Swedish TeamGym : Injury incidence, mechanism, diagnosis and postural control

Teamgym is a fairly new and popular form of gymnastics originating in Scandinavia. Among the gymnastics disciplines teamgym attracts the highest number of gymnasts in Sweden. The discipline differs in several ways from the most known form of gymnastics, artistic gymnastics. It is therefore important to study injury incidence, mechanism and diagnosis in teamgym to be able to develop relevant injury prevention programs. Aim: The main aim of the present thesis was to study injury incidence, injury mechanism, injury site and diagnosis in Swedish teamgym. A second aim was to evaluate if specific exercises for segmental muscle control of the lumbar spine can prevent or reduce low back pain in young female gymnasts. A third aim was to study if, and in that case how, low back pain or lower extremity injuries influence postural control, and also to evaluate the reliability of postural control measurements. Material and method: This thesis included gymnasts during practice and competition. One hundred and eighty-eight gymnasts answered a questionnaire during a National Championship for male and female juniors as well as seniors (study I). Forty-two top level senior male and female gymnasts were followed during one season of training and competition and injuries were registered with respect to diagnosis and mechanism (study II). Fifty-one young top level female gymnasts reported low back pain during a period of 12 weeks. At inclusion they were divided in one intervention group and one control group. After four weeks of baseline an eight-week training program including specific exercises for segmental muscle control of the lumbar spine was introduced and evaluated (study III). Finally, fifty-seven female gymnasts were measured in upright standing on an AMTI force platform (study IV). They were measured standing on hard and foam surface with eyes open and eyes closed during 120 seconds, respectively. A test-retest was conducted to determine the reliability of these measurements. Results: Teamgym gymnasts practice and compete in spite of symptoms from injuries. The injury incidence in top level teamgym was 2.2 / 1000 gymnastics hours, and there was no difference between male and female gymnasts. Most injuries were found in the lower extremity, with the ankle joint being most often injured. The second most injured site was the lower back, where muscle and ligament injuries were represented. The most frequent injury mechanisms were joint compression, joint rotation and hyperextension, and the landing phase of the gymnastics skill was most critical. Half of the injuries were reported at the end of the training session and often while the gymnasts were in a negative state of mood such as stressed or afraid. Gymnasts with low back pain did not experience pain every day. During a period of one month 24 out of 51 gymnasts reported low back pain between one and 28 days. After an eight-week training period with specific exercises for segmental muscle control of the lumbar spine, the intervention group was significantly improved with respect to less number of days with low back pain. A tendency towards the opposite was revealed in the control group. Gymnasts with low back pain showed a larger area of center of pressure, standing on foam surface with eyes closed, than gymnasts with lower extremity injuries. Only gymnasts with low back pain reported pain at the test occasions. Tests with eyes closed were more reliable than tests with eyes open and tests during 120 seconds were in most cases more reliable than tests during 60 seconds. Conclusions: Top level teamgym gymnasts practice and compete in spite of symptoms from injuries. The ankle joint and the lower back are the most common sites for injuries. Gymnasts with low back pain show altered postural control compared to gymnasts with lower extremity injury. This may be due to pain. A specific muscle training program of the local lumbar muscles reduced the number of days with low back pain in young female gymnasts