Adduction of the Glenohumeral Joint is traditionally defined as internal rotation of the Humerus in the frontal plane about an anterior-posterior axis (SOURCE-3). In layman’s terms, Adduction is simply returning the arm to the side from a position of GH Joint - Abduction . “True” Adduction occurs strictly in the frontal plane and is limited to the point where the arm meets the body; however, as a composite movement of The Shoulder Girdle , slight GH Joint - Flexion and/or Scapulothoracic Joint - Protraction allows the arm to be Adducted a further 50-75º across the torso (SOURCE-8). When the arm is Adducted from a position of 90º GH Joint - Abduction , this is known asHorizontal Adduction.
together these bones form the following relevant joints:
Prime movers
Pectoralis Major (also Horizontal Adduction)
Anterior Deltoid (Horizontal Adduction only)
Accessory Muscles - a main responsibility of these is to counter the strong GH Joint - Internal Rotation bias of the Pectoralis Major and Latissimus Dorsi
Stabilisers
Axillary Nerve (Hoirzontal Adduction only)
As the Humerus Adducts towards the body, the arthokinematics of GH Joint - Abduction are reversed. The convex Humeral Head rolls inferiorly while sliding superiorly in close proximity to the Glenoid Fossa’s vertical diameter about an anterior-to-posterior axis (SOURCE-3). These arthrokinematics maximise joint congruency despite the considerable size disparity between the Glenoid Fossa and much larger Humeral Head. In anatomical position full Adduction brings the arm to the side of the body; however, with slight GH Joint - Flexion the arm may be adducted a further 50-75º across the torso (SOURCE-8).
Unopposed Adduction is heavily aided by the force of gravity, whereras against resistance Adduction is a considerably more active process. The notable pull of some of The Shoulder Girdles larger Muscles such as the Latissimus Dorsi and Pectoralis Major makes Adduction the strongest movement available to the Glenohumeral Joint (SOURCE-3+8). The Teres Major , Long Head of Triceps , Posterior Deltoid , Infraspinatus and Teres Minor all make contributions to this movement (SOURCE-3). The precise contribution of these muscles may be contingent on arm position as the Adduction torque Latissimus Dorsi is greatest from low degrees of arm elevation (SOURCE-9+10). Despite the Pectoralis Major and Subscapularis both having anterior insertions on the Humerus and sharing a GH Joint - Internal Rotation bias, the closer proximity of the Subscapularis to the joint allows it to stabilise against the notable anterior displancement of the Pectoralis Major (SOURCE-9).
For the most part, these Adduction muscles share an inferior bias on the Humeral head which significantly increases the subacromial space (SOURCE-10). This increase is exacerbated by the absence of superior shear forces usually created by the contracting Deltoid . This absence may also serve as an explanation for the notably low activity of the Rotator Cuff during this movement (SOURCE-10). Conversely, the Rhomboids play a major Scapula stabilisation role during Adduction and against resistance help facilitate Scapulothoracic Joint - Downward Rotation and Scapulothoracic Joint - Retraction (SOURCE-3+10).
Adduction still occurs across the torso but at shoulder height, usually from a position of 90º GH Joint - Abduction . During this movement the convex Head of the Humerus glides posteriorly on the fixed concavity of the Glenoid Fossa (SOURCE-4). Unlike normal Adduction where the entire Pectoralis Major is active against resistance, only the Clavicular Head is active during resisted Horizontal Adduction (SOURCE-9). This motion is aided by the Anterior Deltoid and Coracobrachialis (SOURCE-9). From 90º of GH Joint - Abduction , roughly 135º of Horizontal Abduction should be avaliable with end-range pulling taut the Posterior Glenohumeral Joint Capsule and having a firm/soft end-feel (SOURCE-4+8+9).
The fact that Adduction increases the subacromial space means it is less likely to share the same impingement fate as other Glenohumeral Joint motions. Further, the lack of Rotator Cuff activity during Adduction suggests the movement is less likely to provoke Rotator Cuff Pathology and vise versa. Like most shoulder motions, it may be subject to Adhesive Capsulitis . Adduction against resistance often reveals Scapular Dyskinesis (SOURCE-8). Similarly with Posterior Glenohumeral Instability , Horizontal Adduction apprehension may be assocaited with excessive movement at the Scapulothoracic Joint (SOURCE-8). Counterintuitively, posteroinferior Glenohumeral Joint Capsule restriction causes a anterosuperior migration of the Head of Humerus and corresponding decrease in Horizontal Adduction range (SOURCE-8). Restricted Horizontal Adduction is associated with forward positioning of the Scapula (ie excess Scapulothoracic Joint - Protraction and anterior Scapular Tilting ) (SOURCE-1). Other soft-tissues that are pulled taut nearing end-range Adduction or Horizontal Adduction are (SOURCE-1):
Posteior Deltoid
Although Posterior Glenohumeral Dislocations are considerably less common, they often involve a traumatic combination of GH Joint - Internal Rotation and Adduction (SOURCE-9).
Adduction of the Glenohumeral Joint may be limited by Pain , mechanical block or protective apprehension caused by several pathologies that affect The Shoulder Girdle . Additionally Adduction may represent a position of vulnerability for traumatic injury or the source of repetitive compressive forces which predisposes multiple acute and chronic injuries.
Acromioclavicular Joint Pathology - a reproduction of Pain or other symptoms at the joint from Horizontal Adduction with overpressure is indicative of pathology. This motion compresses the joints articulating surfaces which may provoke Pain in pathologies such as Osteoarthritis , Distal Clavicle Osteolysis or a ligament Sprain .
Adhesive Capsulitis - from the freezing stage and beyond Adduction may become restricted in response to Contracture formation within the Glenohumeral Joint Capsule and progressive loss of the Axillary Pouch (SOURCE11+12). The loss of Adduction represents global capsular restriction.
Direct shoulder impact with the arm Adducted is a common mechanism of injury in contact sports where unabaited force compresses The Shoulder Girdle and drives the arm into further Adduction (SOURCE-13). This forms the avenue for injuries more closely related to this mechanism such as Acromioclavicular Joint Dislocations and Scapula Fractures as well as other more general injuries like Glenohumeral Dislocation and Glenoid Labrum Tears (SOURCE-13).
Scapular Dyskinesis - although Scapulothoracic Joint - Downward Rotation and Scapulothoracic Joint - Retraction are required to lower the arm to the side of the torso, this is rarely a limiting factor (SOURCE-3+10). Dyskinesis is often a compensatory response to insufficiency from the Glenohumeral Joint and can affect the quality of motion and stressors bestowed upon the associated soft-tissues. Conversely, the same soft-tissue related issues that may compromise Adduction may lead to dyskinetic patterns. Restriction in the Posterior Glenohumeral Joint Capsule often results in excessive Scapulothoracic Joint - Protraction and Anterior Scapular Tilting , while laxity results in excessive Scapulothoracic Joint - Downward Rotation (SOURCE-1+14+15).
Muscle Strain - compromise of the primary Adductors such as the Latissimus Dorsi or Pectoralis Major may cause Pain or weakness during Adduction, particularly when resisted.
Adduction is debatably the least revealing motion from observation as the body at rest should achieve full range of motion. Observation should evaluate related structures which may impair the quality or symmetry of movement, including Scapular Dyskinesis or Thoracic Spine Kyphosis . Where Pain is present, location and the specifics of the noxious movement (position, against resistance, in combination with other movements, etc.) may also be revealing. Observation should also extend to the Adduction muscles for signs of atrophy both at rest and throughout the Range of Motion assessment.Horizontal Adduction may be compensated for with ipsilateral Thoracic - Rotation or Scapulothoracic Joint - Protraction and Pain or apprehension of movement suggests Acromioclavicular Joint pathology.
Adduction of the Glenohumeral Joint forms a part of the Shoulder - Active Range of Motion and Shoulder - Passive Range of Motion assessment. “True” Adduction which is restricted to the frontal plane is limited to arm-to-torso contact; however, as a composite movement of The Shoulder Girdle (with slight GH Joint - Flexion ) the arm can be Adducted across the torso a further 50-75º (SOURCE-8). Starting from a position of 90º GH Joint - Abduction , Horizontal Adduction can also be evaluated with roughly 135º of motion typically available (SOURCE-4+8). Nearing end-range this motion pulls taut the Posterior Glenohumeral Joint Capsule and approximates the Acromioclavicular Joint surfaces which may reveal restriction and/or Pain . It is for these reasons overpressure is often added to end-range, as done with the Cross Body Adduction Stress Test . The end-feel of both Adduction and Horizontal Adduction is described as firm/soft as it approximates soft-tissue (SOURCE-8). If passive (horizontal) Adduction is greater than (horizontal) Adduction the patient can peform actively, neuromusculature inhibition or weakness is implicated.As with most movements of the shoulder, observation should be given to the Scapula for any compensatory patterns that reflect a lack of mobility at the Glenohumeral Joint and comparisons should be made to the asymptomatic side. In terms of Isometric Tests , resisted Adduction often reveals signs of Scapular Dyskinesis on top of muscular insufficiency from the Adductors (SOURCE-8).
The following Shoulder - Special Tests may be relevant in the assessment of dysfunctional (horizontal) Adduction:General
Apley’s Back Scratch - incorporates Extension into movement of bottom arm
Acromioclavicular Joint Pathology
Cross Body Adduction Stress Test - provokes degenerative or traumatic damage
Rotator Cuff Pathology
Lift-Off Test - assesses Subscapularis
Belly Press Test - assesses Subscapularis
Load & Shift Test - evalautes the direction and degree of instability
Jerk Test - evaluates integrity of posteroinferior Glenoid Labrum and therefore posteroinferior instability
Kim Test - evaluates integrity of posteroinferior Glenoid Labrum and therefore posteroinferior instability
Spurling’s Test - evaluates potential Radiculopathy from the Cervical Spine
The following tests may be conducted to rule in/out nerve contribution with C6 , C7 , C8 and T1 Nerve Roots most relevant to Adduction: Cervical - Myotomes (active resisted)
Cervical - Dermatomes - evaluates sensory region
Together the Nerve Roots of C6 - T1 sequentially innervate the majority of the upper limb and hand
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 Adduction 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-5).
Radiography (X-Ray)- evaluates Bone pathology which could mechanically block Adduction. 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-6+7). MRIs are also the preferred technique for evaluating soft tissues such as the Rotator Cuff , Subacromial Bursa and associated morphologies (SOURCE-7). 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-7). For Subacromial Impingement the following view are recommended (SOURCE-7):
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 Adduction 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 (horizontal) Adduction restriction:
Genie Stretch - rudimentary horizontal adduction stretch
Sleeper Stretch - greater emphasis on GH Joint - Internal Rotation
Bent Over Lat Stretch - accessible active stretch with large GH Joint - Flexion or Horizontal GH Joint - Adduction range
Door Frame Shoulder Stretch - self-guided anterior shoulder stretch with large Horizontal GH Joint - Abduction range
Seated Thoracic Rotation with Breathing - large lateral flexion and rotation range coupled with breathing
Shoulder Dislocates - mobility exercise that emphasises the greatest circumduction range possible
As a specific training protocol relates to the underlying cause of Adduction dysfunction, the following lists (horizontal) Adduction-based Strength exercises in rough descending order from most rudimentary:
Active or Active Assisted Horizontal Adduction -
Isometric Chest Squeezes - isometric exercise that isolates Chest
Banded Horizontal Adduction - low load isotonic horizontal adduction exercise
Chest Press Machine - rudimentary horizontal push machine
Pallof Press - low load horizontal push exercise that emphasises anti-rotation of Core
Bench Press - isotonic horizontal push exercise with capacity for high loads
Incline DB Bench Press - unilaterally loaded Bench variation on variable incline
Chest Fly - large horizontal abduction range to emphasise lengthening of the Chest
Half DB Bench Press - unilateral isotonic horizontal pressing motion that emphasises the Anterior Sling
Medicine Ball Chest Press - plyometric horizontal pressing motion, often sports relevant
The following Mobilisation techniques may be relevant in the treatment of Adduction: Joint Play
Anterior Glide on Humerus - Hand Behind Back variation
Scapulothoracic Rotation Glide - during Adduction the Inferior Angle of Scapula medially rotates (SOURCE-4)
Sternoclavicular Joint - during Adduction the medial end of the Clavicle superiorly glides (SOURCE-4)
Acromioclavicular Posterior Glide - advocated by Maitland for the treatment of restriction and/ or Pain associated with Horizontal Adduction or Hand Behind Back (SOURCE-2)
Acromioclavicular Anterior Glide - advocated by Maitland to improve Horizontal Flexion or Extension (SOURCE-2)
Acromioclavicular Inferior Glide - advocated by Maitland for restriction at end-range Horizontal Adduction (SOURCE-2)
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 Adduction is affected, mobilisations may benefit from the addition of movement:
Shoulder - MWM Techniques - Adduction is a key component of many techniques, however, some may be more relevant than others. The following lists those movements that involve Adduction and other movements they’re paired with:
AC Joint - MWM 1 - GH Horizontal Adduction
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
Laudner, K. G., Moline, M. T., & Meister, K. (2010). The relationship between forward scapular posture and posterior shoulder tightness among baseball players. The American journal of sports medicine, 38(10), 2106–2112. https://doi.org/10.1177/0363546510370291
Hengeveld, E., & Banks, K. (Eds.). (2005). Maitland’s peripheral manipulation (4th ed.). Elsevier Butterworth-Heinemann.
Neumann, D. A. (2002). Kinesiology of the musculoskeletal system: Foundations for physical rehabilitation (1st ed.). Mosby.
Clarkson, H. M. (2013). Musculoskeletal assessment: Joint motion and muscle testing (3rd ed.). Wolters Kluwer/Lippincott Williams & Wilkins.
Kim, H., Kim, B., Shim, J., Kwon, H., & Jung, J. (2014). Comparative analysis of acromiohumeral distances according to the locations of the arms and humeral rotation. Journal of physical therapy science, 26(1), 97–100. https://doi.org/10.1589/jpts.26.97
Ludewig, P. M., & Reynolds, J. F. (2009). The association of scapular kinematics and glenohumeral joint pathologies. Journal of Orthopaedic & Sports Physical Therapy, 39(2), 90–104. https://doi.org/10.2519/jospt.2009.2808
Jäschke, M., Köhler, H. C., Weber, M. A., Tischer, T., Hacke, C., & Schulze, C. (2023). Subacromial impingement syndrome: association of multiple magnetic resonance imaging parameters with shoulder function and pain. Archives of orthopaedic and trauma surgery, 143(1), 237–246. https://doi.org/10.1007/s00402-021-04032-6
Magee, D. J. (2014). Orthopedic physical assessment (6th ed.). Saunders.
Standring, S. (Ed.). (2016). Gray’s anatomy: The anatomical basis of clinical practice (41st ed.). Elsevier.
Reed, D., Halaki, M., & Ginn, K. (2010). The rotator cuff muscles are activated at low levels during shoulder adduction: An experimental study. Journal of Physiotherapy, 56(4), 259–264. https://doi.org/10.1016/S1836-9553(10)70009-6
Neviaser, A. S., & Hannafin, J. A. (2010). Adhesive capsulitis: a review of current treatment. The American journal of sports medicine, 38(11), 2346–2356. https://doi.org/10.1177/0363546509348048
Nakandala P, Nanayakkara I, Wadugodapitiya S, Gawarammana I. The efficacy of physiotherapy interventions in the treatment of adhesive capsulitis: A systematic review. Journal of Back and Musculoskeletal Rehabilitation. 2021;34(2):195-205. doi:10.3233/BMR-200186
Crichton, J., Jones, D. R., & Funk, L. (2012). Mechanisms of traumatic shoulder injury in elite rugby players. British journal of sports medicine, 46(7), 538–542. https://doi.org/10.1136/bjsports-2011-090688
Paine, R., & Voight, M. L. (2013). The role of the scapula. International journal of sports physical therapy, 8(5), 617–629.
Farr, S. (Ed.). (2022). Congenital and acquired deformities of the pediatric shoulder girdle. Springer.
Jung, S.-h., Hwang, U.-j., Kim, J.-H., Gwak, G.-T., & Kwon, O.-y. (2022). Effect of improved thoracic kyphosis on forward shoulder posture after mobilization in individuals with thoracic hyperkyphosis. Clinical Biomechanics, 97, 105707. https://doi.org/10.1016/j.clinbiomech.2022.105707