Extensor Digitorum Trigger Points and Referred Pain

Before you read more about extensor digitorum trigger points and learn about the causes of extensor digitorum pain, you may want to find about more about this muscle.

Extensor Digitorum Trigger Points Causes and Symptoms

The extensor digitorum muscle is responsible for extension of the fingers, and pain derived from trigger points in the extensor digitroum could be mistaken for arthritis pain in the fingers or even Tennis elbow because of symptoms at the elbow. Sore and “tender” fingers and aching forearms are also possible, even without actual pain in the joints. Overuse of the fingers in forceful activities such as with pianists, mechanics, carpenters, typists, etc. are likely to cause overload and trigger points in the ED muscle. Overuse of the grip, as in inappropriate grip strength training, are likely also to cause TrP’s in the muscle. Although it would be easy to surmise that maximal grip crushing grip training, as with heavy duty hand grippers, would be the most likely to cause this, it is just as likely to be caused by light grippers used with high repetitions, or other types of grip training done with too much volume or frequency. Also, any kind of repetitive gripping or twisting motion of the hand may be responsible.

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Typing on a computer keyboard causes the finger extensors to be active almost constantly since they must keep the fingers extended over the keyboard between keystrokes. Mouse clicking, likewise, presents the same problem.

A weak grip and painful and/or stiff fingers can be due to extensor digitorum trigger points. The pain is exacerbated when trying to grip any object strongly and upon such activities as shaking hands. Trigger points in this muscle radiate pain down the dorsal forearm, to the back of the hand, and into back of the fingers (dorsally). The pain does not reach the end of the fingers, but may reach as far as the proximal interphalangeal joint. Symptoms will appear in the finger which corresponds to the involved area of the muscle, being the middle or ring finger extensor.

Extensor Digitorum Trigger Points

The image below shows the approximate point that trigger points develop in the muscle.

extensor digitorum trigger points
Extensor Digitorum Trigger Point Locations

Trigger points in the middle finger extensor appear most often. Pain from this extensor TrP radiates down the dorsal forearm and sends concentrated pain to the middle finger. Trigger points in the middle extensor are also capable of occasionally referring pain to the frontal or “volar” part of the wrist. Note that the “front” of the wrist corresponds to the position of the wrist in the anatomic position, where the palms of the hands are facing forward. Some people will call this part of the wrist the inside part but this term is avoided here for clearness, as the inside of the wrist is technically the medial aspect of the joint in the anatomical position.

The image below shows the referred pain pattern of this TrP.

Middle Finger Extensor TrP Referred Pain Pattern

TrP’s in the ring finger extensor send pain down the dorsal forearm, crossing the back of the hand, and concentrating pain into the ring finger. The TrP’s in this part of the muscle may also send pain upwards, toward the outer elbow at the lateral epicondyle region so that symptoms similar to the pain of so-called “tennis elbow” is experienced. This condition, called lateral epicondylitis is actually due to pathology in the common extensor tendons rather than problems in the muscle bellies, whether due to TrP’s or otherwise. However, in addition to the ring extensor of the extensor digitorum, other forearm muscle trigger points, such as the brachioradialis, supinator, and extensor carpi radialis longus, and brevis can send pain to the lateral region of the epicondyle.

Although lateral epicondylitis is called “Tennis Elbow,” it is not only seen in tennis players. While the condition is somewhat commons, especially among middle-aged tennis players, in total, tennis players account for only 55 of cases.

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There is no actual inflammation of the epicondyle. Instead, long-term cases are marked by degenerative changes where the common extensor tendon attaches to the epicondyle. It can be considered an enthesopathy, an enthesis being the place where a tendon inserts into bone.

Since lateral epicondylitis, although initially causing pain only in the lateral elbow eventually tends to spread pain down the arm, pain that is actually being referred from the extensor digitorum or other forearm muscle trigger points can easily be misdiagnosed as lateral epicondylitis, even though no pathology is present in this region. 1Simons, David G., Janet G. Travell, Lois S. Simons, and Janet G. Travell. “Chp. 8: Masseter Muscle.” Travell & Simons’ Myofascial Pain and Dysfunction: the Trigger Point Manual. Baltimore: Williams & Wilkins, 1999. 329. , 2Baldry, Peter, Muhammad B. Yunus, and Fatma Inanici. Myofascial Pain and Fibromyalgia Syndromes: a Clinical Guide to Diagnosis and Management. Edinburgh: Churchill Livingstone, 2001

The image below shows the referred pain pattern of the ring finger extensor TrP.

Ring Finger Extensor TrP Referred Pain Pattern

Finger Flexion Test for Extensor Digitorum

A finger flexion test can be used to help determine which, if any, parts of the extensor digitorum muscles are affected by trigger points. Since extensor digitorum trigger points can be associated with trigger points in the scalene muscles, the same test can be used to test for both, as described in the scalene trigger point article

If one of your fingers sticks out from the others during the finger flex test, and you are unable to get that finger to touch the volar pad without pain, this can indicate a trigger point in the area of the muscle attached to that finger.

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Extensor Digitorum Trigger Point Massage

Using the images above to locate the approximate areas of the trigger points, you should easily be able to palpate the muscle and find the area that elicits a response, which will typically be close to the surface where the taut band can be felt. Those with well-developed forearms will be able to see the muscle working when wiggling or extending the fingers. Others can palpate the muscle two or three inches down from the elbow on the outer surface of the forearm and feel the muscle jumping when working the fingers. Once you locate the trigger points they can be treated with a number of simple devices. The fingers of the opposite hand can, of course, be used but a hard device that can exert deeper and firmer pressure will work best.

A tennis ball can be used against a wall but a small hard rubber bouncy ball, about 1.5 inches in diameter, like the kind sold in party supply or dollar stores, will work even better. Place the ball between a smooth wall and the affected forearm so that the back of your hand is facing the wall and your forearm is horizontal. Using the wall as a rolling surface, roll the ball along the muscle, starting at the middle of the forearm and ending at the elbow. Lean your body weight against the ball to increase pressure as needed. Concentrate the strokes on the most tender areas that house the trigger points.

A firm hand-held roller massage ball works well. Use a roller massage ball in the same manner except hold the support base of the ball in the opposite hand and rest the arm to be massaged comfortable against your stomach so that you can easily access the outer forearm with the ball and apply good pressure.

A Knobble [self-massage tool] will work well held in the hand, and can be used to work a deeper and smaller area. There are many other hand-held self-massage devices that can be used, such as the Jacknobber and the Index Knobber. Use these in a manner similar to the roller ball.

You can perform multiple sessions throughout the day, but keep them to around a minute or two in length. 3Davies, Clair. The Trigger Point Therapy Workbook: Your Self-treatment Guide for Pain Relief. Oakland, CA: New Harbinger Publications, 2004.

Extensor Indices Muscle

While you’re treating the extensor digitorum muscle, go ahead and look for trigger points in the extensor indicis muscle, which are likely to be present. Both the EDC and the EI are usually considered together in trigger point treatment. Trigger points in this muscle sends pain to the radial side of the back of the hand (closer to the index finger). Feel for this muscle on the back of the forearm about three inches from the wrist. It is located between the radius and ulna bones, as shown in the image below. A contraction can be elicited by extending the index finger.4Simons, David G., Janet G. Travell, Lois S. Simons, and Janet G. Travell. “Chp. 8: Masseter Muscle.” Travell & Simons’ Myofascial Pain and Dysfunction: the Trigger Point Manual. Baltimore: Williams & Wilkins, 1999. 329.,5Davies, Clair. The Trigger Point Therapy Workbook: Your Self-treatment Guide for Pain Relief. Oakland, CA: New Harbinger Publications, 2004.

Extensor indicis muscle
Extensor Indicis Muscle

The wall method will probably not work well for this muscle. The Knobble is the better tool for the job. 6Davies, Clair. The Trigger Point Therapy Workbook: Your Self-treatment Guide for Pain Relief. Oakland, CA: New Harbinger Publications, 2004. The image below shows the extensor indicis trigger point and referred pain pattern.

Extensor indicis trigger points
Extensor Indicis Trigger
Point and Referred Pain Pattern

Other Associated Trigger Points

Although it is possible for trigger points in the extensor digitorum finger extensors to develp alone, it is also likely that they will develop as part of the above-mentioned “tennis elbow” associated symptoms, which is characterized by trigger points in the supinator, brachioradialis, and extensor carpi radialis longus muscles. Refer to Simons and Travell’s Myofascial Pain and Dysfunction: the Trigger Point Manual, Volume One: The Upper Extremities for more complete information. 7Simons, David G., Janet G. Travell, Lois S. Simons, and Janet G. Travell. “Chp. 8: Masseter Muscle.” Travell & Simons’ Myofascial Pain and Dysfunction: the Trigger Point Manual. Baltimore: Williams & Wilkins, 1999. 329.,8Morrey, Bernard F., and Joaquin Sanchez-Sotelo. The Elbow and Its Disorders. Philadelphia, PA: Saunders/Elsevier, 2009.,9MacAuley, Domhnall, and Thomas M. Best. “Chp. 21.” Evidence-based Sports Medicine. Malden, MA: BMJ /Blackwell Pub., 2007. 420.

Sources   [ + ]

1. Simons, David G., Janet G. Travell, Lois S. Simons, and Janet G. Travell. “Chp. 8: Masseter Muscle.” Travell & Simons’ Myofascial Pain and Dysfunction: the Trigger Point Manual. Baltimore: Williams & Wilkins, 1999. 329.
2. Baldry, Peter, Muhammad B. Yunus, and Fatma Inanici. Myofascial Pain and Fibromyalgia Syndromes: a Clinical Guide to Diagnosis and Management. Edinburgh: Churchill Livingstone, 2001
3, 5. Davies, Clair. The Trigger Point Therapy Workbook: Your Self-treatment Guide for Pain Relief. Oakland, CA: New Harbinger Publications, 2004.
4, 7. Simons, David G., Janet G. Travell, Lois S. Simons, and Janet G. Travell. “Chp. 8: Masseter Muscle.” Travell & Simons’ Myofascial Pain and Dysfunction: the Trigger Point Manual. Baltimore: Williams & Wilkins, 1999. 329.
6. Davies, Clair. The Trigger Point Therapy Workbook: Your Self-treatment Guide for Pain Relief. Oakland, CA: New Harbinger Publications, 2004.
8. Morrey, Bernard F., and Joaquin Sanchez-Sotelo. The Elbow and Its Disorders. Philadelphia, PA: Saunders/Elsevier, 2009.
9. MacAuley, Domhnall, and Thomas M. Best. “Chp. 21.” Evidence-based Sports Medicine. Malden, MA: BMJ /Blackwell Pub., 2007. 420.