Faculty Bibliography

OBJECTIVE: An apparatus and procedure are described to determine position specific normalization coefficients for surface EMG of upper extremity musculature. STUDY DESIGN: Thirty-nine subjects were tested three times. Repeatability of EMG measurements across test sessions was determined by computing intraclass correlation coefficients. Two-way analysis of variance was used to test upper extremity position dependent differences in EMG measurements. BACKGROUND: EMG measurements are susceptible to error from skin movement and muscle length changes, both of which may occur when upper extremity positions vary. Normalization of the EMG signal without consideration for such positional influences may lead to erroneous conclusions regarding muscle activation during functional tasks. METHOD: An apparatus was designed that allowed subjects to perform three repetitions of maximum elbow flexion, forearm pronation, wrist extension, and wrist flexion with the forearm in neutral and pronated positions. Surface EMG was sampled from eight muscles. Mean EMG on maximum voluntary contraction was computed, and resting EMG was subtracted to obtain EMG normalization coefficients. RESULTS: Upper extremity position affected the EMG normalization coefficient for biceps brachii, which was lower in the pronated position, and extensor carpi radialis, which was higher in the pronated position (P<0.00625). CONCLUSIONS: The apparatus accommodates various combined positions of the elbow, forearm and wrist. The normalization procedure is efficient for testing subjects who are being observed during functional tasks. Only two muscles were affected by upper extremity position, but group trends were not always consistent with individual behavior. This method would ensure the use of appropriate EMG normalization coefficients regardless of individual variation. RELEVANCE: This method is effective for normalizing EMG signals using task specific upper extremity positions. It may be used to test isometric exertions of distal upper extremity musculature for clinical and research purposes

This is a prospective cohort study of patients with acute treated severe sciatica. The objectives of the study are, firstly, to describe the recovery of muscle performance by manual and isokinetic muscle testing in patients with acute severe sciatica over 1 year, and secondly, to discuss the potential clinical relevance of the isokinetic testing of the ankle for patients with acute sciatica. In clinical daily practice, muscle performance is evaluated by means of isometric manual tests. Different authors using manual muscle tests have reported the long-term outcome of the muscle function in patients with sciatica. Overall, the results are good in terms of the recovery of muscle strength. However, it is not clear whether the isometric strength is sufficiently relevant to evaluate the more complete muscle performance of the affected muscles in patients with sciatica. This study presents data on the muscle recovery measured with manual testing and isokinetic testing of patients with severe sciatica. Consecutive patients admitted to the Cantonal Hospital for conservative management of severe acute sciatica were eligible for inclusion in the study. Patients were evaluated at admission, discharge, and follow-up at 3, 6, and 12 months. All the visits included a standardized clinical examination and the completion of questionnaires. Imaging and electromyography were conducted at the first visit. Isokinetic muscle tests at 30 degrees/s and 120 degrees/s were performed at discharge and follow-up visits. Manual and isokinetic tests were performed on foot and ankle flexor and extensor muscles. Eighty-two consecutive patients (66% men), with a mean age of 43 (+/-10.3) years, entered the study. The prevalence of major muscle weakness was low, with 7% of patients unable to perform toe walking and 11% unable to walk on the heel at visit one. Moreover, motor deficit defined as a score of 4 or less (out of 5) was found in 15% of subjects at the first evaluation. Such severe deficits were not found during the last three visits. The isokinetic tests showed a higher prevalence of muscle function impairment. At visit 5, the isokinetic test showed impaired muscle function recovery from 23% to 32%, while the manual test showed almost full recovery. The issues of agreement between manual and isokinetic muscle testing are discussed. In this selected and homogeneous cohort of patients, the prevalence of motor deficit was rather low and the outcome excellent according to the results of the manual testing. Isokinetic muscle tests showed a higher prevalence of deficit and a much slower recovery. The manual muscle test is a crude clinical test. For more indepth muscle performance evaluation, additional testing may be necessary, especially for those patients with physically demanding jobs or activities

This study reports the test-retest reliability of a 25-item occupational risk factor questionnaire that can be self-administered in clinical settings and used in outcome studies of low back pain or return to work programs. Subjects were 24 patients (workers on sick leave due to acute low back pain), 29 co-workers on active duty in the same jobs in a utility company, and 53 supervisors. Eighty-six subjects were re-tested within a mean interval of 7-10 days; one group of 20 supervisors was re-tested within 81 days. The questionnaire was self-administered during individual interviews. Reliability was estimated by the kappa statistic as the agreement on the scores within the raters in each group. The agreement ranged from 'slight' (0.15) to 'almost perfect' (0.93) when the re-test interval was less than 43 days. Patients and non-patients were consistent in their assessment of the job demands. rights reserved

The measurement of the avidity of cytomegalovirus (CMV) immunoglobulin G (IgG) antibodies has been shown by several investigators to be useful in identifying and excluding primary CMV infections in pregnant women. In this work, we examined the diagnostic utility of reflex testing of CMV IgM-positive specimens from pregnant women by using a CMV IgG avidity assay. The utility of this approach was directly dependent on the sensitivity of the CMV IgM assay employed during the initial screen. The higher initial reactivity rate of the AxSYM CMV IgM assay was necessary in order to detect CMV IgM in specimens containing low-avidity CMV IgG antibodies, indicative of a primary CMV infection, which other CMV IgM assays (Behring, Vidas, Captia, and Eurogenetics) fail to detect in some cases. The use of the AxSYM CMV IgM assay, followed by an avidity test, should result in more accurate diagnosis of CMV infection in pregnant women