Management of Back Pain in Primary Care and Long-Term Care Settings Using a Syndrome Recognition Approach

The prevalence of back pain is estimated to be 12% to 28% among the US population.¹ It is estimated that 80% of the long-term care (LTC) population will have musculoskeletal pain, with low back pain accounting for one-third of cases.² Mechanical back pain accounts for the great majority (more than 90%) of cases, most of which will resolve with conservative management.³

Back pain is categorized as acute, subacute, or chronic. Acute back pain is defined as back pain that lasts less than 4 weeks; subacute back pain refers to back pain that last 4 to 12 weeks; and chronic back pain is defined as back pain that lasts greater than 12 weeks.¹ Risk factors for back pain include smoking, obesity, a strenuous job, a sedentary job, low socioeconomic status, workers’ compensation insurance, job dissatisfaction, and psychological disorders such as anxiety, depression, and somatization disorder.¹ When evaluating a patient with back pain, it is important to distinguish between nonspecific back pain and serious systemic etiologies such as spinal cord/cauda equina syndrome, vertebral compression fractures, metastatic cancer, spinal or epidural abscess, and osteomyelitis.¹ This article focuses on the diagnosis and categorization of mechanical causes of back pain in the LTC population.

Anatomy of the Spine 

In order to understand back pain, it is important to recognize the biomechanical relationship between the anatomy of the spine and its supporting structures. The spine has 2 lordotic curves in the cervical and lumbar region and a kyphotic curve in the thoracic region. These curves act as shock absorbers for the spine during physical activity. The body of each vertebra is cushioned by intervertebral disks whose inner nucleus pulposus acts to cushion compressive forces. An outer annulus fibrosus acts as support against the tensile forces placed on the spine during activity. The spinal cord passes through the spinal canal of the vertebral column, giving rise to spinal nerves passing through each intervertebral foramen to innervate tissues, muscles, and organs. Each spinal nerve root innervates a dermatomal region of the body. Compression of the nerve root corresponds to a dermatome 1 level below the nerve root compression in the cervical region at the level of nerve root compression in the thoracic region, and 1 level above the nerve root compression in the lumbar region of the spinal cord.^4,5

The spine is supported anteriorly by the anterior longitudinal ligament, posteriorly by the posterior longitudinal ligament, and laterally by the ligamentum flavum. It is important to note that the anterior longitudinal ligament is stronger and thicker than the posterior longitudinal ligament, which results in increased stability of the anterior aspect of the spine at the cost of mobility during posterior extension. Because of this support structure design, any disk herniation is more likely to be posterior and lateral.^4,5

The spine is also supported by various muscles with fibers running in multiple directions. The co-contraction of interspinales, intertransversarii, and multifidus muscle groups help with even distribution of the compressive force on the intervertebral disks. Transverse-abdominis muscle fibers run horizontally. During contraction, they increase intra-abdominal pressure to provide additional stability for the spine. The rectus abdominis muscle fibers run vertically and, in conjunction with external and internal obliques, which have fibers running in an oblique direction opposite to each other, provide additional support for the spine and pelvis in every plane of motion.^4,5

In addition to analyzing the muscles that support the spine, it is equally important to understand the forces that act on the pelvis, since it is connected to the spine via muscles and bony structures,^4,5 Posteriorly, the pelvis is supported by the gluteal and hamstring muscles.^4,5 Anteriorly, the pelvis is supported by the abdominal muscles described above, along with the iliopsoas and quadriceps muscles.^4,5 Tight iliopsoas muscles, along with decreased lumbar flexion and extension, have been shown to be negatively correlated with low back pain in athletes.⁶ It is important to note that the gluteal muscles and the hamstrings antagonize the actions of the iliopsoas and the quadriceps, respectively.⁶ Imbalances in muscle length will impose forces on bony attachment sites, causing malalignments including sacral torsion, pelvic tilt, and vertebral rotation. For example, a shortened quadratus lumborum and iliopsoas will create an anterior pelvic tilt and pull the lumbar vertebrae anteriorly. This posture narrows the intervertebral foramen and encroaches on spinal nerves attempting to exit the area. In anterior tilt, the patient’s gluteal muscles may also be engaged in an attempt to return the pelvis to a neutral position. Radiating pain due to this bony malalignment will cause muscles crossing these joints to splint the area in protection. Splinting, or guarding, creates ischemic conditions in the involved muscles, contributing to development of back pain.^7,8

Forces on the Spine

It is also important to understand the forces that act on the spine (Figure 1). Compressive and tensile forces act along the axis of the spine; shear forces are perpendicular to the axis of the spine; and torsional forces are rotational forces around the axis of the spine.⁹ The spine is able to handle higher compressive/tensile forces than shear or torsional forces.⁹

During static activities where the spine is not in a neutral position, compressive, shear, and torsional forces are acting on the spine.^9,10 Shear and torsional forces on the spine are exaggerated after a laminectomy or other back operations.^10,11 Furthermore, degeneration of the back structures can be accelerated after surgery.¹¹

Patterns of Back Pain

Knowledge and recognition of cases of back pain by the provider will result in the appropriate use of resources and minimize the cost of treatment. Only 10% of all referrals to spine surgery need operative therapy.³ Only 5% of low back pain cases can be attributed to a serious cause such as inflammatory disease, malignancy, or infection.³ With that said, it is important to note that 5% to 10% of patients with back pain can have a nonmechanical cause for that pain.³ Those patients should undergo further workup.

Acute mechanical back pain can be divided into 2 categories, leg-dominant pain and back-dominant pain. These 2 categories can be subdivided into 2 more categories based on the history and physical examination findings. By understanding the anatomy, support structure, and biomechanics of the spine, providers can categorize acute back pain into 1 of 4 patterns established by the Quebec Task Force and based on patient history, physical characteristics, and physical examination findings (Table 1).¹² This approach can individualize treatment, as opposed to using the “nonspecific back pain” or one-size-fits-all approach.³

Pattern 1 Back Pain

Pattern 1 back pain impacts the greatest number of patients and accounts for the majority of mechanical back pain cases.³ Patients with pattern 1 back pain will have either intermittent or constant back-dominant pain with normal neurologic examination findings.³ Pain is usually aggravated by forward flexion and alleviated by standing or extension.³

Pattern 1 back pain can be further subdivided into 2 categories, prone extension positive (PEP) and prone extension negative (PEN).³ Patients with PEP will have significant alleviation of the back pain with prone extension. Prone extensions performed multiple times per day can have a therapeutic benefit for these patients.³ In patients with PEN, prone extensions will not alleviate the back pain, and the back pain is aggravated with forward flexion.³

The mechanism of pattern 1 back pain is related to the inflammation of or damage to the intervertebral disks.⁷ Given that patients with pattern 1 back pain often experience aggravation with forward flexion, physical therapy should focus on exercises that keep the spine in neutral position or in extension position.^3,13

Pattern 2 Back Pain

Pattern 2 back pain is back-dominant without radiation to the lower extremities.³ Pattern 2 back pain is always intermittent and aggravated by extension.³ Patients with pattern 2 back pain may experience relief with forward flexion. Neurologic examination findings in these patients will be normal.³ The cause of pattern 2 back pain is most likely related to inflammation of the facet joints between the vertebrae caused by degenerative joint disease.¹³ Most patients in LTC who experience low back pain without radicular symptoms likely have pattern 2 back pain, given the older age and greater potential for degenerative joint disease and facet joint arthritis in this population.^2,3,14 Management should focus on decreasing inflammation with a nonsteroidal anti-inflammatory drug (NSAID).^2,3,14,15 Physical therapy should focus on exercises that keep the spine in neutral position or in flexion to relieve pain.^3,13

Pattern 3 Back Pain

Pattern 3 back pain is a constant leg-dominant pain aggravated by movement.³ The mechanism of pattern 3 back pain is related to a prolapsed intervertebral disk compressing the intervertebral spinal nerve roots.¹³ Patients with pattern 3 back pain will have constant pain with positive neurologic signs such as decreased sensation in a specific dermatome and/or decreased motor reflexes.^3,13 Patients with pattern 3 back pain will also have a positive straight leg raise test.³ Disk herniation is most prevalent in adults aged 30 to 50 years.¹⁶ Ninety percent of patients will have clinical improvement in 6 weeks without surgical intervention.¹⁶ Surgical management will provide faster relief; however, long-term outcomes are similar to those of conservative management.¹⁷

Pattern 4 Back Pain

Pattern 4 back pain is characterized by intermittent leg-dominant pain and is distinguished from pattern 3 pain, where the leg-dominant pain is constant.³ Like pattern 1 back pain, pattern 4 back pain can be divided into PEP or PEN.³ PEP pattern 4 back pain is rare. It is defined as exacerbation of the leg pain with forward flexion and improvement with unloaded extensions in the prone extension position.³ PEP pattern 4 back pain can occur in patients with long-standing chronic damage to normal nerve activity or in patients who had pattern 3 back pain that has improved.³ Patients with pattern 4 PEP will have variable neurologic test results ranging from normal to decreased or loss of sensation.³

Patients with pattern 4 PEN will have intermittent leg-dominant pain associated with neurogenic claudication, defined as pain brought on by activity and alleviation with rest.³ Patients with PEN pattern 4 back pain commonly report weakness manifested by loss of balance during activity; however, their neurologic test results during rest are normal.³ Repetitive prone extensions will result in aggravation of the pain in these patients.³ Unlike patients with pattern 3 back pain, patients with pattern 4 PEN will have a normal straight leg raise test result.³ Pattern 4 PEN is more common than pattern 4 PEP, and its mechanism is thought to be related to spinal stenosis, spondylosis, or spondylolisthesis.¹³

Given the degenerative mechanism of pattern 4 back pain, it is likely to be prevalent among older adults who are in LTC.¹⁸ Conservative management involves pain management and physical therapy.^3,13,18 Physical therapy should focus on exercises that keep the spine in neutral or in flexion to avoid aggravation of the pain.^3,18 A surgical approach can be considered in patients who fail conservative management after 3 months.¹⁹

Clinical Points in History and Physical Examination

Given the importance of history-taking and physical examination in syndrome recognition, one must obtain information regarding certain areas as a part of history-taking in a patient with back pain (Box 1).³

Physical examination should include testing the lumbar spinal range of motion, prone extension test (Image 1), assessment of strength, and neurologic testing.³ Neurologic testing involves testing of reflexes, straight leg raise test, sensation, and motor strength.³ Given that most lower back injuries occur at the L4, L5, or S1 level, one should focus the examination at those levels.³

In the LTC setting, neurologic testing may be limited to testing ankle-jerk reflex (which tests the S1 nerve root) and knee-jerk reflex (which tests the L4 nerve root), testing the strength of ankle/great toe dorsiflexion, testing light touch sensation of the feet (with medial, dorsal, and lateral areas of the foot corresponding to the L4, L5, and S1 nerve roots, respectively), and performing a straight leg raise test.¹⁵ These abbreviated tests will detect most pathologies that account for nerve compression causing radiculopathy.¹⁵

While a large majority of patients with mechanical back pain will fall into 1 of the 4 patterns of back pain, the primary care physician should keep in mind several red flags that warrant emergent diagnostic workup, treatment, and subspecialty support (Box 2).^5,15,20

Management

Most mechanical back pain will respond to conservative therapy.^21,22 Conservative therapy includes cognitive behavioral therapy, physical therapy, and pharmacologic therapy.^21,22 Using the approach discussed above, the primary care physician, in conjunction with a multidisciplinary team, can identify movements that aid in alleviation of the patient’s back pain and incorporate those movements into the patient’s rehabilitation protocol.³ This conservative therapy, used as the first-line approach to treating back pain, can reduce the risk of further degeneration of the back structures that can be accelerated with surgical interventions.¹¹ 

Patterns 1 and 2 back pain constitute the majority of mechanical back pain presentations and are most likely to respond to conservative management without the need for surgical intervention.³ An initial conservative approach should be considered for patterns 3 and 4 back pain, but such cases may require more-invasive intervention.³ Pharmacologic choices can include NSAIDs and serotonin- and norepinephrine-reuptake inhibitors for relief of neuropathic pain, as well as short-term opioid therapy.^21,22

Conclusion

As back pain represents a high portion of cases of musculoskeletal pain in the LTC population, understanding the categorization of back pain into 4 patterns by way of a complete history and physical examination will help clinicians recognize the symptoms. By doing so, a clinician, in conjunction with a multidisciplinary team, can identify movements that aid in alleviating the patient’s back pain and make appropriate use of medical resources, including medication, physical therapy, and behavioral therapy, for successful recovery from back pain without invasive procedures. 

References

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15. Bratton RL. Assessment and management of acute low back pain. Am Fam Physician. 1999;60(8):2299-2308.

16. Jordan J, Konstantinou K, O’Dowd J. Herniated lumbar disc. BMJ Clin Evid. 2009;2009:1118.

17. Gugliotta M, da Costa BR, Dabis E, et al. Surgical versus conservative treatment for lumbar disc herniation: a prospective cohort study. BMJ Open. 2016;6(12):e012938.

18. Kalichman L, Hunter DJ. Diagnosis and conservative management of degenerative lumbar spondylolisthesis. Eur Spine J. 2008;17(3):327-335.

19. Omidi-Kashani F, Ebrahimzadeh MH, Salari S. Lumbar spondylolysis and spondylolytic spondylolisthesis: who should be have surgery? An algorithmic approach. Asian Spine J. 2014;8(6):856-863.

20. Portenoy RK, Dhingra LK. Overview of cancer pain syndromes. UpToDate. https://www.uptodate.com/contents/overview-of-cancer-pain-syndromes. Updated August 22, 2017. Accessed February 19, 2019.

21. Chou R. Subacute and chronic low back pain: nonpharmacologic and pharmacologic treatment. UpToDate. https://www.uptodate.com/contents/subacute-and-chronic-low-back-pain-nonpharmacologic-and-pharmacologic-treatment . Updated August 29, 2018. Accessed February 19, 2019. 

22. Qaseem A, Wilt TJ, McLean RM, Forciea MA; Clinical Guidelines Committee of the American College of Physicians. Noninvasive treatments for acute, subacute, and chronic low back pain: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2017;166(7):514-530.