Influence of visual control, conduction, and central integration on static and dynamic balance in healthy older adults

Aging is associated with decreased balance abilities, resulting in an increased risk of fall. In order to appreciate the visual, somatosensory, and central signals involved in balance control, sophisticated methods of posturography assessment have been developed, using static and dynamic tests, eventually associated with electromyographic measurements. We applied such methods to a population of healthy older adults in order to appreciate the respective importance of each of these sensorial inputs in aging individuals. Posture control parameters were recorded on a force-measuring platform in 41 healthy young (age 28.5 +/- 5.9 years) and 50 older (age 69.8 +/- 5.9 years) adults, using a static test and two dynamic tests performed by all individuals first with eyes open, then with eyes closed. The distance covered by the center of foot pressure, sway area, and anteroposterior oscillations were significantly higher, with eyes open or closed, in older people than in young subjects. Significant differences were noted in dynamic tests with longer latency responses in the group of old people. Dynamic recordings in a sinusoidal test had a more regular pattern when performed eyes open in both groups and evidenced significantly greater instability in old people. These data suggest that vision remains important in maintaining postural control while conduction and central integration become less efficient with age.     

Participation in community sports centres: motives and predictors of enjoyment

Research into why people engage in sport and physical recreation has received relatively little attention in both recreation planning and sport psychology. Although there has been a steady flow of North American literature related to participation motivation in competitive youth sport settings, such evidence is of limited value in explaining adult involvement in sport and recreation in Britain. The purpose of this exploratory study was to determine why people participate in sport and exercise in community sports centres and to identify whether these motives predict sport enjoyment. The study was based on a questionnaire-interview of approximately 5 min duration conducted in six community sports centres in Leicester. The sample comprised 336 respondents aged 16 years and over. The subjects were presented with 15 motives for sports participation and indicated their degree of agreement on a 5-point scale. The three most commonly endorsed motives were to maintain health, develop physical fitness and aid relaxation. A factor analysis with oblique rotation revealed four factors:assertive achievement, physical well-being, socio-psychological well-being, and sports mastery and performance. Discriminant analysis showed that males were more motivated to participate for sports mastery and performance and assertive achievement than females. A MANOVA showed that older subjects were more motivated by socio-psychological well-being than younger subjects. Sport enjoyment was best predicted by socio-psychological well-being, sports mastery and performance, and sports importance, although only 14.4% of the variance in enjoyment scores was accounted for. These results confirm other research on age differences in exercise and mental health, as well as gender differences on participation motives.     

The effects of autonomy-supportive coaching, need satisfaction, and self-perceptions on initiative and identity in youth swimmers.

This study tested a sequential process model linking youth sport coaching climates (perceived coach behaviors and perceived need satisfaction) to youth self-perceptions (perceived competence and global self-esteem) and youth development outcomes (initiative, identity reflection, identity exploration). A sample of 119 youth between the ages of 10 and 18 who participated in a community-directed summer swim league completed questionnaires over the course of the 7-week season. Results indicated that coaches' autonomy support, particularly via process-focused praise, predicted youth competence need satisfaction and relatedness need satisfaction in the coaching relationship. Youth competence need satisfaction predicted self-esteem indirectly via perceived competence. Finally, self-esteem predicted identity reflection, and perceived competence predicted both identity reflection and initiative. Effects of age, sex, and perceptions of direct contact with the coach were not significant. Findings suggest that the quality of the coaching climate is an important predictor of the developmental benefits of sport participation and that one pathway by which the coaching climate has its effect on initiative and identity reflection is through developing youth self-perceptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ego development, authoritarianism, and social status: An investigation of the incremental validity of Loevinger's Sentence Completion Test (Short Form).

This study presents two sets of analyses designed to evaluate the relation between a 12-item form of the Washington University Sentence Completion Test of ego development (Short Form; SCT-S) and socioeconomic status (SES). The subjects were a large national random sample of adolescent and young adult men and women who were stratified into three artificial age cohorts. The first set of hierarchical multiple regression analyses indicated that SES accounted for 8 to 13% of the variance in SCT-S scores. Incremental validity of the SCT-S in predicting social attitudes, beyond that predicted by SES, was generally supported for authoritarian aggression and partially supported in predicting masculine sex role expectations. Findings suggest that research on ego development with subjects over age 18 might use level of education as a rough index of SES. For younger subjects, parental factors and education are both important. This study also provides revised age-specific national norms for the SCT-S. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Risk factors for the development of NIDDM in Yonchon County, Korea

OBJECTIVE: To determine the risk factors for the development of NIDDM in Yonchon County of Korea. RESEARCH DESIGN AND METHODS: We studied 1,193 Korean nondiabetic subjects at baseline who participated in a 2-year follow-up study on diabetes in Yonchon County. A 75-g oral glucose tolerance test was performed 2 years after the baseline examination. Age, sex, and anthropometric and metabolic characteristics at baseline were analyzed simultaneously as potential predictors of conversion to NIDDM. We also designed a nested case-control study to determine the role of hyperinsulinemia and/or hyperproinsulinemia in the conversion to NIDDM in patients with newly developed diabetes and control subjects matched for age, sex, BMI, and waist-to-hip-ratio. RESULTS: At 2 years, 67 subjects developed diabetes, as defined by World Health Organization criteria. The age-adjusted incidence was significantly higher in men (6.4%) than in women (3.0%), and the incidence increased as age increased in both sexes. Multiple logistic regression analysis revealed age, male sex, and fasting and 2-h glucose levels to be significant risk factors for the development of NIDDM, whereas waist-to-hip ratio and BMI were not. In a nested case-control study, baseline proinsulin but not insulin levels were significantly higher in subjects who progressed to NIDDM than in those who did not. CONCLUSIONS: In the Korean population, beta-cell dysfunction, as measured by high proinsulin levels, seems to be associated with subsequent development of NIDDM, whereas regional and general obesity and fasting insulin levels, which may be a surrogate for insulin resistance, were not.     

Come out and play: Shyness in childhood and the benefits of organized sports participation.

The purpose of the current study was to examine the role of organised sport participation as a moderator of the links between shyness and psychosocial maladjustment in childhood. Participants at Time 1 were 355 elementary schoolchildren (Mage=10.1 years, SD=0.6); at Time 2, 1 year later, 201 children (56%) were retained. At both time points, children completed self-report assessments of their shyness and aggression, sport participation, and psychosocial adjustment. Parents also rated children's social skills. Overall, results indicated that sport participation was positively related to indices of positive adjustment (e.g., social skills, self-esteem). In contrast, shyness was associated with social skill deficiencies and internalizing problems. However, some evidence was also found to suggest that sport participation plays a unique protective role for shy children. Shy children who participated in sport over time reported a significant decrease in anxiety. Results are discussed in terms of the role of sport as a social context to enhance shy children's peer relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender differences across age in motor performance: A meta-analysis.

Conducted a meta-analysis of 64 studies that reported gender differences on motor performance during childhood and adolescence. Findings yielded 702 effect sizes based on data from 15,518 female and 15,926 male 3–20 yr olds. Age was regressed on effect size, and the relation was significant for 12 of 20 tasks (e.g., balance, catching, grip strength, shuttle run, throw velocity, tapping). Several types of age-related curves were found; the curve for a throwing task was the most distinctive. Five of the tasks followed a typical curve of gender differences across age. For 8 tasks, gender differences were not related to age, and effect sizes were small. Results are discussed in relation to the development of gender differences to biological and environmental sources. A bibliography of the 64 studies is appended. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prevalence, risk factors, and genotype distribution of hepatitis C virus infection in the general population: a community-based survey in southern Italy

In 1996 the prevalence, risk factors, and genotype distribution of hepatitis C virus (HCV) infection were assessed in the general population of a town in southern Italy. The sample was selected from the census by a systematic 1:4 sampling procedure. The participation rate was 96.6%. Among the 1,352 subjects enrolled, 195 (14.4%) tested reactive to antibody to HCV (anti-HCV) with enzyme immunoassay (EIA 3). When further tested with recombinant immunoblot assay (RIBA 3), 170 subjects (87.2%) tested positive, 23 subjects (11.8%) had indeterminate results, and 2 subjects (1%) tested negative. Thus, the overall anti-HCV EIA-positive RIBA-confirmed prevalence was 12.6% (170 of 1,352 subjects) and increased from 1.3% in subjects younger than 30 years to 33.1% in those > or =60 years of age. This latter age group accounted for 72.3% of all anti-HCV-positive subjects. Females tested positive more frequently than males (14.1% vs. 10.5%; P < .05). Alanine transaminase (ALT) concentrations were abnormal in only 4.1% (7/170) of anti-HCV EIA-positive RIBA-confirmed subjects. This suggests that ALT screening is not useful in the detection of anti-HCV-positive subjects in a general population. The results of multiple logistic regression analysis showed that an age of less than 45 years, the use of glass syringes, and dental therapy were all independent predictors of anti-HCV positivity. HCV RNA was detected by polymerase chain reaction in 75.9% of the 195 anti-HCV EIA-positive subjects: in 84.7% (144/170) of the RIBA-confirmed subjects; in 17.4% (4/23) tested as RIBA indeterminate; and in neither of the two subjects who tested RIBA negative. HCV type 1b was detected in 75 subjects (50.7%), type 2b in 1 subject (0.7%), type 2c in 66 subjects (44.6%), type 3a in 4 subjects (2.7%), and type 4 in two subjects (1.3%). These figures differ from those of Italian patients with chronic liver disease in whom genotype 2 is more rare. None of the individuals was infected with more than one genotype. The distribution of the two most common HCV viral types (1b and 2c) was not statistically different in terms of mean age, sex, or risk factors and suggests that they may have had a parallel spread in this community. These findings provide one of the highest overall anti-HCV prevalence rates in a general population with a likely cohort effect, i.e., decreased risk of infection along generations. These observations may indicate an epidemic or focus of hepatitis C that occurred several years earlier. The majority of anti-HCV-positive subjects in the oldest age group and with no clinical evidence suggests that HCV infection is a very prolonged and indolent disease.     

Effects of variability of practice in a movement-education program on motor skill performance

The study investigated the effects of the direct and exploration methods of teaching on the overhand throwing performance of kindergarten children. Variable throwing practice was provided in the exploration method by allowing children to throw 5 different types of balls at a variety of targets. Children given the direct method threw only one type of ball and received specific instruction and demonstrations. Throwing for distance and throwing accuracy were measured on pre- and posttests. A novel throwing task was administered on the posttest to measure skill transfer. The experimental groups received instruction three times per week for 4 wk. in throwing while a control group received no instruction. Significant sex differences in throws were found for distance and accuracy. Analysis of data from the novel task gave no significant effects. The two methods of teaching did not produce different levels of throwing skill.     

A dual-task study of interference between mental activity and control of balance

OBJECTIVE: This study aimed to examine interference between mental activity and control of balance. STUDY DESIGN: In a mixed design, dual-task study, the performance of patients and healthy control subjects was compared on computerized dynamic posturography, on a visuospatial mental task, and when performing the mental task while balancing. SETTING: The study was performed at a tertiary referral outpatient neuro-otology clinic. PATIENTS AND SUBJECTS: The patient group comprised 24 patients seen consecutively at the clinic because of vertigo and dizziness. The control group consisted of 24 subjects with no complaint or medical history of dizziness or balance disorder, matched with the patients for age and gender. MAIN OUTCOME MEASURES: Performance on a visuospatial mental task and on the computerized dynamic posturography test (conditions 4 and 5) was measured. RESULTS: Balancing on the posturography test resulted in a deterioration in performance on the mental task for both patients and control subjects. The effect was more marked when subjects had their eyes closed. Results on the balance test showed that normal subjects and patients with normal balance also swayed more when performing the mental task, whereas patients who had failed the posturography test swayed less when performing the mental task. CONCLUSIONS: These results show that mental performance deteriorates when performing a demanding balance task. In addition, in both normal subjects and patients, balance also may be affected by mental activity in complex and varied ways that merit further investigation.     

Age, intelligence, and MMPI F scores.

This study was designed to determine the effects of age, intelligence, and other variables on the F scale, which is critical for Minnesota Multiphasic Personality Inventory (MMPI) interpretation and research. Data consisted of MMPIs and Wechslers obtained from 407 white hospitalized psychiatric patients over a 7-year period. No significant sex differences on MMPI F scores were found. The major result was that F scores decrease with increasing age for low- and high-IQ subjects, but remain relatively constant for average-IQ subjects. Neither diagnosis nor educational level was found to affect F scores. The use of unrestricted distributions of age, intelligence, and F scores may account for the fact that these findings are not consistent with those reported by previous investigators. (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The validity and reliability of the Violence Risk Scale-Sexual Offender version: Assessing sex offender risk and evaluating therapeutic change.

The Violence Risk Scale-Sexual Offender version (VRS-SO) is a rating scale designed to assess risk and predict sexual recidivism, to measure and link treatment changes to sexual recidivism, and to inform the delivery of sexual offender treatment. The VRS-SO comprises 7 static and 17 dynamic items empirically or conceptually linked to sexual recidivism. Dynamic items with higher ratings identify treatment targets linked to sexual offending. A modified stages of change model assesses the offender's treatment readiness and change. File-based VRS-SO ratings were completed on 321 sex offenders followed up an average of 10 years postrelease. VRS-SO scores predicted sexual and nonsexual violent recidivism postrelease and demonstrated acceptable interrater reliability and concurrent validity. A factor analysis of the dynamic items generated 3 factors labeled Sexual Deviance, Criminality, and Treatment Responsivity, all of which predicted sexual recidivism and were differentially associated with different sex offender types. The dynamic items together made incremental contributions to sexual recidivism prediction after static risk was controlled for. Positive changes in the dynamic items, measured at pre- and posttreatment, were significantly related to reductions in sexual recidivism after risk and follow-up time were controlled for, suggesting that dynamic items are indeed dynamic or changeable in nature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physical self-concept and self-esteem mediate cross-sectional relations of physical activity and sport participation with depression symptoms among adolescent girls.

The authors tested whether physical self-concept and self-esteem would mediate cross-sectional relations of physical activity and sport participation with depression symptoms among 1,250 girls in 12th grade. There was a strong positive relation between global physical self-concept and self-esteem and a moderate inverse relation between self-esteem and depression symptoms. Physical activity and sport participation each had an indirect, positive relation with global physical self-concept that was independent of objective measures of cardiorespiratory fitness and body fatness. These correlational findings provide initial evidence suggesting that physical activity and sport participation might reduce depression risk among adolescent girls by unique, positive influences on physical self-concept that operate independently of fitness, body mass index, and perceptions of sports competence, body fat, and appearance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between static lower extremity measurements and rearfoot motion during walking

Despite the fact that clinicians regularly perform static lower extremity measurements on their patients, to date, little research has been published supporting their ability to predict dynamic rearfoot motion. The abilities of static measurements to predict dynamic foot motion could have important implications considering the fact that excessive rearfoot motion has been associated with various injuries of the lower extremity. The purpose of this study, therefore, was to determine if static lower extremity measurements could be used to predict the magnitude of rearfoot motion during walking. Rearfoot motion of each lower extremity was measured from videotape in 27 healthy young adult subjects with a mean age of 26.1 years. In addition, 17 static measurements were measured and recorded bilaterally for each subject. The results of a multiple regression analysis indicated that the only variable that was able to predict maximum rearfoot pronation was the "difference in navicular height" (r2 = .17). None of the 17 measurements were found to predict time to maximum pronation. These results indicate that static measurements of the lower extremity and foot are poor predictors of dynamic rearfoot motion as measured by maximum pronation or time to maximum pronation in healthy individuals without severe foot deformities.     

Intima-media thickness and diameter of carotid and femoral arteries in children, adolescents and adults from the Stanislas cohort: effect of age, sex, anthropometry and blood pressure

OBJECTIVES: To study carotid and femoral intima-media thicknesses and diameters in relation to age, sex, morphologic status and blood pressure. PARTICIPANTS: The subjects were 369 men and women (aged 10-54 years) from the Stanislas cohort, with no known cardiovascular disease. METHODS: Intima-media thicknesses and diameters were measured by B-mode ultrasonography. The effects of sex, age, smoking, anthropometric variables, cholesterol and blood pressure were studied using bivariate and regression analysis. RESULTS: Carotid and femoral intima-media thicknesses were not affected by age nor by sex up to 18 years of age. Thereafter, they increased sharply in men and remained higher than in women. Values were correlated with systolic blood pressure only in men, and with fat-free mass in children and young adults only at the femoral site. Smoking, body mass index and fat mass were associated with intima-media thicknesses only in adults. Carotid diameter was little affected by age during childhood and in adults. Femoral diameter increased up to the age of 18 in both sexes and remained unaffected by age thereafter. This increase was more pronounced in boys, and so values became consistently greater in males aged over 14 years. Carotid diameter was correlated with body mass index or fat mass whereas femoral diameter was correlated with weight or fat-free-mass in children and men. The opposite was observed in women. CONCLUSION: Sex differences occur before adolescence for arterial diameter, but only at an adult age for intima-media thickness. In young subjects, carotid geometry seems to be influenced by blood pressure and excess body weight, while femoral artery geometry seems to be related to blood pressure and body growth.     

Nicotine given intracerebroventricularly does not inhibit the preovulatory surge of LH and PRL secretion in female rats

Twenty-three cases of Little Leaguer's shoulder were reviewed including the history and physical examination findings, as well as bilateral internal and external rotation anteroposterior comparison radiographs of the proximal humerus. The average follow-up was 9.6 months (range, 1.5 to 54), and all patients were observed until they had either returned to baseball or their symptoms had resolved. The average age of the patients in this series was 14 years. The chief complaint in all patients was pain localizing to the proximal humerus during the act of throwing. The average duration of symptoms was 7.7 months. Nineteen patients (83%) were pitchers. Physical examination revealed tenderness to palpation over the proximal humerus in 20 patients (87%), with 16 (70%) demonstrating specific tenderness over the lateral aspect of the proximal humerus. Swelling, weakness, atrophy, and loss of motion were uncommon findings. All 23 patients demonstrated radiographic widening of the proximal humeral physis of the throwing arm on internal and external rotation comparison anteroposterior radiographs of the shoulder. All patients were treated with rest from baseball throwing for an average of 3 months. Twenty-one of the 23 patients (91%) returned to playing baseball and were asymptomatic. The classic radiographic finding of widening of the proximal humeral physis can easily be seen on bilateral anteroposterior internal and external rotation radiographs of the proximal humerus. Rest from throwing for at least 3 months is recommended, followed by a gradual return to throwing in an asymptomatic shoulder.     

Sagittal plane translations of the knee in anterior cruciate deficient subjects and controls

Static anterior-posterior (AP) laxity is one of the commonly used criteria in selecting patients for cruciate ligament reconstructions, but in reality dynamic AP laxity plays a more important role. The aim of this in vivo study was to compare the sagittal translation of the knee during active and passive motion, signifying dynamic AP laxity, with static AP laxity in healthy subjects (controls) and patients with anterior cruciate ligament deficiency. The sagittal plane knee translations were recorded and compared in both knees of nine healthy subjects (Controls) and seven patients with confirmed unilateral ACL deficiency during dynamic and static situations with an electrogoniometer system. In all groups during the ascents the tibia moved anteriorly in relation to the femur, whereas during the descents it moved posteriorly. The static anterior-posterior translation was significantly smaller in the control knee than in both healthy and injured knees of the ACL deficient group (P < 0.05). The injured knee showed the same laxity (92%) as the uninjured knee during dynamic activities, but it was 46% of static laxity. Also in the injured knees, the dynamic active laxity was larger during descents than ascents (P < 0.05). The results indicate that there is also a change in mechanics of the noninjured knee following injury to the contralateral knee and that this population of patients with ACL deficiency had good control over their abnormal anterior-posterior laxity.     

Static versus dynamic predictions of protective stepping following waist-pull perturbations in young and older adults

The purposes of this study were: (1) to determine the frequency of protective stepping for balance recovery in subjects of different ages and fall-status, and (2) to compare predicted stepping based on a dynamic model (Pai and Patton, 1997. Journal of Biomechanics 30, 347 354) involving displacement and velocity combinations of the center of mass (COM) versus a static model based on displacement alone against experimentally induced stepping. Responses to three different magnitudes of forward waist pulls were recorded for 13 young, 18 older-non-fallers and 18 older-fallers. The COM phase plane trajectories derived from motion analysis were compared with the model-predicted threshold values for stepping. We found that the older fallers had the highest percentage of stepping trials (52%), followed by older-non-fallers (17.3%), and young (2.7%) at the lowest perturbation level. Younger subjects stepped less often than the elderly at the middle level. Everyone consistently stepped at the highest level of perturbation. Overall, the dynamic model showed better predictive capacity (65%) than the static model (5%) for estimating the initiation of stepping. Furthermore, the threshold for step initiation derived from the dynamic model could consistently predict when a step must occur. However, it was limited, especially among older fallers at the low perturbation level, in that it considered some steps 'unnecessary' that were presumably triggered by fear of falling or other factors.     

Multisensory training of standing balance in older adults: I. Postural stability and one-leg stance balance

BACKGROUND: The effects of standing balance training on the ability to maintain stability in both static two-leg and one-leg stance were tested in healthy older adults. METHODS: Subjects (age range 65-90 years) were randomly assigned to a training (n = 12) or control group (n = 12). Training subjects received a 10-hour balance training program which selectively manipulated sensory inputs from the visual, vestibular, and somatosensory systems. RESULTS: Training subjects showed significantly improved stability (root-mean-square values of anteroposterior platform torque) after training in five of the eight training conditions (when somatosensory inputs were changed or when two or more sensory systems were simultaneously manipulated) (p < .006). When tested 4 weeks after completion of training, subjects (a) fell less frequently when the ankle/foot somatosensory inputs were minimized and (b) stood longer on one leg than the control group (p < .001). CONCLUSIONS: Balance training designed to improve intersensory interaction could effectively improve balance performance in healthy older adults.