Biomechanical analysis of Peking Opera hat-wing technique

The Peking Opera hat-wing technique is an intangible cultural heritage. This study adopted a single-subject case study design to characterize the movements of this technique, facilitating its intergenerational preservation and transmission. Biomechanical analysis was conducted to investigate the left-wing toss movement in the hat-wing technique, aiming to reveal the intrinsic biomechanical mechanism of the movement and provide a basis for its inheritance and training. An infrared motion capture system was used to collect kinematic parameters of the markers, and a three-dimensional force platform was employed to gather force data from the actor's left and right feet. Three sets of data-including Center of Pressure (COP) position, head movement parameters, and knee joint angles-were analyzed to elucidate the operating mechanism of the left-wing toss movement. Based on the results, the left-wing toss movement was theoretically segmented, and the initiation principle of the movement was determined. Additionally, factors influencing the sustained movement of the left-wing toss and those required to achieve a relatively static state at the end of the movement were identified. The primary hypothesis was that the phase relationship between the L3 Z-axis displacement-time (L3 Z-T) curve and the head tilt angle-time (α-T) curve can effectively distinguish the initiation, maintenance, and termination stages of the left-wing toss movement. Quantitative analysis of five repeated trials showed high movement repeatability, with a coefficient of variation (CV) < 15% for all key kinematic metrics. Among them, the phase difference (CV = 6.0%) and peak angular velocity (CV = 10.6%) exhibited excellent repeatability (CV < 11%), and other indicators also met the repeatability requirements for single-subject case studies (CV < 15%). During the initiation stage, the peak head tilt angle reached 6° ± 0.8°, and the peak angular velocity was 29.3°/s ± 3.1°/s. Throughout the movement, the COP excursion in the anterior-posterior direction was 4.2 ± 0.5 cm, and the medial-lateral excursion was 2.1 ± 0.3 cm. These findings provide a scientific foundation for the standardized training and intergenerational preservation of the Peking Opera hat-wing technique, highlighting the value of biomechanical analysis in traditional performing arts heritage.