Upper limb

Tendon Sheath of the Long Head of Biceps

Vagina synovialis intertubercularis (tendinis capitis longi musculi bicipitis brachii)

Origin

Surrounds the tendon at the level of the supraglenoid tubercle of the scapula (intra-articular starting point of the tendon)

Insertion

Follows the tendon through the intertubercular groove of the humerus

Function

No contractile function: the synovial sheath reduces friction of the long head of biceps tendon in the intertubercular groove during shoulder movements

Innervation

Not applicable (no muscle tissue); sensory innervation of the surrounding capsule via shoulder joint branches

Movement & chain

Provides frictionless gliding of the long head biceps tendon in the intertubercular groove during shoulder and elbow motions.

Palpation

Palpable in the bicipital groove on the anterior humeral head during slight external rotation of the arm.

Clinical

Biceps tenosynovitis and tendinopathy; positive Speed's and Yergason's tests; subluxation with transverse humeral ligament / subscapularis tears.

Segmental innervation

C5–C6 (musculocutaneous nerve)

In clinical practice

Fluid accumulation in the tendon sheath is an indirect ultrasound sign of shoulder joint pathology, because the sheath communicates with the joint cavity of the glenohumeral joint.

Region in the model

Upper limb