以非控制域理論分析年輕人及老年人 跨越障礙物

Uncontrolled Manifold Analysis of Obstacle-Crossing in Young and Older Adults

蔡瑋純(Wei-Chun Tsai)

指導教授 ： 呂東武

國立臺灣大學/工學院/醫學工程學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.10575

摘要

跌倒為老人罹病與死亡的重要原因；根據統計資料，跌倒是65歲以上老人事故傷害的第二大原因，更是老人事故傷害住院的主因。老年人跌倒常是多種危險因子合併年齡、疾病和環境因素所造成，其中又以跨越障礙物為造成跌倒的主要原因之一，而成功的完成跨越障礙物取決於跨越腳和障礙物之間必須維持足夠的間距，必須要精準地控制跨越腳末端位置，以及站立腳必須要有足夠的肌肉力量來維持穩定，來維持身體的平衡。
本研究利用配備七台紅外線攝影機的動作分析擷取系統量測跨越障礙物之運動學資料，過去文獻觀察跨越腳末端位置與障礙物之垂直距離間隙，來看有無跌倒的風險，然而人類動作中存在著動作變異性，每次的末端位置不盡相同，若變異性很大，則絆倒的風險將會提高；本研究以非控制域領域的方法分析年輕人族群與老年人族群跨越障礙物，除如過去此方法相關文獻一樣看整體動作的穩定性外，並進一步深入探討各關節變異量對跨越腳末端位置變異量的貢獻度，探討此動作的完成於下肢關節哪些是需要控制的，只要有微小變動即會大幅影響末端位置，而哪些又是不用受控制的，任由有許多變異量對末端位置不造成影響。
研究結果顯示，年輕人與老年人跨越障礙物之穩定度皆隨高度而降低；年輕人與老年人皆為在矢狀面對跨越腳末端位置變異量貢獻最大，其中又以髖關節的屈曲/伸展最大、膝關節的屈曲/伸展次之、踝關節最小；而所有下肢關節的內旋/外旋變異量貢獻最小。於前後向站立腳的踝關節屈曲/伸展、內翻/外翻及跨越腳屈曲/伸展變異量的貢獻度大幅提高，而髖關節屈曲/伸展變異量貢獻度隨著高度增加降低，尤其老年人族群比年輕人降低得更多。而老人在高度20-30%髖關節屈曲/伸展貢獻度明顯比年輕人小，在站立腳踝關節內翻/外翻變異量貢獻度明顯增加。於左右向跨越障礙物時，跨越腳的髖關節內旋/外旋變異量及站立腳踝關節內翻/外翻變異量貢獻度大增，其中踝關節貢獻度隨高度增加而呈線性遞增；而老年人在障礙物高度30%時，站立腳的踝關節內翻/外翻和站立腳髖關節內收/外展變異量貢獻度相當，並超越跨越腳內收/外展變異量貢獻度。
由以上結果得知，隨著障礙物高度增加跨越障礙物動作的穩定度會隨之減小；從下肢關節對末端位置變異量的貢獻度觀察到，人們在跨越障礙物的垂直向會優先選擇控制髖關節的屈曲/伸展，使其關節角度變異量不要過大，其次是站立腳的膝關節、踝關節屈曲/伸展，最後是跨越腳的膝關節與踝關節屈曲/伸展；於前後向，高度增高時踝關節中心與跨越腳末端位置距離比在步態時更長，造成對末端位置變異量貢獻度提高；而跨越腳膝關節有較大的變異量，扮演一個保持跨越腳末端位置在前後方向平衡的角色。髖關節屈曲/伸展變異量隨障礙物高度增加呈線性遞減，而站立腳踝關節內翻/外翻變異量貢獻度呈線性遞增；代表跨越障礙物時，髖關節重要性會分散到站立腳的踝關節及跨越腳膝關節；站立腳的髖關節內收/外展為擔任控制左右方向平衡的任務；在跨越障礙物時，站立腳踝關節與跨越腳末端位置的距離增加，而且踝關節本身在內翻/外翻方向上較不穩定有較大的變異性造成整體上對末端位置變異量的貢獻度大增。本研究應用非控制域理論的方法來進一步分析各關節對末端變異量的貢獻度，可更深入瞭解人們存在於跨越障礙物之變異性是由下肢哪些關節主要造成的，而哪些關節相較之下影響較小，在臨床意義上能更深入的解讀與應用。

關鍵字

跨越障礙物 ； 動作分析 ； 非控制域理論分析 ； 運動學

並列摘要

Falls are the secondary cause of accidental deaths and the leading cause to emergency hospitals in persons over the age of 65. Falls of elders’ cause often combine age, illness and environment, among these, crossing obstacles during locomotion has been reported as one of the most frequent causes of falls. To accomplish crossing obstacle, the leading limb should appropriate foot clearance, and the trailing limb has to stable the body when crossing obstacle.
This study use motion analysis system equipped with 7 ultra-high resolution infrared cameras to capture kinematic data. We use uncontrolled analysis method to observe the stability in older and young groups when crossing obstacle, and to know the joint contribution to the crossing toe variability.
The results reveal that both groups’ stability has linearly decreasing trend with increasing obstacle height. For vertical end-point deviation, both groups have greater joint contribution in sagittal plane. First, hip flexion/extension. Second, knee flexion/extension. Third, ankle plantar-/dorsiflexion. Older group have largely decreasing trend of hip flexion/extension contribution with increasing obstacle height than young groups. For anterior-posterior end-point deviation, both groups have greater joint contribution at hip joint, trailing ankle joint and leading knee flex/extension. For medial/lateral end-point deviation, there is greater leading hip abd/adduction and trailing abd/adduction contribution for the 0% condition, and leading hip int/external, trailing ankle inv/eversion contribution are both increased sharply with increasing obstacle height. These shows that people have high priority in controlling hip when walking. Older group will transferred the importance of controlling hip joint to trailing ankle joint when crossing obstacles. This study not only observe the stability of crossing obstacle of young and old group with different height, and more detailed to understand the joint contribution to the end-point deviation, that make it have connection with clinical application.

並列關鍵字

Obstacle crossing ； motion analysis ； uncontrolled manifold analysis

參考文獻

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