背景與目的：定位腰椎節數為臨床施展腰椎測試或進行動作分析研究之重要步驟，然而觸診定位之信、效度不高，利用超音波引導定位之精確度及信、效度皆高，但目前尚未有研究應用在腰椎節數之定位。本研究目的在建立以超音波引導觸診定位腰椎各節棘突之方法，並探討同天施測者內信度及施測者間信度。方法：本研究收集12位無下背痛症狀之健康年輕受試者。利用超音波引導定位腰椎各節之棘突中心點，並測量腰椎第一節至第四節棘突中心點到腰椎第五節的棘突中心點距離及鄰近兩節棘突中心點距離。計算腰椎定位之正確率；以組內相關係數(Intra-class correlation coefficient；ICC)檢測施測者內信度及施測者間信度，以受試者內及受試者間變異係數，代表測量結果之間的變異程度。結果：以超音波引導觸診腰椎節之正確率達83%；正確定位節數者之施測者內信度之ICC值分佈為0.80至0.92；施測者間信度之ICC值分佈為0.68至0.95，除了腰椎L4-5第一次測量之施測者間信度未達統計上的差異，其餘信度測量皆有顯著差異(p<0.05)。同一施測者之受試者內變異係數除腰椎L4-5外(10.6%)，皆小於10%，不同施測者之受試者內變異係數皆小於10%，而受試者間變異係數都小於30%。結論：本研究建立以超音波引導觸診定位腰椎節數之方法，其施測者間及施測者內信度皆為極佳。臨床意義：合併超音波及觸診能定位腰椎節數。

Background and Purpose: The accurate location of lumbar spinous processes is essential for clinical test or movement analysis of lumbar region. However, the reliability and validity for identifying lumbar levels via surface palpation were unacceptable in previous studies. Locating of anatomical structures with sonographic guidance has been shown excellent reliability and validity. The purpose of this study was to establish the methodology and to examine the accuracy and intra-day, inter-session test-retest reliability of locating lumbar spinous process by palpation with sonographic guidance. Methods: Twelve young and healthy subjects participated in this study. Marking location of echogenic hump of spinous process over the skin was identified through ultrasound. The distances of inter-spinous processes between L5 and other lumbar levels, and between the adjacent two lumbar levels were measured by ultrasonography. To assess the test-retest reliability, intra-class correlation coefficient (ICC), within-subject of coefficient of variance (CVw), standard error of measurement (SEM), and shift-error rate were calculated. Results: The shift-error rate, indicating the accuracy of this method, was 8.3% (2/24, n=12). Among the location without shift error (n=10), the intra-rater reliability (ICC: 0.80-0.92) and inter-rater reliability (ICC: 0.68-0.95) of the distance of inter-spinous process between L5 to other lumbar levels were fair to excellent (ICC=0.68-0.95). The intra-rater and inter-rater reliability of the inter-spinous process distance between the adjacent two lumbar levels was less satisfied (ICC=0.27-0.95). The CVw of all measures was within 10% except for the inter-spinous process distance between L4-5. Conclusions: We established the methodology of locating lumbar spinous process by palpation with sonographic guidance, with acceptatable shift-error and testretest reliability. Clinical relevance: The accurate location of lumbar spinous process is possible by the method of palpation with sonographic guidance.