Measuring lower body strength is critical in evaluating the functional performance of older adults. The purpose of this study was to assess the test-retest reliability and the criterion-related and construct validity of a 30-s chair stand as a measure of lower body strength in adults over the age of 60 years. Seventy-six community-dwelling older adults (M age = 70.5 years) volunteered to participate in the study, which involved performing two 30-s chair-stand tests and two maximum leg-press tests, each conducted on separate days 2-5 days apart. Test-retest intraclass correlations of .84 for men and .92 for women, utilizing one-way analysis of variance procedures appropriate for a single trial, together with a nonsignificant change in scores from Day 1 testing to Day 2, indicate that the 30-s chair stand has good stability reliability. A moderately high correlation between chair-stand performance and maximum weight-adjusted leg-press performance for both men and women (r = .78 and .71, respectively) supports the criterion-related validity of the chair stand as a measure of lower body strength. Construct (or discriminant) validity of the chair stand was demonstrated by the test's ability to detect differences between various age and physical activity level groups. As expected, chair-stand performance decreased significantly across age groups in decades--from the 60s to the 70s to the 80s (p < .01) and was significantly lower for low-active participants than for high-active participants (p < .0001). It was concluded that the 30-s chair stand provides a reasonably reliable and valid indicator of lower body strength in generally active, community-dwelling older adults.
The International 10-20 system is a method for standardized placement of electroencephalogram (EEG) electrodes. The 10-20 system correlates external skull locations with the underlying cortical areas. This system accounts for variability in patient skull size by using certain percentages of the circumference and distances between four basic anatomical landmarks. This 10-20 system has recently been used in transcranial magnetic stimulation (TMS) research for locating specific cortical areas. In the treatment of depression (and some types of pain), the desired placement of the TMS coil is often above the left dorsalateral prefrontal cortex (DLPFC) which corresponds to the F3 location given by the 10-20 system. However, for an administrator with little experience with the 10-20 system, the numerous measurements and calculations can be excessively time-consuming. Additionally, with more measurements comes more opportunity for human error. For this reason we have developed a new, simpler and faster way to find the F3 position using only three skull measurements. In this paper, we describe and illustrate the application of the new F3 location system, provide the formulas used in the calculation of the F3 position, and summarize data from 10 healthy adults. After using both the International 10-20 system and this new method, it appears that the new method is sufficiently accurate; however, future investigations may be warranted to conduct more in dept analyses of the method's utility and potential limitations. This system requires less time and training to find the optimal position for prefrontal coil placement and it saves considerable time compared to the 10-20 EEG system.
Transcranial magnetic stimulation (TMS) of the prefrontal cortex can cause changes in acute pain perception. Several weeks of daily left prefrontal TMS has been shown to treat depression. We recruited 20 patients with fibromyalgia, defined by American College of Rheumatology criteria, and randomized them to receive 4000 pulses at 10Hz TMS (n=10), or sham TMS (n=10) treatment for 10 sessions over 2 weeks along with their standard medications, which were fixed and stable for at least 4 weeks before starting sessions. Subjects recorded daily pain, mood, and activity. Blinded raters assessed pain, mood, functional status, and tender points weekly with the Brief Pain Inventory, Hamilton Depression Rating Scale, and Fibromyalgia Impact Questionnaire. No statistically significant differences between groups were observed. Patients who received active TMS had a mean 29% (statistically significant) reduction in pain symptoms in comparison to their baseline pain. Sham TMS participants had a 4% nonsignificant change in daily pain from their baseline pain. At 2 weeks after treatment, there was a significant improvement in depression symptoms in the active group compared to baseline. Pain reduction preceded antidepressant effects. TMS was well tolerated, with few side effects. Further studies that address study limitations are needed to determine whether daily prefrontal TMS may be an effective, durable, and clinically useful treatment for fibromyalgia symptoms.
Background tDCS appears to have modulatory effects on the excitability of cortical brain tissue. Though tDCS as presently applied causes no apparent harm to brain structure or function, a number of uncomfortable sensations can occur beneath the electrodes during stimulation, including tingling, pain, itching, and burning sensations. Therefore, we investigated the effect of topically applied Eutectic Mixture of Local Anesthetics (EMLA) on tDCS-related discomfort. Methods Nine healthy adults received both anodal and cathodal 2.0 mA tDCS for 5 minutes over the prefrontal cortex with the skin pretreated for 20 minutes with either EMLA or placebo cream. Participants rated procedural discomfort 6 times across 8 dimensions of sensation. Results On average, the mean sensation ratings for EMLA-associated tDCS stimulation were significantly lower than placebo-associated stimulation for every cutaneous sensation evaluated. Cathodal stimulation was associated with higher ratings of “sharpness” and intolerability than anodal stimulation. Conclusions Topical EMLA may reduce tDCS-related discomfort.
Competitive swimming requires multiple bouts of high-intensity exercise, leading to elevated blood lactate. Active exercise recovery has been shown to lower lactate faster than passive resting recovery but may not always be practical. An alternative treatment, electrical muscle stimulation, may have benefits similar to active recovery in lowering blood lactate but to date is unstudied. Therefore, this study compared submaximal swimming and electrical muscle stimulation in reducing blood lactate after sprint swimming. Thirty competitive swimmers (19 men and 11 women) participated in the study. Each subject completed 3 testing sessions consisting of a warm-up swim, a 200-yard maximal frontcrawl sprint, and 1 of 3 20-minute recovery treatments administered in random order. The recovery treatments consisted of a passive resting recovery, a submaximal swimming recovery, or electrical muscle stimulation. Blood lactate was tested at baseline, after the 200-yard sprint, and after 10 and 20 minutes of recovery. A significant interaction (p < 0.05) between recovery treatment and recovery time was observed. Blood lactate levels for the swimming recovery were significantly lower at 10 minutes (3.50 +/- 1.57 mmol.L-1) and 20 minutes (1.60 +/- 0.57 mmol.L-1) of recovery than either of the other 2 treatments. Electrical muscle stimulation led to a lower mean blood lactate (3.12 +/- 1.41 mmol.L-1) after 20 minutes of recovery compared with passive rest (4.11 +/- 1.35 mmol.L-1). Submaximal swimming proved to be most effective at lowering blood lactate, but electrical muscle stimulation also reduced blood lactate 20 minutes postexercise significantly better than resting passive recovery. Electrical muscle stimulation shows promise as an alternate recovery treatment for the purpose of lowering blood lactate.
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