超音波回饋訓練於腹肌收縮之量化評估

Abstract

背景：復發性下背痛的病人在接受即時超音波影像回饋的特定穩定運動訓練可以減少疼痛和障礙。視覺回饋可以加強深層肌肉的收縮，如腹橫肌、多裂肌以及骨盆底肌在過去研究皆有定性的報導。為了確切瞭解腹部肌肉收縮表現及其訓練效果，量化腹部肌肉收縮時候的超音波參數十分重要，然而無症狀之成人或病人接受超音波影像回饋後腹部肌肉收縮量化表現在目前並無任何定量的研究。 目的：本研究目的有二：第一是建立一套可信的超音波參數量化量測，第二部分是測試復發性腰痛患者使用超音波回饋在訓練前、訓練前期、訓練後期、訓練後、以及四天之後留存的腹部肌肉收縮表現。無症狀受試者接受相同訓練其量化之超音波回饋訓練做為基準參考標準。 方法：第一部分的研究，使用同一張超音波影像由同一名測試者分析兩次的結果來分析每一次分析的信度，以及使用同一群受試者，由同一名測試者在不同兩天測試的結果，來分析其隔天測試的信度。參加本實驗的18名受試者都是大學生。平均年齡是22.6±2.5歲。本研究所用的即時超音波影像儀器是5-12MHz的線性探頭，並在B-mode下顯示影像。測量所有受試者在仰躺姿勢下的腹橫肌以及腹內斜肌在休息與最大收縮時候的厚度以及前腹筋膜滑動程度。信度包括計算組內相關係數以及受試者內變異係數來分析測試的變異。本研究的第二部份，15名年齡介於20至35歲復發性下背痛以及15名同年齡層無下背痛症狀受試者參加本實驗。記錄每一次訓練(20次)以及測試的超音波影像(訓練前、訓練後以及四天後留存)。方法使用和第一部分研究所建立的良好信度之量測。使用重覆量測變異數分析(五個時間點)分析訓練前、訓練前期、訓練後期、訓練後以及留存時參數的變化。 結果：在同一張圖片由同一位測試者分析兩次的信度方面，休息時以及最大收縮時的腹橫肌以及腹內斜肌厚度的組內相關係數皆大於0.75，表示優良信度。所有超音波參數的受試者內變異係數小於10%，表示受試者內變異小。在同一群受試者由同一位測試者測試兩天的信度方面，所有超音波參數的組內相關係數都大於0.75，表示優良信度。所有超音波參數除了右側的滑動以外的受試者內變異係數小於10%，表示受試者內變異小。前腹筋膜滑動和腹橫肌標準化厚度之間沒有相關(r=0.079, p=0.643)。研究的第二部分，無腰痛受試者間的前腹筋膜滑動、腹橫肌的標準化厚度以及主要活化比量化參數，沒有顯著的改變。復發性腰痛患者訓練前與訓練前期之滑動、腹橫肌的標準化厚度以及主要活化比有明顯進步(p=0.001, 0.009, 0.003)，超音波參數都顯示有留存現象。 結論：在清楚的任務教導、監控動作的正確性以及使用內在標記校正在收縮時超音波探頭的滑動，控制了測量可能的誤差後，腹橫肌以及腹內斜肌厚度以及滑動的測量是可信的。復發性下背痛病人使用即時超音波影像回饋，教導腹肌收縮使用後，腹部肌肉收縮控制之量化參數於訓練前期即有較明顯進步。所有參數於四天後仍維持相同程度之表現。未來可進一步探討超音波回饋應用於治療下背痛患者的適當有效模式。

Background: Visual feedback has been reported to enhance the contraction of the deep muscles, such as the transversus abdominis (TrA), the multifidus, and the pelvic floor muscles. While exploring the effect of using ultrasound images as feedback for deep muscle training, most of the studies used visual determination to detect whether the performance of the abdominal muscles is improved or not. Lack of quantitative and reliable measurements were known to assess the performance of the deep abdominal muscles. Purposes: The purposes of this study were 1) to establish a quantitative and reliable measurement of ultrasound parameters, and 2) to examine the performance of abdominal muscle contraction using ultrasound feedback for both asymptomatic adults and subjects with recurrent low back pain at the pre-training, initial phase of training, final phase of training, post-training, and four days of retention. Methods: In the first part of the study, the intra-image intra-rater and between-day intra-rater reliability designs were employed to explore the variability of measurement between measurements and between days. Eighteen participants in this study were university age students. The mean (±SD) age of the subjects was 22.6±2.5 years. The real-time ultrasound imaging was viewed in this study in B mode with a 12 to 5 MHz linear-array transducer. We measured thickness both at rest (Thr) and during maximal contraction (Thm) of the transversus abdominis (TrA) and obliquus internuus (OI) as well as lateral movement of the anterior abdominal fascia of TrA (△x) both at rest and during maximal contraction. Reliabilities were calculated using intra-class correlation coefficient (ICC), and within-subject coefficient of variance (CVw) to explore the variability of measurement. For the second part of the study, 15 subjects with recurrent low back pain (LBP), aged ranged from 20 to 35 years old, and 15 of age-matched subjects without LBP participated. The ultrasound images of each trial of training (20 trials) and testing (three trials at the pre-training, initial phase of training, final phase of training, post-training, and retention) were recorded. The outcome measures were the same as those in the first part of the study. Changes of variables in the two groups (subjects with and without recurrent LBP) during pre-training, post-training and retention were assessed using analyses of variance (ANOVA) with repeated measures. Results: In the study about intra-image intra-rater reliability, the ICC values of Thr and Thm of TrA and OI were all above 0.75, indicating excellent reliability. The CVw of all ultrasound parameters were less than 10%, indicating small variability within subjects. Similar results were found for between-day intra-rater reliability except that the CVw value of Δx on right side was above 10%. For patients with recurrent low back pain, improvement of △x, normalized thickness of TrA, and the preferential activation ratio was noted from pre-training to the initial phase of training (p =0.001, 0.009, 0.003 respectively) and such effect could be lasted for four days. However, no significant changes in training performance were found for asymptomatic subjects. Conclusions: In the first part of this study, after controlling the possible errors during measurement, by clear instruction of the task, monitor preciseness of the movement, and using an internal marker to adjust the movement of the ultrasound transducer during contraction, measurement of thickness of OI and TrA and Δx were reliable both at rest and during maximum contraction. For the second part of this study, using real-time ultrasound feedback to teach abdominal muscle contraction and quantitatively measuring the outcome of ultrasound parameters, patients with recurrent low back pain demonstrated better abdominal muscle control after several practices, and such control could be maintained at the same level of performance up to 4 days. Optimal mode of ultrasound feedback remained to be determined for patients with recurrent low back pain.