Rowley K Michael, Jarvis Danielle N, Kurihara Toshiyuki, Chang Yu-Jen, Fietzer Abbigail L, Kulig Kornelia
Division of Biokinesiology and Physical Therapy, University of Southern California, 1540 East Alcazar Street, CHP-155, Los Angeles, CA 90089, USA. Tel 323-442-2911, fax 323-442-1515.
Med Probl Perform Art. 2015 Sep;30(3):152-6. doi: 10.21091/mppa.2015.3029.
Tendinopathy of the flexor hallucis longus (FHL), colloquially referred to as "dancer's tendinitis," is a common condition in dancers and attributed to high demand on this muscle in positions of extreme ankle plantarflexion and metatarsophalangeal (MTP)) flexion and extension. Despite such a high prevalence, there has been little research into preventative or nonsurgical interventions. As a means to identify potential targets for prevention and intervention, this study aimed to characterize toe flexors in dancers by measuring strength, flexibility, function, and FHL tendon morphology. Dancers (n=25) were compared to non-dancers (n=25) in toe flexor isometric strength, first MTP joint range of motion, foot longitudinal arch flexibility, balance ability, endurance during modified heel raises without use of the toes, and FHL tendon thickness, cross-sectional area, and peak spatial frequency. Significant differences were found in functional first MTP joint extension (dancers 101.95°, non-dancers 91.15°, p<0.001), balance ability during single-leg stance on the toes (dancers 11.43 s, non-dancers 5.90 s, p=0.013), and during modified heel raises (dancers 22.20 reps, non-dancers 28.80 reps, p=0.001). Findings indicate that dancers rely on toe flexors more than non-dancers to complete balance and heel raise tasks. Efficacy of using this modified heel raise task with the toes off the edge of a block as a means to train larger plantarflexors and as a nonsurgical intervention should be studied in the future. Improving interventions for FHL tendinopathy will be impactful for dancers, in whom this condition is highly prevalent.
拇长屈肌肌腱病(FHL),通俗地称为“舞者肌腱炎”,是舞者中的常见病症,归因于在踝关节极度跖屈以及跖趾关节(MTP)屈伸的姿势下该肌肉承受的高负荷。尽管患病率如此之高,但针对预防或非手术干预的研究却很少。作为识别预防和干预潜在靶点的一种手段,本研究旨在通过测量力量、柔韧性、功能以及FHL肌腱形态来对舞者的趾屈肌进行特征描述。将25名舞者与25名非舞者在趾屈肌等长力量、第一跖趾关节活动范围、足纵弓柔韧性、平衡能力、不使用脚趾进行改良提踵时的耐力以及FHL肌腱厚度、横截面积和峰值空间频率方面进行了比较。在功能性第一跖趾关节伸展方面(舞者为101.95°,非舞者为91.15°,p<0.001)、单腿踮脚尖站立时的平衡能力(舞者为11.43秒,非舞者为5.90秒,p=0.013)以及改良提踵时(舞者为22.20次重复,非舞者为28.80次重复,p=0.001)发现了显著差异。研究结果表明,与非舞者相比,舞者在完成平衡和提踵任务时更多地依赖趾屈肌。未来应研究将这种脚趾不接触木块边缘的改良提踵任务作为训练更大跖屈肌的一种手段以及作为非手术干预的效果。改善FHL肌腱病的干预措施对舞者将具有重要意义,因为这种病症在舞者中非常普遍。