探討動態與靜態施力下平衡力與下肢肌群相關性研究

Evaluation of the Relationship between Posture Stability and Lower Limbs Muscle Activities

黃沛敏(Pei-Min Huang)

指導教授 ： 江行全

元智大學/工程學院/工業工程與管理學系/碩士(2012年)

https://doi.org/10.6838/YZU.2012.00316

摘要

隨著年齡增長，感覺系統功能中的肌肉骨骼系統也會逐漸退化，使得肌力降低、肌纖維數目減少以及運動控制異常，而這些問題對於平衡的控制及恢復影響甚鉅，為了找出肌肉對於平衡的相關性，本研究針對二十四名年輕人，男性十二名、女性十二名，透過八種實驗站立情境，探討有無軟墊站立及有無視覺輔助時，下肢肌群對於平衡力的影響，同時量測一分鐘的壓力中心點訊號及肌電訊號，利用傳統分析指標、多尺度熵、希伯特─黃轉換及95%信心水準複數平面面積分析壓力中心點訊號及肌電訊號，分別探討不同情境下，兩筆生理訊號之間的變化與分析方法之間的差異，並且利用同步性分析探討肌肉與平衡力的相關性。
分析結果顯示COP訊號與EMG訊號的傳統指標都具有鑑別有無軟墊站立及有無視覺輔助的情況，COP傳統分析指標方面，以總距離TOTEX(單位：mm)指標為例，開眼靜態有軟墊值為9.41±1.49、開眼靜態無軟墊值為5.93±1.07、閉眼靜態有軟墊值為15.88±2.89及閉眼靜態無軟墊值為6.43±1.02，統計檢定有無軟墊站立及有無視覺輔助都具顯著性(p-value<0.05)，EMG傳統分析指標方面，以內腓腸肌的%MVC RMS指標為例，開眼靜態有軟墊值為6.18±3.36、開眼靜態無軟墊值為3.75±2.67、閉眼靜態有軟墊值為8.92±3.85及閉眼靜態無軟墊時值為4.50±2.82，統計檢定有無軟墊站立及是有無視覺輔助都具顯著性(p-value<0.05)，在多尺度熵分析方面則是COP訊號的鑑別能力較好，以左右方向(ML)的複雜度為例，開眼靜態有軟墊值為12.45±2.43、開眼靜態無軟墊值為14.92±2.58、閉眼靜態有軟墊時值為13.00±3.53及閉眼靜態無軟墊值為13.08±4.67，統計檢定有無軟墊站立或者是有無視覺輔助都具顯著性(p-value<0.05)，但趨勢與預期相反，有軟墊的複雜度高於無軟墊的複雜度，閉眼的複雜度高於開眼的複雜度，EMG訊號無一致趨勢，利用希伯特─黃轉換及95%信心水準複數平面面積分析可得到與傳統分析指標一致的結果，其中COP訊號的IMF4能鑑別有無軟墊站立的差異，平均頻率為2.28Hz，以開眼有無軟墊來說，有軟墊站立時95%信心水準的複數平面面積值為0.06±0.10，無軟墊站立值0.01±0.01，統計檢定達顯著性(p-value<0.05)，有無視覺輔助則是利用IMF5結果較顯著(p-value<0.05)，平均頻率為0.81Hz，EMG的影響都落於IMF2至IMF3，藉此方法更能確定有無軟墊站立及有無視覺輔助對這兩筆生理訊號確切影響的頻率範圍，最後，利用總體經驗模態分解法得知低頻範圍的EMG與COP平均頻率分佈較相似，在統計上無顯著性(p-value>0.05)，利用同步性分析該頻率範圍的兩筆生理訊號，結果顯示，人體平衡穩定時，EMG與COP訊號的同步性較低，數值約為0.006至0.008，相反的，人體平衡不穩定時，EMG與COP訊號的同步性較高，數值約為0.01至0.015，且在統計上具顯著性(p-value<0.05)。

關鍵字

壓力中心點 ； 肌電訊號 ； 傳統指標 ； 希伯特─黃轉換 ； 多尺度熵 ； 總體經驗模態分解法 ； 95%信心水準複數平面面積 ； 同步性分析

並列摘要

With the increase in age, degeneration of the lower limb muscles resulted in balance ability declines. Once ability of balance is decreased, person will fall easily. The aim of this study is to find the relationship between the lower limb muscle activities and the balance. There were 24 participants, including 12 male and 12 female. The center of pressure (COP) and electromyography (EMG) signals were measured synchronously in the experiment, then applied traditional COP indeces, multi-scale entropy, Hilbert-Huang transform and 95% confidence circle area to analyze COP and EMG signals. Finally, the synchronization index was used to investigate the relationship between the lower limb muscle activities and the balance. The results showed that the traditional COP indeces can significantly distinguish standing states, including with foam, without foam, eyes-open and eyes-closed. The TOTEX value is 9.41±1.49 mm in eyes-open with foam, and is 5.93±1.07 mm in eyes-open without foam; in eyes-closed with foam is 15.88±2.89 mm and in eyes-closed without foam is 6.43±1.02 mm. The multi-scale entropy showed significantly different in COP data. In ML direction, the complexity index is 12.45±2.43 in eyes-open with foam, is 14.92±2.58 in eyes-open without foam; in eyes-closed with foam is 13.00±3.53 and in eyes-closed without foam is 13.08±4.67. But the results were contrary to expectation. In EMG result, there is no consistent trend. Using the HHT and 95% confidence circle area can obtain same results as using traditional indeces. The IMF4 can significantly distinguish the standing with foam versus without foam. The average frequency for IMF4 is 2.28 Hz in this study. For instance, 95% CC-Area is 0.06±0.10 in eyes-open with foam and is 0.01±0.01 in eyes-open without foam. The IMF5 can significantly distinguish eyes-open stand and eyes-closed stand. The average frequency for IMF5 is 0.81 Hz in this study. This method can find the narrow frequency band that is influenced by the situational changes.
Finally, using the ensemble empirical mode decomposition (EEMD) can find degree of correlation between EMG and COP data at lower frequency. The synchronization index showed the lower synchronization when body is unbalanced. The synchronization index is 0.006 to 0.008. On the other hand, the synchronization index shows the high synchronization when body is balanced. The synchronization index is 0.01 to 0.015.

並列關鍵字

Electromyography (EMG) ； Traditional index ； Hilbert-Huang transform (HHT) ； Ensemble empirical mode decomposition (EEMD) ； Multi-scale entropy (MSE) ； Synchronization analyze ； Center of pressure (COP)

參考文獻

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