infraspinatus

棘下筋

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/08/27 23:07:04」(JST)

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Infraspinatus muscle
Muscles connecting the upper extremity to the vertebral column (posterior view).
Infraspinatus muscle (shown in red) seen from behind.
Latin	musculus infraspinatus
Gray's	subject #123 441
Origin	infraspinous fossa of the scapula
Insertion	middle facet of greater tubercle of the humerus
Artery	suprascapular and circumflex scapular arteries
Nerve	suprascapular nerve
Actions	Lateral rotation of arm and stabilizes humerus

In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa. As one of the four muscles of the rotator cuff, the main function of the infraspinatus is to externally rotate the humerus and stabilize the shoulder joint.

Human anatomy

Origin and insertion

It attaches medially to the infraspinous fossa of the scapula and laterally to the middle facet of the greater tubercle of the humerus.

The muscle arises by fleshy fibers from the medial two-thirds of the infraspinatous fossa, and by tendinous fibers from the ridges on its surface; it also arises from the infraspinatous fascia which covers it, and separates it from the teres major and teres minor.

The fibers converge to a tendon, which glides over the lateral border of the spine of the scapula, and, passing across the posterior part of the capsule of the shoulder-joint, is inserted into the middle impression on the greater tubercle of the humerus. The trapezoidal insertion of the infraspinatus onto the humerus is much larger than the equivalent insertion of the supraspinatus, the reason why the infraspinatus is involved in rotarcuff tears about as frequently as the supraspinatus.

Relations

The tendon of this muscle is sometimes separated from the capsule of the shoulder-joint by a bursa, which may communicate with the joint cavity.

Innervation

The suprascapular nerve innervates the supraspinatous and infraspinatous muscles. These muscles function to abduct and laterally rotate the arm, respectively.

Action

Infraspinatus is the main external rotator of the shoulder. It also assists with shoulder extension. When the arm is fixed, it abducts the inferior angle of the scapula. Its synergists are teres minor and the deltoid.

The infraspinatus and teres minor rotate the head of the humerus outward (external, or lateral, rotation); they also assist in carrying the arm backward (extension of the glenohumeral joint).

Additionally, the infraspinatus reinforces the capsule of the shoulder joint.

Variation

The infraspinatus is frequently fused with the teres minor.

Evolutionary variation

The pectoral muscles — the pectoralis major and pectoralis minor — evolved from a primitive muscle sheet that connected the coracoid to the humerus. In late reptilians and early mammals, this muscle structure was displaced dorsally; while most of its components evolved into the pectoralis major, some fibers eventually attached to the scapula and evolved into the supraspinatus, the infraspinatus, and parts of the subscapularis.

Additional images

Infraspinatus muscle (shown in red). Animation.  Muscles on the dorsum of the scapula, infraspinatus is labelled 8 (posterior view).  Infraspinatus muscle  Infraspinatus muscle  Left scapula. Posterior surface.  Left humerus. Posterior view.  Infraspinatus muscle

References

This article incorporates text from a public domain edition of Gray's Anatomy.

External links

• LUC infs
• SUNY Figs 03:03-04
• infraspinatus+muscle at eMedicine Dictionary
• ExRx

UpToDate Contents

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• 1. 肩部の身体診察 physical examination of the shoulder
• 2. 回旋筋腱板の腱障害 rotator cuff tendinopathy
• 3. 回旋筋腱板断裂の症状と診断 presentation and diagnosis of rotator cuff tears
• 4. 肩関節の訴えがある患者の評価 evaluation of the patient with shoulder complaints
• 5. 肩インピンジメント症候群におけるリハビリテーションの原理および実践 rehabilitation principles and practice in shoulder impingement syndromes

English Journal

• Complete Fatty infiltration of intact rotator cuffs caused by suprascapular neuropathy.

• Leclere LE1, Shi LL2, Lin A3, Yannopoulos P4, Higgins LD5, Warner JJ6.Author information 1Department of Orthopaedic Surgery, Naval Medical Center San Diego, San Diego, California, U.S.A.2Department of Orthopaedic Surgery and Rehabilitative Medicine, University of Chicago, Chicago, Illinois, U.S.A.3Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.4Harvard Shoulder Service, Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, Massachusetts, U.S.A.5Sports Medicine and Shoulder Service, Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, U.S.A.6Harvard Shoulder Service, Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, Massachusetts, U.S.A. Electronic address: jwarner@partners.org.AbstractSuprascapular neuropathy is generally considered to be a diagnosis of exclusion, although it has been described in association with several activities and conditions. To our knowledge, this is the first description of suprascapular neuropathy with complete neurogenic fatty replacement in patients with intact rotator cuff tendons in the absence of traction or compression mechanisms. We present 4 cases of patients who presented with complete fatty infiltration of the supraspinatus (1 patient), infraspinatus (2 patients), and both (1 patient) resulting from suprascapular neuropathy. Each of these patients underwent arthroscopic suprascapular nerve decompression and subsequently had immediate improvement in pain and subjective shoulder value.
• Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.Arthroscopy.2014 May;30(5):639-44. doi: 10.1016/j.arthro.2014.01.010. Epub 2014 Mar 14.
• Suprascapular neuropathy is generally considered to be a diagnosis of exclusion, although it has been described in association with several activities and conditions. To our knowledge, this is the first description of suprascapular neuropathy with complete neurogenic fatty replacement in patients wi
• PMID 24630957

• Disruption of the anterior-posterior rotator cuff force balance alters joint function and leads to joint damage in a rat model.

• Reuther KE1, Thomas SJ, Tucker JJ, Sarver JJ, Gray CF, Rooney SI, Glaser DL, Soslowsky LJ.Author information 1McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.AbstractThe rotator cuff assists in shoulder movement and provides dynamic stability to the glenohumeral joint. Specifically, the anterior-posterior (AP) force balance, provided by the subscapularis anteriorly and the infraspinatus and teres minor posteriorly, is critical for joint stability and concentric rotation of the humeral head on the glenoid. However, limited understanding exists of the consequences associated with disruption of the AP force balance (due to tears of both the supraspinatus and infraspinatus tendons) on joint function and joint damage. We investigated the effect of disrupting the APforce balance on joint function and joint damage in an overuse rat model. Twenty-eight rats underwent 4 weeks of overuse to produce a tendinopathic condition and were then randomized into two surgical groups: Detachment of the supraspinatus only or detachment of the supraspinatus and infraspinatus tendons. Rats were then gradually returned to their overuse protocol. Quantitative ambulatory measures including medial/lateral, propulsion, braking, and vertical forces were significantly different between groups. Additionally, cartilage and adjacent tendon properties were significantly altered. These results identify joint imbalance as a mechanical mechanism for joint damage and demonstrate the importance of preserving rotator cuff balance when treating active cuff tear patients.
• Journal of orthopaedic research : official publication of the Orthopaedic Research Society.J Orthop Res.2014 May;32(5):638-44. doi: 10.1002/jor.22586. Epub 2014 Jan 25.
• The rotator cuff assists in shoulder movement and provides dynamic stability to the glenohumeral joint. Specifically, the anterior-posterior (AP) force balance, provided by the subscapularis anteriorly and the infraspinatus and teres minor posteriorly, is critical for joint stability and concentric
• PMID 24464961

• Isolation of infraspinatus in clinical test positions.

• Hughes PC1, Green RA2, Taylor NF3.Author information 1Department of Physiotherapy, La Trobe University, Australia; Melbourne Shoulder Clinic, Australia. Electronic address: phillip@melbourneshoulderclinic.com.au.2Department of Rural Human Biosciences, La Trobe University, Australia.3Department of Physiotherapy, La Trobe University, Australia.AbstractOBJECTIVES: Existing clinical tests for infraspinatus lack accuracy and differentiation from supraspinatus is difficult. We aimed to find a position that isolated infraspinatus contraction from supraspinatus and to analyse the contraction characteristics of lower (oblique) and upper (transverse) parts of infraspinatus.
• Journal of science and medicine in sport / Sports Medicine Australia.J Sci Med Sport.2014 May;17(3):256-60. doi: 10.1016/j.jsams.2013.05.011. Epub 2013 Jul 1.
• OBJECTIVES: Existing clinical tests for infraspinatus lack accuracy and differentiation from supraspinatus is difficult. We aimed to find a position that isolated infraspinatus contraction from supraspinatus and to analyse the contraction characteristics of lower (oblique) and upper (transverse) par
• PMID 23809837

Japanese Journal

• 肩関節挙上角度と棘下筋の活動性の関係 : 上肢挙上位におけるClosed kinetic chain運動の筋電図学的分析

• 南場 芳文,藤井 瞬,大谷 啓尊 [他]
• 神戸国際大学リハビリテーション研究 (5), 11-19, 2014-03
• NAID 40020062670

• 超音波検査によるプロ野球投手の棘下筋の質的評価 (第24回日本臨床整形外科学会学術集会)

• 内薗 幸亮,原 正文,緒方 隆裕 [他]
• 日本臨床整形外科学会雑誌 38(1), 79-83, 2013-07
• NAID 40019767438

• バドミントン競技選手における肩関節周囲筋の疼痛に関する考察

• 兒嶋 昇,升 佑二郎,野瀬 朋洋,Masu Yujiro,野瀬 朋洋,Nose Tomohiro
• 法政大学スポーツ健康学研究 4, 39-46, 2013-03
• … As the contracture of muscles, such as the anterior and middle scalene muscles, as well as the infraspinatus, was likely to cause pain, it may be effective to perform conditioning to reduce such muscle contracture during coaching in order to reduce the occurrence of impairment, and improve performance. …
• NAID 120005255273

Related Links

• Infraspinatus - ExRx (Exercise Prescription) on the Internet

Other Names Rotatory Cuff Back Heads Superior Middle Inferior Movement Shoulder External Rotation Transverse Abduction Transverse Extension Posterior Stability Abduction (see notes) Attachments

• infraspinatus | Flickr - Photo Sharing!

attached to the scapula, below the spine of the scapula ... + Add cristy_kay Member since 2009 Taken on February 28, 2009 Canon PowerShot SD1000 137 Views 0 Galleries

Related Pictures

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★リンクテーブル★

リンク元

「棘下筋」

「棘下筋」

　　[★]

英

infraspinatus (K), infraspinatus muscle

ラ

musculus infraspinatus

関

上肢の筋

起始

• 肩甲骨(棘下窩)

停止

• 上腕骨(大結節)

神経

• 肩甲上神経

機能

• 肩関節の外旋、伸展

カテゴリ

• 肩関節の筋