Staphylococcus aureus in the nose and throat of Iowan families.

The study objective was to determine the prevalence of Staphylococcus aureus colonisation in the nares and oropharynx of healthy persons and identify any risk factors associated with such S. aureus colonisation. In total 263 participants (177 adults and 86 minors) comprising 95 families were enrolled in a year-long prospective cohort study from one urban and one rural county in eastern Iowa, USA, through local newspaper advertisements and email lists and through the Keokuk Rural Health Study. Potential risk factors including demographic factors, medical history, farming and healthcare exposure were assessed. Among the participants, 25.4% of adults and 36.1% minors carried S. aureus in their nares and 37.9% of adults carried it in their oropharynx. The overall prevalence was 44.1% among adults and 36.1% for minors. Having at least one positive environmental site for S. aureus in the family home was associated with colonisation (prevalence ratio: 1.34, 95% CI: 1.07-1.66). The sensitivity of the oropharyngeal cultures was greater than that of the nares cultures (86.1% compared with 58.2%, respectively). In conclusion, the nares and oropharynx are both important colonisation sites for healthy community members and the presence of S. aureus in the home environment is associated with an increased probability of colonisation.

Increased carotid intimal-medial thickness and coronary calcification are related in young and middle-aged adults. The Muscatine study.

BACKGROUND: Increased carotid intimal-medial thickness (IMT) and coronary artery calcification (CAC) are used as 2 markers of early atherosclerosis. Our objectives were to assess whether increased IMT and CAC are related and to determine the relationship between cardiovascular risk factors and carotid IMT in young adults. METHODS AND RESULTS: A sample of 182 men and 136 women aged 33 to 42 years living in Muscatine, Iowa, underwent B-mode carotid ultrasound to determine the mean of 12 measurements of maximal carotid IMT. CAC was defined as calcification in the proximal coronary arteries in >/=3 contiguous pixels with a density of >/=130 HU. The mean IMT was 0.788 mm (SD 0.127) for men and 0.720 mm (SD 0.105) for women. CAC was present in 27% of men and 14% of women and was significantly associated with IMT in men (P<0.025) and women (P<0.005). With multivariate analysis, after adjustment for age, significant risk factors for carotid IMT were LDL cholesterol (P<0.001) and pack-years of smoking (P<0.05) in men and LDL cholesterol (P<0.001) and systolic blood pressure (P<0.01) in women. These risk factors remained significant after CAC was included in the multivariate model. CONCLUSIONS: There is an association between increased carotid IMT and CAC and between cardiovascular risk factors and increased IMT in young adults. Carotid IMT may provide information in addition to CAC that can be used to identify young adults with premature atherosclerosis.

Carotid intimal-medial thickness is related to cardiovascular risk factors measured from childhood through middle age: The Muscatine Study.

BACKGROUND: Higher carotid intimal-medial thickness (IMT) is associated with cardiovascular risk factors and is predictive of coronary artery disease and stroke in older adults. Carotid IMT was measured in young and middle-aged adults to determine its relationship with risk factors measured (1) in childhood, (2) currently, and (3) as a "load" from childhood to adulthood. METHODS AND RESULTS: Carotid ultrasound studies were performed in 346 men and 379 women aged 33 to 42 years who were representative of a cohort followed since childhood and who live in Muscatine, Iowa. The mean of the measurements of maximal carotid IMT at 12 locations was determined for each subject. A medical questionnaire was completed, and measurements of anthropometric characteristics and risk factors were obtained. The mean maximum carotid IMT was 0.79+/-0.12 mm for men and 0.72+/-0.10 mm for women. On the basis of multivariable analysis, the significant current predictors of IMT were age and LDL cholesterol in both sexes and diastolic blood pressure in women. Total cholesterol was a significant childhood predictor in both sexes, while childhood body mass index was significant only in women. For men, LDL cholesterol, HDL cholesterol, and diastolic blood pressure were predictive of carotid IMT in a risk factor load model, whereas in women, LDL cholesterol, body mass index, and triglycerides were predictive. CONCLUSIONS: Higher carotid IMT in young and middle-aged adults is associated with childhood and current cardiovascular risk factors, as well as risk factor load.

Analyzing laboratory marker changes in AIDS clinical trials.

Repeated measurements of laboratory markers of immunologic or disease status, such as CD4 lymphocyte counts and HIV p24 antigen levels, can be important end points in comparative clinical trials. In this report, we consider comparison of treatment groups with respect to such markers, focusing on a distribution-free approach in which each participant's data are characterized by a single summary statistic. The summary statistics examined are (a) the slope of the least-squares regression of the marker, (b) the average of the last r measurements, and (c) the difference between the averages of the last r and the first s measurements. Under various models of marker time trends, these methods are compared with regard to statistical power. It is found that the slope is usually more efficient than the other two types of summaries. Adaptations for missing data are discussed and illustrated in an analysis of CD4 counts from a recent AIDS clinical trial.

Risk factors for Candida species colonization of neonatal intensive care unit patients.

BACKGROUND: Candida spp. are increasingly important pathogens in neonatal intensive care units (NICU). Prior colonization is a major risk factor for candidemia, but few studies have focused on risk factors for colonization, particularly in NICU patients. METHODS: A prospective, multicenter cohort study was performed in six NICUs to determine risk factors for Candida colonization. Infant gastrointestinal tracts were cultured on admission and weekly until NICU discharge and health care worker hands were cultured monthly for Candida spp. RESULTS: The prevalence of Candida spp. colonization was 23% (486 of 2157 infants); 299 (14%), 151 (7%) and 74 (3%) were colonized with Candida albicans, Candida parapsilosis and other Candida spp., respectively. Multiple logistic regression analysis adjusting for length of stay, birth weight < or = 1000 g and gestational age < 32 weeks revealed that use of third generation cephalosporins was associated with either C. albicans (155 incident cases) or C. parapsilosis (104 incident cases) colonization. Use of central venous catheters or intravenous lipids were risk factors for C. albicans, whereas delivery by cesarean section was protective. Use of H2 blockers was an independent risk factor for C. parapsilosis. Of 2989 cultures from health care workers' hands, 150 (5%) were positive for C. albicans and 575 (19%) for C. parapsilosis, but carriage rates did not correlate with NICU site-specific rates for infant colonization. CONCLUSIONS: We speculate that NICU patients acquire Candida spp., particularly C. parapsilosis, from the hands of health care workers. H2 blockers, third generation cephalosporins and delayed enteral feedings alter gastrointestinal tract ecology, thereby facilitating colonization.

An introduction to time-trend analysis.

Healthcare professionals often are presented with data that appear to indicate an upward or downward trend over time. For example, admissions of acquired immunodeficiency syndrome (AIDS) patients appear to be increasing, cesarean section rates appear to be decreasing, or nosocomial pneumonia rates appear to be increasing. Critical decisions sometimes are based on such trends, which often are presented without a statistical analysis. Those responsible for decision making may be left wondering whether these apparent trends represent only chance variation. Graphs showing trends over time generally present one of three kinds of outcome data: counts (eg, three AIDS admissions), proportions (eg, 10 cesarean sections per 100 total deliveries), or person-time data (eg, 13 cases of nosocomial pneumonia per 10,000 patient days). Using familiar examples and a minimum of technical language, we illustrate the analysis of time trends.

Community characteristics associated with elder abuse.

OBJECTIVES: To help define the relationship between elder abuse rates and counties' demographics, healthcare resources, and social service characteristics. DESIGN: County-level data from Iowa were analyzed to test the association between county characteristics and rates of elder abuse between 1984 and 1993 using univariate correlation analysis and stagewise linear regression. SETTING: Ninety-nine counties in Iowa. PARTICIPANTS: Iowa residents aged 65 years and older. MEASUREMENTS: County-level population-adjusted numbers of abused elderly, abused children, children in poverty, high school dropouts, physicians and other healthcare providers, hospital beds, social workers and caseworkers in the Department of Human Services (DHS). RESULTS: Community characteristics that had a positive association with rates of reported or substantiated elder abuse at the P < .001 level were population density, children in poverty, and reported child abuse. Lower substantiated elder abuse rates were associated at P < .05 with higher community rates of high school dropouts, number of chiropractors, and number of nurse practitioners. After adjusting for number of DHS caseworkers and reported child abuse rates (a surrogate for workload) a district effect persists for substantiated elder abuse cases (P = .002). CONCLUSION: County demographics are risk factors for reported and substantiated elder abuse. The strongest risk factor for reported elder abuse was reported child abuse. The difference in districts may reflect differences in resources and/or differing characteristics of caseworkers who substantiate elder abuse. The risk factors may reflect conditions that influence the amount of elder abuse or the detection of existing elder abuse.

Cytomegalovirus transmission in child care homes.

BACKGROUND: Children attending child care centers have high rates of cytomegalovirus (CMV) excretion. Women exposed to such children have an increased risk of acquiring CMV infection, and primary infection places the offspring of such women at risk of congenital CMV infection. We studied family child care homes to determine if this child care alternative might represent a safe haven from CMV. METHODS: One hundred thirty-two women providing care in their homes were studied using a latex agglutination method to determine the rate of CMV seropositivity at baseline. Women who were seronegative for CMV were then sampled prospectively at 6-month intervals between March 1991 and August 1994 to determine the annual rate of CMV acquisition. A point prevalence of CMV excretion in family homes was determined by sampling 106 children from 25 randomly selected homes. Cytomegalovirus isolates were compared by molecular analysis using polymerase chain reaction-based methods to identify transmission. RESULTS: At baseline, 57.6% of the 132 providers were seropositive for CMV. Seropositive providers were more likely to be caring for toddlers (aged 1-2 years) (67% vs 46%; P=.02) and had worked in child care somewhat longer (median of 28.5 vs 21.5 months; P=.11). Using stepwise logistic regression, the strongest predictors of seropositivity at baseline were caring for children aged 1 to 2 years (odds ratio [OR] =2.37; P=.02) and number of months as a child care provider (OR= 1.17 for an increase of 24 months as provider; P=.08). Six or more years as a provider was highly associated with seropositivity (OR=3.27; P=.02). During follow-up, 5 of 51 seronegative providers seroconverted, yielding an annual infection rate of 6.8%. The point prevalence survey of children from the 25 homes (14 had seropositive providers) identified 8 CMV-excreting children. Three children in 1 home had indistinguishable isolates by polymerase chain reaction mapping. The provider seroconverted and excreted an isolate with a molecular profile indistinguishable from that of the children. CONCLUSIONS: The prevalence of CMV excretion is low among children attending child care homes (8% vs 15% in prior studies of child care centers; P=.07), and only 1 (20%) in 5 of the homes had CMV-excreting children. However, the overall CMV seroconversion rate of home child care providers was comparable to the rate observed among providers in child care centers. Families who use family home child care as an alternative to large child care centers are exposed to a low and unpredictable risk of CMV infection.

The association between manual removal of the placenta and postpartum endometritis following vaginal delivery.

OBJECTIVE: To determine whether manual removal of the placenta after vaginal delivery is a risk factor for postpartum endometritis. METHODS: A retrospective cohort study of vaginal deliveries compared 1052 patients who had manual removal of the placenta with 1085 patients whose placentas delivered spontaneously. Subjects were selected randomly from the 25,687 vaginal deliveries at the University of Iowa Hospitals during 1979-1992. The presence of endometritis was determined using information in medical records. The data were analyzed using odds ratios (OR) and multiple logistic regression. RESULTS: After controlling for confounding variables, manual removal of the placenta was associated with postpartum endometritis (adjusted OR 2.9, 95% confidence interval [CI] 1.7-4.9). Other risk factors for endometritis included maternal age less than 17 years (OR 3.3, 95% CI 1.5-7.2), postpartum anemia (OR 2.9, 95% CI 1.9-4.5), and membranes ruptured longer than 24 hours (OR 2.5, 95% CI 1.4-4.3). CONCLUSION: Manual removal of the placenta is a risk factor for postpartum endometritis after vaginal delivery.

Anal incontinence after anal sphincter disruption: a 30-year retrospective cohort study.

OBJECTIVE: To compare the prevalence of anal incontinence remote from delivery (approximately 30 years postpartum) in 29 women whose index delivery was complicated by anal sphincter disruption versus a matched control group of 89 women who had an episiotomy without extension to the anal sphincter and versus a group of 33 women who delivered via cesarean. METHODS: In this retrospective cohort study, a structured questionnaire was sent to women in the above categories who delivered at a university hospital between 1961 and 1965 and for whom we could obtain current addresses. Outcome measures included frequent fecal and flatus incontinence and bothersome fecal and flatus incontinence. RESULTS: The three groups did not differ significantly in age, weight, age at delivery, parity, weight of largest baby, postmenopausal status, estrogen replacement usage, most medical conditions, or rectocoele, rectovaginal fistula, or incontinence surgeries. Frequent flatus incontinence was reported by nine (31.0%), 38 (42.7%), and 12 (36.4%) women in the anal sphincter disruption, episiotomy, and cesarean groups, respectively (not significant). The number of women with bothersome flatus incontinence was higher in the anal sphincter disruption group: 17 (58.6%) versus 27 (30.3%) in the episiotomy only group and versus five (15.2%) in the cesarean group (P = .001). Frequent fecal incontinence was reported by two (6.9%), 16 (18.0%), and 0 women (P = .008 between cesarean and episiotomy only groups), whereas bothersome fecal incontinence was reported by eight (27.6%), 23 (25.8%), and five (15.2%) women (not significant) in the anal sphincter disruption, episiotomy only, and cesarean groups, respectively. CONCLUSION: Regardless of the type of delivery, anal incontinence occurs in a surprisingly large number of middle-aged women.

Predictors of neonatal resuscitation, low Apgar scores, and umbilical artery pH among growth-restricted neonates.

OBJECTIVE: To identify risk factors associated with poorer immediate neonatal outcomes among growth-restricted neonates. METHODS: Records of all 530 growth-restricted neonates born between January 1989 and February 1995 were reviewed. Outcomes included resuscitation measures, Apgar scores, and umbilical blood gas values. Neonates were assigned to one of six anesthetic groups, and outcomes were compared. Predictors of poorer outcomes were examined using logistic and linear regression. RESULTS: Neonates exposed to general anesthesia were more likely to be intubated (37.9% versus 4.1%, P < .001, Pearson chi2) and had lower mean 1- (4.0 versus 7.0) and 5-minute (6.5 versus 8.4) Apgar scores (P < .01, Scheffé) than those in all other anesthetic groups. They also had significantly lower umbilical artery (UA) pH values than neonates who received nalbuphine, epidural, or no anesthesia (7.21 versus 7.28, 7.26, 7.29, respectively; P < .01, Scheffé). Factors that significantly and independently predicted intubation among all neonates included exposure to general anesthesia (odds ratio [OR] 4.1; 95% confidence interval [CI] 1.9, 8.9) and lower infant weight (OR 10.1 per kg decrease; CI 5.1, 20). Factors predicting UA pH at most 7.15 included preeclampsia (OR 3.0; CI 1.5, 5.9) and older maternal age (OR 1.3 per 5 years; CI 1.02, 1.64); vertex delivery (OR 0.5; CI 0.2, 0.9) was protective. Factors predicting a 5-minute Apgar less than 7 were meconium (OR 1.5 per category going from none to terminal to light to heavy; CI 1.04, 2.3), general anesthesia (OR 6.9; CI 2.6, 18.2), lower infant weight (OR 16.5 per kg decrease; CI 7.8, 34.5), and vaginal breech delivery (OR 7.0; CI 1.8, 28.6); cesarean delivery (OR 0.2; CI 0.08, 0.66) was protective. Spontaneous vertex delivery raised the UA pH, and preeclampsia, amnioinfusion, breech delivery, and general anesthesia significantly and independently lowered the UA pH among all neonates. For infants delivered by cesarean, "fetal distress," preeclampsia, previous spontaneous abortion, failed forceps use, and nalbuphine significantly and independently predicted lower UA pH. CONCLUSION: Risk factors for poorer immediate neonatal outcomes among growth-restricted neonates include preeclampsia, fetal distress, breech delivery, forceps use, nalbuphine during labor, lower infant weight, and general anesthesia.

The effects of smoking on ovarian function and fertility during assisted reproduction cycles.

OBJECTIVE: To investigate the effects of cigarette smoking on ovarian function and fertility in women undergoing assisted reproduction cycles. METHODS: We assessed the effects of smoking on ovarian function and fertility in a cohort of 499 women. Questionnaires were designed to quantify past smoking exposure and to determine whether the woman was smoking during the treatment cycle. Ovarian function characteristics and pregnancy rates were compared among current smokers, past smokers, and nonsmokers. RESULTS: Compared with nonsmokers, both current and past smokers have reduced gonadotropin-stimulated ovarian function. A history of increasing tobacco exposure was associated with decreasing serum estradiol concentrations, numbers of retrieved oocytes, and numbers of embryos. On average, for every 10 pack-years of cigarette smoking, 2.5 fewer mature oocytes and 2.0 fewer embryos were obtained. Women who smoked during their treatment cycle had approximately a 50% reduction in implantation rate and ongoing pregnancy rate compared with women who had never smoked. Women who quit smoking before their treatment cycle had the same pregnancy rate as nonsmokers. CONCLUSION: Cigarette smoking is associated with a prolonged and dose-dependent adverse effect on ovarian function. Smoking appears to have a more transient toxic effect on fertility, because current smokers, but not past smokers, had a markedly reduced pregnancy rate after treatment cycles compared with nonsmokers. Women should quit smoking before assisted reproduction cycles.

Value of preoperative CA 125 level in the management of uterine cancer and prediction of clinical outcome.

OBJECTIVE: To enhance cost-effective management of uterine cancer by predicting the likelihood of extrauterine disease and survival on the basis of preoperative parameters. METHODS: A retrospective review of preoperative CA 125 levels from 210 women with endometrial carcinoma was performed. The relationship of preoperative CA 125 levels to various preoperative and postoperative histopathologic factors was investigated. RESULTS: Elevated CA 125 (greater than 35 U/mL) correlated (P < .05) with higher stage, higher grade, increased depth of myometrial invasion, positive cytology, pelvic or para-aortic lymph node metastases, and reduced actuarial survival (P < .001). Multivariate analysis of preoperative factors showed that an elevated CA 125 level was the most important predictor for poor survival (P < .001). Moreover, a preoperative CA 125 level greater than 65 U/mL was the most significant predictor of extrauterine disease and carried a 6.5-fold higher risk (95% confidence interval 2.5, 17.1). A logistic model to predict extrauterine disease was developed. The model has a sensitivity of 62%, specificity of 91%, positive predictive value of 69%, and negative predictive value of 88%. CONCLUSION: A CA 125 level should be included as part of the preoperative workup for all patients with uterine cancer. Patients with a preoperative CA 125 level less than or equal to 20 U/mL should be considered as candidates for vaginal hysterectomy unless unfavorable histology or a high-grade (grade II or III) tumor is present. In our series, this approach would have eliminated 24% of the abdominal staging procedures, with a risk of less than 3% for extrauterine disease, while lowering treatment-related morbidity and cutting costs in the treatment of this common female cancer.

Charting patients' course: a comparison of statistics used to summarize patient course in longitudinal and repeated measures studies.

Investigators conducting longitudinal studies of psychiatric illnesses often analyze data based on psychiatric symptom scales that were administered at multiple time points. This study examines the statistical properties of seven indices that summarize patient long-term course. These indices can be used to compare differences between two or more groups or to test for changes in symptoms over time. They may also be treated as outcome measures and correlated with other clinical variables.The performance of each of the seven indices was assessed using data from two large ongoing studies of psychiatric patients: a longitudinal study of affective disorders and a longitudinal study of first-episode psychosis. These two datasets were subjected to bootstrapping techniques in order to calculate both type I error rates and statistical power for each summary statistic. Of the seven indices, Kendall's tau performed the best as a measure of patients' symptom course. Kendall's tau appears to offer more statistical power to detect change in course, yet its average type I error rate was comparable to the other indices.

Tracking physical fitness and physical activity from childhood to adolescence: the muscatine study.

PURPOSE: Physical fitness and physical activity tracking data enhance our understanding as to when children settle into their long-term exercise and fitness patterns and, therefore. provide insight as to when programs focusing on preventing sedentary adults behaviors should be initiated. METHODS: In this paper, the tracking of physical fitness and physical activity was examined in a 5-yr population-based study of children and adolescents in Muscatine, IA. Study subjects (N = 126) were pre- or early-pubescent at baseline (mean age boys 10.8 yr and girls 10.3 yr). Physical fitness was measured using direct determination of oxygen uptake and maximal voluntary isometric contraction while physical activity was assessed via questionnaire. RESULTS: Boys classified as sedentary based on initial measurements of TV viewing and video game playing were 2.2 times more likely than their peers to also be classified as sedentary at follow-up. Tracking of most physical fitness and physical activity variables was moderate to high, indicating some predictability of early measurements for later values. Sedentary behavior tracked better in boys, whereas vigorous activity tended to track better in girls. CONCLUSION: These observations suggest that preventive efforts focused on maintaining physical fitness and physical activity through puberty will have favorable health benefits in later years.

Variability in the learning experiences of family practice residents during an obstetrics rotation.

BACKGROUND AND OBJECTIVES: Residency rotations do not necessarily provide the same clinical experience to each resident. This study quantified and explained the variability in participation in deliveries by family practice residents during an obstetrics rotation at a community hospital. METHODS: We collected prospectively completed resident experience logs from 17 residents and information from the hospital Summary of Delivery forms for 1,166 deliveries. The data were analyzed using methods to account for within-supervisor correlation. RESULTS: Participation and delivery rates varied markedly. In stepwise conditional regression analysis, resident participation in deliveries was positively associated with prior resident involvement during the labor and negatively associated with occurrence of the delivery on the night shift and with male gender of the resident. Resident performance of delivery was positively associated with non-instrumented vaginal delivery, prior resident involvement during the labor, and patient multiparity and negatively associated with male resident gender. CONCLUSIONS: We found substantial variability in resident experience and identified several factors associated with increased resident experience. Variability of experience among residents in clinical rotations should be assessed to ensure that all residents receive adequate training.

Understanding logistic regression analysis through example.

Logistic regression is a valuable statistical tool that is often used in primary care research. When researchers explore the association between a possible risk factor and a disease, they attempt to control the effects of extraneous factors (confounders) that can obscure the true association. Using logistic regression, researchers can simultaneously control for the effects of multiple confounders. When investigators use logistic regression, they make subjective decisions about which factors to include in the analysis and in the final predictive model. Critical readers must understand basic concepts of logistic regression and potential problems with its use before they can accurately interpret study results. This article uses a familiar example to explain the principles of logistic regression to make it understandable to nonstatisticians.

Skills that Iowa family physicians desire in a new physician partner.

BACKGROUND AND OBJECTIVES: The importance of specific skills in primary care continues to be debated. As a result, there is not consensus on which skills need to be stressed during residency training. Our project asked community-based family physicians to rate the importance of specific skills in a new family physician partner. METHODS: Data were collected through a cross-sectional survey of all active members of the Iowa Academy of Family Physicians. Participants were surveyed by mail, using a list of 83 skills pertinent to primary care. Physicians were asked to rate the importance of a new member of their practice having the individual skills on this list. RESULTS: A total of 546 family physicians (67%) completed questionnaires. Fourteen skills (seven cognitive and seven psychomotor) were reported to be "essential" or "very important" by at least 80% of the physicians. A total of 43 skills were rated as "essential" or "very important" by at least 50% of responding family physicians. Many of the hospital-based procedural skills, particularly those used in an intensive care setting, were rated as less important. The importance ratings of many skills were associated with the physicians' ages, size of their primary hospitals, and availability of other medical specialties. CONCLUSIONS: Family physicians tended to rate office-based procedural skills, counseling skills, and management skills as "essential or very important" to their practices. These rating might be used to guide residency training in family practice.

The effect of physician characteristics on compliance with adult preventive care guidelines.

BACKGROUND AND OBJECTIVES: This study identified physician characteristics and attitudes related to self-reported compliance with adult prevention guidelines. METHODS: A questionnaire was mailed to family practice and internal medicine residents and faculty at the University of Iowa (n = 209). The questionnaire's 78 items fell into seven categories, including physician demographics, history-taking practices, counseling practices, self-perceived effectiveness in changing patient behavior, beliefs about preventive care, knowledge about preventive care, and perceived barriers to the delivery of preventive care. RESULTS: Compliance with history-taking recommendations was independently associated with high knowledge scores, female physician gender, and high self-perceived effectiveness in changing patient behavior. The only factor that was independently associated with counseling efforts was self-perceived effectiveness in changing patient behavior. CONCLUSIONS: Factors that were independently associated with self-reported preventive care efforts include female physician gender, knowledge about preventive care guidelines, and perceived effectiveness in changing patient behavior. After controlling for these factors, other variables such as lack of time, lack of reminder systems, attitudes about preventive care, and amount of formal preventive care education were not related to self-reported compliance with counseling and history-taking recommendations.

Interinnominate motion and symmetry: comparison between gymnasts and nongymnasts.

Some clinical approaches to the treatment of low back pain evaluate and treat observed asymmetries of pelvic posture and motion. Scientific evidence suggests the motion available between the innominate bones is small and variable in nature. The purposes of this investigation were 1) to determine if interinnominate motion of subjects without low back pain was symmetrical in reciprocal test posture combinations, 2) to assess innominate bone symmetry in standing, and 3) to determine if a difference in the magnitude of interinnominate motion was present between a subject group which performs more frequent flexibility activities compared with a subject group representing the general population. Thirty-four subjects (eight male gymnasts, nine female gymnasts, eight male nongymnasts, and nine female nongymnasts) were evaluated in standing and three other reciprocal postures (modified standing, modified sitting, and half-kneeling). In each posture, the Metrecom Skeletal Analysis System was used to obtain coordinates for the anterior and posterior iliac spines. Projection angles were used to determine the relative positions of the right and left innominate bones. Results suggest that stand to right modified standing and stand to left modified standing oblique sagittal interinnominate composite motions were symmetrical, stand to right modified sitting and stand to left modified sitting oblique sagittal interinnominate composite motions were asymmetrical, and stand to right half-kneel and stand to left half-kneel oblique sagittal interinnominate composite motions' symmetrical properties were mixed depending on the group. Gymnasts as a group were found to have asymmetrically positioned innominate bones while nongymnasts as a group had symmetrically positioned innominate bones.