Single-Limb Balance Performance in Subjects with Ankle Sprains

腳踝扭傷患者之單腳站立平衡表現

林純彬(Chun-Pin Lin)

《中華民國物理治療學會雜誌》 21卷1期 (1996/01) Pp. 46-58

https://doi.org/10.29616/JPTAROC.199601.0006

摘要

本篇研究旨在探討腳踝扭傷對單腳站立平衡的影響。研究方法是對14名單側腳踝扭傷的受試者，用反作用測力板來測量其姿勢運動。以反作用力板測得的壓力中心軌跡圖則運用機率分析(random-walk analyses)，計算出3組參數－分散係數(diffusion coefficients)、指數參數(scaling exponents)、轉折點座標(critical Point coordinates)，以比較患側與健側的差異。結果顯示患側的長時距內外方向之分散係數顯著大於健側值，此項結果意謂著在較長時距下，站立於患側，內外方向穩定度較差。其餘參數，健側與患側並無顯著差異。指數參數的結果顯示對於較短時距，姿勢控制系統採用開放迴路機轉；對於較長時距，則採用閉路迴路機轉。為了進一步探討受試者的平衡策略，根據分散係數二極化的結果，再將受試者區分為2組，而發現兩種不同的平衡行為。第一組的6名受試者，其患側的前後及二維平面方向之轉折點時距(critical time interval)顯著大於健側，表示站立於患側時，姿勢控制轉換至閉路迴路機轉的延緩。第二組的8名受試者，大部份的患側的分散係數值大於健側值，顯示站立於患側時，穩定度較差。本篇研究的結果驗證腳踝扭傷後，單腳站立的平衡表現受到改變，而這項改變可能與腳踝扭傷的經常復發有關。

關鍵字

平衡 ； 腳踝扭傷 ； 本體感覺

並列摘要

The purpose of this study is to investigate the influence of ankle sprains on single-limb stance balance performance. Postural movements during one-leg standing were studied in 14 subjects with unilateral ankle sprains using a force platform. Random-walk analyses were applied to center-of-pressure (COP) trajectories. Three sets of parameters-diffusion coefficients, scaling exponents, and critical point coordinates-were computed from resultant stabilogram-diffusion plot (mean square COP displacement vs. time interval). Values were then compared between the sprained and uninjured sides. Results demonstrated significantly larger long-term mediolateral diffusion coefficients on the sprained side. This finding implied that standing on a sprained leg is less stable over long-term intervals of time than standing on an uninjured leg in mediolateral direction. No significant differences between the sprained side and the uninjured side were found in other parameters. The results for the scaling exponents revealed that open-loop control mechanisms in postural control system are utilized over short-term intervals of time, whereas closed- loop control schemes are employed over long-term intervals of time. In order to study the strategies used by the subjects, the subjects were divided into two subgroups based on dichotomous findings of the diffusion coefficients. Two patterns of altered balanced behavior were identified. Six subjects grouped in subgroup I demonstrated delayed switch to closed-loop control when standing on the sprained leg, as supported by significantly larger anteroposterior and planar critical time intervals on the sprained side. Eight subjects categorized in subgroupⅡ demonstrated reduced stability when standing on the sprained leg. This was indicated by four significantly larger diffusion coefficients (long-term planar and all short-term diffusion coefficients) on the sprained side. The results of this study suggest that modified balance performance occurs following ankle sprain.

並列關鍵字

Balance ； Ankle sprain ； Proprioception