention. Significant increases were noted in the proportions of providers who felt confident they knew how to manage low-back pain, who believed their patients were satisfied, and who claimed they reassured patients that they did not have serious disease. The intervention, however, had little impact on the prevalence of negative feelings about patients with back pain or frustration with patients who wanted their doctor to “fix” their problem. The intervention had a similar impact on health maintenance organization and fee-for-service physicians.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

A physician education intervention was previously found to have significantly improved perceived physician knowledge, confidence, and patient-reassuring behavior in the treatment of low-back pain. This study examined whether this intervention, presented in a health maintenance organization clinic, had an effect on patient outcomes. Outcomes of care for 148 patients seen for low-back pain before the intervention were compared with outcomes of care for 157 patients seen after the intervention. Patients were telephoned 2–4 weeks after their back-pain visit and were asked about symptom improvement, amount of disability, and satisfaction with care. Satisfaction was measured with a three-dimensional instrument for low-back pain developed specifically for this study, which was found to be valid and reliable. The preintervention and postintervention patient cohorts were similar in terms of key baseline variables. Despite its apparent benefit to physicians, the intervention did not result in significant improvements in any patient outcomes, even for the subset of patients whose physicians had perceived the greatest benefit.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Some parameters of the electromyographic power spectrum of the paraspinal muscles were recorded and analyzed with regard to their ability to discriminate between normal controls and patients with back pain classified as “avoiders” or “confronters” by their responses to the Pain Behavior Checklist. In terms of the activity of the multifidus muscle, the avoider group displayed spectral changes towards lower frequencies, reduced variability in the density spectrum, and higher values of estimated initial frequencies. Measures of the activity of the iliocos- talls lumborum did not contribute in any significant way to these group differences. Based on these findings, and on the available literature concerning the histology and physiology of paraspinal muscles, it is proposed that the observed characteristics of the avoider group may be due to a reduced ratio of slow twitch to fast twitch muscle fibers in the multifidus.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

This study compared the effects of sitting with portable supports in either a kyphotic or lordotic posture on low-back and referred pain. Two hundred ten patients with low-back and/or referred pain were randomly assigned to either a kyphotic posture or lordotic posture group. The kyphotic and lordotic postures were facilitated by the use of a flat foam cushion or lumbar roll, respectively. Pain location, back pain, and leg pain intensity were assessed over a 24–48-hour period under both standardized clinical settings and general sitting environments. When sitting with a lordotic posture, back and leg pain were significantly reduced and referred pain shifted towards the low back. This study demonstrates that in general sitting environments a lumbar roll results in: 1) reductions in back and leg pain; and 2) centralization of pain. These findings do not apply to patients with stenosis or spondylolisthesis, whose symptoms may be aggravated by use of a lumbar roll.

ISSN:0362-2436    

出版商:OVID    

年代:1991

数据来源: OVID