Manual Muscle Test

Supraspinatus

· 1. Neurological & Functional Insights

· Initiates the first degrees of abduction and provides dynamic centering of the humeral head.

· High mechanoreceptor density coordinating fine elevation control.

· Prevents inferior humeral translation especially in early range.

· 2. Clinical Relevance

· Common site of tendinopathy and degenerative tears.

· Inhibition causes poor abduction and deltoid overload.

· Key early-phase stabilizer in scapulohumeral rhythm.

· 3. Origin

· Supraspinous fossa

· 4. Insertion

· Superior facet of greater tubercle

· 5. Innervation

· Suprascapular nerve (C5–C6)

· 6. Actions – Open Kinetic Chain (OKC)

· Initiates abduction

· Assists external rotation

· 7. Actions – Closed Kinetic Chain (CKC)

· Centers humeral head

· Provides compressive stability

· 8. Associated Ligaments

· Superior GH ligament

· Coracohumeral ligament

· 9. Associated Organs

Fascial:

· Supraspinous fascia

· Superior shoulder capsule

Viscerosomatic:

· C5–C6

TCM:

· Small Intestine meridian

VM:

· Scapular fascial tension influencing supraspinatus tone

Infraspinatus

· 1. Neurological & Functional Insights

· Primary external rotator of the GH joint.

· Provides strong posterior stability against anterior translation.

· Works synergistically with teres minor for overhead control.

· 2. Clinical Relevance

· Inhibited in anterior shoulder pain and impingement.

· Critical for deceleration phase in throwing.

· Weakness increases anterior glide risk.

· 3. Origin

· Infraspinous fossa

· 4. Insertion

· Middle facet of greater tubercle

· 5. Innervation

· Suprascapular nerve (C5–C6)

· 6. Actions – Open Kinetic Chain (OKC)

· External rotation

· Horizontal abduction

· 7. Actions – Closed Kinetic Chain (CKC)

· Posterior humeral stabilization under load

· 8. Associated Ligaments

· Posterior GH capsule

· 9. Associated Organs

Fascial:

· Posterior scapular fascia

Viscerosomatic:

· C5–C6

TCM:

· Small Intestine meridian

VM:

· Posterior shoulder fascial restrictions

Teres Minor

· 1. Neurological & Functional Insights

· Works with infraspinatus to provide external rotation.

· Key posterior stabilizer preventing anterior glide.

· Important for fine-tuning humeral head centering.

· 2. Clinical Relevance

· Weak in overhead athletes; often overloaded with IR dominance.

· Supports late-cocking and deceleration phases.

· Essential for posterior cuff balance.

· 3. Origin

· Lateral border of scapula

· 4. Insertion

· Inferior facet of greater tubercle

· 5. Innervation

· Axillary nerve (C5–C6)

· 6. Actions – Open Kinetic Chain (OKC)

· External rotation

· Adduction support

· 7. Actions – Closed Kinetic Chain (CKC)

· Posterior stabilization under load

· 8. Associated Ligaments

· Posterior GH capsule

· 9. Associated Organs

Fascial:

· Posterior scapular fascia

Viscerosomatic:

· C5–C6

TCM:

· Small Intestine meridian

VM:

· Posterior cuff fascial tension patterns

Subscapularis

· 1. Neurological & Functional Insights

· Primary internal rotator and anterior stabilizer of GH joint.

· Resists anterior humeral translation in vulnerable positions.

· Contributes heavily to joint compression and centering.

· 2. Clinical Relevance

· Dysfunction contributes to anterior instability.

· Large contributor to internal rotation deficits.

· Commonly overloaded in throwers and swimmers.

· 3. Origin

· Subscapular fossa

· 4. Insertion

· Lesser tubercle of humerus

· 5. Innervation

· Upper & lower subscapular nerves (C5–C7)

· 6. Actions – Open Kinetic Chain (OKC)

· Internal rotation

· Adduction

· Extension in certain angles

· 7. Actions – Closed Kinetic Chain (CKC)

· Anterior joint stability during loading

· 8. Associated Ligaments

· Anterior GH capsule

· Coracohumeral ligament

· 9. Associated Organs

Fascial:

· Anterior shoulder capsule

Viscerosomatic:

· C5–C7

TCM:

· Heart / Pericardium region association

VM:

· Anterior capsule fascial restrictions

Deltoid (Anterior / Middle / Posterior)

· 1. Neurological & Functional Insights

· Primary power muscle for GH elevation.

· Three heads allow multi‑plane movement control.

· Works synergistically with rotator cuff to maintain humeral head centering.

· 2. Clinical Relevance

· Overactivity without cuff balance increases superior humeral migration.

· Important in restoring functional overhead mechanics.

· Posterior fibers crucial for deceleration and posture.

· 3. Origin

· Lateral clavicle

· Acromion

· Spine of scapula

· 4. Insertion

· Deltoid tuberosity

· 5. Innervation

· Axillary nerve (C5–C6)

· 6. Actions – Open Kinetic Chain (OKC)

· Anterior: flexion, IR, horizontal adduction

· Middle: abduction

· Posterior: extension, ER, horizontal abduction

· 7. Actions – Closed Kinetic Chain (CKC)

· Stabilizes humerus against trunk during pushing or pulling

· 8. Associated Ligaments

· Acromioclavicular capsule

· Coracoacromial arch

· 9. Associated Organs

Fascial:

· Deltoid fascia

· Brachial fascia

Viscerosomatic:

· C5–C6

TCM:

· Large Intestine meridian pathway region

VM:

· Shoulder girdle fascial tension affecting deltoid recruitment

Pectoralis Major

· 1. Neurological & Functional Insights

· Powerful adductor and internal rotator contributing to anterior shoulder stability.

· Strong influence on thoracic posture and rib mechanics.

· Provides dynamic control during pushing and horizontal actions.

· 2. Clinical Relevance

· Shortening contributes to rounded shoulders and anterior humeral glide.

· Overactivation common in pushing-dominant athletes.

· Important for restoring scapulohumeral balance.

· 3. Origin

· Clavicular head: medial clavicle

· Sternal head: sternum & costal cartilages 1–6

· 4. Insertion

· Lateral lip of bicipital groove

· 5. Innervation

· Medial & lateral pectoral nerves (C5–T1)

· 6. Actions – Open Kinetic Chain (OKC)

· Adduction

· Horizontal adduction

· Internal rotation

· Flexion (clavicular fibers)

· Extension from flexed position (sternal fibers)

· 7. Actions – Closed Kinetic Chain (CKC)

· Assists rib elevation in forced breathing

· Stabilizes anterior thorax during pushing

· 8. Associated Ligaments

· Anterior GH capsule

· Sternocostal attachments

· 9. Associated Organs

Fascial:

· Pectoral fascia

· Anterior thoracic fascia

Viscerosomatic:

· T1–T4

TCM:

· Heart / Lung meridian region

VM:

· Anterior chest wall tension altering GH mechanics

Latissimus Dorsi

· 1. Neurological & Functional Insights

· Large posterior chain driver integrating spine, pelvis, and arm.

· Contributes to humeral extension, adduction, and internal rotation.

· Key link in cross-body myofascial slings.

· 2. Clinical Relevance

· Tightness restricts overhead elevation.

· Common contributor to anterior pelvic tilt and rib flare.

· Important for high-force pulling and trunk-shoulder coupling.

· 3. Origin

· Spinous processes T7–L5

· Thoracolumbar fascia

· Iliac crest

· Inferior ribs

· 4. Insertion

· Floor of bicipital groove

· 5. Innervation

· Thoracodorsal nerve (C6–C8)

· 6. Actions – Open Kinetic Chain (OKC)

· Extension

· Adduction

· Internal rotation

· 7. Actions – Closed Kinetic Chain (CKC)

· Trunk elevation (crutch gait, transfers)

· Posterior chain stabilization

· 8. Associated Ligaments

· Thoracolumbar fascia connections

· 9. Associated Organs

Fascial:

· Posterior thoracolumbar fascia

Viscerosomatic:

· T6–T9

TCM:

· Bladder meridian region

VM:

· Diaphragmatic and visceral drag altering lat recruitment

Teres Major

· 1. Neurological & Functional Insights

· Acts as ‘lat’s little helper’ in IR, adduction, and extension.

· Important for humeral control in midrange pulling.

· Resists anterior humeral translation.

· 2. Clinical Relevance

· Overactivity seen in IR-dominant patterns.

· Important for strengthening in posterior chain deficits.

· Can restrict overhead ROM when shortened.

· 3. Origin

· Inferior angle of scapula

· 4. Insertion

· Medial lip of bicipital groove

· 5. Innervation

· Lower subscapular nerve (C5–C6)

· 6. Actions – Open Kinetic Chain (OKC)

· Internal rotation

· Adduction

· Extension

· 7. Actions – Closed Kinetic Chain (CKC)

· Posterior humeral stability during pulling

· 8. Associated Ligaments

· Posterior GH capsule

· 9. Associated Organs

Fascial:

· Posterior scapular fascia

Viscerosomatic:

· C5–C6

TCM:

· Small Intestine meridian region

VM:

· Posterior shoulder fascial tension interacting with teres major

Module references

· Standring S, ed. Gray’s Anatomy: The Anatomical Basis of Clinical Practice. Elsevier.

· Neumann DA. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. Elsevier.

· Kendall FP et al. Muscles: Testing and Function with Posture and Pain. Lippincott Williams & Wilkins.

· Netter FH. Atlas of Human Anatomy. Elsevier.

· Barral JP, Mercier P. Visceral Manipulation. Eastland Press (framework-specific associations).

· Deadman P, Al-Khafaji M, Baker K. A Manual of Acupuncture. Journal of Chinese Medicine Publications (traditional channel associations).

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