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Biomedical subjects

T G Mayer

Publications and source records attributed to T G Mayer.

At least 37 records · Page 2Linked to original sources
PubMed1993

Optimal spinal strength normalization factors among male railroad workers.

In spite of increasing interest in techniques and devices for quantifying trunk strength and lifting capacity, relatively little research has been done to determine optimal normalizing factors for strength. The isolation of the ideal factors is a critical prerequisite for comparison of patient data to expected physical capacities in the uninjured population. In the present study, 160 incumbent railroad workers from four heavy laboring jobs were tested for isokinetic trunk strength and lumbar/cervical isokinetic lifting capacity as part of a study to establish normative data (Union Pacific RR, Omaha, NE). Three variables relating height and weight were studied to determine optimal normalization: actual body weight (BW), ideal weight (IW) and adjusted weight (AW). "IW" is actually a height/weight variable based on a weight control chart specifying ideal weights for given heights and genders. "AW" represents the lesser of BW or IW. Subjects were tested for isokinetic trunk extension/flexion for lumbar (floor-to-knuckle) and cervical (knuckle-to-shoulder) lifts. Results demonstrated that the isolated trunk strength tests showed the best correlation coefficients with BW for flexion-extension work at 60 and 150 per sec. Moreover, the correlation coefficients between the lumbar isokinetic lifting peak force measures and BW were high (ranging 0.49-0.67, P < 0.001), with much lower correlations for AW or IW. By contrast, cervical correlations between Liftask peak force and the height/weight variables were all lower, and were also better for AW than for BW or IW (ranging 0.37-0.50). It appears that body weight is the best normalizing factor for isokinetic trunk flexor/extensor strength and lumbar (floor-to-knuckle) lifting.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Differentiation between somatic and cognitive/affective components in commonly used measurements of depression in patients with chronic low-back pain. Let's not mix apples and oranges.

Patients with chronic low-back pain are frequently diagnosed as depressed. However, many of the neurovegetative signs of depression may also result from pain. The purpose of the present study was 1) to investigate the relationship between commonly used measurements of depression and pain perception; and 2) to examine the utility of differentiating between somatic signs and cognitive/affective symptoms of depression in patients with chronic low-back pain. The Beck Depression Inventory and the Hamilton Psychiatric Rating Scale for Depression were divided into cognitive/affective and somatic subscales. These measures, as well as the Minnesota Multiphasic Personality Inventory, were administered to 111 patients with chronic low-back pain. Analyses revealed significant correlations between depression scores and self-reported pain intensity. The cognitive/affective subscale of the Beck Depression Inventory resulted in the only nonsignificant correlation with pain intensity. These findings suggest that commonly used measurements of depression are confounded with pain symptomatology and that the cognitive/affective category of the Beck Depression Inventory may prove to be a more accurate measurement of depression in patients with chronic low-back pain.

Adult↗
PubMed1991

The SCL-90R evaluated as an alternative to the MMPI for psychological screening of chronic low-back pain patients.

The efficacy of using the SCL-90R as an alternative measure to the MMPI in the psychological screening of chronic low-back pain (CLBP) patients was investigated. The MMPI and the SCL-90R were administered to 99 CLBP patients (63 men and 36 women) at the time of admission to a functional restoration treatment program. The SCL-90R was readministered after successful completion of the treatment program. Analyses indicated that there were significant changes on almost all SCL-90R clinical scales from pretreatment to post-treatment (P less than 0.01). Moreover, there were adequate levels of correlation between corresponding MMPI and SCL-90R scales (r ranged from 0.35 to 0.51). However, analyses of the interscale correlations of the SCL-90R indicated that it may be a single-factor instrument that assesses general psychological distress. It was suggested that the SCL-90R may be used as a screening device for psychological distress in CLBP patients, but if more detailed information about the patients' psychological condition is needed, the MMPI will be a more useful instrument.

Adult↗
PubMed1990

Improved physical performance outcomes after functional restoration treatment in patients with chronic low-back pain. Early versus recent training results.

Functional restoration, a medically supervised team treatment approach that addresses deficits that accompany the deconditioning process in patients with chronic low-back pain, has emerged as a viable rehabilitation alternative. While the primary emphasis of this treatment approach has remained unchanged since its inception over 6 years ago, recent rapid advances in quantification technology and understanding of the complexity of the chronic low-back pain (CLBP) syndrome have led to more sophisticated and aggressive rehabilitation efforts. In the current study, the authors examined two groups of patients with CLBP, from the treatment program's initial (n = 45) and most recent years (n = 57) of operation, respectively, to determine if the evolution of the treatment program has resulted in increased gains in physical capacity between these groups of patients. Patients in each group were assessed on measures of isokinetic trunk strength and spinal range of motion at program admission and discharge. Both groups demonstrated improved physical capacity levels, but the recent group also demonstrated considerably higher physical capacity levels than the early group, at both program admission and discharge. It was concluded that functional restoration continues to be successful with CLBP patients, and that increased preprogram training and education may facilitate a more rapid elimination of inhibitory factors (ie, pain, fear of reinjury), which often impede and slow physical training.

Adult↗
PubMed1990

Changes in MMPI profile levels of chronic low back pain patients following successful treatment.

The present study evaluated changes in the Minnesota Multiphasic Personality Inventory (MMPI) profile levels of chronic low back pain (CLBP) patients following successful treatment for their disability. A total of 69 patients were evaluated at admission and 6 months after completing the treatment program. Results demonstrated significant decreases of the Hysteria, Depression, and Hypochondriasis scales toward normal ranges at the 6-month evaluation. These results indicate that MMPI profile levels of CLBP patients are significantly reduced to normal ranges following successful treatment.

Adult↗
PubMed1989

Comparison of CT scan muscle measurements and isokinetic trunk strength in postoperative patients.

The present study compared the computed tomography (CT) scan muscle area/muscle density and isokinetic trunk strength of a group of spinal surgery patients (35 males and 11 females) 3 months postoperatively. Analyses showed trunk strength means to be below 50% of gender-specific "normal" values obtained by evaluating a normative sample. Extensor strength was more significantly affected than flexors. Single-cut CT scans performed at the time of isokinetic trunk strength assessment demonstrated psoas and erector spinae atrophy through a significant decrease in muscle density, with only a trend towards decreased cross-sectional area. Findings also indicated that there was a significant correlation between increased mechanical trunk strength performance and greater muscle density on CT scan. Strength was significantly lower for the male patients undergoing spinal fusion compared with those undergoing disc excision. However, no significant difference was found in strength measures between: males with high versus low pain level and working versus nonworking males at the time of evaluation.

Adult↗
PubMed1989

Psychosocioeconomic predictors of treatment success/failure in chronic low-back pain patients.

The present study evaluated various psychosocioeconomic variables in chronic low-back pain (CLBP) patients being treated in a functional restoration rehabilitation program. The purpose of the study was to identify those factors that may have predictive value with respect to treatment outcome. Three groups of patients (Success, Failure, Dropout) were examined based on outcome and follow-up data 1 and 2 years after program completion. Once group assignment was made based on outcome, a variety of psychologic, socioeconomic, and demographic data obtained at the time of program admission was analyzed to determine if there were differences among the groups. Several factors were found to distinguish among the groups, including Minnesota Multiphasic Personality Inventory (MMPI) and Millon Behavioral Health Inventory (MBHI) scale scores, prior surgical history, level of worker compensation, and pain intensity ratings. These results confirm the presence of psychosocioeconomic differences among CLBP patients and suggest the need for continued research in this area to improve treatment efficacy in these patients.

Adult↗
PubMed1989

A psychosociomedical prediction model of response to treatment by chronically disabled workers with low-back pain.

There has been much interest in identifying variables that can predict which individuals are susceptible to developing chronic low-back pain. There currently are a number of studies that are evaluating primary predictors (which uninjured workers are likely to develop chronic low-back pain) and secondary predictors (which workers with acute episodes will develop chronic pain). The present study reports the first results from a large-scale investigation of tertiary predictors. Specifically, it addresses the issue of what psychosociomedical variables are predictive of success/failure in response to a comprehensive Functional Restoration treatment program by workers who are chronically disabled with low-back pain. Three stages were involved in the development of this prediction model. First, a group of treatment and research professionals who had extensive experience in the area of chronic low-back pain identified an array of 42 variables, from a larger pool of quantified physical, psychosocial, and medical parameters rated to be important with this patient population.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Lumbar myoelectric spectral analysis for endurance assessment. A comparison of normals with deconditioned patients.

A myoelectric protocol to objectively discriminate between test subjects based on trunk muscular performance differences (endurance) was investigated in a group of 11 healthy volunteers and ten industrial patients undergoing functional restoration for chronic disabling spinal disorders. The subjects performed a standardized exercise protocol, holding their upper torso unsupported for successive fixed-time trials while electromyographic (EMG) signals were recorded from erector spinae. A Fast Fourier Transform allowed calculation of the initial mean power frequency (MPF) for each trial. Isokinetic extensor trunk strength was independently measured at each session for comparison with myoelectric signal analysis. The investigation revealed significant differences in group statistics between patients in early rehabilitation and their subsequent tests, as well as between their initial test and the normal subject scores. However, test sensitivity for identifying patients with "low endurance" is questionable. There was no significant correlation between EMG initial MPF measures and isokinetic extensor trunk strength measures, even though all patients showed isokinetic improvement. Data suggest that the protocol used and myoelectric power spectrum temporal shifts may have some value for identification of individual subjects with endurance limitations (or fatigue resistance) in patients of this type. However, lack of a "gold standard" for comparison presents difficulties in documenting the value and validity with respect to endurance. The test may be of value to measure relative loads.

Adult↗
PubMed1989

Quantifying postoperative deficits of physical function following spinal surgery.

This study evaluates the degree of objectively quantified physical deconditioning of spinal surgery patients. The object is to evaluate the data in terms of the pain and disability claimed by 35 male and 11 female patients three months after spinal surgery. Among the males, two subgroups (i.e., disc excision or spinal fusion) were evaluated. All patients reported subjective indices of pain/disability and completed quantified tests of lumbar motion, sagittal trunk strength, lifting capacity, and bicycle ergometry. In general, true lumbar motion was markedly restricted to 50%-60% and trunk strength means were below 50% of gender-specific normative values. There were similar deficits for lifting capacity. Those who had spinal fusions tended to perform poorly, with a relatively high incidence of pain/disability. There were no differences found between the male group and subgroups who were gainfully employed or had a brief period of disability prior to surgery or had low subjective pain/disability. These results indicate that a patient's subjective pain/disability were not a reliable measure of functional capacity by three months postoperatively. Regardless of working status, pain level, or brevity of disability, there was a significant loss of performance ability and risk of persistent dysfunction after surgical treatment.

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PubMed1988

Progressive isoinertial lifting evaluation. I. A standardized protocol and normative database.

Dynamic tests of trunk strength and lifting capacity have become more popular in recent years, offering certain advantages over static isometric tests in measuring patient progress in functional restoration programs for spinal disorders. However, equipment for performing such tests is expensive to buy, complex to run, and requires technical expertise and clinical volume unavailable in most physician offices. In this study, a new dynamic test known as Progressive Isoinertial Lifting Evaluation (PILE) is described, which draws upon prior psychophysical and isoinertial methods. An industrial sample of 61 male and 31 female incumbent workers were tested using the PILE, and a variety of anthropometric normalizing factors were evaluated. The isolation of an "Adjusted Weight" (AW) normalizing factor is documented, after which normative data are presented for male and female workers utilizing lumbar (0-30 inches) and cervical (30-54 inches) dynamic protocols.

Adult↗
PubMed1988

Immunohistochemical analyses of skin graft rejection in mice. Kinetics of lymphocyte infiltration in grafts of limited immunogenetic disparity.

We have examined the nature and kinetics of T cell infiltration into murine first-set skin allografts across a variety of histocompatibility differences. Both Ly 1+2- and Ly 2+ cells migrate into grafts that differ with respect to discrete class I, class II, or minor H barriers. The lymphoid cells in the allograft did not express MEL 14 or the B cell antigen B220. The cells in the graft progress from the vascular anastomosis region into the dermis with apparent homing and clustering about hair follicles and epithelial cells at the dermoepidermal junction. Microscopic necroses appear in a patchy distribution in these areas. The intensity of the infiltrate is related to the nature of the alloantigen recognized but it does not correlate with the tempo of rejection. Class II-disparate allografts evoke a peak response (mean 62 +/- 34 T cells/0.1 mm2) that is 2-6-fold greater than class I-disparate allografts or syngeneic control peak responses (mean 14 +/- 2.4 T cells/0.1 mm2). Although a difference at a minor H antigen evoked an intense peak T cell response (192 +/- 33 T cells/0.1 mm2), the mean survival time of the allografts was significantly longer than that observed with class I or class II differences. The IL-2 receptor+ subset of activated T cells is extremely rare in syngeneic grafts, but ranges from 0 to 56% of infiltrating T cells in allografts. We conclude that all major T cell subsets contribute to the in situ response to all classes of alloantigens, but at the apparent exclusion of the MEL 14+ T cell pool and B cells.

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