Derived from the Ancient Greek word for “body,” somatic pain refers to pain originating from the skin or the musculoskeletal system (muscles, fascia, joints, bones, ligaments, tendons, etc.), more specifically to differentiate from the mind or the viscera. Somatic pain is a subset of nociceptive pain, a normal response to noxious stimulus to these tissues.1
The differential diagnoses of pain from the abdomen and pelvis can be broad and vague, with nociception originating from any organ system. As such, a thorough history and review of systems is paramount in elucidating causative pain generators, including gender-specific considerations.
- Injuries to the musculoskeletal system of the abdomen and pelvis may include abdominal or pelvic muscle strains or sprains, pelvic fractures, sacroiliac dysfunction, pubic symphysis dysfunction and diastasis pubic symphysis.
- High-velocity trauma can also cause Morel-Lavallée lesions (degloving injury of skin and subcutaneous tissue from underlying fascia) which commonly affect the thigh, hip, and pelvis2.
- Referred pain to the abdomen and pelvis may occur from failed back surgery from T9-L1 (or rarely from muscles attaching to this region like latissimus dorsi2,3), vertebral lesions of the spine, as well as degenerative joint disease of sacroiliac joints and lumbar spine zygapophyseal joints.
- Chronic post-surgical pain may result following gastrointestinal surgery, hysterectomy, or hernia repair.5
- Some post-operative pain (especially following lower abdominal surgery) stems from cicatricial entrapment of cutaneous nerves.
- Infections, including lower urinary tract infections (UTI) and upper UTI (extending beyond the bladder), commonly present with irritation of the urethra and peri-urethral skin. Gender-specific considerations include prostatitis, prostatodynia, as well as vulvar and vaginal canal pain.
- Masses that cause somatic pain of the abdomen and pelvis commonly include abscesses, hematomas, and tumors of the iliopsoas, pelvic bones, and other tissues.
Epidemiology including risk factors and primary prevention
Somatic abdominal and pelvic pain cover a wide variety of individual diagnoses, each with its own prevalence, risk factors and prevention. Diagnoses may include nerve injury, myotendinous strain/sprain/trauma, childbirth trauma, fractures, ligamentous injury, infection, masses/tumors, neuralgia, post-surgical pain and/or complications as well as rheumatologic disease. Because of the etiologic uncertainty, between 30%-50% of chronic pelvic pain diagnoses remain uncertain and are classified as “chronic pelvic pain without obvious pathology.17”
- The prevalence of chronic pelvic pain alone is estimated to affect one out of every seven women with an estimated cost of $881 million annually in the United States.12
- Risk for chronic post-surgical pain is 20-32%; epidural anesthesia as opposed to general anesthesia may reduce this risk5
- Abdominal oblique muscle strains constitute about 5% of all baseball injuries, with a re-injury rate around 12%, complete treatment with physical therapy and sufficient core muscle strengthening may reduce re-injury6
- Athletic pubalgia, “sports hernia” (disruption of the rectus abdominus muscle from the pubic tubercle) may occur in recreational, high school, college, or professional athletes7
- Chronic pelvic pain is present in 5-43% of women, with musculoskeletal disorders present in 75-85% of these women8
- Chronic Abacterial Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is also a significant male-specific problem representing 9% of all urologic visits, one study estimating a prevalence of 3.2% of males under 50.13,14
Nerves of the Anterolateral Abdominal Wall (may be susceptible to injury or irritation with abdominal surgery)
- Thoracoabdominal (T7-T11) – muscles of anterolateral abdominal wall and overlaying skin
- 7th-9th lateral cutaneous branches of the 7th- 9th intercostal nerves – skin of right and left hypochondriac regions
- Subcostal (T12) – muscles of anterolateral abdominal wall and overlaying skin
- Iliohypogastric (L1) – internal oblique, transversus abdominis, skin over the iliac crest, upper inguinal and hypogastric regions
- Ilioinguinal (L1) – inferior-most internal oblique, transversus abdominis, skin over lower inguinal region, mons pubis, anterior scrotum and labia majora
Pelvic Nerves (susceptible to injury during childbirth or surgery)
- Sacral plexus may be compressed by fetal head
- Obturator nerve vulnerable during lymph node retrieval in lateral pelvic wall
- Pudendal nerve is often involved with genital pain
Muscles of anterolateral abdominal wall (susceptible to strain/sprain, as a group called oblique muscle strain or side strain): Side strains are common in sports where trunk rotation generates power for the upper extremities like baseball, tennis, golf, cricket, and Olympic throwing events.6
- Rectus Abdominis
- Transverse abdominal
- Internal Oblique
- External Oblique
- Pyrimidalis (absent in 20% people)
- Walls and Floor of the pelvic cavity (susceptible to childbirth trauma)
- Obturator Internus – lateral wall
- Piriformis – posterolateral wall
- Coccygeus (isciococcygeus)
- Levator Ani (“Pelvic Myalgia”)
- Pubococcygeus (most commonly torn during childbirth trauma)
Bones (and associated ligaments)
Pelvic Girdle: Susceptible to fracture from high force injuries and childbirth trauma, ligamentous injuries as well as rheumatologic problems, such as ankylosing spondylitis.
- Pubic Symphysis
- Sacroiliac Joints
Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time):
Disease progression in abdominal and pelvic somatic pain will vary widely depending on the specific diagnosis. Correct early diagnosis and treatment can abate progression to the chronic pain state.
Pain is characterized by a sudden, sharp onset of pain with localized tenderness
Recovery Stage: In routine healing, the patient’s somatic pain will continue to improve with decreased use of analgesics and improved function.
Untreated or undertreated pain may progress to the chronic pain state. Chronic pelvic pain may be a result of viscero-visceral, viscero-somatic or somato-visceral convergence,7,8 whereby pathology in one viscera or myotome may create pathology in another organ or muscle group which share the same innervation levels in the central nervous system.
Metastases to pelvic girdle or abdominal wall may be a pain-generating source or may lead to pathologic fractures or tissue injuries.
Essentials of Assessment
Identify location, onset, and palliative/provocative factors. Assess quality, radiation of pain, severity and timing. Past surgical history, including remote and recent surgeries, as well as pregnancies and delivery history may provide direction to identify traumatic cause in abdominal and/or pelvic pain. Visceral source for the pain must be ruled out, including red flags for malignancy or infection. Psychosocial aspects include psychiatric illness (ex. depression or anxiety), catastrophizing, disability and history of rape or abuse.
- General assessment of appearance and degree of discomfort, including a detailed dermatologic exam to assess for surgical/traumatic scars
- Vital signs to help to rule out systemic or visceral pathologies
- Abdominal examination including palpation, percussion and auscultation to evaluate both superficial musculature as well as to rule out visceral pathologies including masses, hernias, ascites, hepatomegaly or splenomegaly. Carnett’s Sign (worsened abdominal pain with tension of abdominal muscles) can help distinguish visceral from abdominal wall pain.
- Comprehensive musculoskeletal assessment, as per Baker, “musculoskeletal dysfunctions contribute to signs and symptoms of CPP and in many cases may be the primary factor.18”
- Pelvic and genital examination including bimanual examination for cervical, adnexal and uterine tenderness as well as pelvic floor muscle tenderness. Provocative pelvic maneuvers can include the P4 Test (hip flexed to 90 degrees while supine), Pace (abduct leg against resistance) and Freiberg (forced internal rotation of leg) maneuvers for piriformis syndrome, and pelvic floor muscle test.
- Rectal examination including prostate examination
- Special Tests: CVA percussion (Pasternacki’s sign) for renal pathology, rebound, guarding, Murphy’s sign for gall bladder pathology, Rovsing’s sign for appendicitis
- Evaluation with provocative maneuvers for myofascial pain (trigger points, referral patterns)
- Hip examination including ROM, muscle testing and FABERE/FADIR tests
- Psychiatric, psychosocial, and psychosexual assessment to evaluate for depression, anxiety, somatization, physical or sexual abuse, drug abuse or dependence, family problems, marital problems, or sexual problems.
Functional Assessment: Mobility, Self-care, Cognition/Behavior/Affective state
Severe abdominal and/or pelvic somatic pain, such as that caused by pelvic fractures or post-operative pain, may limit a patient’s independence with mobility and/or self-care. Both inpatient and outpatient evaluations of patients with severe pain should address this possibility. Chronic abdominal and/or pelvic pain has a strong association with psychological comorbidities, including anxiety, depression and disability.
Laboratory studies are used to rule out visceral and systemic causes of abdominal and pelvic pain, including (but not limited to): urinalysis, complete metabolic panel, amylase, lipase, stool occult blood, PAP smear, CRP, ESR, CK, CBC. If visceral source for pain is suspected, referral to an internist, gastroenterologist or gynecologist is appropriate.
Imaging may be ordered to rule out visceral pathology or for definitive diagnosis of musculoskeletal pathology. Musculoskeletal ultrasound is gaining increased utilization for abdominal wall sprains, strains and nerve injuries.3,6,7 Plain films will show most fractures as well as pubic symphysis diastases, though advanced imaging (MRI or CT) may be required in some cases if strong clinical suspicion persists despite negative X-rays.
Supplemental Assessment Tools
- Pelvic EMG to evaluate for pelvic floor dysfunction
- Pudendal nerve conduction study
- Perineometry (instrumental measurement of pelvic muscle tone and/or strength)
- Diagnostic nerve blocks
- Behavioral and psychological screening
- Pain Catastrophizing Scale10
- Musculoskeletal ultrasound
Early Prediction of Outcomes
Patients with prior psychiatric diagnoses, prior history of drug and/or alcohol abuse, unemployed status, higher pain catastrophizing scores, higher emotional distress, less family/social support and poor motivation may be more likely to progress to chronic pain state 10,11
For athletes with injuries inhibiting return to play, it is important to ensure the athletic directors, managers, patient and physicians are on the same page so as to allow proper healing and decrease the risk for re-injury.
For patients with chronic pain, a social worker or case manager may be utilized to assist with home assessments and to evaluate for safety in cases where physical or sexual abuse is apparent or suspected.
Social Role and Social Support System
Support groups or counseling may be available for patients with chronic pain or cancer pain, as well as patients with a history of physical abuse or rape. For patients for whom their pain inhibits or interferes with sexual activity, specialized support is needed and may be crucial.
Ethical and Legal Considerations
Patients with a history of polysubstance abuse may face physician bias when presenting with pain. Use of opiates in patients with a history of substance abuse is controversial and often under-prescribed for patients with real pain and this past medical history.
Unnecessary progression to opiate use may contribute to a patient’s progression to the chronic pain state, upsetting the balance between maleficence and beneficence.
Rehabilitation Management and Treatments
Available or Current Treatment Guidelines
The hallmark of treatment for somatic abdominal and pelvic pain relies on proper diagnosis of the underlying pathology.
- The treatment and rehabilitation program for abdominal and pelvic pain depend on the exact cause or the specific pain treatment used for medical management. Just like any treatment plan, conservative therapies or management (e.g. patient education, pharmacotherapy, psychotherapy, exercise, or physical therapy) should be trialed first before aggressive treatment. This can provide improved quality of life for the patient.
Postoperative pain and fractures may require more aggressive acute pain treatment to prevent progression to the chronic pain state. Pain from metastases to the pelvic girdle or abdominal wall may also require high amounts of pain medications and more aggressive treatments.
- When conservative treatment therapies fail, aggressive methods can be used. Such examples are ablative procedures, sacral neuromodulation, neurolysis, hysterectomy, vulvar/vestibular surgery, resection, and prostatectomy.16
At different disease stages:
- Activity modification
- It is important for patients to modify their type of activity when initial symptoms or new onset of abdominal/ pelvic pain occur. Patient education about activity modification plays a big role in treatment. In urogynecology disorders change in bladder diary and diet regimens should be encouraged for the patient.16 Patients should avoid consumption of acidic drinks, coffee, or alcohol to decrease the further complications of abdominal or pelvic floor related pain.
- Tylenol, NSAIDs first line
- Opiates may be indicated for severe pain, post-operative pain, fractures
- Muscle relaxants may be considered
- Gradual increase in activity
- Core or pelvic floor muscle strengthening
- Behavioral modification can play a critical role in the patient education. Such modified behaviors as timed urination and controlled fluid intake can provide symptomatic improvement in patients with weakness in pelvic floor muscles.16
- Physical therapy
- Core or pelvic floor muscle strengthening
- Includes all of the above
- Botulinum toxin type A for abdominal or pelvic wall muscle spasms8
- A study was conducted to see the effects of botulinum injections with patients that suffer myofascial pelvic pain resistant trigger points and found improvement was observed in 58% of patients with myofascial pelvic pain at eight weeks after the application of botulinum toxin to the iliococcygeus, puborectalis, obturator internus, and rectus muscles with physiotherapy program.16
- Interventional procedures and Surgical techniques
- Nerve blockades such as Ilioinguinal, iliohypogastric, genitofemoral nerve blocks, as well as sympathetic ganglion blocks (celiac/hypogastric plexus, Ganglion of Impar) may be considered in the treatment of CPP.16
- Spinal injections have success when a referred or radiculopathic pain is suspected. Caudal ESI (epidural steroid injection) play a particularly relevant role in CPP.
- Temporary yet consistent response to nerve blocks may guide the interventionalist to consider more permanent procedures, such as chemical neurolysis, pulsed frequency neuromodulation, or radiofrequency ablation.
- Considered as a permanent measure, neuromodulation with spinal cord stimulators or peripheral nerve stimulators can be considered if all other prior measures have been trialed, or if patient is found to be an exceptional candidate with a permanent disease/illness.
- Other surgical techniques may include pre-sacral neurectomy, laparoscopy and hysterectomy.12
Pre-Terminal or End-of-Life Care
- Cancer-related abdominal wall pain may require opiates or interventional procedures including nerve blocks. Palliative radiation may be considered with bony metastases.
Spectrum of Treatment Approaches
Treatment availability may vary greatly depending on regional resources. Physical therapists trained in pelvic floor rehab are often sparse, as may be physiatrists with knowledge in this area. Accordingly, these patients may be cared for by gynecologists and internists. It is important to advocate for the patient to utilize all resources available, and to proceed in a step-wise, risk-averse pattern.
- Benzon et al (2017) described an algorithm for a step-wise, interventional approach to CPP12:
- physical therapy ® trigger point injection ® lumbosacral epidural steroid injection ® peripheral nerve block ® sympathetic block ® spinal cord stimulator ® surgery ® intrathecal pump
Patient & Family Education
Both the patient and family members should be kept informed of diagnosis and disease progression, treatment options and potential complications of treating or not treating the disease process, as well as reasonable goals and expectations throughout the different stages of treatment and recovery.
Translation into Practice: Practice “Pearls”/Performance Improvement in Practice (PIPs)/Changes in Clinical Practice Behaviors and Skills
Treatment of somatic abdominal and pelvic pain requires adequate diagnosis of the underlying cause. The WHO analgesic ladder can be used as a guide for medication management.
A multidisciplinary, team-based approach is required to adequately care for patients with chronic somatic abdominal and pelvic pain. Close and frequent communication between patient, primary provider and consultants helps to provide necessary perspective for appropriate diagnosis and management. Members of this multidisciplinary team might include: Gynecologists, Psychologists, Physiotherapists, Urogynecologists, Gastroenterologists, Neurologists, Physiatrists, Social Workers, Internists, General Surgeons, and Pain Medicine physicians.
Gaps in the Evidence- Based Knowledge
There is a sparseness of high quality, evidence-based literature pertaining to somatic abdominal and pelvic pain, with much of the evidence coming from case studies or small case series.7 The amount of evidence-based literature pertaining to somatic abdominal and pelvic pain have increased over the years, but it remains inadequately low. Diagnosis in abdominal and pelvic somatic pain remains challenging, with much variability between physicians. Some of these challenges relate to: 1) knowledge/exposure of the physician in specific realms of anatomy and pathophysiology; 2) persistence and patience on the part of the patient and physician, considering a potentially lengthy diagnostic approach and inadequate analgesia with inaccurate diagnoses; 3) the complex nature of these body regions; 4) and the lack of evidence-based evaluation and treatment protocols.
Cutting Edge Concepts and Practice
- Several new medical therapies have demonstrated potential for a targeted pharmaceutical approach.12
- Ziconotide: an N-type calcium channel inhibitor (derived from conotoxin, from the snail Conus Magnus). Ziconotide prevents the release of Substance P and other nociceptive peptides.
- EMA401: a competitive antagonist of angiotensin 2 type 2 receptor (thought to be involved in neuropathic pain).
- Selective Nav1.7 Blockers: the Nav1.7 channel is a well-known sodium channel that is present in nociceptive neurons. With little to no presence in the CNS or vital organ systems, alluding to a safer side-effect profile, targeted therapies are being developed.
- Monoclonal Antibodies (MAB): Tanezumab is a monoclonal antibody directed against nerve growth factor. Several studies are underway in its efficacy for chronic abacterial prostatitis and interstitial cystitis.
- Neural blockade of the thoracolumbar nerves supplying the anterior abdominal wall through transversus abdominis plane (TAP) provides sensory blockade of the T6-L1 dermatomes.15 This procedure is typically used for acute pain management following abdominal surgery. However, case reports exist using this procedure for chronic pain syndromes.3 Following initial ultrasound guided TAP block, a pulse generator or infusion pump may be placed for long term pain relief.10
- Robot-assisted pelvic and abdominal surgeries may provide a less-invasive surgical solution with fewer risks of chronic post-surgical pain, possibly due to reduced intra- and post-surgical risk factors (more research is required).
- Complementary and alternative modalities are being utilized more commonly in the treatment of chronic pain syndromes, including CPP. Such modalities might include: Yoga, acupuncture, pelvic floor massage, topical heat (at 38.9 degrees C for 12 hours/day), electrical stimulation, and vitamin supplements/herbal therapies (ex. saw palmetto, thiamine, turmeric/curcumin…though these have yet to demonstrate validity).
- Ganong, William R. Review of Medical Physiology. New York: McGraw-Hill Medical, 2005. Print
- Scolaro, John A. MD, MA; Chao, Tom MD; Zamorano, David P. MD the Morel-Lavallée Lesion: Diagnosis and Management, Journal of the American Academy of Orthopaedic Surgeons: October 2016 – Volume 24 – Issue 10 – p 667-672 doi: 10.5435/JAAOS-D-15-00181
- Asensio-Samper JM, De Andrés-Ibáñez J, Fabregat Cid G, Villanueva Pérez V, Alarcón L. Ultrasound-guided transversus abdominis plane block for spinal infusion and neurostimulation implantation in two patients with chronic pain. Pain Pract. 2010 Mar-Apr;10(2):158-62.
- Sandford PR, Barry DT. Acute somatic pain can refer to sites of chronic abdominal pain. Arch Phys Med Rehabil. 1988 Jul;69(7):532-3.
- Bouman EA et al. Reduced incidence of chronic postsurgical pain after epidural analgesia for abdominal surgery. Pain Pract. 2014 Feb;14(2): E76-84.
- Conte SA, Thompson MM, Marks MA, Dines JS. Abdominal muscle strains in professional baseball: 1991-2010. Am J Sports Med. 2012 Mar;40(3):650-6.
- Ahumada LA, Ashruf S, Espinosa-de-los-Monteros A, Long JN, de la Torre JI, Garth WP, Vasconez LO. “Athletic pubalgia: definition and surgical treatment”. Ann Plast Surg. 2005;55 (4): 393–6.
- Bhide AA, Puccini F, Khullar V, Elneil S, Digesu GA. Botulinum neurotoxin type A injection of the pelvic floor muscle in pain due to spasticity: a review of the current literature. Int Urogynecol J. 2013 Sep;24(9):1429-34.
- Moore, Keith L. and Arthur F. Daley. Clinically Oriented Anatomy, Fifth Edition. Maryland: Lippincott Williams & Wilkins, 2006. Print.
- The Pain Catastrophizing Scale: Development and validation. Sullivan ML, Bishop SR, Pivik J. Psychological Assessment. Dec 1995; 7(4): 524-532.
- Guirguis MN, Abd-Elsayed AA, Girgis G, Soliman LM. Ultrasound-guided transversus abdominis plane catheter for chronic abdominal pain. Pain Pract. 2013 Mar;13(3):235-8.
- Benzon, H.; Raja, S.; Fishman, S.; Liu, S.; Cohen, S.; Essentials of Pain Medicine, Fourth Edition. Philidelphia: Elsevier, 2018.
- Zhang R, Sutcliffe S, Giovannucci E, et al.: Lifestyle and risk of chronic prostatitis/chronic pelvic pain syndrome in a cohort of United States male health professionals. J Urol 194:1295–1300, 2015.
- Schaeffer AJ: Etiology and management of chronic pelvic pain syndrome in men. Urology 63:75–84, 2004.
- Tsai HC, Yoshida T, Chuang TY, et al. Transversus Abdominis Plane Block: An Updated Review of Anatomy and Techniques. Biomed Res Int. 2017; 2017:8284363. doi:10.1155/2017/8284363
- Bradley MH, Rawlins A, Brinker CA. Physical Therapy Treatment of Pelvic Pain. Phys Med Rehabil Clin N Am. 2017 Aug;28(3):589-601. doi: 10.1016/j.pmr.2017.03.009. Epub 2017 May 12. PMID: 28676366.
- Stovall TG, Ling FW, Crawford DA: Hysterectomy for chronic pelvic pain of presumed uterine etiology. Obstet Gynecol 75:676–679, 1990.
- Baker PK: Musculoskeletal origins of chronic pelvic pain. Diagnosis and treatment. Obstet Gynecol Clin North Am 20:719–742, 1993
Original Version of the Topic:
Stephanie E. Rand, MD. Somatic Abdominal and Pelvic Pain. Published 4/14/2016.
Ameet Nagpal, MD, MS, Med
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Jason N. Beckstrand, DO
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Adedeji O. Olusanya, DO, MPH
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