利用三維動態X光量測正常年輕人於自行車運動中膝關節之運動

Abstract

活體研究人體膝關節進行自行車踩踏運動時不同踩踏方式下的運動學分析有助於預防運動傷害以及增加復健效率。目前對於自行車踩踏過程中精確的活體非侵入式三維運動學量測與研究仍然缺乏。本研究目的為建構以雙平面動態X光結合斷層掃瞄骨頭模型方法為基礎的自行車運動學量測平台，量測十二位正常年輕男性在高阻力踩踏與低阻力踩踏情況下之精確三維膝關節運動學，更進一步搭配磁振造影而得的軟骨厚度計算關節表面運動學、以簡化後的前十字韌帶與後十字韌帶計算長度變化與伸長量變化。並且利用自主伸曲運動計算活體韌帶初始長度。 本研究結果發現，正常人進行自行車踩踏運動，無論高阻力踩踏或低阻力踩踏，其踩踏過程的運動模式大致上相似。高阻力對於關節角度產生最顯著的影響在於矢狀面的屈曲角度降低，尤其在踩踏的動力輸出期。阻力使得踩踏動力輸出期之膝關節表面接觸點在膝關節彎曲角度70度以下顯著往後側移動。踩踏過程中後十字韌帶伸長量顯著大於前十字韌帶伸長量，但阻力對韌帶伸長量影響並不顯著。 本研究建構的自行車運動量測平台未來可運用在不同踩踏方式下膝關節運動學的研究。本研究結果呈現的精確運動學資訊可提供更進一步的研究。另外，本研究中成功利用精確量測自主伸曲運動搭配磁振造影所得之韌帶附著位置找尋韌帶等長纖維的方法未來將可提供活體非侵入式決定個人化韌帶重建位置的參考。

In-vivo measurement of the three-dimensional (3D) kinematics during cycling is essential for the prevention of injuries due to overuse and improving the rehabilitation efficacy. The methods for measuring accurate 3D kinematics during cycling were still lacking. The purposes of the current study were to establish a platform for measuring knee kinematics during cycling based on the technique combining CT bone models and bi-planer fluoroscopy. Twelve normal young subjects were recruited, aiming to measure the knee kinematics during loaded and unloaded cycling. The thickness of the articular surfaces cartilage was calculated from MRI model and the surface kinematics was calculated. The elongation of simplified anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) changes were reported. And the reference lengths of the ligaments were determined by isolated knee flexion and extension motion. The findings of the current research are as follows. The patterns of loaded and unloaded cycling are shown similar, but the flexion angles are significantly decreased especially during power phase under loaded cycling. The load also affected the position of the articular contact points on tibial plateau especially when knee flexion angle lower than 70°. The elongation of the simplified PCL was shown larger than that of ACL. The load did not affect the elongation of the ACL and PCL. The established platform can be helpful f, and the knee kinematics presented in the research can be helpful for advanced study. Furthermore, the method used to define isometric fibre of ACL and PCL in this research may be useful to provide in vivo, noninvasive and subject-specific determination of the ligament replacement.