A Subject-specific Computational Model to Investigate an Ankle Inversion Ligamentous Sprain Injury and Evaluate the Intelligent Anti-sprain System

踝關節內翻扭傷為常見的肌肉骨骼傷害，並佔約五分之一的運動創傷的。外側韌帶拉扯是導致踝關節內翻扭傷的主因。踝關節內翻會導致患處紅、腫、痛、肌肉力量下降及本體感覺退化。創傷若處理不當更會引致慢性踝關節不穩而影響運動表現，結果須要付上高昂的醫療開支。正因為踝關節扭傷影響著每個人的日常生活及運動參與，故此有必要就扭傷機制進行深入的研究。本實驗室擁有智能防扭傷裝置專利，原理是通過肌電刺激腓骨肌來糾正踝關節內翻動作。本論文是透過了解踝關節的受傷機制以達至防止扭傷的研究目的。關節扭傷的臨床定義為踝關節突然內翻，這個解釋流於質性層次。另外，運動力學實驗室大多利用傾斜平台模擬足踝內翻動作來進行量性研究，但因為這種模擬未能反映真實傷患的過程，造成數據難以貼近真實的受傷機制。綜合以上質性和量性研究的缺點，最直接的方法是研究真正的扭傷個案。本實驗室曾紀錄一位受試者於跑步鞋測試中踝關節扭傷的過程，發現實驗室進行的動作及受傷強度都遠低於比賽上的扭傷個案。礙於學術道德的考量，無法在實驗室複製真實扭傷。因此，本論文的第一部份利用基於模型建立的圖像配對技術，以網球運動為樣本進行動作分析來了解其運動學的受傷機制。三維電腦生物力學模型一直被廣泛地用於研究關節活動、估計韌帶拉力、關節扭力等動力學數據。本論文的第二部份是透過建立一個個人化踝關節三維電腦生物力學剛體模型來估計受試者在實驗室扭傷的韌帶拉力及關節扭力。該模型 與死體實驗量度的數據作驗證，兩者的韌帶拉力結果相近。通過驗證後，再進行受傷過程模擬，令本論文有了運動學及動力學的數，據來有助了解真實踝關節內翻的受傷機制。本論文的最後一部份是利用該模型來評估及改良智能防扭傷裝置技術，在模型中加入扭力元素代替在腓骨肌上的肌電刺激效果。我們希望模擬所得的結果，有助日後把專利技術改良及商業化成為產品。Ankle sprain is one of the most common injuries in sports with a majority of 85% are lateral ankle ligamentous sprain. The injury mechanism was suggested to be supination or a combination of inversion and plantarflexion. Recent quantitative studies revealed that plantarflexion might absent from a lateral sprain. Hence, the mechanism is still controversial and yet to be understood.Computational modelling is an effective approach to predict soft tissue behaviours around the ankle in responding to injurious motions, and the effectiveness of the intelligent anti-sprain system. This information is difficult and even impossible to be measured experimentally on living humans. This thesis has three major objectives. The first objective is to develop a subject-specific computational rigid-body model of the ankle joint. The bone geometry is obtained by computer tomography of a real subject's lower limbs. Spring elements were added to the model in representing the ligaments. Experimental ligament stiffness of various physiological motions of ankle were obtained using three cadaveric ankle specimens being used for model validation. The second objective is to further understand the ankle ligamentous sprain injury mechanisms by simulating the subject-specific model. The model was driven by the temporal injury kinematics in gaining knowledge of the grade I lateral ankle sprain injury happened in our laboratory. Joint torque and ligament stiffness were estimated in causing this injury. The third objective is to evaluate the effectiveness of the intelligent anti-sprain system in restricting the rapid inversion motion and inversion velocity of the ankle joint. In addition to the temporal injury kinematics simulation, an eversion torque was added to the ankle model to represent the corrective eversion motion. The thesis highlighted the importance of incorporating subject-specificity in the computational model to study injury biomechanics, and to evaluate the patented intelligent anti-sprain system. Methodologies used in this thesis are not limited in understanding the ankle inversion ligamentous sprain injury mechanism but could be an aid to study other musculoskeletal injuries and as a guide in developing subjectspecific injury preventive devices and designing rehabilitation training programme.Ha, Chui Wai Sophia.Thesis Ph.D. Chinese University of Hong Kong 2016.Includes bibliographical references (leaves ).Abstracts also in Chinese.Title from PDF title page (viewed on …).Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only