Correlation of trunk muscle strength with age in children 5 to 18 years old.

OBJECTIVE: To determine the correlation of trunk muscle strength with age in children and the effect of gender on changes in trunk muscle strength. MATERIAL AND METHODS: Strength of the back extensors and back flexors was evaluated in 137 healthy boys and 109 healthy girls who were 5 to 18 years old. Anthropometric determinations of height and weight were done in all study subjects. Maximal back muscle strength was measured with an isometric dynamometer (BID-2000). Standardized positioning techniques were used to allow comparison with the follow-up evaluations. RESULTS: Regression analysis revealed significant increases in trunk strength with increasing age; the strength of the boys began diverging from that of the girls at age 9 to 10 years. Back extensor strength also increased with increasing height and weight, and expected differences were noted between boys and girls. Strength levels ranged from 80 to 774 newtons (18 to 174 lb). Mean back extensor strength in 2-year age intervals ranged from 153 newtons (34.4 lb) in girls 5 to 7 years old to 504 newtons (113.3 lb) in boys 16 to 18 years of age. (Each newton is equal to 0.2248 lb.) CONCLUSION: Results of this study demonstrated that age, height, and weight are all important predictors of trunk strength in children, and the effects of these factors are modulated by gender.

Correlation of back extensor strength with thoracic kyphosis and lumbar lordosis in estrogen-deficient women.

Aging and osteoporosis have been associated with skeletal changes. Back extensor strengthening exercises are highly recommended for management of back pain, especially back pain related to osteoporosis. To our knowledge, the correlation of thoracic kyphosis, lumbar lordosis, and sacral inclination with back extensor strength, physical activity, and bone mineral density has not been critically studied in healthy, active, estrogen-deficient women. In a study of 65 such women (ages 48-65 yr), back extensor strength, bone mineral density, and physical activity score were evaluated and measured. These factors were then correlated with radiographic factors: (1) vertebral body ratios (anterior/posterior height) calculated for each vertebra from T-4 through L-5; (2) kyphosis index determined by adding the anterior heights of each vertebral body, T-4 through T-12, and then dividing the total by the corresponding sum of the posterior heights of each vertebral body; (3) thoracic kyphosis; (4) lumbar lordosis; and (5) sacral inclination. Back extensor strength had a significant negative correlation with thoracic kyphosis (r = -0.30, P = 0.019) and a positive correlation with lumbar lordosis (r = 0.26, P = 0.048) and sacral inclination (r = 0.34, P = 0.009). However, bone mineral density and physical activity score did not show any significant correlations with the radiographic factors. The results indicate that the stronger the back extensor, the smaller the thoracic kyphosis and the larger the lumbar lordosis and sacral inclination. We conclude that back extensor strength is an important determinant of posture in healthy women. However, prescribing back extensor strengthening exercises alone may also increase lumbar lordosis, which is not desirable.

Initial clinical experience with dextran-coated superparamagnetic iron oxide for detection of lymph node metastases in patients with head and neck cancer.

PURPOSE: To investigate the efficacy of magnetic resonance (MR) imaging with dextran-coated superparamagnetic iron oxide in the differentiation of metastatic and benign nodes in patients with head and neck cancer. MATERIALS AND METHODS: MR imaging was performed before and after intravenous administration of iron oxide in 12 patients. Ninety-one pathologically proved nodes were visually analyzed, and 66 lymph nodes were quantitatively analyzed by measuring signal intensity in visually selected regions of interest. RESULTS: Forty of 42 histologically proved metastatic nodes and 41 of 49 benign nodes were detected, yielding 95% sensitivity and 84% specificity. The signal intensity ratio of benign nodes was substantially lower than that of metastatic nodes, indicating better differentiation of metastatic and benign nodes. Furthermore, 13 of 14 normal-sized nodes were detected. CONCLUSION: MR imaging with iron oxide can enable specific differentiation of metastatic and benign nodes in patients with head and neck cancer. This agent may potentially enhance the detection of metastatic lymph nodes and deserves further investigation.

Muscle strength in osteoporotic versus normal women.

Strong back muscles contribute to good posture and skeletal support. Osteoporosis, being a metabolic bone disease, should not affect muscle strength. In this study we were interested in comparing the back extensor strength (BES) of osteoporotic and normal women. Fifty-five women ages 40-85 years who had a documented diagnosis of osteoporosis and were referred for initiation of proper exercise programs were included in our study after meeting the inclusion criteria. They all had evaluation of their posture, back and upper extremity strength, and physical activity score through our Rehabilitation of Osteoporosis Program--Exercise (ROPE). In addition, to avoid the interference of pain on application of maximal effort, we did not include subjects with acute back pain or those who experienced back pain with maximal effort during the testing trial. BES for osteoporotic women ranged from 16 to 65 lb (mean +/- SD, 36.5 +/- 15.5) for ages 40-59 years, 9 to 55 lb (mean +/- SD, 29.9 +/- 10.6) for ages 60-69 years, 6 to 52 lb (mean +/- SD, 24.3 +/- 10.2) for ages 70-79 years, and 17 to 27 lb (mean +/- SD, 21.2 +/- 4.2) for ages 80 years or older. Comparison of these data with the BES of 25 normal women, with statistical adjustment for age, demonstrated that the osteoporotic women had significantly lower BES than the normal women. A longitudinal study of a larger group of women would be of great interest for clarifying whether the weakness of back extensors precedes and, indeed, contributes to compression fractures of the spine.

A useful technique for measurement of back strength in osteoporotic and elderly patients.

Improvement of back extensor strength (BES) can be used as a therapeutic method for patients with chronic back pain and osteoporosis. The method of evaluation must be reliable and accurate without compromising the condition of the patient. We report the development of a back isometric dynamometer (BID-2000) designed specifically by two of us to address these concerns in elderly patients with osteopenia or osteoporosis. As the demographics of the general population change, increasing numbers of patients will need the type of monitoring that the BID-2000 provides. Aging has been shown to cause a reduction in the number of functional muscle motor units. To examine this effect on BES, we tested 50 normal, healthy women who were 30 to 79 years old. Proper testing of BES in patients with fragile vertebrae should include isometric measurement in the prone position, maneuverability of the device to allow comfortable positioning of the patient, and simplicity of technique to minimize repetitious performance of maximal contraction. The BID-2000 incorporates each of these features and also provides meaningful results inexpensively. The device offers a safe, reliable (coefficient of variation = 2.33%), and valid (P = 0.001) method of evaluation. The results of our study demonstrated moderate, steady reduction of BES with increasing age and with each successive decade.

Clinical application of percutaneous cardiopulmonary bypass for high risk coronary angioplasty.

Percutaneous cardiopulmonary bypass support was electively instituted prior to coronary angioplasty in 16 patients at high risk for hemodynamic collapse. In all cases the dilated artery supplied greater than 2/3 of the functioning myocardium. Eight patients had moderate LV dysfunction with ejection fraction 25-40%. Eight patients had an ejection fraction less than 20%. A 21 French cannula and a 17 French cannula were percutaneously inserted into the femoral vein and artery. Cardiopulmonary bypass support was instituted using a Bio-Medicus centrifugal pump just prior to coronary angioplasty at flow rates of 3.5-5 liters/minute. Thirteen patients had single vessel angioplasty and three patients had multivessel angioplasty. Complete loss of systolic function was observed in 9 (56%) patients. This finding when present confirms the absolute requirement for cardiopulmonary support. Technical success was achieved in all 16 patients (100%), clinical success was achieved in 14 patients (88%). Patient followup (mean 10 months) revealed 3 patients with class I-II angina and 10 patients were asymptomatic. There was one late death. In conclusion, percutaneous cardiopulmonary bypass support for carefully selected high risk patients may allow coronary angioplasty to be performed safely and effectively despite complete loss of systolic function during balloon inflation.

The Amos decision: will we see changes in the workplace?

A recent decision by the U.S. Supreme Court (in Corporation of the Presiding Bishop v. Amos) upheld, and slightly expanded, the exemption of religious organizations from the Title VII prohibitions against discrimination on the basis of religion, as stated in amended Section 702 of the Civil Rights Act of 1964. How this decision will affect hiring practices, if at all, among Catholic healthcare institutions remains to be seen, but the potential for change is inherent. The Amos case now allows organizations to expand the area of questions to include a person's religious affiliation, beliefs, and values. Based on the facts of this case, it would also allow a religious employer to inquire as to that person's religious practices and his or her standing in the Church. While the authors point to the traditional Catholic practice of openness in "hiring catholic" as evidence that the ruling will have minimal impact in day-to-day personnel decision making, they note the door is open to allow changes, and pressures to change may mount. Certain employment decisions for leadership positions, including those of an organizational, corporate, and business nature, may now include clearly religious criteria. In addition, the declining number of religious members in may religious institutes that sponsor healthcare facilities may put additional pressure on those institutions to "hire Catholic" when selecting lay leaders to ensure that the employer's mission and values will be carried out.

Aircraft Observations of the Infrared Emission of the Atmosphere in the 700-2800-cm(-1) Region.

Atmospheric emission spectra in the 700-2800-cm(-1) region have been measured from an aircraft at 9.45-11.89-km altitudes. All measurements were made viewing at the zenith at a spectral resolution of 2 cm(-1). The measurements were obtained using interferometer spectrometers, and the atmospheric radiation was modulated with a liquid nitrogen cooled chopper that eliminated the thermal emission of the spectrometers from the measured spectra. Essentially all the features of the spectra can be identified with known constituents of the atmosphere. The comparison with a theoretical emission calculation using a tropical atmospheric model was satisfactory except for the H(2)O that showed a smaller concentration by a factor of 5 than was assumed in the model at these altitudes.

Infrared Chemiluminescence of the Reaction N + O(2) ? NO + O.

The chemiluminescent nature of the reaction N + O(2) ? NO + O followed by N + NO ? N(2) + O has been investigated in the steady state through detection of characteristic infrared radiation emitted by NO molecules. Both Deltaupsilon = 1 radiation at 5.4 micro and Deltaupsilon = 2 at 2.7 mu exhibit linear dependence on O(2) pressure. In the case of the overtone, low-resolution spectra are obtained at several O(2) pressures, and it is shown that under the experimental conditions reported here the spectra should closely reflect the initial vibrational distribution of the NO molecules as they are formed. From the spectral results we are able to estimate an overtone quantum efficiency for the reaction N + O(2) ? NO(double dagger) + O. Depending upon the experimentally reported value of the rate for this reaction, the quantum efficiency is between 0.2 and 0.5.