糖尿病患者於跨越障礙物時下肢關節之生物力學及關節間協調的研究

Abstract

糖尿病是患者於行走或跨越障礙物時跌倒導致住院甚至死亡的主要危險因子之一。若糖尿病患者跌倒而造成外傷或骨折時，其併發症的發生率及醫療資源的消耗都較非糖尿病患者來得大。據統計目前台灣地區45歲以上國人每十位就有一位罹患糖尿病，而非胰島素依賴型（第二型）糖尿病之盛行率則為6.23%。針對第二型糖尿病患者跨越障礙物之模式完整的下肢運動學與力動學分析，將有助於設計預測或預防跌倒之方法。 本研究旨在建立第二型糖尿病患者之下肢本體感覺能力資料，並以此為基礎進一步探討健康及罹患第二型糖尿病患者跨越不同高度障礙物時下肢之生物力學，以瞭解糖尿病本身及其相關併發症對行走及跨越障礙物之影響。作法上，係利用一配有七台紅外線攝影機之動作分析系統量測受測者於跨越三種高度障礙物（受測者腳長之10%、20% 及30％）時全身之運動學資料，並利用兩塊測力板量測地面反作用力，搭配數學模型以求得力動學資料。 結果顯示糖尿病患者於踝關節在承重情況下會有過多的踝背屈重置對位，反映出患者下肢末稍關節位置感覺缺損之現象。當跨越障礙物時，糖尿病患者改變下肢生物力學以致跨越瞬間其跨越腳與障礙物之間隙小於健康正常人。當前腳跨越時，此一異常步態乃是由骨盆較前傾，站立後腳較背屈，擺盪腳較少髖外展所構成，同時也伴隨著較小的髖外展力矩但較大的膝屈曲及踝蹠屈力矩。當後腳跨越時，此一異常步態與骨盆較前傾，擺盪之後腳較少的髖膝屈曲雖有助於重心之降低，但卻也造成跨越瞬間其跨越腳與障礙物之間隙小於健康正常人。另外骨盆較前傾雖有助於減少絆到的風險，但卻也伴隨著較大的踝蹠屈力矩，而增加踝關節負擔。糖尿病患者跨越障礙物時不管是前腳跨越或是後腳跨越，下肢關節運動都作了一些的改變，以至於其關節間的協調型態有顯著的改變，結果並顯示在跨越障礙物時，糖尿病患者在矢狀面上以穩定地但異於常人之關節間協調應付相關併發症所造成的影響。關節間協調之型態及穩定度可以用來當作治療介入成效的評估。而關節間協調之型態及變異性亦可用來評估治療效果。 總結而言，糖尿病患者跨越障礙物時前腳及後腳都有較低的足部與障礙物之間隙，會增加跌倒的危險性。針對無明顯周邊神經疾病等併發症之糖尿病患者，在設計運動治療計畫時，建議加入膝屈曲及踝蹠屈之肌力訓練，並建議針對此類輕微糖尿病患者加強末梢本體感覺訓練，尤其是踝關節在承重情況時的下肢訓練。

Patients with type II diabetes mellitus (DM) have been reported to be at a high risk of falling which may be related to the presence of multiple risk factors, including the disease itself, problems with gait and balance, and peripheral neuropathy (PN). However, PN alone may not be enough for the assessment of fall risks in patients with DM, especially for those with no to minimal PN. It is noted that patients with no to minimal diabetic PN show degraded postural control and gait performance. Apart from deviations in gait, other changes are also present in these patients before PN is diagnosed, including reduced ankle muscle strength and impaired joint position sense (JPS) of the distal joints, which have been shown to affect gait performance. The purpose of this study was to compare the end-point trajectory and joint kinematic and kinetic patterns of the lower extremities as well as inter-joint coordination between healthy subjects and individuals with DM during obstacle-crossing. Fourteen patients with type II DM, with no to minimal PN, and fourteen healthy controls walked and crossed obstacles of three different heights (10%, 20% and 30% of leg length) while kinematic and kinetic data were measured using a motion analysis system and two forceplates. Compared to normal controls, the DM group had similar walking speeds and horizontal foot-obstacle distances but significantly reduced leading and trailing toe-obstacle clearances, suggesting an increased risk of tripping over the obstacle. When the leading swing toe was above the obstacle, the DM group showed greater pelvic anterior tilt, stance ankle dorsiflexion, and smaller swing hip abduction, with reduced hip abductor moments but greater knee flexor and ankle plantarflexor. When the trailing swing toe was above the obstacle, patients with DM showed smaller swing hip and knee flexion which resulted in reduced trailing toe-obstacle clearance. It appears that the DM group had adopted a particular biomechanical strategy using altered but stable inter-joint coordination control. Although the stable inter-joint coordination may enable the patients with DM to accommodate reliably the mechanical demands related to DM complications during obstacle-crossing, the altered inter-joint coordination control with reduced swing toe-clearance may increase the risk of falling during obstacle-crossing. It is suggested that patients with type II DM, with no to minimal PN, should also be targeted for fall prevention. Possible therapeutic intervention to decrease falls may include strengthening of the knee flexors and ankle plantarflexors, together with proprioception and balance training. Normal and reliable inter-joint coordination should both be considered as an outcome of therapeutic intervention, and the patterns and variability of inter-joint coordination can be used to evaluate treatment effects.