Pulsed Shortwave Diathermy and Prolonged Long-Duration Stretching Increase Dorsiflexion Range of Motion More Than Identical Stretching Without Diathermy

OBJECTIVE: To compare the effects of 3 treatments on ankle dorsiflexion range of motion: prolonged long-duration stretching, pulsed shortwave diathermy followed by stretching, and pulsed shortwave diathermy, stretching, and ice combined. DESIGN AND SETTING: A 2 x 5 x 15 repeated-measures (on 2 factors) design guided this study. Range-of-motion change in triceps surae flexibility was the dependent variable. The 3 independent variables were treatment group, pretest and posttest measurements, and day. Treatment group had 4 levels: control, stretching (10 minutes of stretching via the weight and pulley), diathermy and stretching (20 minutes of diathermy and 10 minutes of stretching), and diathermy, stretching, and ice (20 minutes of diathermy, 10 minutes of stretching applied after 15 minutes of diathermy, and 5 minutes of ice applied during the last 5 minutes of stretching). Each subject received 14 treatments throughout 3 weeks, with a follow-up measurement taken 6 days after the last treatment. SUBJECTS: Forty-four healthy college-student volunteers not involved in any flexibility program. MEASUREMENTS: We measured ankle dorsiflexion using a digital inclinometer before and after treatment. RESULTS: After 14 days of treatment, the range-of-motion increase was greater after heat and stretching than after stretching alone. After 6 additional days of rest, the heat and stretching range-of-motion increase was greater than that for stretching alone. CONCLUSION: Pulsed shortwave diathermy application before prolonged long-duration static stretching was more effective than stretching alone in increasing flexibility throughout 3 weeks. After 14 treatments, prolonged long-duration stretching combined with pulsed shortwave diathermy followed by ice application caused greater immediate and net range-of-motion increases than prolonged long-duration stretching alone.     

The Stretching Window Part Two: Rate of Thermal Decay in Deep Muscle Following 1-MHz Ultrasound

Thermal ultrasound can be effective in increasing extensibility of collagen, thus aiding joint mobilization and stretching. In 1995, we reported on the rate of temperature decay following 3-MHz ultrasound in subcutaneous tissues. We repeated that study at 1-MHz frequency to see if the stretching window is different for deep muscle. Twenty subjects had two 23-gauge thermistors inserted 2.5 cm and 5 cm deep into their triceps surae muscle. We administered 1-MHz continuous ultrasound at 1.5 W/cm(2) until the tissue temperature increased 4 degrees C (vigorous heating). Immediately following the treatment, we recorded the rate at which the temperature dropped at 30second intervals. We ran a stepwise nonlinear regression analysis to predict temperature decay as a function of time following ultrasound treatment. There was a significant nonlinear relationship between time and temperature decay. At 2.5 cm, the average time for the temperature to drop each degree was: 1 degrees C = 2:34; 2 degrees C = 6:35; 3 degrees C = 12:10: and 4 degrees C = 21:14. At 5 cm, the average time for the temperature to drop each degree was: 1 degrees C = 2:31, 2 degrees C = 6:50: 3 degrees C = 14:32; and 4 degrees C = 27:49. Based upon prior research, thermal decay of 1-MHz ultrasound was slower than 3 MHz, and the deeper tissue cooled at a slower rate than superficial tissue following 1-MHz ultrasound. The data illustrated that the stretching window was open longer for deep-seated structures than for superficial ones.     

The VO2 response to exhaustive square wave exercise: influence of exercise intensity and mode

We investigated the oxygen uptake (O₂) response to exhaustive square wave exercise of approximately 2, 5 and 8 min duration in cycling and running. Nine males completed a ramp test and three square wave tests on a motorised treadmill and the same four tests on a cycle ergometer, throughout which gas exchange was assessed (Douglas bag method). The peak O₂ from the ramp test was higher for running than for cycling [mean (SD): 58.4 (2.8) vs. 55.9 (3.7) ml.kg^–1.min^–1; P=0.04]. However O_2max (defined as the highest O₂ achieved in any of the four tests) did not differ between running and cycling [60.0 (2.9) vs. 58.5 (3.3) ml.kg^–1.min^–1; P=0.15]. The peak O₂ was similar (P>0.1) for the 5 and 8 min square wave tests [98.5 (1.8) and 99.2 (2.3) %O_2max for running; 97.0 (4.2) and 97.5 (2.0) %O_2max for cycling] but lower (P<0.001) for the 2-min test [91.8 (2.5) and 89.9 (5.5) %O_2max for running and cycling respectively]. O₂ increased over the final two 30-s collection periods of the 2-min test for cycling [O₂=0.18 (0.15) l.min^–1; P<0.01] but not running [O₂=0.00 (0.09) l.min^–1; P=0.98]. We conclude that in the aerobically fit the peak O₂ for square wave running or cycling at an intensity severe enough to result in exhaustion in approximately 2 min is below O_2max. In running, O₂ plateaus at this sub-maximal rate.     

Trichomonas vaginalis: diagnosis and clinical characteristics in pregnancy

Objective: The objectives of this study were to 1) determine the prevalance and characterize the symptomatology of Trichomonas vaginalis (TV) infection in pregnant women on entry into prenatal care in an inner-city population; 2) compare conventional microscopic methods vs. culture techniques in diagnosing TV in both symptomatic and asymptomatic pregnant patients; and 3) correlate wet mount microscopic and microbiologic characteristics of varying manifestations of trichomoniasis.Methods: One thousand two hundred sixty patients in an inner-city population were tested at entry into prenatal care for TV by saline wet mount and culture techniques. Other tests for lower genital tract infection were also performed. Vaginal symptoms were ascertained through standardized questioning prior to examination. Standard microscopic and microbiologic data were also obtained for analysis. Wet mounts were systematically examined and considered negative if no TV was identified in 10 high powerfields (HPFs). Cultures were inspected from days 4 to 7 or until positive results were obtained. Results were analyzed using McNemar's test for correlated proportions, chi-squared test, or Fisher exact test where appropriate.Results: Culture and wet mount results were available in 1,175 patients. TV infection was documented by one or both techniques in 110/1,175 (9.4%). Culture methods detected 105/110 (94.5%) of all patients while wet mount detected 90/110 (73%) (P <0.001). Vaginal symptoms were present in only 20/110 patents (18.2%). Among asymptomatic patients, culture detected 94% while wet mount detected 70% (P < 0.001). Among symptomatic patients, wet mount and culture were both effective and diagnosed 85% and 95% of infections, respectively (P = not significant). Patients with TV were more likely to have increased vaginal fluid wlaite blood cells (WBCs) and more severe vaginal flora disruption than uninfected controls. Subgroup analysis revealed wet mount-positive/culture-positive patients were more likely to have vaginal flora disruption, as evidenced by decreased lactobacilli and elevated vaginal pH, than wet mount-negative/culture-positive subjects. Coexistent infection rates were similar regardless of wet mount status. Elevated vaginal fluid WBCs were more common among patients with symptoms.Conclusions: 1) Screening pregnant women for TV based solely on symptomatology is ineffective in this population; 2) culture techniques detected more infections than conventional microscopic evaluation; and 3) significant increases in vaginal fluid WBCs and altered vaginal flora are found in both symptomatic and asymptomatic TV, suggesting that both infestations have the potential to adversely affect pregnancy outcome. Studies on the influence of TV on pregnancy outcomes are ongoing.     

Detection of Trichomonas vaginalis using the polymerase chain reaction in pregnant and non-pregnant women

Objective:Trichomonas vaginalis vaginal infections are often both asymptomatic and difficult to detect by current methods. We evaluated the ability of a newly developed polymerase chain reaction (PCR) assay to identify T. vaginalis in vaginal samples from pregnant and non-pregnant women.Methods: In the 1st study, we compared the prevalence of T. vaginalis detection by PCR and culture using Diamond's medium in 52 women with symptoms of vaginal infection. In the 2nd study, T. vaginalis was detected using PCR and wet mount microscopy in 131 asymptomatic pregnant women.Results: Among the women with symptoms of vaginitis, 7 (13.5%) were PCR-positive for T. vaginalis. Six of the PCR-positive women, but none of the PCR-negative women, were culture-positive for this organism. All but 1 of the women with candidal vaginitis or bacterial vaginosis were PCR-negative for T. vaginalis. Among the asymptomatic pregnant women, all of whom were negative for T. vaginalis by wet mount, l0 (7.6%) were PCR-positive for T. vaginalis.Conclusions: PCR offers a rapid and sensitive alternative to culture and microscopy for the detection of T. vaginalis vaginal infections in both symptomatic and asymptomatic women.     

The Effect of Estrogen Deficiency on Calcium Balance in Mature Rats

The role of estrogen in the regulation of calcium balance is still poorly understood. A calcium balance study was performed to examine the effects of estrogen status in relation to fecal calcium loss as a component of bone loss after oophorectomy (OOX) in the mature rat. The components of the classic calcium balance were compared with calcium balance estimates obtained from whole body bone density. Six month or older Sprague Dawley rats were allocated to either a sham-operated or OOX group and fed a 0.1% calcium diet. The bone mineral density (BMD) and bone mineral content (BMC) were measured at baseline, 6 weeks, and 9 weeks. A calcium balance was done for 6 days before and 6 weeks post OOX. The fall in BMD from baseline to 9 weeks in the OOX group was significantly greater than in the sham-operated group. The calcium balance was more negative at baseline than at 6 weeks in both groups of animals because they had not adapted to the low calcium diet. However, the increase in calcium balance was significantly less in the OOX animals than in the sham-operated animals. The greater the rise in calcium balance from the baseline to the 6 weeks balance the less the fall in the calcium content of the whole body (Spearman correlation: r = 0.604 P = 0.008). The fall in fecal calcium, but not urine calcium or calcium consumed, was negatively correlated with the change in whole body BMC (Spearman correlation: fecal calcium r =−0.763 P = 0.001). Thus, the primary effect of estrogen deficiency on calcium balance in the mature rat appears to be calcium flux in the bowel, rather than renal calcium handling. Received: 16 April 1997 / Accepted: 22 September 1998     

Health insurance: an eye on American welfare

One of the great myths about the United States is that it does not have a welfare state. The myth is largely founded on the fact that America is one of the few remaining western nations with no national health insurance scheme to protect its citizens against the crippling costs of medical and hospital care. However, that does not mean that the United States does not have an extensive welfare system, writes John Draper.