Hand Surgery Source

Muscle Test: Brachioradialis

Test, Exam and Signs
Origin: Humerus (lateral supracondylar ridge, proximal 2/3)
Lateral intermuscular septum (anterior)
Insertion: Radius (lateral side of shaft just proximal to styloid process)
Innervation: Cervical root(s): C5–6
Nerve: radial nerve

 

Grading of muscle strength:

Grade

Strength

Description

  5*

Normal

Completes range of motion and holds against maximal finger resistance

  4*

Good

Completes range against moderate resistance

3

Fair

Completes range of motion with no resistance

2

Poor

Completes range of motion

1

Trace

Palpable or visible contractile activity, which may or may not be accompanied by a flicker of motion

0

Zero

No contractile activity

*The distinction between Grades 4 and 5 is based on comparison with the normal hand and, barring that, extensive experience in testing the hand.

Position of patient's hand and upper extremity

  • Short sitting with arms at sides. The forearm is in mid-position between pronation and supination.

Examiner’s actions

  • Stand in front of the patient toward the test side. The hand applying resistance is contoured over the volar (flexor) surface of the forearm proximal to the wrist. The other forearm is placed over the anterior surface of the upper arm and applies counterforce by resisting any upper arm movement.

Instructions for the patient

  1. “Bend your elbow. Hold it. Don’t let me pull it down.”
Presentation Photos and Related Diagrams
  • BR anatomy illustration
    BR anatomy illustration
  • This illustration represents the anatomy of the muscle and tendon origin and insertion. Should an individual sustain a laceration as depicted, the observer can assume that the underlying tendon may be at risk for complete transection. A proper examination is needed to determine the integrity of the tendon.
    This illustration represents the anatomy of the muscle and tendon origin and insertion. Should an individual sustain a laceration as depicted, the observer can assume that the underlying tendon may be at risk for complete transection. A proper examination is needed to determine the integrity of the tendon.
Definition of Positive Result
  • In muscle testing, a normal result is a positive one. During a normal muscle test, the examiner should observe a normal muscle contraction that can move the joint or tendon against full resistance.
Definition of Negative Result
  • In muscle testing, an abnormal result is a negative one. During an abnormal muscle test, the examiner should observe an abnormal muscle contraction that can move the joint or tendon. In a complete denervation injury, such as a complete nerve laceration, there will be no evidence of any muscle function and the muscle testing grade will be zero.
Comments and Pearls
  • The patient’s wrist flexors should remain relaxed throughout the test, as contracting the wrist flexor muscles may assist with elbow flexion.
Diagnoses Associated with Tests, Exams and Signs
References
  1. Hislop JH, Avers D, Brown M. Daniels and Worthingham's Muscle Testing, Techniques of Manual Examination and Performance Testing. 9th ed. St. Louis, Missouri: Elsevier Saunders, 2014, pp. 138–202.