Search PubMed⌕ Search

Biomedical subjects

T G Mayer

Publications and source records attributed to T G Mayer.

At least 55 records · Page 3Linked to original sources
PubMed1988

Progressive isoinertial lifting evaluation. II. A comparison with isokinetic lifting in a disabled chronic low-back pain industrial population.

The Progressive Isoinertial Lifting Evaluation (PILE), as described in Part I of this series of articles, is a simplified test combining psychophysical and isoinertial protocols to provide an unconstrained lifting assessment. In the second part of this study, 100 chronically disabled low-back pain patients (57 men and 43 women) were studied at two points: 1) at initial evaluation, when referred for possible entry into a comprehensive Functional Restoration treatment program; and 2) at the conclusion of the treatment (an average 7 weeks later). Results of simultaneous lumbar PILE and Cybex Liftask (Lumex, Ronkonkoma, NY) tests are presented, showing that patients may frequently double or triple initial lifting capacity after undergoing the functional restoration training program, achieving lifting levels at or above normal for incumbent industrial workers. Overall, results demonstrate that the PILE test can be an effective baseline screening test for lifting capacity under certain circumstances. Although several drawbacks affecting the PILE as an isolated test are discussed, its usefulness as part of a battery of physical capacity tests making up a quantitative functional evaluation is clearly demonstrated. Finally, the potential use of PILE as a safe, inexpensive, simple, and relevant screening test for frequent lifting capacity in worker selection is discussed.

Back Pain↗
PubMed1987

A prospective two-year study of functional restoration in industrial low back injury. An objective assessment procedure.

One hundred sixteen consecutive patients entered a functional restoration treatment program for chronic low back pain and were compared with 72 patients not treated. A two-year follow-up survey reached more than 85% of both groups; its findings were compared with earlier results of a five-month and one-year follow-up. Analysis demonstrated that 87% of the treatment group was actively working after two years, as compared with only 41% of the nontreatment comparison group. Moreover, about twice as many of the comparison group patients had additional spine surgery relative to the treatment group. The comparison group continued with an approximately five times higher rate of patient visits to health professionals in the second year as the treatment group. Also, treatment group reinjury rates were no higher than those expected in the general population, while nontreatment subjects had a higher incidence of reinjury. Finally, a small treatment "dropout" group did poorest of all, with results in almost all areas even worse than those of the comparison group patients.

Adult↗
PubMed1987

Assessment of lumbar function.

There are several problems associated with the conventional assessment of disability in the low back, and none are more disturbing to the clinician than the absence of visual feedback to measure physical capacity. This problem forces an assessment of impairment that is often based on a subjective patient self-report and inaccurate goniometric mobility measures that lead to broad variances in impairment/disability ratings. The problems of present rating systems can be investigated and potential solutions gained by new technology. Speculation is warranted on further developments in the assessment of lumbar impairment and disability.

Activities of Daily Living↗
PubMed1987

Myoelectric spectral analysis and strategies for quantifying trunk muscular fatigue.

Objective techniques for assessing trunk musculature with respect to fatigue-related characteristics do not exist. Based on work that relates frequency spectral shift in myoelectric signals to muscular fatigue at other body sites, a study was carried out to investigate and evaluate strategies for application of these techniques to the lumbar musculature. Through evolution of test administration procedures to reduce test time and discomfort as well as data interpretation methods to account for interindividual variability observed in data, an approach was developed for objective measurement of fatigue rate. While abdominal and lumbar muscle groups were assessed in 40 healthy subjects with results presented for 50% and 100% maximum voluntary contraction load levels, the methodology is discussed with emphasis on erector spinae results. The approach involves a normal function fatigue plot. The plot relates fatigue rate as measured by myoelectric spectral characteristics to muscle load normalized by body weight and is independent of the maximum voluntary contraction concept. This relationship forms the basis of comparison of the measured fatigue rate for a subject with questionable function to expected normal values determined from the plot, given the measured load level.

Adult↗
PubMed1986

Million Behavioral Health Inventory: its utility in predicting physical function in patients with low back pain.

The present study evaluated the use of psychologic measures, in particular, the relatively new Million Behavioral Health Inventory (MBHI), in predicting change in physical function of chronic low back pain patients undergoing a functional restoration program. The first 134 consecutive patients completing this program were assessed. Results demonstrated that various clinical scales of the MBHI were predictive of improvement in physical function. In addition, various scales enabled discrimination between patients who completed the program and those who prematurely dropped out. Although this inventory shows promise in helping to predict response to treatment, no single psychologic test can reliably be used as the sole predictor in clinical cases.

Adult↗
PubMed1985

Fatal systemic fluorosis due to hydrofluoric acid burns.

A patient with a 70% hydrofluoric acid burn developed systemic dissemination of fluoride ion from a 9% to 10% body surface area exposure on the lower extremities. Severe hypocalcemia and intractable ventricular arrhythmias resulted. This case is the second documented occurrence of hypocalcemia from hydrofluoric acid burns. It is the first case to document myocardial injury and systemic fluorosis from a skin burn.

Acidosis↗
PubMed1985

Quantification of lumbar function. Part 2: Sagittal plane trunk strength in chronic low-back pain patients.

A prototype sagittal plane trunk strength tester was used to measure trunk strength in 286 chronic low-back pain patients. Initial data for this patient group are compared with data acquired previously from a group of controls, adjusted for age, sex, and body weight. Distinct patterns characterize the patient sample as opposed to the controls: Patient values for both flexors and extensors were markedly decreased, with greater variability; Extensor strength was affected more significantly than flexor strength; Discrepancies between patients and controls were greater for females than for males; High-speed dropoff ratios were much lower for patients, both in flexion and extension. These results demonstrate that strength deficits are a major factor in the deconditioning syndrome associated with chronic low-back pain.

Adult↗
PubMed1985

Quantification of lumbar function. Part 3: Preliminary data on isokinetic torso rotation testing with myoelectric spectral analysis in normal and low-back pain subjects.

A prototype isokinetic torso rotation unit and an EMG signal processing system were utilized to obtain preliminary information on torso rotation. In Study 1, range-of-motion was found to be surprisingly uniform between low-back pain patients and normal subjects, although there was a significant strength variation between them at all isokinetic speeds tested. Both female patients and normal females showed approximately 70%-75% of the strength (torque/body weight) levels relative to their male counterparts. The decrement in trunk strength at high speeds was proportional for both patients and controls and was not nearly as dramatic as the decrement seen in the sagittal plane. In Studies 2 and 3, anatomic relationships evaluated by EMG testing of obliques and erector spinae showed that the contralateral abdominal obliques were the most consistent muscles providing a significant torsional moment to the spine.

Adult↗
PubMed1985

Quantification of lumbar function. Part 4: Isometric and isokinetic lifting simulation in normal subjects and low-back dysfunction patients.

The present study collected the first normative data on a new dynamic isokinetic lifting device and compared a normal subject sample (n = 65) with a chronic low-back pain patient sample (n = 68) on this device. In addition, a comparison was made between isometric lifting measures collected for these controls and patients, and a normative industrial sample used in an earlier isometric testing protocol. Results demonstrated significant differences between controls and patients on all measures. An unanticipated finding was the greater lifting capacity levels of the present normal sample relative to those reported in the earlier isometric testing. These findings demonstrate that dynamic lifting simulation offers an important new tool for medical and industrial assessment, and conservative medical management.

Adult↗
PubMed1985

Characterization of in vivo-activated allospecific T lymphocytes propagated from human renal allograft biopsies undergoing rejection.

To evaluate in situ lymphocyte responses in cell-mediated immune tissue injury, we have developed an approach for propagation of human allospecific T lymphocytes directly from tissue biopsies. We have utilized renal allograft tissue obtained from eight patients undergoing cellular rejection. Needle biopsy tissue was cultured in medium containing interleukin 2 (IL 2), including recombinant-DNA-produced IL 2. In each case, lymphoblasts migrated out of the tissue and increased in numbers, especially adjacent to the tissue. In two cases in which there was no cellular infiltrate present in the biopsy, no lymphocytes proliferated in vitro. Instead, fibroblasts eventually filled the wells from these allograft biopsies. The continued presence of the allograft tissue enhanced the viability and growth of the lymphoblasts in cultures from rejecting allografts. The isolated lymphoblasts had surface markers of mature OKT3+ lymphocytes of either OKT4+ or OKT8+ subsets. OKT8+ cells predominated. There was variability (41 to 97%) in the percentage of T lymphoblasts that bore surface HLA-DR antigens. In assays of lymphoblasts obtained from eight separate renal allografts, there was donor-specific cytotoxicity, and in all but two of the cases there was donor-induced proliferation. The specificity of the cytotoxic reaction was tested by using 51Cr-labeled, PHA-stimulated target cells prepared from a panel of HLA-typed donors. Proliferation was tested after 48 hr in the presence of mitomycin C-treated peripheral blood mononuclear cells as stimulator cells by using only 10(4) responder T lymphoblasts. Of particular note was that the cytotoxicity of the isolated lymphoblasts showed specificity against both "private" HLA class I alloantigens (of the allograft donor) as well as "public" cross-reacting epitopes. This method permits the propagation and functional characterization of in vivo-activated T lymphoblasts that are obtained from the actual sites of immune-mediated injury. Preliminary studies of other tissues with diverse inflammatory processes indicate the possible widespread applicability of obtaining in vivo-activated lymphocytes.

Antigens, Surface↗
PubMed1985

Quantification of lumbar function. Part 1: Isometric and multispeed isokinetic trunk strength measures in sagittal and axial planes in normal subjects.

The goals of this study were to: evaluate the repeatability of a method of measuring trunk strength; measure isometric and isokinetic strength of trunk flexors, extensors and rotators; explore relationships among these muscle groups; and compare a torque to body weight adjustment measure versus lean body weight. One hundred twenty-five normal subjects (62 males, 63 females) were tested using a Cybex prototype trunk extension-flexion system. Sixty-seven subjects (25 males, 42 females) were tested using a prototype torso rotation unit. Fifty were tested on both devices. Results demonstrated that the strength data were reliable, with strength being greatest in extension. The following were also learned-torque output declined slightly with increased speed; extensor-flexor strength remained consistent from 18 to 44 years; extension-flexion ratios exceeded 1.1:1; left to right rotation ratios remained 1:1; there was no significant difference between torque adjusted to body weight or to lean body weight.

Adult↗
PubMed1984

Use of noninvasive techniques for quantification of spinal range-of-motion in normal subjects and chronic low-back dysfunction patients.

Quantitative measures of physical function (range of motion, strength, stability) are critical to musculoskeletal care of the extremities, yet such objective measures in the spine are currently unavailable. In this paper, the authors present a simple, single inclinometer modification of the method of Loebl, which offers the opportunity to separate the components of the compound motion of hip and spine. Analysis of the motion in normal and chronic low-back pain patients allows differentiation of the groups, demonstration of progress in rehabilitation programs, determination of impairment, and provides tests of patient compliance and level of motivation.

Adult↗
PubMed1983

Soft tissue strain and facet face interaction in the lumbar intervertebral joint--Part I: Input data and computational technique.

A numerical simulation was devised to determine ligament strains, facet face interaction, and disk fiber strain in the lumbar intervertebral joint under load. This technique uses experimentally derived load deflection and morphologic data from lumbar cadaver specimens from which initial and displaced soft tissue attachment points can be calculated. This allows the strain data to be derived. The effect of disk bulge is also considered. The calculated strains of most ligaments except the facet capsular ligaments were found to be insensitive to anatomical measurement variability of +/- 1 mm.

Adolescent↗
PubMed1983

Soft tissue strain and facet face interaction in the lumbar intervertebral joint--Part II: Calculated results and comparison with experimental data.

A numerical simulation of soft-tissue strain and facet face interaction in the lumbar intervertebral joint under load was performed. The results, compared with a previous experimental sectioning study, showed that disk fiber strain was the main mechanism in shear resistance, except posterior shear, where the facets were main load bearing members. In axial compression, compression of the annulus was found, with a significant decrease in compressive strain resulting from annulus bulging, but no contact was found in the facet joints. The posterior ligaments, except for the facet capsules and ligamentum flavum, were found to be active only in flexion and lateral bending, while the facets and the disk both played major roles in resisting axial torsion moments.

Biomechanical Phenomena↗
PubMed1981

Short vs long scalp flaps in the treatment of male pattern baldness.

Hair transplantation has been used to restore the bald pate for 25 years. The dissatisfaction of some physicians and patients with the difficulty in obtaining natural density and the length of time necessary to achieve cosmetically acceptable coverage has been a stimulus to the development of scalp flap surgery. The flaps have the advantage of transferring large amounts of hair that give immediate and continuous coverage, normal density, and an improved hairline. Surgeons have applied this technique to areas affected by disease and trauma, as well as male pattern baldness. There are differences between the short temporoparietal flaps and the larger Juri flaps with regard to patient selection, planning, design, technique, complications, and most importantly, results.

Age Factors↗