Infraspinatus

Pointer Plus The Pointer Plus is an easy to use trigger point (TP) locator which incorporates a push button stimulation feature to immediately treat Trigger point pain.

The Infraspinatus is a rotator cuff muscle of the shoulder.

Anatomical Attachments:

• Origin: Attaches to the medial 2/3 of the infraspinatus fossa of the scapula.
• Insertion: Attaches to the greater tuberosity of the humerus.

Action: It rotates the head of the humerus laterally and assists in stabilizing the humerus in the glenoid cavity.

Synergist: Deltoid, Supraspinatus, Teres major and minor, Subscapularis.

Antagonist: Pectoralis major and minor, Subclavius, Serratus anterior, Latissimus dorsi, Trapezius, Rhomboid major and minor, Levator scapulae.

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Nerve Supply: Suprascapular Nerve (C5, C6).

Vascular supply: Suprascapular and scapular circumflex artery.

• Primary: The pain is experienced deep within the anterior aspect of the shoulder. It frequently is experienced within the glenohumeral joint, and occasionally posterior shoulder pain is referenced, but this could be due to the simultaneously active triggers in the Teres minor. According to Travell and Simons, all patients experience deep anterior shoulder pain with referral to the anterolateral aspect of the arm and radial aspect of the forearm and hand, excluding the digits. Occasionally, the infraspinous trigger located at the vertebral border of the scapula refers pain into the suboccipital region.
• Satellite or associated triggers: Anterior deltoid, Supraspinatus, Biceps brachii, Teres minor, Teres major, Latissimus dorsi, Subscapularis, Pectoralis major.

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Trigger Point Signs and Symptoms: There is diminished grip strength and the inability to place the dorsum of the hand to their mid- or low- back (decreased internal rotation with adduction of the arm). The individual may state that they have the inability to reach into their hip pocket on the affected side.

Trigger Point Activating and Perpetuating Factors: Persistent reaching behind with the arm extended and/or slightly abducted, such as pulling a hand truck or attempting to check a fall when falling backwards.

Differential Diagnosis: (Segmental, Subluxation, Somatic dysfunction) C5 C6 or C7 radiculopathy, Brachial plexus injuries, Thoracic outlet syndrome, Subdeltoid bursitis, Bicipital tendinitis, Osteoarthritis, Rheumatoid arthritis, Cervical arthritis or spurs, Rotator cuff tear, Rotator cuff tendinitis, Supraspinatus tendinitis, Neurogenic arthropathy (Charcot’s joint), Adhesive capsulitis (Frozen shoulder), Brachial neuritis, Complex Regional Pain Syndrome (Reflex sympathetic dystrophy or Shoulder hand syndrome), Angina pectoris, Myocardial infarction, Pneumothorax, Bone cancer, Bone fracture, Myasthenia gravis, Multiple sclerosis, Dislocation/Subluxation of Glenohumeral joint, Shoulder pointer, Sprain/Strain injury, Eosinophilic fasciitis, Tetanus, Systemic infections or inflammation, Nutritional inadequacy, Metabolic imbalance, Toxicity, Side effects of medication.

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