Hackett Referral Patterns

fig21_11Hackett Referral Patterns are named for George S. Hackett, M.D., who not only introduced the term Prolotherapy in 1955 in the first edition of his book Ligament and Tendon Relaxation Treated by Prolotherapy, but also discovered, after years of treating patients, that injury to a ligament in one part of the body can send, or refer, pain to another part of the body. When a weakened ligament or tendon is stretched, the sensory nerves become irritated, causing local and referred pain throughout the body. These patterns were outlined in Hackett’s observations, which he mapped after giving 20,000 ligamentous injections in diagnosing and treating ligament and tendon relaxation in 1,816 patients over a 20-year period, and which are now referred to as Hackett Referral Patterns. They are shown in the figures on this page.

Dr. Hackett was not alone in his work. Around the same time that he was studying ligament trigger points, Janet Travell, M.D., White House physician for presidents Kennedy and Johnson, was studying muscle trigger points and diagramming their referral pain patterns. Ligament laxity referral patterns and muscle trigger point patterns are very similar because they have the same etiology, or cause. The similarity of their findings is shown in the figure shown above. In fact, in addition to her work with muscle trigger points and referral patterns, Dr. Travell also reported that acute sprains of the ankle were accompanied by multiple trigger points around the ligament and referred pain to the ankle and foot. Others have identified trigger points resulting from acute sprains around the knee, wrist and metacarpophalangeal joint of the thumb that were eliminated with Prolotherapy.


It has now been well established that an injury in one part of the body can affect other, distant body parts, especially in regard to ligament injury. For example, when dye is injected into the nerves of the ligaments of the lower neck, the dye will travel four segments above and four segments below the injection site. This implies that ligament laxity at one vertebral level could manifest pain, muscle tension, adrenal or autonomic dysfunction four segments above or below the actual injury site. Knowledge of referral pain patterns, along with a complete patient medical history, allows physicians who practice Prolotherapy to make accurate diagnoses of specific weak ligaments, even before performing an examination.

Examples of referred pain


Unfortunately, most athletic trainers, chiropractors, family physicians, orthopedic surgeons and physical therapists do not know that ligaments can refer pain to a distant site. And the more severe an injury is, the more likely that a referral pain pattern will exist. Unfamiliarity with referral pain patterns can lead to misdiagnoses as well as inappropriate treatments, as is often the case with conditions such as sciatica, carpal tunnel syndrome and tarsal tunnel syndrome. For example, the sacroiliac ligaments, located in the lower back, refer pain to the lateral foot, which causes the symptoms resulting in a common misdiagnosis of sciatica. Pain traveling down the back into the leg and foot is usually from ligament weakness in the sacroiliac joint, not from a pinched sciatic nerve. Other examples include the lateral collateral and annular ligaments, which refer pain down the lateral forearm and into the thumb, index and middle fingers. This is the source of most carpal tunnel syndrome complaints, and often incorrectly diagnosed as carpal tunnel syndrome. Similarly, the medial collateral ligament refers pain down the medial aspect of the forearm into the ring and little fingers, which simulates cubital tunnel syndrome of ulnar nerve entrapment at the elbow. The list goes on and on:

–the hip joint ligaments refer pain down the leg to the big toe
–the sacrotuberous and sacrospinous ligaments refer pain to the heel
–the iliolumbar ligament refers pain into the groin or vagina; in fact, an iliolumbar ligament sprain should be considered for any unexplained vaginal pain, testicular pain, or groin pain.

Prolotherapy and pain referral patterns

A typical Prolotherapy treatment involves a properly trained physician palpating the exact site of the injury, reproducing the pain, and then confirming the diagnosis with the actual injections. This is possible because an anesthetic is contained in the Prolotherapy solution. The pain is then usually eliminated immediately after the treatment due to the effect of the anesthetic being injected right into the source of the pain-the fibro-osseous junction. Familiarity with referral pain patterns allow Prolotherapy specialists to appropriately target Prolotherapy treatments to the correct site in order to eliminate a wide range of chronic pain sources.