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Shoulder Muscles Cheat Sheet (DRAFT) by

Shoulder muscles + Conditions

This is a draft cheat sheet. It is a work in progress and is not finished yet.


Anterior Division: Anterior border and superior surface of the lateral third of clavicle
Middle Division: Superior surface of the acromion
Posterior: Lower Edge of the crest of the scapular spine
Insertion: Deltoid Tubercle @ Midshaft of humerus
Nerve: Axillary Nerve (C5-6)
Movement: All fibres vertical abduct the arm, medial rotation and flexion (agonist of pec maj - anterior division), lateral rotation and extension (agnoist of lats + teres major- posterior)
- Antagonist to Lats
- Suspec­table to tears, fatty atrophy + enthes­opathy (acromial = serone­gative spondy)
- Prevents posterior disloc­ation of the humeral head when a person carries heavy loads

Deltoid - Palpation

Trigger points

Trigger points of middle

Trigger Points of Anterior

Trigger Points of Posterior

Rotator Muscles



Origin: Medial 2/3 of the supras­pin­atous Fossa
Insertion: Superior facet of the Greater Tubercle of the Humerus
Nerve Supply: Supras­capular Nerve (C5-C6)
Action: Abducts and stabilises Humeral Head
- Prevents head of the humerus slipping inferiorly
- Tears (high- riding humeral head + acromi­ohu­meral distance <7mm)

Supras­pin­atous - Palpation

Trp of Supras­pin­atous

Belly Trp

Tendon Trp


Origin: Medial 2/3 of the Infras­pin­atous fossa
Insertion: Middle Facet of the Greater Tubercle of the Humerus
Nerve: Supras­capular Nerve C5-C6
Action: Lateral rotation + stabil­isation of the Humerus
- Synergists (working together) are teres minor + deltoid

Infras­pinatus - Palpation

Trps Infras­pin­atous

Belly Trps

Patient complains of a deep shoulder ache - can be mistaken for GH joint problems

Tendon Trp

Teres Minor

Origin: Upper 2/3 of the dorsal surface of the scapula
Insertion: Lower facet of greater Tuberosity of Humerus
Nerve: Axillary Nerve (C5-6)
Action: Lateral rotation, Weak adduction + stabil­isation of the Humerus
- Prevents humeral head from sliding upwards as arm is abducted
- Atrophy of this muscle can be caused by rotator cuff tears

Teres Minor - Palpation

Trp - Teres minor


Teres Major

Origin: Oval Area on the Dorsal Surface of the inferior scapular angle
Insertion:Medial Lip of the intert­ube­rcular sulcus
Nerve: Lower Subsca­pular Nerve (C5-C7)
Action: Extension and medial rotation of the humerus
- Injuries of this muscle are rare - usually in profes­sional and high level athletes (baseball pitchers)
- Assists the Lats in moving a raised humerus downwards and backwards

Teres Major Trp

Teres Major - Palpation

Teres Major Trp

- Hypera­bdu­ction may be restricted


Origin: Medial 2/3 of the Subsca­pular Fossa
Insertion: Lesser Tubercle of the Humurus
Nerve: Upper and Lower Subsca­pular Nerves C5-C6
Action: Medial rotation of the humerus and stabil­isation of the GH Joint
- Prevents displa­cement of the head of the humerus

Subsca­pularis Trps

- Uncomf­ortable and unpleasant feeling in shoulder, hard to localise. Cannot get comfor­table.

Subsca­pularis Trps

Subsca­pularis - Palpation


Shoulder Girdle


Serratus Anterior

Origin: Fleshy digita­tions from the outer surfaces of upper 8-9 ribs - lower 4 external oblique)
Insertion: Costal surface of the inferior angle of the scapula
Nerve: Long thoracic nerve of Bell (C5-C7)
Action: Works with Pec minor to protract the scapula in pushing movemm­ents, upper fibres suspend scapular, lower fibres works with the traps to pull the inferior angle forward (upward rotation)
- Antagonist - Rhomboid Major + Minor, Traps
- Serrare = to saw
- Nerve of Bell suspec­table to certain surgeries (lymph node clearance from the axilla)

SA Trp

SA - Palpation

SA Trp

SA Trp

- Activated by prolon­ged­/vi­gorous running, push-ups , overhead lifting or severe cough


Origin: Lower six tx vertebrae, thorac­olumbar fascia, posterior part of iliac crest, lower 3 or 4 ribs, inferior angle of scapula
Insertion: Floor of intert­ube­rcular groove of the humurus
Nerve: Thorac­odorsal Nerve (C6-C8)
Action: Adduction, Extension and Medial Rotation of the humurus - deep inspir­ation + forced expiration

Lats - Palpation

Lats Trp

Lats Trp

- Infras­capular pain usually not aggravated by movements
- Bra straps can activate Trps
- Associated with SIJ Dysfun­ction, chronic shoulder and back pain, GH problems
- PseudoTOS - (Lats, Teres major, Pecs major, Subsca­pul­aris)
- Used for breast recons­tru­ction + Cardiac surgery (cardi­omy­opl­asty)

Pec Major

Clavicular Anterior surface of medial half of the clavicle
Sternal: Anterior surface of sternum, 6th-7th costal cartilage, 6th rib, aponeu­rosis of external oblique
Insertion: Lateral lip of the unterr­ube­rcular sulcus of the humurus
Clavic­ular: C5-6
Sternal: C6-T1
Action: Adducts and medially rotation of the humerus
- Antagonist = Deltoid
- Pectus = breast
- Trained by: barbell bench press, dumbbell bench press, machine bench
- Injured by powerl­ifting (US and MRI)
- Women less suspec­table to pec injuries (more muscle elasti­city, larger tendon to muscle diameter)
- Affected arm mobilised for 6-8weeks, then 2 months after surgery, rehab is introduced
- Return to sport usually at 6 months

Pec Major - Palpation

Pec Maj Trp

Pec Maj Trp

Rounded shoulders

Pec Minor

Pec Minor

Origin: Upper margins and outer surfaces of 3-5th Ribs, near their cartilages + Fascia of external interc­ostals
Insertion: Coracoid process of the scapula (Upper surface)
Nerve: Medial and Lateral Pectoral Nerve (C5-T1)
Action: Draws scapula forward with Serratus Anterior - Works with LS and Rhomboids to rotate the scapular

Pec Minor - Palpation

Pec Minor Trp

- Mimics Cx radicu­lopathy - tight fibres can press on brachial plexus­/ax­illary artery
- Mimics Cardiac ischaemia


Origin: First rib + costal cartilage
Insertion: Middle third of the clavicle
Nerve: Subclavian Branch of the Brachial Plexus (C5-C6)
Action: Pulls point of shoulder down and forward - protects subclavian vessels when clavicle f#

Subclavius - Palpation

Subclavian Trps

- Mimics C6 radicu­lopathy
- Can cause Vascular TOS - When shortens, draws clavicle towards Subclavian artery + vein

Upper Traps

Origin: EOP, Superior nuchal lines, Supras­pinous ligament, Spinous process C7-T12
Insertion: Lateral third of clavicle (super­ior), Medial acromial margin and superior lip of the crest of the scapular spine (medial), aponeu­rosis, medial end of the scapula spine
Nerve: Spinal part of the accessory nerve, sensory branches from ventral rami C3-C4
Action: Ipsila­teral lateral flexion of the head, Contra­lateral rotation of the head, Bilate­rally extends the head, Bilate­rally shrugs the shoulders
- Antagonist = serratus Anterior, Lats, Pec Major
- Trained by: Elevation of shoulder - hang clean, shoulder shrug
- Traps Palsy - damage of spinal accessory nerve - difficulty with adduction and abduction of the arm , drooping shoulder and shoulder and neck pain
- Traps commonly affected in facios­cap­ulo­humeral muscular dystrophy (FSHD) - upper fibres spared until later

Upper Traps - Palpation

Upper Traps Trp

- Tight bra straps + heavy coats can activate these trps
- Gothic Shoulders (raised shoulders)
- Trps can overlap - SCM, Subocc­ipital, Temporalis

Middle and Lower Traps

Middle: T1-T5 Sps
Lower: T6-T12 Sps
Nerve: Spinal part of the accessory nerve, sensory branches from ventral rami C3-C4
Action: Scapular retraction and stabil­isation
- Trained by pulling shoulder blades together (middle)
- Trained by drawing shoulder blads downwards (Lower)

Mid + Lower traps - Palpation

Left -mid
Right - Lower

Mid + Lower Traps Trp

Mid + Lower Traps Trp

- Trps in the Middle Traps can cause Trps in the Upper
- Middle traps are disinh­ibited when pec major is hypertonic (Antag­oni­stic)

Dysfun­ctional Shoulder

Glenoh­umeral hypomo­bility with inhibition of the lower scapular stabil­isers, stiff thoracic spine and possible fear avoidance behaviour
Manage­ment: Spencer technique with humeral head kinematic release and subsca­pularis kinematic release if required
Facili­tated stretching of hypertonic muscles involved in upper crossed posture / trigger point / kinetic release of overactive muscles +/- streng­thening exercises of inhibited muscles
Brugger microb­reak, thoracic adjust­ment, mobili­sation, wall angel exercise etc for the thoracic stiffness
BQ for assessment of any psycho­social issues plus cognitive behavi­oural therapy, motiva­tional interv­iewing and active listening
Scapular dyskinesis with reduced external rotation of the shoulder
Manage­ment: Scapular dyskinesis managed by facili­tated stretching of hypertonic muscles involved in upper crossed posture/ trigger point / kinetic release of overactive muscles followed by streng­thening exercises of inhibited muscles
Scapul­oth­oracic mobili­sation with active arm movements may improve scapular tracking
Facili­tated stretching of external rotators of the glenoh­umeral joint
Glenoh­umeral hypomo­bility, tight subsca­pularis with trigger point and referral pain from cervical manipu­lable lesions
Manage­ment: Spencer technique with humeral head kinematic release and subsca­pularis kinematic release if required
Trigger point therapy to subsca­pularis
manipu­lable lesions may be treated with adjust­ment, mobili­sation or facili­tated stretching of the cervical spine (PIR)
Core Treatment: Spencer technique
Scapular stabil­sation with movement mobili­sation
Subsca­pularis kinetic release
Humeral head kinetic release