Referred Visceral Pain: What Every Sports Medicine Professional Needs to Know CHRISTINE BOYD STOPKA, PhD, ATC, and KIMBERLY L. ZAMBITO, MS Department of Exercise and Sport Sciences University of Florida N ANY type of contact sport, ber of visceral afflictions cause no the athlete is susceptible to other signs except the referred abdominal trauma. Fortu- pain (8). ately, abdominal injuries pnsent micleildinRsymp- This article explores the sub- occur relatively infrequently. Nev- toms by referring pain to 1 ject of referred pain in some depth so that if it does occur, it can be ertheless, when they do occur, ! superficial areas of tlie immediate identification, treat- body well removed from detected and understood. Early ment, and medical referral is im- tlie injury site. detection and understanding perative. The alternative to such will facilitate a proper evaluation action could be disastrous. Thus Referred pain may be tlie and expedite treatment for the the athletic trainer or therapist's onlv indication of injury, athlete. ability to fully and accurately as- thus atliletic trainers and The mechanisms for referred sess abdominal trauma to the ath- I therapist5 need to be pain are discussed. Diagrams &re lete is paramount in avoiding a aware of tliis phenomenon. included to clarify these mecha- potential fatality (2). 2 Ry understanding the fiisms. In addition, specific ex- Abdominal injuries can pre- concept of referrcd pain, amples of referred pain from sent misleading symptoms. athletic trainers and visceral organs subject to athletic Specifically, visceral organs are tlierapists hu y precious injury are presented. Finally, ba- relatively insensitive to pain- ' time for atliletcs while sic concepts are summarized even from stimuli such as cutting securing medical care. and implications for the athletic or burning. trairier or therapist are stressed. Referred pain may be the only type of pain that is felt when vis- person can feel pain in a part of ceral organs are damaged (8). But the body that is well removed Mechanisms referred pain can be confusing from the site of injury (2). It is ex- for Referred Pain and may result in the delay of tremely important to recognize proper medical referral, since a this phenomenon because a nurn- The various parts of the human body do not all perceive pain in the same way. &important &ar- Editor's Note: This article has been updated and is reprinted with pennission froin the Journal 4 Athletic Training, official publication of the NATA. It was originally published in 1980, Vol. 15(1), acteristic of pain relative to vis- pp. 20-25. ceral injury is its teridency to 01999 Human an January 1999 The Professional Journal for Athletic Trainers and Therapists 29 irradiate and give rise to referred skin in the area where the pain is arm or to both shoulders, arms, pain (1,13). Visceral pain is usu- felt enter the same segment of and hands. Occasionally anginal ally referred to a cutaneous sur- the spinal cord as do the neurons pain may be projected posteriorly face. For example, pain due to that actually conduct the pain to the area of the left scapula at heart damage may be experienced stimuli from the visceral organ. the interscapular region (lo), as in as pain of the left upper arm or An appreciation of this merger left ventricular involvement. pain passing down the arm into the into a common path is essential to With respect to the lungs, ex- hand (8,13). Splenic injury may be an understanding of the distribu- treme damage may occur in the referred to the left shoulder and tions of visceral pain. Concisely absence of pain until inflamma- arm, which is known as Kehrlssign stated, Visceral pain will be noted in tion extends to the parietal pleura. (8). Pain from the liver may be re- that somatic area with which it shares The pleural irritation then gives ferred to the right shoulder (10). afinal common path. rise to pain along the dermatomes These misdirections of pain Figure 3 illustrates the rela- corresponding to the spinal lev- sensation appear to be due to the tionship of the visceral organs and els of the incoming afferent im- excitation of a common pool of their afferent pathways. Exactly pulses C8-T8 (10). neurons within the spinal cord, where these visceral afferents en- The diaphragm is supplied by brain stem, or cortex acted on by ter the spinal cord and mingle somatic nerves that enter C3-C5. different afferent sources (13). with somatic afferents is the key Any painful stimulus to the pari- Mechanisms for referred pain to the principle of referred pain. etal peritoneum is referred along are illustrated in Figure 1, which Figure 4, the dermatomes (3) (i.e., the corresponding cutaneous depicts the general organization segments of cutaneous sensation nerves. Thus diaphragmatic pain for the afferent pathways of vis- with respect to each spinal level), is characteristically referred to the ceral pain at one spinal level. directly complements Figure 3 by shoulder area's cutaneous distri- According to Guyton (8), "It identifying the corresponding bution of C3-C5 (9). is generally believed that visceral area of somatic sensation due to Trauma to the esophagus gives pain fibers may synapse in the the intersecting visceral afferents. rise to pain on the sternal region spinal cord with certain neurons Under some circumstances, of the thorax corresponding to the transmitting pain sensation from only slight trauma to the abdo- site of the lesion (i.e., an upper the skin" (p. 510). Their synapses men may result in hemorrhage. esophageal lesion yields manu- may actually cross so that stimu- Free blood in contact with the brial pain; a lower esophageal le- lation of visceral pain fibers re- peritoneum results in peritonitis, sion yields xiphoid pain or pain sults in the sensation of cutaneous which in itself is a medical emer- in the epigastrium (8).Esophageal pain (see Figure 2). Furthermore, gency This too presents referred afferent fibers enter the lower cer- according to MacBryde, "referred pain cotrespondingto the location vical and all thoracic levels, but pain may be due in part to reflex of the incoining afferent impulses. especially T5-T6 (8), which corre- muscle spasm, also mediated sponds to the above regions of through intraspinal nerve connec- Examples af perceived pain. tions" (p. 183). Splenic afferent impulses The perception of visceral Refevmd Pain course the phrenic nerve at the pain can be extended to many Figure 3b illustrates the specific C3-C5 levels (5), presenting sharp other spinal levels. This fact dem- pathologies of referred pain from cutaneous pain projecting to the onstrates the existence of inter- each selected organ. For example, left shoulder and about one third of the way damthe arm. mediate neurons connecting the cardiac pain is experienced by sub- I posterior horn cells, as well as in- sternal discomfort projected to the This region does not really I ternuncial cells connecting the neck and left jaw, as well as the correspond to that of the spinal higher and lower segments of the left shoulder and arm over the dis- levels of the phrenic nerve. Ap- cord. This may be the mechanism tribution of the ulnar nerve. This parently as noted earlier, longi- responsible for the characteristic is because dermatomes TI-T8 are tudinal intermediate neurons referral of splenic pain. generally involved. within the spinal cord itself be- A main point to understand is Less frequently, pain may be come involved, mediating and that the neurons that supply the referred to the right shoulder and projecting the impulses farther i January 1999 I I .