PURPOSE This study aimed to: 1) compare the differences in static lower-extremity alignment (SLEA) between female ballet dancers (BD) and non-ballet dancers (NBD); 2) investigate the differences among gesture leg (GL) and supporting leg (SL) in BD and dominant leg (DL) in NBD; and 3) compare limb asymmetry between groups. METHODS Twenty-nine female BD and 20 NBD were recruited for this study. The quadriceps, tibiofemoral, rearfoot, and genu-recurvatum angles, tibial torsion and varum, and navicular drop height were measured. An independent t-test was conducted to compare SLEA and limb asymmetry between groups. One-way analysis of variance with Bonferroni post-hoc tests were performed to determine the differences among the GL, SL and DL. RESULTS BD showed lower quadriceps and rearfoot angles, less tibial varum and navicular drop, and greater tibiofemoral angle (p<.005) than NBD. BD showed less quadriceps angle asymmetry but greater tibial torsion asymmetry (p<.01) than NBD. GL and SL in BD showed differences in quadriceps, tibiofemoral, rearfoot angle, tibial torsion and navicular drop compared to NBD. CONCLUSIONS Repetitive dance movements can transfer varying forces to the GL and SL, potentially contributing to SLEA asymmetry. An intervention strategy that can reduce SLEA asymmetry in BD is needed, as is the identification of elements of ballet training that contribute to maintaining a normal SLEA.
PURPOSE The purpose of this study was to investigate the characteristics of field and on-ice performances of ice-hockey players and the relationship of performance with subjective joint pain and dysfunction. METHODS A total of 25 male college icehockey players were evaluated for 19 items of performance. Pain and dysfunctions in the lower extremities and lower back were confirmed through the Foot and Ankle Outcome Score, Knee Injury and Osteoarthritis Outcome Score, Hip Dysfunction and Osteoarthritis Outcome Score, and Osweatry Disability Index questionnaire. Players with similar performance characteristics were classified through a cluster analysis, and differences in performance and patient-reported outcomes between clusters were analyzed with a one-way analysis of variance. RESULTS The ice-hockey players were classified into “lower muscular strength and performance (cluster 1),” “lower cardiorespiratory endurance (cluster 2),” and “high muscular strength and performance (cluster 3).” Players in cluster 1 had more frequent ankle and knee joint dysfunctions and pain compared to those in cluster 3. Several performance test items affected the subjective joint score, and the related performance items were more in the proximal joint than in the distal joint. CONCLUSIONS Ice hockey players should perform training to supplement their individual lack of on-ice and field performance. Since performance may be limited because of joint dysfunction and pain, a joint-specific intervention strategy should be applied to improve physical and athletic performances.
