The effect of pre-season dance training on physical indices and back pain in elite cross-country skiers: a prospective controlled intervention study.

OBJECTIVE To evaluate the effect of pre-season dance training on back pain, joint mobility, and muscle flexibility, and on speed and agility in elite cross-country skiers. METHODS 26 skiers participated (mean (SD) age, 19 (3.9) years). An intervention group (n = 16) had 12 weeks of dance training; a control group (n = 10) did not dance; otherwise both groups followed a similar pre-season physical training programme. Joint mobility and muscle flexibility of the spine, hip, and ankle were measured. Two sports related functional tests (slalom and hurdle) were also done. All measurements/tests were carried out before and after the dancing period. RESULTS Four (of six) subjects from the intervention group who initially complained of ski related back pain did not report back pain after the dance training; the three subjects with back pain from the control group were unchanged. At study onset the intervention group had a slightly impaired range of motion in the spine compared with the control group. After dance training, there was a better relation between kyphosis of the thoracic spine and lordosis of the lumbar spine, and a 7.1 degrees increase in hip flexion with the knee extended (p = 0.02). In the control group hip extension decreased by 0.08 m on average (p = 0.01). No positive effects of dance training on sports related functional tests were observed. CONCLUSIONS Preseason dance training improved the range of hip motion and joint mobility and the flexibility of the spine. These improvements might explain the reduction in ski related back pain in the intervention group.