著者

西中 直也 近 良明 Banks Scott A 三原 研一 鈴木 一秀 大田 勝弘 牧内 大輔 松久 孝行 筒井 廣明 杉本 英治 蒲田 和芳

出版者

日本肩関節学会

雑誌

肩関節 (ISSN:09104461)

巻号頁・発行日

vol.32, no.3, pp.509-512, 2008 (Released:2008-11-21)

参考文献数

16

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The glenoid bare spot commonly is observed in the adult shoulder. Carter et al. proposed that cartilage thickness was affected by normal homeostatic loads. The purpose of this study was to measure glenohumeral translation during shoulder abduction in order to explore development of the glenoid bare spot. 10 healthy shoulders (average 31.1 years old) were studied. 3D models of the scapula and humerus were created from CT scans. Motions were recorded with fluoroscopy during active abduction in neutral rotation for unloaded and a 3kg loaded trial. 3D motions were determined using model-based 3D-to-2D registration. Humeral translation was referenced in the superior/inferior direction to the assumed location of the bare spot (center of the circle described by the bony margins of the inferior glenoid). The bare spot location averaged 4.3mm inferior to the superior/inferior midpoint of the glenoid. Glenohumeral contact was 2.6 and 3.1mm superior to the bare spot for unloaded and loaded conditions with the arm at the side. The humeral head moved upward gradually with abduction to 4mm above the bare spot above 70° abduction (p>0.05, 0 vs 3kg). The glenoid surface stabilizes humeral head translation. Carter et al. suggested that cartilage grew thickest with high mechanical demands (compression and sliding) and thinner where demands were low. Humeral translation away from the bare spot with abduction suggests that lower loads were experienced when the humeral head was near the bare spot and larger loads were experienced with humeral translation away from the bare spot. These kinematic observations were consistent with Carter's framework for cartilage growth and provided a plausible explanation for the development of the glenoid bare spot.

著者

古屋 貫治 西中 直也 鈴木 昌 松久 孝行 小原 賢司 磯崎 雄一 大澤 一誉 田鹿 佑太朗 木村 亮介 筒井 廣明

出版者

日本肩関節学会

雑誌

肩関節 (ISSN:09104461)

巻号頁・発行日

vol.43, no.2, pp.593-597, 2019

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<b>【目的】</b>プロ野球投手のメディカルチェック(MC)でみられる,MR画像のposterosuperior impingement(PSI)と身体機能 との関係は不明である.今回,PSIと当院で重視しているゼロポジション保持機能との関連性について検討した.<BR><b>【方法】</b>当院のMCで,2年連続でゼロポジション保持機能と投球側MR画像を調査しえたプロ野球投手8名を対象とした.ゼロポジション近似肢位での外旋筋力(Zero外旋),肘伸展筋力(Zeroリリース)を両側測定し,MR画像の経年変化でPSI不変群4例と増悪群4例を比較した.<BR><b>【結果】</b>両群ともZero外旋,Zeroリリース,Zero外旋/リリース比は左右差がなく,投球側のZero外旋/リリース比のみPSI増悪群で有意に高かった(p=0.0209).<BR><b>【結論】</b>PSIとZero外旋、Zeroリリースの筋力は相関がみられなかったが,投球側のZero外旋/リリース比には相関がみられた.画像でPSI所見がみられた場合は新たな障害発生のリスクとなる可能性があるため,注意深く経過を診ていく必要がある.