背景與目的：造成肩峰下夾擠症候群(subacrominal impingement syndrome, SIS)有許多原因，其中之一為不良的頸胸椎姿勢導致盂肱關節和肩胛胸廓關節產生不適當地動作型態，本研究目的是探討SIS與頸胸椎姿勢、頭胸椎關節滑動性、以及上肢神經張力之相關性。方法：本研究徵召27位SIS個案和28位對照組。所有受測者均接受姿勢評估、椎間關節活動度檢測以及上肢神經張力檢查。結果：兩組在頭部前傾角度、胸椎後彎角度、每一節椎間關節活動度與三條上肢神經張力測試性皆有顯著差異(p<.05)。逐步對數迴歸分析的結果顯示頸椎第五節單邊後前移動、頸椎第六節側邊平移、橈神經張力與尺神經張力，這四個變數與SIS有最大的相關存在。結論與臨床意義：頸胸椎的姿勢、椎間關節活動度與上肢神經張力和肩峰下夾擠症候群有關聯性，其中橈神經張力增加、尺神經張力增加、頸椎第5節單邊後前側移動以及頸椎第6節側邊平移受限更與SIS顯著相關。此結果可提供給臨床工作者在評估SIS患者時一個新的思考方向。

Background and Purpose: Subacromial impingement syndrome (SIS) is resulted from a variety of factors, Evidence shows that poor posture of the cervical and thoracic spine may contribute to the problem because it leads to inadequate scapulothoracic and glenohumeral kinematics. The purpose of this study was to investigate whether cervico-thoracic spinal posture, intervertebral joint mobility test and upper limb neural tests were associated with subacromial impingement syndrome. Methods: This was a cross-sectional, case-control design. Twenty-seven individuals with subacromial impingement syndrome and 28 asymptomatic subjects were recruited. We examined two posture variables (forward head and thoracic kyphosis angles), tested intervertebral joint mobility on four vertebral levels (C5/6, C6/7, C7/T1, T1/T2), and performed upper limb nerve (median, radial, and ulnar nerves) tension tests on all subjects. Results: The posture, intervertebral joint mobility, and upper limb tension variables showed significant differences between the two groups (p<.05). Significant association was observed between positive radial nerve tension test, positive ulnar tension test, restricted C5/6, C617 intervertebral joint mobility and the presence of the subacromial impingement syndrome. Conclusion and Clinical Relevance: The association between variables of the cervico-thoracic spine and presence of the subacromial impingement syndrome was confirmed, with positive radial nerve tension test, positive ulnar tension test, and restricted C5/6 and C6/7 intervertebral joint mobilily showing the strongest association. Clinicians need to thoroughly examine the cervico-thoracic spine when assessing the patient with subacromial impingement syndrome.