The prevalence of exercise-induced asthma among school children

Exercise-induced asthma (EIA) is one of the major factors that affect optimal performance in sport. The prevalence of EIA is reported to be on the increase among school children worldwide. The aim of this study was to indicate EIA prevalence among primary-school children in South Africa. A field study determined the prevalence of EIA. A convenience sample of 127 children aged 8 to 16 years was selected. A health- screening questionnaire was used. The criteria for selection were that the subjects should be non- asthmatics and should not have any other illness during the screening that could interfere with the results. Peak expiratory flow rate (PEFR) was measured pre- and post-exercise using an ASSESS peak flow meter. The subjects did a six-minute run on a school playground. The post-exercise PEFR was measured within 10 minutes of exercise. The determinant of EIA was ≥ 10% decrease in PEFR after exercise. A total of 112 (88%) subjects participated in the study. Fifteen subjects were excluded (eight had asthma, five had respiratory tract infection and two had other illnesses). The average exercise heart rate was ± 80% of predicted maximal heart rate. The prevalence of EIA was 23% (n = 26). The incidence of a history of allergic rhinitis was statistically significantly increased among those with positive tests (p = 0.027). This study highlights the need to screen all children so that EIA can be determined and addressed appropriately.Keywords: exercise; asthma; prevalence; children; spor

Q-angle, Pelvic width, and Intercondylar notch width as predictors of knee injuries in women soccer players in South Africa

Objective: To investigate the association between the three anatomical factors of Q-angle (QA), pelvic width (PW) and Intercondylar notch width (INW) and knee injuries among the U-23 female soccer players of South AfricaMethods: The study is a case-control prospective study design. Twenty four U-23 women soccer players of the South African team were purposively chosen to participate in this study. Participants were divided into two groups: group1 (Case) was those with knee injuries, while those without injuries were in group-2 (Control). PW and INW were measured after Xrays of the hip were taken while the QA was measured manually with the goniomenter. Association between anatomical factors and knee injuries were tested with ANOVA.Results: Q-angle ranged from 140 to 180 for both injured and non injured groups. PW was between 24 -29 cm for both injured and non injured groups. INW was between 1.3mm and 2.8mm for the right and between 1.4mm and 2.5mm for the left notch for the injured group, while INW for the right and left of the non injured group were between 1.7mm to 2.1mm and 1.8mm to 2.1mm, respectively No significant association between knee injuries and each of the anatomical factors was found QA (p= 0.74), PW (p=0.34), INW (right and left respectively) (p=0.142 & p=0.089).Conclusion: The three anatomical factors of QA, PW and INW could not be used to predict knee injuries amongst the U-23 female players in South Africa.Keywords: Pelvic width; Q-Angle; Intercondylar Notch Width; Female Soccer; Knee Injurie

Effect of submaximal warm-up exercise on exercise-induced Asthma in African School Children

Background: Regular physical activity has long been regarded as an important component of a healthy lifestyle. Exercise-induced asthma (EIA) is one of the major problems interfering with the performance of exercise. A warm-up exercise programme has been cited as a non-pharmacologic means of reducing EIA, but its effect has not been fully elucidated. Objective: The aims of this study were to determine the prevalence of unrecognized EIA in Pretoria primary school children, determine the effect of a warm-up exercise programme on EIA and to establish the relationship between history of allergy, family history of asthma and EIA. Methods: A random sample of 640 school children was selected. The study was divided into three phases. In phase one, a descriptive cross-sectional study was done using the standardized European Community Respiratory Health Survey (ECRHS) questionnaire. In phase two, non-asthmatic participants that returned a completed questionnaire were included in the field study. Pre-test and post-test experimental designs were used, where peak expiratory flow rate (PEFR) was measured at baseline and within ten minutes after exercise. A total of 340 subjects completed the Free Running Asthma Screening Test (FRAST); EIA was defined as a decrease in baseline PEFR ≥ 10% after exercise and 75 children (22%) had EIA. In phase three, 29 of the 75 subjects participated in the warm-up programme which was performed in the laboratory and subjects acted as their own controls. Predefined protocols for the study were followed. Results: Seventy-five (22%) of the 340 participants had EIA. The mean age, height and weight were 10.51 years, 139.26 cm and 33.45 kg, respectively. Exercise-induced asthma symptoms were cough (25%), chest pain (16%), wheeze (12%) and chest tightness (12%). The history of allergy was 75%, family history of allergy 40% and positive history of allergy when near animals, feathers or in dusty areas 38%. Wheezing during or after exercise, wheezing when near animals, feathers or in dusty areas and chest pain was significant (p < 0.05). The mean PEFR after exercise without warm-up was 4.43 L/min. The mean PEFR after exercise (warm-up) was 4.98. The mean percentage change in PEFR between exercise without warm-up and exercise with warm-up was 14.83%. The paired t-test showed a significant difference between PEFR with warm-up and PEFR without warm-up (p < 0.05). Conclusion: There was a high prevalence of EIA among study participants. Exercise-induced asthma symptoms were significant for wheezing and chest pain. Exercise after warm-up was significant in reducing EIA. This study reports the effect of warm-up exercise on EIA and highlights the need to screen school children for EIA