Physical Injuries in Dancers-Risk Factors

Range of joint motion and physical injuries in young dancers

Background: Little data is available on changes in joint range of motion (ROM) in dancers and non-dancers with age.
Hypothesis: In dancers, joint ROM will increase with age while in non-dancers it will decrease, independent of the joint studied.
Methods: The study population included 1,314 female dancers, age 8-16 years, who participate in different types of dancing classes (classical ballet, modern dance, jazz, etc.), and 226 non-dancers of similar age. ROM was measured for the hip, knee, ankle, foot, and spinal joints.
Results: The pattern of differences in ROM with age varied in different joints and types of movement: a) In combined ankle and foot plantar-flexion (pointe), ankle plantar-flexion and hip external rotation, no difference among dancers, while diminished with age in the non-dancers; b) In ankle dorsiflexion, neither shows any difference with age. ROM is significantly greater in the non-dancer groups; c) In knee flexion, hip flexion and hip internal rotation, ROM decreases with age in both groups; d) In hip abduction, ROM decreases in dancers and remains constant in the non-dancers; e) In hip extension, ROM increases in both groups; f) In lower back and hamstrings, ROM increases among dancers and remains constant among non-dancers.
Conclusions: Dancers and teachers should realize that passive joint ROM is unlikely to improve with age. Therefore the major goal of dancing program should focus on exercises which retain the dancers' joints natural flexibility rather than trying to improve them.

Growth and Development of Dancer girls, Age 8 to 16 Year

A descriptive, cross-sectional cohort study with convenience control sample was carried out in order to follow changes with age in body structure and adipose tissue distribution in young dancers compared to non-dancers girls.
The subjects were 1,482 female dancers, age 8-16 years (mean age = 13.3), and 226 female non-dancers of similar age cohorts. Fourteen anthropometric measurements were recorded and eleven indices calculated.
For most anthropometric measures: height, acromial height, asis height, sitting height, dactylion height, leg length ,foot length, foot circumference, foot width, biacromial breadth, biiliac breadth, no significant differences between the two groups in each age cohort were found. The only significant difference relates to the extent and distribution of adipose tissue: At age 8, both groups show similar weight while at age 13 non-dancers girls are significantly heavier (by as much as 8 KG). At age 15, weight differences between the dancers and non-dancers decrease to only 2Kg. The differences in weight with age are further supported by other measures, such as skinfold thickness and chest circumference. Pattern of adipose tissue distribution differ among the two groups. Menarche was delayed in dancers by a year and a half (approx. 13 vs. 11.5 years).
In conclusion, dancers and non-dancer girls manifest similar growth pattern and body dimensions. Toward menarche, non-dancer girls gain weight more rapidly, being 20% heavier at age 13 than dancers. The diminution in weight differences at age 15 is probably due to a strong social pressure towards a “skinny” body among teenagers. Additionally, there is a clear difference in body fat distribution and delay in the onset of menarche among dancers.

Growth and development of Southern Sinai Bedouin children

The Sinai Peninsula, with its 61,200 sq.Km; is almost entirely desert and its native population adapted to a nomadic way of life. The Peninsula, enclosed by the Gulfs of Suez and Eilat, two branches of the Afro-Asiatic Rift Valley, is topographically divided into metamorphic and magmatic Southern Desert and a sedimentary, sandy Northern part which is continues with the Israeli costal line in the East and the Delta of the Nile in the West.
The present paper deals with Bedouin tribes of the South. They are geographically and culturally isolated from the Northern populations and are called "Towara" (mountain people), reflecting the elevated topography of the region. Ten tribes inhabit the area, differing considerably in origin, customs and traditions. Gebeliya, Sawalcha, Hamada, Aliqat, Beni-Wassal, Muzeina, Cheweitat, Awlad Said, Qararsha and Tarabin. Intensive survey of these tribes was conducted during the years 1979-1981. Among the many issues dealt with was the growth and development of Bedouin children.