Effects of frequency of static stretching on straight-leg raise in elementary school children.

AIM: The aim of this study was to evaluate the efficacy of different frequencies of a stretching exercise program on lower extremity range of motion (ROM) in prepubertal schoolchildren. METHODS: A total of 62 children were divided into 3 groups (experimental groups: A, B; control group: C). Experimental group A performed hamstring stretches for 5 min during the Physical Education classes over a full school term (9 months), 2 sessions per week (31 weeks, 62 sessions of Physical Education). Experimental group B performed hamstring stretches for 5 min during the Physical Education classes and during a specific extracurricular physical activity, over a full school term (9 months), 4 sessions per week (31 weeks, 62 sessions of Physical Education and 62 sessions of after-school physical activities). Control group followed the standard class program of Physical Education classes. Hamstring flexibility was measured using the straight leg raise test before and after the program. RESULTS: No significant differences were revealed in ROM before and after the Physical Education classes for the control group. However, significant improvements in ROM were shown in the two experimental groups (P<0.001). Four days per week produced a greater rate of gains in ROM (16.9 degrees) than 2 days per week (9.3 degrees). For all groups, the initial and the final ROM between the right and left sides were similar. CONCLUSION: This study indicates that a full school term (9 months) incorporating static stretching as part of the Physical Education classes and the extracurricular physical activities significantly increases the ROM of the hamstrings in prepubertal schoolchildren. The study also suggests that the increase of the frequency of stretching is effective for increasing ROM.

Primary lung cancer in Mexico city: a report of 1019 cases.

A retrospective study was performed in patients diagnosed with primary lung cancer, and admitted to the Instituto Nacional de Enfermedades Respiratorias between 1984 to 1992. One thousand and nineteen patients were studied, 636 males and 383 females. We found a higher incidence in the group among 61-70 years of age in both sexes. The highest percentage of tumors were from the adenocarcinoma variety, followed by the epidermoid carcinoma, while the small-cell carcinoma presented a lower incidence. Smoking has been associated with the development of lung cancer. Many of our patients were smokers. The highest frequency was in smokers with a smoking habit of more than 30 years and a rate of more than 10 cigarettes per day. However, an important part of the patients with cancer did not have a smoking habit, which led us to believe that there are other etiological possibility factors (genetic or environmental) that could be involved. Most of the cases of cancer were staged as stage IIIb and stage IV and the patients had an ECOG of 1-2. The main symptoms were coughing, sputum, dyspnea and thoracic pain. This data shows an increasing frequency of lung cancer in Mexico city as well as other countries, it also shows that it is going to be a serious health problem in the future. We consider that in order to improve the prognosis, it is necessary to increase the educational and orientation campaigns among the adult population with or without a smoking history.