高齡者動體視力與步態速度隨老化之變異情形

Variation of dynamic visual acuity and walking velocity through aging in elderly

緒論：高齡者發生跌倒的時機好發於正在步行時，步行是日常生活中的最基本運動形式之一，由於高齡者在步行過程中處於自身移動，外在物體處於靜止或移動的一種運動狀態。在此情況下，高齡者的動體視力會影響到對外在物體訊息的接收正確性與時效性，進而影響其平衡能力，甚至於造成是否失衡跌倒。所以，高齡者步行速度的快慢涉及到視覺功能運作是否正常的關鍵因素，當高齡者步行速度快於其動體視力所能反應時，高齡者在步行中便容易發生跌倒，所以衍生高齡者動體視力與步行速度隨年齡增長的變化情形為何等研究問題。因此，本研究目的為探討65歲以上高齡者動體視力與步行速度之變異情形。方法：60位可正常步行的65歲以上高齡者參與本研究，以視覺測試系統進行動體視力測試，以600pfs的JVC高速攝影機拍攝高齡者步行10公尺的影像，再以Siliconcoach動作分析系統分析高齡者正常步態速度與最快步態速度。結果： (1) 65歲至82歲高齡者的動體視力、正常步態速度、最快步態速度等皆隨年齡增長，而具衰退或變慢趨勢。 (2) 動體視力隨年齡增長的衰退大於正常步態速度和最快步態速度的衰退，且77歲年齡區間 (77、78、79歲) 以上高齡者的動體視力衰退率顯著多於步行速度的衰退率，顯示此年齡之後的高齡者，其動體視力可能無法應付正常步態速度所產生的視覺訊息接收。結論：65歲至82歲高齡者的動體視力與步行速度隨老化有衰退現象，且動體視力的衰退較步行速度的衰退快，高齡者在77歲後需留意動體視力的維持，或減慢步行的速度，以提升高齡者步態安全和避免跌倒風險。

Introduction:Walking is one of essential movements in daily life. However, elderly often fall down during walking. Walking is considered as a condition that elderly is moving while other objects are still. In this case, dynamic visual acuity would be influence on correction and prescription of detecting useful information. Furthermore, dynamic visual acuity is a critical factor to keep balance during walking. It easily causes elderly fall when walking velocity is faster that visual function deal with information. Therefore, the purpose of this study was to investigate the changes on dynamic visual acuity and walking velocity with aging in elderly who above 65 years old. Methods:Sixty elderly who could walk normally were as participants in this study. The Visual System, a JVC high-speed camera, and the Siliconcoach motion analysis software were used to measure vision ability and walking velocity. Results:The results revealed that dynamic visual acuity, comfortable walking velocity, and fastest walking velocity decreased by ageing. The decline of dynamic visual acuity was greater than those of comfortable walking velocity and fastest walking velocity when elderly was above age of 77 (p<.05). It showed that dynamic visual acuity might not responded accurately to walking demand at 77 years old. Conclusion:It concluded that dynamic visual acuity and walking velocity decreased while age increasing in elderly as 65-82 years old. The decline of dynamic visual acuity greater than those of comfortable walking velocity and fastest walking velocity. In order to enhance safety of walking or reduce risk of falling, the elderly who over 77 years old should maintain the dynamic visual acuity or walking slower.