normal  medium  large

Muscle Test and Tendon Exam: Flexor Pollicis Longus (FPL)

Test, Exam and Sign Description

Origin:             Radius (anterior surface of middle 1/2) and adjacent interosseous membrane

                        Ulna (coronoid process, lateral border [variable])

                        Humerus (medial epicondyle [variable])

 

Insertion:         Thumb (base of distal phalanx, palmar surface)

 

Innervation:    Cervical root(s):  C7 and C8

                        Nerve: median nerve (anterior interosseous branch)

 

Grading of muscle strength:

Grade

Strength

Description

  5*

Normal

Completes full range of motion against maximal finger resistance

  4*

Good

Tolerates moderate resistance

3

Fair

Completes full range of motion with no resistance

2

Poor

Completes partial range of motion

1

Trace

Slight contractile activity

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

  • Forearm is supinated, the wrist is in neutral and the metacarpophalangeal (MP) joint of thumb is in extension.

 

Examiner’s Actions

  • Stabilize the MP joint of the thumb firmly in extension by grasping the patient’s thumb across that joint. Apply resistance with the other hand against the palmar surface of the distal phalanx of the thumb in the direction of extension.

 

Instructions for the patient

  • “Bend the end of your thumb. Hold it. Don’t let me straighten it.”
Presentation Photos and Related Diagrams
  • FPL Muscle Testing
    FPL Muscle Testing. (Hover over right edge to see more images)
  • FPL
    FPL anatomy illustration
  • FPL
    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 0.
Comments and Pearls
  • Do not allow the distal phalanx of the thumb to extend at the beginning of the test. If it is extended and then relaxes, the examiner may think that active flexion has occurred
Diagnoses Associated with Tests, Exams and Signs
CERVICAL RADICULOPATHY
COLLES' FRACTURE
TRIGGER THUMB
TRIGGER THUMB PEDIATRIC
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.

2. Kendall FP, McCreary EK, Provance PG. Muscles Testing and Function. 4th ed. Baltimore, MD: Williams & Wilkins, 1993, pp. 235–298.