2026-11-092026-11-09https://scholars.csmu.edu.tw/handle/123456789/38806Background: Clinicians often subscribe walking aids for patients with impaired balance and instruct them how to use these aids properly; however, the full mechanisms these walking aids improve function are not well understood. In fact, viewing the role of walking aids purely in terms of absolute biomechanical forces may underestimate its potential use in rehabilitation of patients with impaired standing balance. A light contact of the index finger with a surface has been reported effective in reducing postural sway, even though the force level applied is far below that necessary to provide mechanical support. In this line of research, there are four fundamental problems. Firstly, although results of research so far have probed into two possible mechanisms, distinct from each other, no study has been designed specifically to test which mechanism(s) is(are) really true; Mechanism One proposed that somatosensory information from touch provided a reference of postural orientation, whereas Mechanism Two argued the touch effects come from executing another supra-postural task; better understanding of the mechanism of light touch effects would shape clinical usage of walking aids. Secondly and thirdly, there is few research testing light touch effects in contexts of dynamic balance and of a cognitive task, which are both the demands of real life tasks. Fourthly, application studies of light touch effects are limited in people with sensory deficits under various contexts. Objectives: The overall goals of the research are to explore the mechanisms of light touch effects and to test their applications in various contexts to people with sensory deficits. Methods: This two-year project comprises four phases with eight experiments. Experiments 1-1 and 1-2 double dissociate Mechanisms One and Two in contexts of moving touching surface, in order to test which mechanism(s) is(are) really true. Experiment 1-1 has sway gain 2 or -1 to postural sway, so that only Mechanism One is allowed to operate. Experiment 1-2 has oscillating amplitude perceivable or unperceivable, so that only Mechanism Two is allowed to operate. Experiments 2-1 and 2-2 adopt paradigms of dynamic balance while asking participants to take a step or resist perturbations, in order to test the light touch effects under contexts of dynamic balance. Experiment 3 tests the light touch effects with an additional cognitive task of visual search. Experiments 4-1 to 4-3 replicate paradigms in Experiments 2-1, 2-2 and 3 in people with sensory deficits, including amputations, peripheral neuropathy due to diabetes and elder fallers. Expected contributions: It is hoped that results of the research can bring fundamental insights into mechanisms of light touch effects on balance, which could provide a basis for further relevant research. Furthermore, understanding of the application of light touch effects in various contexts and in different populations could help to bridge basic science and clinical use. In the future, the results of this project will help to shape clinical training of people with impaired balance ability.研究背景臨床工作人員常建議平衡損傷的病人訂購行走輔具，並教導他們如何正確地使用這些輔 具；然而行走輔具幫助促進功能的完整機轉還沒有被系統化地加以研究。事實是，單純從提供力學 支持的觀點來看待行走輔具，可能低估了行走輔具在平衡損傷復健上的應用潛力。研究已發現手指 輕觸物體可以幫助平衡控制，但是這個研究領域尚存在著四個問題。第一，雖然研究結果已經指向 兩個截然不同的可能機轉，目前還沒有研究特別設計來測試輕觸幫助姿勢穩定的機轉究竟為何；機 轉一假設手指的輕觸覺提供了身體搖晃的訊息，機轉二假設輕觸效果來自更高階的手指控制任務； 更多了解輕觸效果的機轉將改變我們臨床上應用行走輔具的方式。第二及三，很少研究測試動態平 衡反應與增加認知任務的情境中的輕觸效果；這些情境更接近日常生活的狀況，也更能夠應用到臨 床上。第四，應用輕觸效果於知覺損傷者的研究尚未完整測試各種不同情境之輕觸效果。 研究目的本研究旨在探討輕觸效果的機轉以及其在不同情境下之應用。 研究方法本兩年之研究共分四期八個實驗。實驗1-1 利用雙倍於或相反於身體搖晃的手指接觸面， 允許機轉一的操作而排除了機轉二；實驗1-2 則利用不可感知或可感知之規律搖晃之手指接觸面， 允許機轉二的操作而排除了機轉一；以上雙重分離機轉一與二的實驗將測試這兩個機轉是否同時為 真或只存在其一。實驗2-1 與2-2 採用動態平衡實驗設計，要求受試者跨步或抵抗平衡干擾，以測 試輕觸穩定姿勢的效果在動態情境下是否仍存在。實驗3 測試增加另一認知任務對輕觸效果的影響。 實驗4-1 到4-3 運用實驗2-1 到3 的設計於下肢知覺損傷者，包括截肢、糖尿病與老年跌倒者這些 平衡能力不佳的族群。 研究預期貢獻預期本研究結果將能增加學界對輕觸幫助姿勢穩定的基本運作機轉的了解，亦能作為 未來相關研究的基礎。此外，增加對輕觸效果在不同情境與不同族群之應用的了解，能夠幫助建立 基礎研究與臨床運用的橋樑，未來將能夠應用到臨床上幫助訓練平衡能力不佳的族群。Project