Biceps Brachii

Authors

Affiliations

Nathaniel Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Muscle	Origin	Insertion	Innervation	Action
Biceps brachii Long head	Supraglenoid tubercle of scapula Adjacent rim of Glenoid Labrum	Radial tuberosity Bicipital aponeurosis	Musculocutaneous n. C5 - C6	Elbow: Flexion, Supination GHJ: Flexion, Stabilization of humeral head during deltoid contraction, Abduction, IR
Biceps brachii Short head	Coracoid process	Radial tuberosity Bicipital aponeurosis	Musculocutaneous n. C5 - C6	Elbow: Flexion, Supination GHJ: Flexion, Stabilization of humeral head during deltoid contraction, Abduction, IR

Long Head

Origin

• Supraglenoid tubercle of scapula^1,2
• Adjacent rim of Glenoid Labrum²

Insertion

• Radial tuberosity¹
• Bicipital aponeurosis¹

Innervation

Musculocutaneous N. (C5, C6)^1,2

Action

• Shoulder: Flexion
• GHJ: Abduction, Internal rotation, Stabilization of humeral head during deltoid contraction¹
• Elbow: Flexion; Supination¹

Note

How does the Biceps Brachii Long head function as a GHJ stabilizer?

• “Cadaver studies strongly suggest that the long head of the biceps restricts anterior translation of the humeral head”²
  
• “force generated in the muscle resists superior translation of the humeral head—an important force needed to control the natural arthrokinematics of abduction”²

Note

“When the elbow is flexed, the biceps brachii acts as a powerful supinator because the lever arm is almost perpendicular to the axis of pronation/supination.”¹

Short Head

Origin

• Coracoid process of Scapula¹

Insertion

• Radial tuberosity¹
• Bicipital aponeurosis¹

Innervation

Musculocutaneous N. (C5, C6)¹

Action

• Shoulder: flexion¹
• GHJ: Abduction, Internal rotation, Stabilization of humeral head during deltoid contraction¹
• Elbow: Flexion, Supination¹

Note

Note: When the elbow is flexed, the biceps brachii acts as a powerful supinator because the lever arm is almost perpendicular to the axis of pronation/supination.¹

Anatomy

• Biceps Brachii Long Head tendon moves laterall from its origin, makes a right angle to place it in the anterior aspect of the humerus³
  • This turn may cause abnormal wearing of the tendon³

Tendon

The tendon of the Long Head of the Biceps Brachii “…crosses over the humeral head as it courses distally toward the intertubercular groove on the anterior humerus”²

Clinical Relevance

The biceps may have a role in GHJ stabilization⁴

Dysfunction

Biceps dysfunction is difficult to diagnose “One confounding factor is that there is no known pain pattern specific for the biceps tendon. Although biceps tendon pain can radiate down the front of the shoulder, pain into the front of the shoulder can be secondary to a variety of causes, including rotator cuff injury”^{gillPhysicalExaminationPartial2007?}

From Gill 2007

“Biceps tendon lesions have been long recognized as a potential source of shoulder pain”^{gillPhysicalExaminationPartial2007?}

Palpation test

• signs of biceps tendon injury.
• Eliciting point tenderness by palpation of the biceps tendon in the biceps groove 3 to 6 cm below the anterior acromion with the arm in approximately 10° of internal rotation^{gillPhysicalExaminationPartial2007?}
• area of point tenderness should move as the arm rotates internally and externall^{gillPhysicalExaminationPartial2007?}
• Positive test: “pain elicited in the bicipital groove to deep pressure in the involved shoulder compared with no pain elicited with similar pressure to the bicipital groove of the opposite shoulder”^{gillPhysicalExaminationPartial2007?}
• “Overall, tenderness on palpation had a sensitivity of 53%, a specificity of 54%, an accuracy of 54%, and a likelihood ratio of 1.13”^{gillPhysicalExaminationPartial2007?}

Palpation

Tests

• Speed’s Test

• Palpation

• Speeds + Biceps palpation

  • “If the patient had a positive Speed’s test and pain with biceps palpation, the combined positive tests yielded a sensitivity of 68%, a specificity of 49%, an accuracy of 59%, and a likelihood ratio of 1.31”^{gillPhysicalExaminationPartial2007?}

“Two commonly used techniques for making the diagnosis of biceps tendinitis are Speed’s test and palpation that elicits tenderness over the bicipital groove.”^{gillPhysicalExaminationPartial2007?}

Speed’s Test

• Patient standing with the elbow extended and the forearm in supination, the arm was elevated to 90° and extended slightly horizontally^{gillPhysicalExaminationPartial2007?}
• Pt resists the downward force applied by the examiner⁵
• Positive: Pain was localized to the bicipital groove area in the anterior shoulder⁵

Possible tests for biceps injury

• Some researchers suggest that the lift-off test can be positive for pts with biceps tendon injury^{gillPhysicalExaminationPartial2007?}
• Theorizing that attempting to lift the affected arm off the back might provoke pain or weakness secondary to biceps tendon tear^{gillPhysicalExaminationPartial2007?}

“Only the lift-off test and the belly press test had a likelihood ratio of more than 2.0. These 2 tests had low sensitivities (0.28 and 0.17, respectively) but high specificity (0.89 and 0.92, respectively)”⁵

Rehabilitation

Reading list

• The Management of Biceps Pain: Non-Operative & Surgical⁶

References

1.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.

2.

Neumann DA, Kelly ER, Kiefer CL, Martens K, Grosz CM. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed. Elsevier; 2017.

3.

Dutton M. Dutton’s Orthopaedic Examination, Evaluation, and Intervention. 5th ed. McGraw Hill Education; 2020.

4.

Itoi E, Kuechle DK, Newman SR, Morrey BF, An KN. Stabilising function of the biceps in stable and unstable shoulders. The Journal of Bone and Joint Surgery British Volume. 1993;75(4):546-550. doi:10.1302/0301-620X.75B4.8331107

5.

Gill C, Cho TA. Neurologic Complications of COVID-19. CONTINUUM: Lifelong Learning in Neurology. 2023;29(3):946-965. doi:10.1212/CON.0000000000001272

6.

Moore Z, Cain EL, Wilk KE. The Management of Biceps Pain: Non-Operative & Surgical. International Journal of Sports Physical Therapy. 2022;17(3):330-333. doi:10.26603/001c.33646