Doctor of Physical Therapy Program, Oklahoma City University, 2501 N. Blackwelder, Oklahoma City, OK 73106, USA.
Med Probl Perform Art. 2023 Sep;38(3):155-163. doi: 10.21091/mppa.2023.3019.
There are no universally accepted requirements or uniform protocols to determine when dancers can safely commence dancing en pointe (shod relevé). The purpose of this study was to examine dancer-specific biomechanics of adolescent pointe dancers and explore factors that may help determine pointe readiness.
Dancers (n=26; median age 14 yrs [IQR=13-16]) were stratified into two groups based on the ability to stand on the pointe shoe box as per a plumb line (Group 1: on the box; Group 2: not on the box) during parallel, shod relevé. Measurements included unshod weight-bearing range of motion (ROM) of ankle plantarflexion (PF) and first metatarsophalangeal (MTP) extension and shod posture assessment during first position elevé (rising into relevé with turned out, straight legs). Qualisys 3D motion capture and AMTITM force plates recorded dancers performing 10-15 repetitions of first position elevé. Comparison of three kinematic and three kinetic variables aimed to describe group differences during unshod and shod conditions. Wilcoxon signed-rank test assumed no difference between groups with a Bonferroni correction (p<0.0083).
During unshod parallel relevé, ROM was different between groups for first MTP extension (deg; MedGroup1: 90°, IQR 80°-90°; MedGroup 2: 70°, IQR: 70°-80°, p<0.0001) but no statistical difference in ankle PF (deg; p=0.0098). There were no differences in C7 displacement (m; p=0.5055), ankle PF moment (p=0.1484), or hip mediolateral and anteroposterior moments (p=0.8785 and 0.8785, respectively) during shod first position relevé, indicating that both groups tend to engage the same dominant muscle groups (trunk extensors, ankle dorsiflexors, hip flexors, and hip abductors) during elevé.
Dancers in Group 1 demonstrated greater first MTP extension during unshod relevé compared to dancers in Group 2. Weight-bearing ROM could be a valuable tool in predicting pointe readiness of adolescent ballet dancers.
目前尚无普遍接受的标准或统一的方案来确定舞者何时可以安全地开始穿着足尖鞋（足尖立起）跳舞。本研究的目的是检查青少年足尖舞者的舞者特异性生物力学，并探讨可能有助于确定足尖准备情况的因素。
根据能否沿铅垂线站立在足尖鞋盒上（组 1：能站在盒子上；组 2：不能站在盒子上），将 26 名舞者（中位年龄 14 岁[IQR=13-16]）分为两组，在平行站立的足尖鞋上进行测试。测量包括未穿鞋时踝关节跖屈（PF）和第一跖趾关节（MTP）伸展的负重活动范围（ROM）以及第一位置 Elevé（伸直、外展的直腿进入足尖立起）时的足尖鞋姿势评估。Qualisys 3D 运动捕捉和 AMTITM 力板记录舞者完成 10-15 次第一位置 Elevé 的重复动作。旨在描述未穿鞋和穿鞋条件下组间差异的三个运动学和三个动力学变量的比较。Wilcoxon 符号秩检验假设组间无差异，Bonferroni 校正（p<0.0083）。
在未穿鞋的平行足尖立起中，第一 MTP 伸展的组间 ROM 存在差异（度；MedGroup1：90°，IQR80°-90°；MedGroup2：70°，IQR：70°-80°，p<0.0001），但踝关节 PF（度；p=0.0098）无统计学差异。C7 位移（m；p=0.5055）、踝关节 PF 力矩（p=0.1484）或髋关节内外侧和前后向力矩（p=0.8785 和 0.8785，分别）在穿鞋的第一位置 Elevé 时无差异，这表明两组在 Elevé 时都倾向于使用相同的优势肌肉群（躯干伸肌、踝关节背屈肌、髋关节屈肌和髋关节外展肌）。
与组 2 相比，组 1 的舞者在未穿鞋的足尖立起中第一 MTP 伸展更大。负重活动范围可能是预测青少年芭蕾舞舞者足尖准备情况的有用工具。
