University of Bern, Institute of Sport Science, Dance Science, Bremgartenstrasse 145, 3012 Bern, Switzerland. Tel +41-316315665.
Med Probl Perform Art. 2021 Mar;36(1):45-53. doi: 10.21091/mppa.2021.1007.
Dancing requires a high range of motion in the foot as well as a good shock-absorbing system formed by the foot and ankle joints. Although there is a broad consensus in dance that excessive calcaneal eversion can cause injury and should be avoided, calcaneal eversion is discussed controversially in the dance literature. An increased research focus on the biomechanics of dance, particularly research pertaining to the foot and ankle joints, might help to resolve this controversy.
The study's main purpose was to generate hitherto lacking kinematic data of calcaneal eversion in a dancer's demi-plié.
Thirty-two contemporary dancers performed three trials in two different conditions: demi-plié in parallel and in turned-out positions. The motion capture system FASTRAK was used to measure calcaneal eversion and foot and lower leg alignment during demi-plié.
Maximal calcaneal eversion in turned-out demi-pliés was 3.36°±4° and total range of motion (i.e., maximal minus minimal angle) of calcaneal eversion was 3.73°±1.42°, where the large standard deviations indicate substantial variability across participants. Calcaneal eversion was significantly different between turned-out (3.36°±4°) and parallel (1.17°±4.06°) demi-pliés, as was the alignment of the lower leg and foot, where the lower leg tracked more medially relative to the foot during turned-out pliés. Crucially, both the magnitude of calcaneal eversion and its temporal coupling with ankle dorsiflexion were highly variable across participants.
Average calcaneal eversion is a poor indicator of the role calcaneal eversion plays in the demi-plié of contemporary dancers. Rather, the temporal coupling between calcaneal eversion and ankle dorsiflexion needs to be considered.
舞蹈需要脚部具备较大的活动范围和由足部及踝关节构成的良好减震系统。尽管舞蹈界普遍认为过度的跟骨外翻会导致损伤，应予以避免，但跟骨外翻在舞蹈文献中仍存在争议。如果对舞蹈生物力学，尤其是足部和踝关节的研究更加关注，或许有助于解决这一争议。
本研究的主要目的是获取舞蹈演员在半蹲位时跟骨外翻的运动学数据。
32 名现代舞者在两种不同的姿势下完成了 3 次试验：平行半蹲和外开半蹲。使用 FASTRAK 运动捕捉系统测量半蹲时的跟骨外翻角度以及足部和小腿的对线关系。
外开半蹲时最大跟骨外翻角度为 3.36°±4°，跟骨外翻总活动范围（最大角度减去最小角度）为 3.73°±1.42°，其中较大的标准差表明参与者之间存在较大的变异性。外开半蹲时的跟骨外翻角度（3.36°±4°）明显大于平行半蹲（1.17°±4.06°），小腿和足部的对线关系也不同，外开半蹲时小腿相对于足部更向内侧移动。重要的是，跟骨外翻的幅度及其与踝关节背屈的时间耦合在参与者之间存在高度变异性。
跟骨外翻的平均值并不能很好地反映跟骨外翻在现代舞者半蹲中的作用。相反，需要考虑跟骨外翻和踝关节背屈之间的时间耦合。
