RESUMEN
BACKGROUND: Russian current (RC), a well-known neuromuscular electrical stimulation operating at 2500 Hz, has demonstrated significant strength improvement over traditional exercises due to its high tolerance and low pain provocation. Despite extensive NMES parameter research, the specific effects of expert modes, particularly ON2 and Rest, remain unexplored. This study investigates the direct effect of these expert modes on quadriceps muscle strength in healthy adults. METHODS: This is a single-blind, randomization-controlled trial. Forty-eight healthy university students (31 females, 17 males) were assigned in two randomized experimental groups either the ON2 or Rest mode for a 15-minute electrical stimulation session. Quadriceps maximum voluntary isokinetic contraction measurements were taken before and directly after RC application using Biodex Medical Systems 4 pro isokinetic dynamometer. RESULTS: Both RC modes significantly increased the quadriceps muscle torque in healthy adults compared to baseline (p<0.05). Baseline mean torque was 123.28 (SD = 38.8), and post- RC mean torque was 136.67 (SD = 45.76). Deviation from normality was observed at baseline (p = 0.034) and persisted post-RC application (p = 0.017). The Wilcoxon test reported significant increases in quadriceps muscle knee torque for both ON2 and Rest groups (p < 0.001). The lack of ties in ranks and negative Z-values highlight the robustness of the observed effects. CONCLUSION: The findings of this study align with previous research on NMES and RC supporting the idea that electrical stimulation enhances muscle strength, selecting the appropriate RC expert modes can assist physiotherapist in tailoring rehabilitation program to achieve their specific strength goals.
Asunto(s)
Extremidad Inferior , Músculo Cuádriceps , Masculino , Adulto , Femenino , Humanos , Músculo Cuádriceps/fisiología , Torque , Método Simple Ciego , Fuerza Muscular/fisiología , Estimulación Eléctrica , Federación de RusiaRESUMEN
Adrenocortical carcinoma (ACC) is a rare malignancy whose risk factors are unclear. We explored the association of ACC risk with exposure to selected environmental factors, with a focus on cigarette smoking. We conducted a hospital-based case-control study at The University of Texas MD Anderson Cancer Center. Cases (n = 432) patients with ACC treated at MD Anderson, and controls (n = 1,204) were healthy and genetically unrelated spouses of patients at MD Anderson who had cancers not associated with smoking. Information on the subjects' demographic features and selected risk factors was collected using a structured, validated questionnaire and medical records review. Unconditional logistic regression was used to calculate adjusted odds ratios (AORs) via the maximum-likelihood method. Cases had a younger mean (± standard deviation) age than did controls (47.0 ± 0.7 and 60.0 ± 0.3 years, respectively), and the majority of cases were female (60.6%) and non-Hispanic white (82.4%). We found a markedly increased risk of ACC among male cigarette smokers, with an AOR = 1.8 (95% confidence interval [CI] =1.2-2.9), but not among female smokers (AOR = 1.1, 95% CI = 0.7-1.6). Family history of cancer was associated with increased risk of ACC (AOR = 2.8, 95% CI 1.9-4.3) and in both men and women, whereas alcohol consumption was associated with reduced risk in men (AOR = 0.2, 95% CI = 0.1-0.3) but not women (AOR = 0.7, 95% CI = 0.5-1.1). Understanding these risk factors and their underlying mechanisms may help prevent ACC in susceptible individuals and eventually identify new therapeutic options for ACC.