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Biomedical subjects

J R Stout

Publications and source records attributed to J R Stout.

25 records · Page 2Linked to original sources

Anthropometric estimation of thigh muscle cross-sectional area.

The purpose of this investigation was to derive and validate circumference and skinfold equations for estimating the anatomical cross-sectional area (CSA) of the quadriceps, hamstrings, and total thigh muscles. Forty-three adult male (mean age +/- SD = 25 +/- 5 yr) volunteers underwent magnetic resonance imaging (MRI) to determine the CSA of the thigh muscles at the midfemur level as well as midthigh circumference and anterior thigh skinfold assessment. Multiple regression analyses were used to derive equations for predicting quadriceps, hamstrings, and total thigh muscle CSA of the dominant limb from the anthropometric dimensions on a random sample of 30 of the subjects. Cross-validation (CV) analyses were performed for each equation on: (a) the nondominant thigh of the derivation group (N = 30); (b) the dominant thigh of the CV group (N = 13); and (c) the nondominant thigh of the CV group (N = 13). The CV total error values for the quadriceps, hamstrings, and total thigh muscle CSA ranged from 5.4 to 14.4, 3.3 to 5.5, and 10.0 to 25.4 cm2, respectively. The anthropometric equations are recommended for one-time estimates of muscle CSA values in healthy, well-nourished young adult males when more sophisticated procedures are not available.

Adult↗

Validity of skinfold equations for estimating body density in youth wrestlers.

The present investigation examined the validity of 16 skinfold equations for predicting body density (BD) in youth wrestlers (mean age +/- SD = 11.0 +/- 1.3 yr) by comparing the values to those obtained from underwater weighing. Forty-eight members of youth wrestling clubs (mean BD +/- SD = 1.0634 +/- 0.0125 g.cm-3) volunteered to serve as subjects. The statistical analyses included examination of the constant error (CE), standard error of estimate (SEE), correlation coefficient (r), and total error (TE). The results of this investigation indicated that all of the equations resulted in TE values that were > or = 0.0106 g.cm-3 (range = 0.0106-0.0229 g.cm-3) which corresponded to > or = 4.9% body fat. The TE values were too large to provide accurate estimates of body composition in the present sample of youth wrestlers. Future studies should use the CE values from the present investigation to adjust the intercepts of the skinfold equations in the present study and cross-validate the modified equations on young male athletes.

Body Composition↗

Validity of percent body fat estimations in males.

The present investigation examined the validity of selected skinfold (Sum3), near-infrared interactance (F5000 and F1000), and bioelectrical impedance (BIA) equations for estimating percent body fat (% fat) in young adult males (mean age +/- SD = 22 +/- 3 yr) by comparing the estimates with values obtained from underwater weighing. Fifty-seven Caucasian male (mean % fat +/- SD = 15.1 +/- 6.2) volunteers served as subjects. The statistical analyses included examination of constant error (CE), standard error of estimate (SEE), r, and total error (TE). The results indicated that the Sum3 equation had the lowest SEE (2.7% fat) and TE (3.6% fat) as well as the highest validity coefficient (r = 0.90). The F5000, however, had the lowest CE (-1.0% fat). Based on these findings, the Sum3 equation is recommended over the F5000 (TE = 4.2% fat), F1000 (TE = 6.1% fat), and BIA (TE = 5.0% fat) equations for estimating % fat in young adult males.

Adipose Tissue↗

Follow-up study of memory deficits after ECT.

Twenty-four patients received ECT induced by either alternating sine wave or brief pulsed-square wave stimulus and were evaluated at follow-up for clinical functioning and subjective memory loss. The hypothesis of less memory loss in the group receiving a weaker stimulus (pulsed-square wave) was not supported. The two treatment groups and a group of controls showed no significant differences on the memory test. On measures of clinical functioning the sine wave group scored better on every measure than the square wave group, although not significantly better.

Adult↗

Changes in neuropsychological test performance after electroconvulsive therapy.

A group of 231 psychiatric patients were evaluated (with the Wechsler Adult Intelligence Scale and the Halstead-Reitan Neuropsychological Test Battery) before and after electroconvulsive therapy. Improvement during the course of therapy was shown in 96% of the measures and significant improvement (p less than 0.05) occurred in 37.5% of the measures, indicating generally improved functioning. The performance of these patients on the pre-ECT testing was generally in the range characteristic of patients with documented brain damage, but the score improved during the course of treatment to the borderline normal level.

Dominance, Cerebral↗

Effects of exercise training and amino-acid supplementation on body composition and physical performance in untrained women.

The purpose of this study was to determine the effects of 6 wk of essential amino acid (EAA) supplementation on body composition and exercise performance in untrained women (n = 21). Subjects were randomly assigned to a placebo (cellulose) or an EAA (average daily dose of 18.3 g of EAAs in pill form) group. Each subject participated in aerobic and heavy-resistance training three times per week. Body composition was assessed via dual x-ray absorptiometry analysis. Muscular endurance was determined via treadmill time to exhaustion, and strength was assessed by the total amount of weight lifted for one set to exhaustion at an estimated 12 repetitions maximum. No changes occurred in either group for body weight, lean body mass, fat mass, or bone mineral content. Treadmill time to exhaustion (TTE) improved significantly (P < 0.05) in the EAA group (mean +/- SD; pre-TTE = 13.15 +/- 3.67 min, post-TTE = 14. 73 +/- 4.26 min), whereas the placebo group did not change significantly. The total weight lifted at the subject's maximum 12 repetitions did not significantly change in either group. In previously untrained individuals, the ingestion of EAAs combined with aerobic and heavy-resistance training for 6 wk did not have a significant effect on body composition or muscular strength; however, aerobic muscular endurance increased significantly.

Absorptiometry, Photon↗