External Rotation, also know aslateral rotation, of the Glenohumeral Joint is defined as axial rotation of the Humerus around its longitudinal axis (SOURCE-7). In layman’s terms this describes turning the upper arm away (or behind) the body, depending on the arms position. About 60-70º of External Rotation should be available to the Glenohumeral Joint, which increases to 90º when the arm is in 90º GH Joint - Abduction (SOURCE-7+10). As with all movements of The Shoulder Girdle , External Rotation is accompanied by accessory movements at the Scapulothoracic Joint and the Sternoclavicular Joint .
together these bones form the:
Deltoid (posterior fibres)
Connective Tissue Glenohumeral Joint Capsule
Ventral Arm Chain - restriction
Dorsal Arm Chain - painful
Deep Back Arm Line - restriction
Superficial Front Line - restriction
Deep Back Arm Line - painful
During External Rotation of the Glenohumeral Joint , the convex Head of Humerus rolls posteriorly and glides anteriorly on the fixed Glenoid Cavity about the long axis of the Humerus (SOURCE-7+10). These arthrokinematics maximise joint congruency despite the considerable size disparity between the Glenoid Fossa and much larger Humeral Head. In anatomical position (with arm by side) 60-70º of External Rotation should be available to the Glenohumeral Joint (SOURCE-7). Conversely, with the arm in 90º GH Joint - Abduction , External Rotation range may should increase to ~90º (SOURCE-7+10). Maximal External Rotation typically encorporates some Scapulothoracic Joint - Retraction (SOURCE-7).
This movement is facilitated by Infraspinatus , Posterior Deltoid and Teres Minor (SOURCE-9+15). When elevated in the Scapula plane, the up to 80% of the total External Rotation Torque is produced by the Posterior Deltoid (SOURCE-9). Collectively the Rotator Cuff displays “pre-setting” activity to stabilise the Glenohumeral Joint in anticipation of movement, with Infraspinatus and Supraspinatus most active, followed by Biceps Brachii and nominal contributions from the eccentrically loaded Subscapularis (SOURCE-4). The Anterior Glenohumeral Joint Capsule generates passive tension while the contraction of the Infraspinatus pulls tight the posterior capsule and guides the movement (SOURCE-7).
External Rotation forms an integral component of the later stages of arm elevation ( GH Joint - Abduction or GH Joint - Flexion ). External Rotation of the elevating Humerus allows the Greater Trochanter to clear from under the Coracoacromial Arch, preventing Subacromial Impingement (SOURCE-9).
While Humeral Retroversion may lead to thickening of the Posterior Glenohumeral Joint Capsule and predispose injury to the Rotator Cuff , the adaptive increase in External Rotation is thought to be of benefit to overhead throwing athletes as it increases ball Velocity (SOURCE-5).
Glenohumeral Joint External Rotation is often described as the Humerus rotating about a fixed Scapula , however, it can also occur with a fixed Humerus about a rotating Scapula . This Scapula-on-Humerus Rotation occurs as the concave Glenoid Fossarolls and slidesin same direction (SOURCE-7)
Most often a loss of External Rotation is attributed to a restricted Pectoralis Major or Latissimus Dorsi , while a pattern of excessive Scapulothoracic Joint - Retraction during External Rotation could indicate tightness in the Anterior Glenohumeral Joint Capsule , GH Joint - Internal Rotation muscles and/ or poor Scapulothoracic Joint muscle control (SOURCE-11). The following soft-tissues are pulled taut as External Rotation nears end-range (SOURCE-10):
Anterior Glenohumeral Joint Capsule - restriction of this tissue then results in excessive posterior translation of Humerus during External Rotation (SOURCE-15)
During Scaption, increased External Rotation of the Humerus reduces the extent of Anterior Scapular Tilting and Scapular Winging (SOURCE-8). A loss of External Rotation, therefore, could exacerbate these symptoms and increase the likelihood of conditions such as Subacromial Impingement (SOURCE-8). A chronic loss of External Rotation is pathomechanical as it prevents the Head of Humerus from adequately clearing the Coraco-Acromial arch during arm elevation, thereby predisposing the underlying tissues to Subacromial Impingement (SOURCE-9).
External Rotation is often subject to excessive demand through repetitive strain or high-force trauma, with either predisposing injury to the Glenohumeral Joint . While there are many External Rotation-related tasks that may be compromising, overhead throwing is notorious as it demands maximal External Rotation and eccentrically loaded External Rotation ( GH Joint - Internal Rotation ) through a full range at a high velocity. Heightened External Rotation demand often evokes physiological adaptations with morbid associations:
Humeral Retroversion - from a structural perspective, Humeral Retroversion may be an adaptive response to an increased demand of External Rotation and consequent thickening of the Posterior Glenohumeral Joint Capsule (SOURCE-5). A greater degree of Humeral Retroversion is associated with an increase in available External Rotation range (SOURCE-5+6)
Global Range Shift - as displayed inGlenohumeral Internal Rotation Deficit (GIRD), through increased demand there may be an adaptive soft-tissue response (typically the posteroinferior Glenohumeral Joint Capsule ) that shifts the arc of shoulder rotation to favour greater External Rotation at the expense of GH Joint - Internal Rotation (SOURCE-14). While this may be a physiological response, it may also be the source of subsequent pathology
Through these mechanisms or other means of developing Posterior Glenohumeral Joint Capsule restriction, maximal External Rotation may lead toInternal Impingementof the Shoulder and the associated cascade of Rotator Cuff pathology ( Tears or Tendinopathy ) or Glenoid Labrum Tear s, in particular SLAP Lesions .In terms of trauma, forced External Rotation from a combined position of GH Joint - Abduction , External Rotation and GH Joint - Extension leaves the shoulder particularly vulnerable to Anterior Glenohumeral Dislocation (SOURCE-9). Traumatic injury that features External Rotation may compromise many of the same capsulolabroligamentous structures as repetitive strain; however, given the notably greater force behind injury, it is likely to incur osseous damage such as Fractures or Avulsion Fractures . These injuries include Hill-Sachs Lesion s, Bony Bankart Lesions or fractures of the Head of Humerus or Glenoid Cavity of Scapula . Additionally, given the forceful mechanism of soft-tissue compromise, Internal Impingement is not the only means by which the capsulolabroligamentous structures may be harmed. Excessive stretch of the Anteroinferior Glenohumeral Capsular Ligaments and Glenohumeral Joint Capsule during Glenohumeral Dislocation results in severe ligamentous rupture as seen in Bankart Lesions or Humeral Avulsion of the Glenohumeral Ligaments .
Insufficient External Rotation may be compensated for with Scapulothoracic Joint - Depression , GH Joint - Adduction , Thoracic - Rotation and Elbow - Extension (in 90º GH Joint - Abduction ) (SOURCE-15).
External Rotation of the Glenohumeral Joint may be limited by Pain , mechanical block or protective apprehension caused by several pathologies that affect The Shoulder Girdle . Additionally External Rotation may represent a position of vulnerability for traumatic injury or the source of repetitive compressive forces which predisposes multiple acute and chronic injuries.
Adhesive Capsulitis - restricted passive and active External Rotation is an early symptom that is both highly sensitive and specific, particularly when strength of the Rotator Cuff is unaffected (SOURCE-1+2)
Rotator Cuff Pathology - as the Infraspinatus and Teres Minor account for two of the three External Rotation muscles, Rotator Cuff pathlogy should be suspected when passive range exceeds active range (SOURCE-2). Forming a bidirectional relationship, in the presence of a restricted Posterior Glenohumeral Joint Capsule External Rotation may cause internal impingement (as discussed inInjury) which threatens soft-tissues such as the Infraspinatus . External Rotation dysfunction and Rotator Cuff pathology often share a mechanism of injury such as overhead throwing.
Subacromial Impingement - failure of the Humerus to adequately Externally Rotate during arm elevation results in the Greater Tuberosity encroaching on the undersurface of the Coracoacromial Arch and impinging the intersecting soft-tissue ( Supraspinatus Tendon , Subacromial Bursa , Long Head of Biceps ). This may be provoked by active resisted External Rotation which may be Pain ful or weak. An additional positive finding on the Empty Can and Painful Arc is highly indicative of impingement (SOURCE-3).
Anterior Glenohumeral Instability - External Rotation, particularly when in 90º GH Joint - Abduction , is a point of particular vulnerability as there is less static resistance to anterior translation of the Head of Humerus . This may lead to recurrence and/or associated pathology such as Glenohumeral Dislocation or Glenoid Labrum Tear .
The following observable signs may be related to External Rotation of the Glenohumeral Joint :
Resting Arm Position - the relative tone of the shoulders rotators can be suggested by the resting position of the Cubital Fossa, The Hand and Thumb , where they should be neutrally rotated. If they are more laterally facing, this suggests an increased tone in the External Rotators
Muscle Atrophy - of the Infraspinatus , Teres Minor or Posterior Deltoid
Abrasion Sign- crepitis throughout rotation from a position of 90º GH Joint - Abduction indicates abrasion of a torn Tendon margins against the Coracoaromial Arch (SOURCE-15)
Scapular Dyskinesis - a loss of External Rotation of the Humerus may lead to an increase in Anterior Scapular Tilting and Scapular Winging (SOURCE-8)
External Rotation of the Glenohumeral Joint represents a major component of the Shoulder - Active Range of Motion and Shoulder - Passive Range of Motion assessment. Typically 60-70º of External Rotation is available with the arm by the side, while 90º of External Rotation is typical when the arm is in 90º GH Joint - Abduction (SOURCE-7+10). This number may be greater in certain athletic populations such as throwers (SOURCE-15). Maximal External Rotation is often accompanied by Scapulothoracic Joint - Retraction , which also forms a common avenue for compensation (SOURCE-7+15). To mitigate compensation during Range of Motion assessment, the patient should be positioned supine or side-lying (SOURCE-15). External Rotation is often assessed in 90º GH Joint - Abduction as it better isolates movement to the Rotator Cuff and is typically more revealing/ provocative (SOURCE-10). Caution should be given to overpressure as this position is particularly vulnerable to Anterior Glenohumeral Dislocation (SOURCE-15). A gain in External Rotation usually corresponds with a decrease in GH Joint - Internal Rotation (SOURCE-15). This emphasises the imporance of comparison to the asymptomatic side asGlenohumeral Internal Rotation Deficit (GIRD)is prevalent among certain populations and may predispose several shoulder pathologies. A GIRD ≥20º difference between sides or a ≥5º difference in theTotal Arc of Motionis generally considered pathological (SOURCE-15).If passive External Rotation is greater than External Rotation the patient can peform actively, neuromusculature inhibition or weakness is implicated.
The following Shoulder - Special Tests may be relevant in the assessment of dysfunctional External Rotation: Glenohumeral Instability
Rotator Cuff Integrity
Internal/Posterior Impingement
Spurling’s Test - evaluates potential Radiculopathy from the Cervical Spine
The following tests may be conducted to rule in/out nerve contribution with C5 and C6 Nerve Roots most relevant to External Rotation: Cervical - Myotomes (active resisted)
GH Joint - Abduction - C5 / C6
Elbow - Flexion - C5 / C6
Cervical - Dermatomes - evaluates sensory region
Together the C5 and C6 Nerve Roots innervate the lateral neck, shoulder, arm and hand to include the Thumb and Index Fingers
Reflex - diminished reflex indicates potential lesion at corresponding Nerve Root
Upper Limb Nerve Tension Tests
The following imaging modalities may be relevant for the evaluation of External Rotation dysfunction:
Ultrasonography (Ultrasound)- a highly accessible imaging modaility with real-time capabilities for the evaluation of soft-tissues including the Subacromial Bursa , Rotator Cuff and their Tendons . A major limitation of this modaility is that it is highly operator dependent. Compared to other imaging modailities, Ultrasounds are less expensive/more practical in the evaluation ofAcromiohumeral Distance, a metric that determines the Subacromial Space (SOURCE-11).
Radiography (X-Ray)- evaluates Bone pathology which could mechanically block External Rotation. In addition to visualisation of traumatic injuries such as Fractures to the Head of Humerus or Acromion of Scapula , X-Rays may reveal degenerative osseous changes such as Osteoarthritis , Sclerosis , Osteophytes (bone spurs) and joint space narrowing (Glenohumeral Joint or resting Acromiohumeral Distance).
Magnetic Resonance Imaging MRI- can be used to directly measure the acromiohumeral space with a reduction anticipated in impingement or measure associated metrics such as the width of the Subdeltoid Bursa which indicates impingement through the presence of Bursitis (SOURCE-12+13). MRIs are also the preferred technique for evaluating soft tissues such as the Rotator Cuff , Subacromial Bursa and associated morphologies (SOURCE-13). A “Halo-sign” around Long Head of Biceps Tendon may suggest severity as it represents Glenohumeral Joint effusion and synovial thickening may be visualised in chronic cases (SOURCE-13). For Subacromial Impingement the following view are recommended (SOURCE-13):
Proton-density and T1-weighted images in coronal plane
T2-weighed images in sagittal plane - high signal fluid within Bursa is a direct sign of Inflammation
MR-arthrography with contrast injection - capable of revealing more subtle findings like lesions of the Cartilage or Glenoid Labrum
The treatment of External Rotation dysfunction should be specific to the underlying cause. For rehabilitation of common underlying conditions such as Acromioclavicular Joint pathology, Scapular Dyskinesis or Adhesive Capsulitis , see their respective pages.
The following Stretching techniques may directly or indirectly improve External Rotation restriction:
Shoulder External Rotation Stretch - rudimentary active stretch with large GH Joint - External Rotation range and several variations
Door Frame Shoulder Stretch - Pectoralis Major variation
Dowel External Rotation Stretch - self-guided GH Joint - External Rotation stretch with overpressure
Seated Thoracic Rotation with Breathing - large lateral flexion and rotation range coupled with breathing
Bent Over Lat Stretch - accessible active stretch with large GH Joint - Flexion or Horizontal GH Joint - Adduction range
Split Stance Biceps Stretch - self-guided anterior shoulder stretch with large GH Joint - Extension range
Banded Capsule Rolls - split stance biceps variation that emphasises shoulder rotation
Shoulder Dislocates - mobility exercise that emphasises the greatest circumduction range possible
Bretzel 1.0 - wholebody technical stretch that incorporates anterior shoulder
Bretzel 2.0 - variation with greater hip extension range
Wheel Pose - full bridge variation that lengthens entire anterior chain
As a specific training protocol relates to the underlying cause of External Rotation dysfunction, the following lists External Rotation-based Strength exercises in rough descending order from most rudimentary:
Rotator Cuff Pendulums - oscillatory motion that afford a distracting glide to the Humeral Head
Rotator Cuff Banded Rotations - light low range isotonic rotation exercises
Prone Shoulder External Rotations - adds gravity or light load to Apprehension Test position
Side-Lying Shoulder External Rotations - maximises effect of gravity against External Rotation with upper arm fixed against torso
Standing Shoulder External Rotations - incorporates upright torso posture
Bottoms-Up Kettlebell Walk - isometric push/ stability exercise with or without perturbation
Lat Pulldown - rudimentary weighted isotonic vertical pull movement with a high range of motion which requires External Rotation
Overhead Press - isotonic vertical push exercise with large overhead range which requires External Rotation
DB Shoulder Press - unilaterally loaded overhead press variation
Face Pulls - bilateral isotonic horizontal pull exercise that emphasises GH Joint - External Rotation
Straight Arm Lat Pulldown - isotonic motion that emphasises Lats and straight arm strength and requires External Rotation
Push Press - wholebody, explosive variation of the Overhead Press
DB Hang Clean - unilateral clean progression, often performed explosively
Pull-Up - bodyweight or greater load through large overhead motion
Kneeling Landmine Press - wholebody, explosive vertical pressing exercise with large overhead range
Split Stance Landmine Press - crossbody, standing variation of the Kneeling Landmine Press
DB Snatch - unilateral isotonic, explosive shoulder exercise with large overhead range
Rope Climb - pull-up variation with entire load bestowed on alternating arm
DB Snatch to Step-Up - wholebody DB Snatch variation that emphasises diagonal functional patterns
The following Mobilisation techniques may be relevant in the treatment of External Rotation: Joint Play
Anterior Glide on Humerus - stretches Anterior Glenohumeral Joint Capsule which may restrict movement
Posterior Glide on Humerus - to normalise GIRD if present
Lateral Distraction on Humerus - at either 0º or 90º Flexion, with the latter particularly relevant for Adhesive Capsulitis (SOURCE-1)
Scapulothoracic Joint - Retraction - required for maximal External Rotation
Sternoclavicular Posterior Glide - required for maximal Scapula Retraction
Cervical Spine - for instances of Radiculopathy a PACVP , PAUVP or TVP may be applied to relevant Cervical segment(s) in addition to the following techniques:
Thoracic Spine - mobilisations of the upper segments may improve symptoms of shoulder dysfunction, where a rounded shoulder posture is present (SOURCE-16):
Mobilisation with Movement - as External Rotation is affected, mobilisations may benefit from the addition of movement:
Shoulder - MWM Techniques - External Rotation is a key component of many techniques, however, some may be more relevant than others. The following lists those movements that involve External Rotation and other movements they’re paired with:
Shoulder - MWM 3 - given healthy GH Joint - Abduction kinematics require External Rotation, this technique may be beneficial
Shoulder - MWM 4 - (mid-range) GH Abduction, Flexion or Scaption
Shoulder - MWM 5 - (end-range) GH Flexion, Abduction or Scaption
Shoulder - MWM 8 - External Rotation
Sleeper Stretch MWM - to normalise GIRD if present
Cervical Spine - in addition to NAGS or SNAGS applied to a relevant Cervical segment, the following techniques may be indicated with suspected Radiculopathy :
Thoracic Spine - mobilisations of the upper segments may improve symptoms of shoulder dysfunction, where a rounded shoulder posture is present (SOURCE-16)
Reverse NAGS - particularly useful for pain or restriction associated with movement of the Upper Thoracic region
Dry Needling the following muscles may be relevant in the treatment of restricted External Rotation, with techniques detailed on their respective pages:
GH Joint - Internal Rotation Muscles (if restricted)
External Rotation Muscles (if weak/ inhibited and contain “trigger points”)
Posterior Deltoid
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