PubMed Health⌕ Search

Biomedical subjects

D A Neumann

Publications and source records attributed to D A Neumann.

At least 55 records · Page 3Linked to original sources
PubMed1990

An electromyographic analysis of the hip abductor muscles during a standing work task.

Research data strongly suggest that osteoarthritis of the hip occurs statistically more often on the right side. A possible contributing factor to this right-sided bias in frequency may be that the articular cartilage on the right hip is subjected to relatively higher muscular-based forces throughout a lifetime. As an initial attempt to study this possibility, this research examined healthy persons to determine the existence of a "dominant" hip similar to that expressed for handedness. Electromyographic (EMG) analysis was used to compare the electrical activity between the right and left hip abductor muscles during a standardized standing work task using 40 right-handed and 40 left-handed healthy subjects. Analysis of the data showed that the hip muscle on the side of the subject's handedness produced higher normalized EMG activity than did the opposite hip; however, the differences were not all statistically significant. The trend of this data set, however, warrants further research into a possible association between hip dominance, asymmetrical muscle use, and the development of hip osteoarthritis.

Adult↗
PubMed1989

Biomechanical analysis of selected principles of hip joint protection.

This review article discusses the role of the hip abductor muscles in the generation of forces at the hip joint. The biomechanical rationale behind selected clinical principles of hip joint protection for the patient with hip osteoarthritis is discussed. These principles are based primarily on the benefit of reducing the magnitude of hip abductor muscle forces during walking. The specific hip joint protection principles that are analyzed are loss of body weight, walking with an antalgic limp, the use of a cane, proper methods of load carriage, and the reasons for certain orthopedic surgeries. The reduction of these myogenic hip joint forces for the patient with a painful hip and/or hip with arthritis should be considered an important component of the clinical management of the hip.

Biomechanical Phenomena↗
PubMed1989

Electromyographic analysis of hip abductor musculature in healthy right-handed persons.

The right hip abductor (HA) musculature has been reported to demonstrate stretch weakness attributable to chronic elongation imposed by standing posture common to right-handed healthy individuals. Research has shown side-specific differences in maximal isometric torque-hip abduction angle curves for the HA muscles in a similar population. The purposes of this study were to assess isometric hip abduction torque in a sample of 40 healthy right-handed persons and to compare side differences in the HA muscles' neural drive index across a wide range of hip abduction angles. The neural drive index was defined as the magnitude of the normalized surface electromyographic activity divided by the absolute magnitude of a submaximal (20% of maximal) isometric HA muscle torque. Data were collected while subjects were positioned supine with trunk and pelvis stabilized. Statistical analysis of the data did not support earlier research on right HA muscle stretch-weakness; however, trends in the data suggest the need for further research. We also discuss the functional role of the passive noncontractile elements of the HA musculature.

Adult↗
PubMed1988

Comparison of maximal isometric hip abductor muscle torques between hip sides.

A posturally induced "stretch weakness" of the right hip abductor muscles has been reported in many healthy right-handed persons in the literature. The purpose of this study was to test for differences in the maximal isometric hip abduction torque produced between hip sides across multiple hip abduction angles. The torques were measured on 40 healthy right-handed individuals using a specialized torque-testing table at hip abduction angles of -10, 0, 10, 20, 30, and 40 degrees. Statistical analysis of the results did not demonstrate a specific "weakness" of the right hip abductor muscles at the hip angle used to clinically test them. The results, however, did demonstrate statistically significant differences in the torque-hip angle slopes across hip sides. We hypothesized that these slope differences may result from muscle adaptation to lengths imposed by standing posture. We discuss how manual muscle testing procedures may bias the likelihood of encountering stretch weakness in muscles that are habitually maintained at near-maximal elongation.

Adult↗
PubMed1987

Salmonella newport infections transmitted by fiberoptic colonoscopy.

During a 2-week period following the colonoscopy and biopsy of a patient with acute Salmonella newport gastroenteritis, S. newport was recovered from colonic aspirates or fecal specimens of eight of 28 patients from whom specimens were cultured during or after colonoscopy. Two of the eight persons from whom S. newport was isolated developed acute gastroenteritis, two had asymptomatic infections, and four had positive aspirates collected through a colonoscope but did not become infected. Although S. newport was never recovered from the four colonoscopes used during the outbreak, cultures of one of the colonic biopsy forceps grew S. newport. Contamination of the equipment most likely occurred during colonoscopy of the index patient. Inadequate disinfection of the equipment allowed the organism to survive and possibly to cross-contaminate other colonoscopes, and the organism was then transmitted to other patients by use of the contaminated colonoscopes or the contaminated biopsy forceps. Implemented control measures terminated the outbreak.

Adult↗
PubMed1986

Influence of route of administration on the humoral response of channel catfish (Ictalurus punctatus) to Yersinia ruckeri.

Channel catfish were inoculated intraperitoneally, intramuscularly, or intraesophageally with Yersinia ruckeri. Three antigen doses were administered by each route of injection. Four fish from each treatment were sacrificed at 5-day intervals for 40 days. Serum from each individual was tested for antibody activity against Y. ruckeri by indirect enzyme-linked immunosorbent assay (ELISA). High titers of anti-Y. ruckeri antibody were elicited by all doses (10(5) to 10(9) cells/g of fish) regardless of the route of administration. Mean titers for saline injected fish ranged up to 1:64 for each route of inoculation while mean titers for bacteria injected fish ranged up to 1:4096. Mean titers of 1:128 or greater were observed by day 15 post injection; titers peaked about day 30 and diminished thereafter. Channel catfish were most responsive to the antigen (10(7) to 10(9) cells/g of fish) when administered intramuscularly although lower doses (10(5) to 10(6) cells/g of fish) administered intraperitoneally elicited a substantial response. There was little evidence of dose-dependent responses for any of the routes of immunization. The rapid onset of relatively high serum titers suggests that the fish were mounting a secondary response to Yersinia ruckeri.

Animals↗
PubMed1985

Effect of load and carrying position on the electromyographic activity of the gluteus medius muscle during walking.

Physical therapists often teach people with hip osteoarthritis ways to decrease gluteus medius muscle activity of the stance limb during gait. The rationale for decreasing this muscle activity is that hip muscle contraction needed for frontal plane hip stabilization is responsible for a large component of the hip joint compressive forces during stance. The magnitude and carrying position of external loads during walking are both variables that influence requirements of gluteus medius muscle force. Therefore, the purpose of this study was to determine through EMG, the relative amounts of gluteus medius muscle electrical activity produced during the stance phase of gait when subjects used varying combinations of load size (10 and 20% of body weight) and carrying position of the hands (contralateral or ipsilateral to a given hip, or anterior or posterior to the chest). We studied 24 healthy subjects and used their EMG activity during the stance phase of gait as an indication of the relative amount of myogenic hip compression force. Results indicated statistical differences in EMG according to carrying condition with the contralateral position (with loads of 10 and 20% of body weight) producing the highest levels of EMG. We discuss the kinesiologic reasons for results and the prevention of hip osteoarthritis in occupational settings.

Adult↗
PubMed1979

The visible vessel as an indicator of uncontrolled or recurrent gastrointestinal hemorrhage.

Although endoscopic examination in patients with bleeding of the upper gastrointestinal tract has improved diagnostic accuracy, it has not been useful in predicting clinical outcome and has not been shown to improve the patients' prognoses. This article describes a subgroup of patients with acute upper gastrointestinal bleeding whose clinical outcome can be predicted at the time of endoscopy. In 28 of 317 patients who underwent endoscopy, a "visible vessel" was seen in an ulcer presumed to be the bleeding site. All 28 were later recommended for operation because of recurrent (86 per cent) or uncontrolled (14 per cent) hemorrhage. In contrast, 75 per cent of the remaining 289 patients in whom vessels were not seen, whether or not bleeding from ulcers, had single bleeding episodes managed medically. Since patients with a "visible vessel" can be expected to have uncontrolled or recurrent hemorrhage, surgical treatment should be considered at the time of endoscopy if such a vessel is seen.

Acute Disease↗