Scapular DyskinesisMSc Physiotherapy Student PlacementMusculoskeletal Out-PatientsBy Tony Tompos

ContentsIntroduction to Scapular DyskinesisMuscular attachments of the scapulaTypes of Scapular DyskinesisDynamic scapular stabilityScapular Dyskinesis and shoulder

injuryScapular Assessment and Corrective

manoeuvres Treatment

Scapular DyskinesisScapular dyskinesis has been identified as (1)‘abnormal static scapular position and/or dynamic scapular motion characterised by medial border prominence or(2) ‘inferior angle prominence and/or early scapular elevation or shrugging on arm elevation’ and/or(3) ‘rapid downward rotation during arm lowering’ (Kibler & Sciascia, 2010 p.300)

Scapular Dyskinesis

However due to the difference in dynamic scapular motion and static position of the scapula; when describing the static position of the scapula, if an asymmetry is observed, then this should be referred to as ‘altered scapular resting position’ rather than scapular dyskinesis (Kibler & Sciascia, 2010 p.301)

Scapular DyskinesisScapular Dyskenis is a non-specific response to a painful shoulder condition, rather than a specific response to certain glenohumeral pathology.It has multiple causative factors including Nerve injury, Muscle weakness/imbalance, AC joint injury, superior labral tears and rotator cuff injury.Dyskenisis can alter the roles of the scapula during scapulo-humeral rhythm and may be due to alterations in bony stabilisers, muscle activation patterns or lack of strength in the dynamic muscle stabilisers. (Kibler, 1998, p.325).

Muscular attachments of the Scapula

Muscles Attaching to Scapula involved in Scapulothoracic Rhythm

Rhomboid Minor Rhomboid Major Levator Scapulae Pectoralis Minor Trapezius Serratus Anterior

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Muscular attachments of the Scapula

Muscles Attaching to Scapula involved in ScapuloHumeral Rhythm

Subscapularis Supraspinatus Infraspinatus Teres Minor Teres Major Deltoid

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Types of Scapular Dyskinesis

Type 1 - Infero-medial scapula border prominence.This becomes more evident in the cocking position of overhead sports.  It is often associated with tightness anteriorly (inflexibility of the pectoralis major/ minor muscles) with weakness of the lower trapezius and serratus anterior muscles.  This is often noticed in the early stages of shoulder disorders (Funk, 2013).

Sevinsky, 2013

Types of Scapular Dyskinesis

Type 2 - Medial border prominence This pattern displays winging of the entire medial border of the scapula at rest.  It becomes more prominent in the cocking position and after repetitive elevation of the upper extremity.  It is caused by fatigue of the scapula stabilising muscles (trapezius and rhomboids) (Funk, 2013).

Sevinsky, 2013

Types of Scapular Dyskinesis

Type 3 - Supero-medial border prominenceThis type of dyskinesis is displayed as a prominence of the superior- medial border of the scapula and is often associated with impingement and rotator cuff injury (Funk, 2013).

Sevinsky, 2013

Dynamic Scapular Stability

Stabilisation of the scapula and motion on the thorax is provided by the coupling of the upper and lower Trapezius with the Serratus anterior and Rhomboid muscles. Scapular elevation during arm elevation is accomplished through coupling of the Serratus anterior and lower Trapezius with the upper Trapezius and Rhomboids.Returning from upwards elevation, the appropriately positioned Trapezius, when working efficiently, helps maintain the Scapula against the Thorax (Kibler & Sciascia, 2010 p.301)

Dynamic Scapular Stability

Serratus anterior is a key stabiliser of the Scapula as it contributes to all components of three-dimensional motion of the scapula during arm elevation. It helps produce scapular upward rotation, posterior tilt, and external rotation whilst stabilising the medial border and inferior angle, thus preventing scapular winging (Ludewig, 1996, P.57). The primary role of the Serratus Anterior during activities such as throwing, and shoulder elevation is to act as an external rotator/stabiliser of the scapular during arm motion (Kibler & Sciascia, 2010, P.301)

Dynamic Scapular Stability

Optimal muscle activation of the shoulder joint occurs whilst the Scapula is retracted and externally rotated. Scapula retraction results from synergistic muscle activations in patterns from the hip and trunk through the scapula to the arm, thus facilitating maximal activation of the muscles attached to the scapula. The retracted scapula can then act as a stable base for the origin of all rotator cuff muscles (Kibler & Sciascia, 2010, P.301).

Scapular Dyskinesis and Shoulder Injury

Positions of scapular protraction have been shown to limit maximal rotator cuff strength. Excessive scapular protraction, a posture which is frequently seen in patients with scapular dyskinesis, can decrease maximum rotator cuff strength by 23% (Kebaetse et al, 1999, P.945).A study by Kibler et al, found Supraspinatus strength increased by 24% in a position of scapular retraction in patients with shoulder pain, and 11% in patients without shoulder pain (Kibler et al, 2006,P.1643)

Scapular Dyskinesis and Shoulder Injury

Scapular Dyskinesis is associated with prominence of the medial scapular border and a biomechanical position of scapular internal rotation and protraction. The protracted shoulder is a less than optimal position for muscle strength (Kibler & Sciascia, 2010, P.302).Muscle activation studies have shown that increased protraction is due to a combination of increased pectoralis minor and lattisimus dorsi activation and decreased lower trapezius and serratus anterior activation. This altered scapula-humeral rhythm tends to allow migration of the humeral head away from the joint centre (Illyes & Kiss, 2006, P.673)

Scapular Dyskinesis Assessment and corrective manoeuvres

The Scapular Assistance Test (SAT) helps evaluate scapular contributions to impingement and rotator cuff strength. In the SAT, gentle pressure is applied to assist scapular upward rotation and posterior tilt as the patient elevates the arm. The test is positive when the painful arc of impingement symptoms is is relieved and the arc of motion is increased.

Scapular Dyskinesis Assessment and corrective manoeuvres

The Scapular Resistance Test (SRT) evaluates contributions to rotator cuff strength and labral symptoms. In the SRT the Physiotherapist grades the Supraspinatus muscle strength via standard manual muscle testing (A) or evaluates labral injury with the dynamic Labral shear test. The physio then places and stabilises the scapular in a retracted position. The test is positive if supraspinatus strength is increased or the symptoms of internal impingement in the labral injury are relieved in the retracted position.

Scapular Dyskinesis Assessment and corrective manoeuvres

Neither the SRT or the SAT are capable of diagnosing a specific form of shoulder pathology, however a positive SAT or SRT shows that Scapular Dyskinesis is directly involved in producing the patients symptoms and would indicate the need for the inclusion of early scapular rehabilitation exercises to improve scapular control (Kibler & Sciascia, 2010, P.303).

TreatmentBony injury and/or tissue derangement such as AC joint separation, clavicle fractures, labral tears or rotator cuff disease may require surgical intervention before treatment of scapular dyskinesis can be addressed. However, the large majority of cases of dyskinesis are caused due to muscle weakness, inhibition or inflexibility and can be managed with conservative rehabilition. The goal of initial treatment is to achieve the position of optimal scapular function – Posterior tilt, external rotation and upward elevation (Kibler & Sciascia, 2010, P.303).

Treatment

Rehabilitation emphasis should start proximally and end distally. Proximal control of core stability, leading to an increased control of three dimensional control scapular motion is achieved through a rehab regimen in which larger muscles of the lower extremity and trunk are utilised during the treatment of the scapula and shoulder.Hip and trunk flexion facilitate scapular protraction, whilst hip and trunk extension along with trunk rotation, aid in facilitating scapular retraction.

Treatment

Scapular stabilisation protocols should focus on re-educating the muscles to act as dynamic scapular stabilisers as maximal rotator cuff strength is achieved via a stabilised, retracted scapula. Scapular control should be achieved prior to emphasising rotator cuff strength and should emphasise closed chain, humeral head co-contractions. A logical progression of exercises (isometric to dynamic) should be focussed on strengthening the lower trapezius and serratus anterior whilst minimising upper trapezius activation.

Scapula Stability Exercises

Closed Chain Scapular Clock exercises

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Scapula Stability Exercises

Blackburn Open Kinetic Chain Exercise

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Scapula Stability Exercises

Scapular Retraction Depression with theraband in 4 positions (Hold 6 secs)

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Questions?

ReferencesFunk L (2013) Available at: http://www.shoulderdoc.co.uk/article.asp?article=930

Illyes A & Kiss RM (2003) Kinematic and muscle activity characteristics of multidirectional shoulder joint instability during elevation. Knee Surgery, Sports Traumatology, Arthroscopy 14:673-85

Kibler BW & Sciascia A, (2010) Current Concepts: Scapular Dyskinesis. British Journal of Sports Medicine, 2010; 44: 300-305.

Kibler BW (1998) The role of the scapula in function. American journal of sports medicine 26:325-37.

Kebbatse M, Mclure P, Pratt NA (1999) Thoracic position effect on shoulder range of motion, strength, and three-dimensional kinematics. Archives of physical medicine and rehabilitation 80:945-50

Ludewig PM, Cook TM, Nawoczenski D (1996) Three dimensional scapular orientation and muscle activity at selected positions of humeral elevation. Journal of orthopaedic sports and physical therapy. 24:57-65

Sevinsky S (2013) Scapular Dyskinesis. Available at: http://www.smogshoulder.com/images/Scapular_dyskinesis.pdf