BACKGROUND:In isokinetic testing researches,the effect of sport training on the development of teenager muscle groups is less reported. OBJECTIVE:To assess the muscle strength of shoulder,hip and knee joints in different teenager populations with isokinetic testing system. DESIGN,TIME AND SETTING:The contrast observation was performed at the laboratory of Institute of Physical Education,Hebei Normal University between October and December 2006. PARTICIPANTS:Control group included 30 volunteers without sport training randomly selected from four middle schools in Shijiazhuang,15 male and 15 female;training group included 30 volunteers with sprint training randomly selected from Shijiazhuang Sports School,15 male and 15 female. METHODS:We used Kinitech isokinetic testing system(Kylingk,Austrilia) to test the shoulder,hip and knee joint of the 60 participants according to 3 different angular velocities:60( ?) /s,120(?) /s and 240( ?) /s. MAIN OUTCOME MEASURES:Peak torque(PT) values of extensor and flexor groups in shoulder,hip and knee joints. RESULTS:The 60 volunteers were all included in the result analysis. PT values of shoulder joints were bigger in the male training group than in the control group at 60( ?) /s,120( ?) /s and 240( ?) /s(P 0.05) ;PT values of hip joints were bigger in the male training group than in the control group at 60( ?) /s,120( ?) /s and 240( ?) /s(P 0.05) ;PT values of knee joints were bigger in the male and female training group than in the control group at 60( ?) /s,120( ?) /s and 240( ?) /s(P

0.05),while there were significant differences at speed of 240?/s(P

Objective: To learn the current status of scoliosis of children and its influencing factors, so as to provide reference for the prevention and treatment. Methods: A total of 1 500 students selected from 4 kindergartens and 3 primary schools in Shijiazhuang were tested by static posture assessment and Adams flexion test to get the values,and self designed questionnaire was designed to investigate the related factors. Results: Totally 78 students were found with scoliosis, accounting for 5.47%. Among them, 17 boys (2.31% in boys) and 61 girls (8.85% in girls) were found with scoliosis, and the differences were of statistical significance ( P <0.01). And the main risk factors of scoliosis in children included holding too much, less crawling, poor sitting and standing posture, lack of vitamin D and calcium, long term unilateral exertion sports, insufficient exercise time, improper height of table and chair, as well as being girl( OR =1.58, 0.58, 2.22, 2.13, 3.02, 2.18, 2.14, 2.86, 3.04, 2.59, 1.16, P <0.05). Conclusion The detection rate of scoliosis in children is very high,the education department and parents should pay more attention for prevention, scientific rearing methods can effectively reduce the incidence of scoliosis in children.