Stanley Sai-chuen Hui

Validity of the modified back-saver sit-and-reach test: a comparison with other protocols.

PURPOSE Studies have shown that the classical sit-and-reach (CSR) test, the modified sit-and-reach (MSR), and the newly developed back-saver sit-and-reach (BS) test have poor criterion-related validity in estimating low-back flexibility but yielded moderate criterion-related validity in hamstring flexibility. The V sit-and-reach (VSR) test was found to be practical but the validity has not been established. The purpose of this study was to propose a modified back-saver sit-and-reach (MBS) test, which incorporated all advantages of the various protocols, and to compare the criterion-related validity and reliability of all these tests. METHODS 158 college students (F = 96, and M = 62; age = 20.77 +/- 2.51) performed CSR, VSR, BS (left and right leg), and MBS (left and right leg) tests in a randomized order. Scores from each test were then correlated with the criterion measures. RESULTS For all sit-reach tests, intraclass reliability (single trial) was very high (r = 0.89-0.98). MBS yielded significant and highest r with low-back and hamstring criterion for men (r = 0.47-0.67) and women (r = 0.23-0.54). The low-back and right hamstring validity of MBS for men were significantly (P < 0.01) higher than those from BS and CSR, whereas no differences in criterion-related validity were found between the MBS and other protocols in women. The ratings of perceived comfort among the sit-and-reach protocols were significantly different (P < 0.001) from each other. The rating for MBS was observed the most comfortable test as compared with other protocols. CONCLUSION The MBS test is not only a reliable test for hamstring and low-back flexibility, it is also a more practical with improved validity for hamstring and low-back flexibility in men than previous protocols.

Reliability and validity of psychosocial and environmental correlates measures of physical activity and screen-based behaviors among Chinese children in Hong Kong

BackgroundInsufficient participation in physical activity and excessive screen time have been observed among Chinese children. The role of social and environmental factors in shaping physical activity and sedentary behaviors among Chinese children is under-investigated. The purpose of the present study was to assess the reliability and validity of a questionnaire to measure child- and parent-reported psychosocial and environmental correlates of physical activity and screen-based behaviors among Chinese children in Hong Kong.MethodsA total of 303 schoolchildren aged 9-14 years and their parents volunteered to participate in this study and 160 of them completed the questionnaire twice within an interval of 10 days. Intraclass correlation coefficients (ICCs), kappa statistics, and percent agreement were performed to evaluate test-retest reliability of the continuous and categorical variables, respectively. Exploratory factor analyses (EFAs) were conducted to assess convergent validity of the emergent scales. Cronbachs alpha and ICCs were performed to assess internal and test-retest reliability of the emergent scales. Criterion validity was assessed by correlating psychosocial and environmental measures with self-reported physical activity and screen-based behaviors, measured by a validated questionnaire.ResultsReliability statistics for both child- and parent-reported continuous variables showed acceptable consistency for all of the ICC values greater than 0.70. Kappa statistics showed fair to perfect test-retest reliability for the categorical items. Adequate internal consistency and test-retest reliability were observed in most of the emergent scales. Criterion validity assessed by correlating psychosocial and environmental measures with child-reported physical activity found associations with physical activity in the self-efficacy scale (r = 0.25, P < 0.05), the peer support for physical activity scale (r = 0.25, P < 0.05) and home physical activity environmental (r = 0.14, P < 0.05). Childrens screen-based behaviors were associated with the family support for physical activity scale (r = -0.22, P < 0.05) and parental role modeling of TV (r = 0.12, P = 0.053).ConclusionsThe findings provide psychometric support for using this questionnaire for examining psychosocial and environmental correlates of physical activity and screen-based behaviors among Chinese children in Hong Kong. Further research is needed to develop more robust measures based on the current questionnaire, especially for peer influence on physical activity and parental rules on screen-based behaviors.

The relationship between heart rate reserve and oxygen uptake reserve in children and adolescents.

The purpose of the present study was to examine the relationship between oxygen uptake (VO2) and heart rate (HR) responses during rest and exercise in Chinese children and youth and to evaluate the relationships between maximal heart rate (%HRmax), heart rate reserve (%HRR), peak oxygen uptake (%VO2peak), and oxygen uptake reserve (%VO2R) in Chinese children and youth. Forty-nine Chinese children and youth were studied at rest and during a graded maximal exercise test on treadmill. Resting, submaximal and peak HR and VO2 were collected. Regression analyses were conducted to investigate the associations between the various forms of HR and VO2 measures. The equivalency between %HRR and %VO2R for adults was examined for children using data obtained in this study. Results indicated that all regression lines between HR measures and VO2 measures were significantly different from the line of identity (p < .05), except the regression line for %HRR versus %VO2peak in boys. The equivalency between %VO2R and %HRR for adults was not demonstrated in children and adolescents in this study. In contrast, %HRR was more closely equivalent to %VO2peak. Because a strong linear relationship was found between HR and VO2, HR measures, in terms of either %HRmax or %HRR, would still be a practical variable for prescribing appropriate exercise intensity for children and adolescents. Unlike results found for adults, a given %HRR in children and youth was not equivalent to its corresponding %VO2R.

Low levels of awareness of suboptimal health conditions in a high-risk working population: The “better health for better Hong Kong” health promotion campaign

The incidences of cardiovascular risk factors such as obesity and diabetes are rising in many Asian populations. In April 2000, a 5-year territory-wide health promotion campaign supported by Li Ka Shing Foundation was launched in Hong Kong by the Health InfoWorld of Hospital Authority. From the general working class, 4,832 Chinese people were randomly recruited into this campaign. There were 2,370 men (49.0%) and 2,462 women (51.0%; median age = 43.0 years, range = 17-83 years). Of these, 37.5% were obese (BMI ≥ 25 kg/m2 or waist circumference ≥80 cm in women and ≥90 cm in men), 22.3% had hypertension, 11.6% were smokers, 31.0% had hypercholesterolaemia (total cholesterol ≥5.2 mmol/l), 2.2% had diabetes, and 0.7% had a past history of cardiovascular disease. There were 1,338 participants (27.7%)who had 2 ormore risk factors (more men than women: 36.9% vs. 18.9%,p < .001). Despite this high prevalence of multiple risk factors, most (83.1%) perceived their health status as satisfactory (more men than women: 85.6% vs. 80.7%, p < .001). In conclusion, the combination of high prevalence of multiple risk factors and low levels of awareness of their suboptimal health status herald a looming epidemic of life-threatening diseases in a group of middle-aged Hong Kong people. Massive public education is an important and essential, although it may not be self-sufficient, factor to reduce the socioeconomic impacts of this epidemic.

Effect of age and gender on energy expenditure in common activities of daily living in a Chinese population

Purpose. It is important to quantify the amount of energy expended in various common household tasks to provide objective information regarding physical activity recommendations in health promotion, weight management, or rehabilitation programs for older people with chronic diseases. These activities may be age/gender sensitive and culturally specific, and not included in current Compendium of Metabolic Equivalent (MET) values. This study measures the energy expenditure of commonly performed activities of daily living tasks in a Chinese population, examining age and gender differences. Method. Thirty younger adults (15 M, 15 F) and 78 older adults (26 M, 52 F) were recruited and energy expenditure was measured at rest and during activities using indirect calorimetry. Results. Energy expenditure (O2 consumption/min/Kg) was lower in subjects aged ≥60 years compared with those <60 years but they also spend more time completing the task. No gender differences were observed. Conclusion. New MET values are derived for these two populations. These values would be useful in planning rehabilitation programmes for Chinese subjects with chronic diseases.

Effects of Tai Chi and Walking Exercises on Weight Loss, Metabolic Syndrome Parameters, and Bone Mineral Density: A Cluster Randomized Controlled Trial

Tai Chi and walking are both moderate-intensity physical activity (PA) that can be easily practiced in daily life. The objective of the study was to determine the effects of these two PAs on weight loss, metabolic syndrome parameters, and bone mineral density (BMD) in Chinese adults. We randomized 374 middle-aged subjects (45.8 ± 5.3 years) into 12-week training (45 minutes per day, 5 days per week) of Tai Chi (n = 124) or self-paced walking (n = 121) or control group (n = 129). On average, Tai Chi and walking groups lost 0.50 and 0.76 kg of body weight and 0.47 and 0.59 kg of fat mass after intervention, respectively. The between-group difference of waist circumference (WC) and fasting blood glucose (FBG) was −3.7 cm and −0.18 mmol/L for Tai Chi versus control and −4.1 cm and −0.22 mmol/L for walking versus control. No significant differences were observed regarding lean mass, blood pressure, triglycerides, total cholesterol, high-density and low-density lipoprotein cholesterol, and BMD compared to control. Change in lean mass, not fat mass or total weight loss, was significantly correlated to the change in BMD. Our results suggest that both of these two PAs can produce moderate weight loss and significantly improve the WC and FBG in Hong Kong Chinese adults, with no additional effects on BMD.

Validity of bioelectrical impedance measurement in predicting fat-free mass of Chinese children and adolescents.

Background The current study aimed to examine the validity of various published bioelectrical impedance analysis (BIA) equations in estimating FFM among Chinese children and adolescents and to develop BIA equations for the estimation of fat-free mass (FFM) appropriate for Chinese children and adolescents. Material/Methods A total of 255 healthy Chinese children and adolescents aged 9 to 19 years old (127 males and 128 females) from Tianjin, China, participated in the BIA measurement at 50 kHz between the hand and the foot. The criterion measure of FFM was also employed using dual-energy X-ray absorptiometry (DEXA). FFM estimated from 24 published BIA equations was cross-validated against the criterion measure from DEXA. Multiple linear regression was conducted to examine alternative BIA equation for the studied population. Results FFM estimated from the 24 published BIA equations yielded high correlations with the directly measured FFM from DEXA. However, none of the 24 equations was statistically equivalent with the DEXA-measured FFM. Using multiple linear regression and cross-validation against DEXA measurement, an alternative prediction equation was determined as follows: FFM (kg)=1.613+0.742×height (cm)2/impedance (Ω)+0.151×body weight (kg); R2=0.95; SEE=2.45kg; CV=6.5, 93.7% of the residuals of all the participants fell within the 95% limits of agreement. Conclusions BIA was highly correlated with FFM in Chinese children and adolescents. When the new developed BIA equations are applied, BIA can provide a practical and valid measurement of body composition in Chinese children and adolescents.

Comparisons of Measured and Self-Reported Anthropometric Variables and Blood Pressure in a Sample of Hong Kong Female Nurses

Objectives To assess the validity of self-reported weight, height, body mass index (BMI), waist circumference and blood pressure compared with standardized clinical measurements and to determine the classification accuracy in overweight/obesity and central adiposity. Methods This pilot study was integrated into a life-course study entitled “Hong Kong Womens Health Study” among 1,253 female nurses in Hong Kong who were aged 35 years to 65 years. Data were collected from self-administered questionnaires that were mailed to the respondents. Of these participants, we obtained the standard body measurements of 144 (11.5%) at our research center. We then compared the self-reported anthropometric variables and blood pressure with the measured data to assess validity based on the level of misreporting, percentage of agreement, consistency, sensitivity and specificity. Results The self-reported and measured values were highly correlated in terms of anthropometry and blood pressure (correlation coefficients ranged from 0.72 to 0.96). Height was overestimated at an average of 0.42 cm, and waist circumference was underestimated at 2.33 cm (both P<0.05), while no significant differences were observed from weight, blood pressure and BMI (all P>0.05). The proportions of overweight, obesity, and central adiposity by self-reported data did not vary greatly from the measured data (all P>0.05). The self-reporting resulted in correct classifications of BMI, waist circumference, and systolic blood pressure in 85%, 78%, and 87% of women, with corresponding Kappa index values of 0.79, 0.55, and 0.82, respectively. Sensitivity and specificity were 84.6% and 95.7%, respectively, with respect to overweight/obesity detection, whereas those for central adiposity detection were 70.6% and 83.8%, respectively. Conclusion In a sample of female Hong Kong nurses, the self-reported measures of height, weight, BMI, waist circumference and blood pressure were generally valid. Furthermore, the classification accuracies of overweight/obesity and central adiposity were acceptable.

Mindfulness-Based Baduanjin Exercise for Depression and Anxiety in People with Physical or Mental Illnesses: A Systematic Review and Meta-Analysis

Objectives: we used a quantitative method to systematically synthesize the emerging literature and critically evaluate the effects of Baduanjin on depression and anxiety in people with physical or mental illnesses. Additionally, we determined if the number of total Baduanjin training sessions is associated with decreased anxiety and depression levels. Methods: both English and Chinese databases were searched for potential studies published between January 1982 and October 2017. The eligible randomized controlled trials were considered for meta-analysis. Effect size (Hedge’s g) was computed for the pooled effects while the random-effect model was set. For moderator analysis; Subgroup meta-analysis for categorical variables and meta-regression for continuous variables were performed. Results: the aggregated result has shown a significant benefit in favour of Baduanjin on anxiety (Hedge’s g = −0.99; CI −1.63 to −0.74) and depression (Hedge’s g = −1.07; CI −1.3 to −0.83). For continuous potential moderators; meta-regression indicated a significant effect for total hours in Baduanjin practice (β = −0.0053; 95% CI −0.009 to −0.0014; p = 0.008). With regard to depression; meta-regression indicated a significant effect for total sessions of Baduanjin practice (β = −0.0023; 95% CI −0.006 to −0.0004; p = 0.028). Conclusions: the encouraging findings indicate the efficacy of Baduanjin exercise in reducing depression and anxiety symptoms in people with physical or mental illnesses. However; the results should be interpreted with caution because of existing methodological limitations (e.g., high risk of bias; Baduanjin combined with other behavioral interventions; and heterogeneity of control groups).

Association between Physical Activity Knowledge and Levels of Physical Activity in Chinese Adults with Type 2 Diabetes.

Background Physical activity (PA) is an important treatment regimen for diabetes. The purposes of this study were to evaluate people’s knowledge of how exercise influences wellbeing (termed “PA knowledge” or “knowledge of PA” in this paper) and the resulting association with levels of PA in Chinese adults with Type 2 diabetes, and to identify the valuable demographic and lifestyle factors that possibly influence the association between PA knowledge and level of PA. Methods Two hundred and fifty-eight adults with Type 2 diabetes completed an interviewer-administered survey at a diabetes clinic in Hong Kong. Data on demographics, lifestyle factors and diabetes-related medical indicators were obtained. A 20-item questionnaire was developed to measure PA-related knowledge (one point scored for each correct answer; aggregate score up to 20 points). level of PA was measured by the International Physical Activity Questionnaire. Results The proportions of correct answers to each question ranged from 19.4 to 90.7%. Compared with poorly educated participants, those with university education level and above had PA knowledge scores 1.7 points higher (14.3 vs. 12.6, P<0.05). Younger, female, and obese participants were more likely to have lower level of PA (all P<0.05). After adjustment for age, gender, (BMI) and education level, the odds of having a moderate-to-high level of PA was 19% greater with 1 unit increase in PA knowledge score [95% confidence interval (CI): 1.09–1.29; P<0.001], this association was strongest in participants with tertiary education level or above [odds ratio (OR): 1.35; 95% CI: 1.03–1.77; P<0.05]. Conclusions PA knowledge was positively associated with level of PA. Education level significantly influenced the association between PA knowledge and level of PA, leading to the suggestion of vulnerable groups to target for PA improvement in the face of diabetes.