Medical Rehabilitation – Lumbar Axial Pain

CHAPTER 90 Medical Rehabilitation – Lumbar Axial Pain




INTRODUCTION


Axial low back pain is a common complaint of patients visiting physicians who practice musculoskeletal and pain medicine. The majority of these patients are diagnosed with non-specific back pain, which is presumed to be caused by muscle or ligament soft tissue damage, while many of these patients will actually have pain associated to injury to the posterior elements or the disc. These patients are thought to have a good prognosis for recovery; they improve in 4–12 weeks after the onset of pain, and the strategies of treatment used focus only on short-term management. In reality, many of these patients have future episodes of back pain associated with recurrent injury to the disc and associated structures and some will present with chronic back pain. Patients with unresolved pain may develop significant changes in the quality of their life including reduced health perception, happiness, social participation, and restriction of function.1 In addition, significant direct and indirect healthcare costs are associated with chronic low back pain.2


Low back pain should be considered a symptom of a clinical problem and not a specific diagnosis. Clinicians dealing with the rehabilitation of patients with low back pain should avoid non-specific terminology to describe the patient’s diagnosis such as lumbar strain, lumbago, or myositis. An understanding of the epidemiology of back pain, functional anatomy, and biomechanics of the spine, as well as the pathophysiology of the disease process is required to appropriately manage back pain. In addition, a complete history, physical examination, and appropriate diagnostic studies are paramount for the clinician who rehabilitates patients with this common disorder. Attempts should be made to establish a specific diagnosis for the cause of the axial back pain, which includes the site of injury with the pain generator, the clinical symptoms which require appropriate treatment, biomechanical changes associated to the tissue injury, and finally the functional abnormalities which result from the disease process.


The overwhelming majority of patients with back pain will not require surgery and should be managed with conservative treatments which include rehabilitation and functional restoration.35 The goals of rehabilitation are to return the individual with low back pain to normal function. This requires achieving control of pain, adequate flexibility, strength, and muscle balance as well as neuromuscular coordination that would allow the return to normal activities. Evaluation, management, and rehabilitation of low back pain also require that the clinician understands the vocational and avocational demands of the patients and their goals.


Unfortunately, there is limited positive scientific evidence on the results of a structured rehabilitation program in the management of back pain. In this chapter, the authors will review some of the scientific evidence available that relates to therapeutic interventions used in rehabilitation such as physical modalities, rest and physical activity, exercise, manual therapy, and education. In addition, the authors will discuss their approach to the patient with back pain, and how they combine the available scientific information with their clinical experience in the management of this very common and often difficult patient problem.



FACTORS INFLUENCING REHABILITATION



Epidemiology


Understanding the patterns of injury and clinical presentation of low back pain is important for the planning of therapeutic, rehabilitative, and preventive strategies. Low back disorders are prevalent in all societies and the etiology of these disorders is multifactorial including individual/intrinsic as well as external/extrinsic factors.


The annual incidence of low back pain in the general population is 5%, with many patients presenting between the ages of 30 and 50 years, and a significant number of cases resolving within 4 weeks of presentation. Of these patients, particularly the ones who present with pain at an early age, a significant number will present with recurrence of the symptoms, and some will develop chronic disability. Therefore, a functional rehabilitation program should be instituted early in the disease process.68


Some individual risk factors for pain are modifiable and include obesity, cigarette smoking, and low fitness level.9,10 Occupational factors associated with back pain include vibration, static work posture, flexed posture, frequent bending and twisting, lifting and material handling.11,12 Psychosocial factors associated with back pain and recurrence of symptoms include dissatisfaction with work, long duration of initial treatment, recurrent treatment, and being disabled from work.1315 Other factors, such as heredity, may not be modifiable but also play a role in the development of low back pain. Familial predisposition to back pain and degenerative disc disease has been described and may be important in patients who present at an early age (Table 90.1).1619


Table 90.1 Risk Factors for Axial Low Back Pain





























Epidemiologic Evidence
Individual/Intrinsic External/Extrinsic
Age Static work postures
Gender Prolonged sitting
Abdominal girth Frequent lifting, pushing and pulling
Smoking Frequent trunk rotation
Muscle weakness/loss of endurance Vibration exposure
Reduced/excessive flexibility Repeated lumbar flexion
Sedentary life style Activity early in the day

Sports and recreational activities are also associated with the development of back pain, wherein 10–15% of all sports injuries are related to the spine. Rotational, torsional, and compressive stresses to the spine are associated with the development of intrinsic disc disease.20,21 Activities in daily life that involve frequent bending and lifting may also lead to back pain. Individuals caring for elderly or disabled family members present with an increased prevalence of back pain.22



Functional anatomy and biomechanics


A review of the anatomy and biomechanics of the spine is beyond the scope of this chapter; however, an understanding of the functional anatomy as well as basic concepts of biomechanics of the lumbar spine is important for the clinician who treats and rehabilitates patients with low back pain.


The basic functional unit of the lumbar spine is the three-joint complex formed by two consecutive vertebra, the intervertebral disc, and the zygapophyseal joints. The anterior elements of the lumbar spine sustain the compression loads applied to the vertebral column including body weight and loads associated with contraction of the back muscles. The posterior elements regulate the passive and active forces applied to the vertebral column and regulate motion. The zygapophyseal joints are typical synovial joints endowed with cartilage, capsule, meniscoids, and synovial membrane. The articular facets exhibit variations in both the shape of their articular surfaces and their orientation. In the lumbar spine the only movement permitted is a sliding motion in a vertical direction, executed during flexion and extension.23


Muscle function is very important for the lumbar spine since ligaments provide little static stability and in the absence of muscle activity the spine could buckle with low compressive loads. The erector spinae are composed of two major groups: the longissimus and iliocostalis. They are primarily thoracic muscles that act on the lumbar spine with a long moment arm ideal for lumbar spine extension. The small rotatores and intertransversarii muscles are basically length transducers and position sensors. The multifidi which cross 2 or 3 segmental levels are theorized to work as spinal stabilizers.24


Other muscle groups important for low back function are the quadratus lumborum, which has a direct insertion in the lumbar spine and acts as a weak lateral flexor, and the abdominal muscles which include: the transversus abdominus, internal and external oblique, and rectus abdominus. These muscles are important in flexion of the trunk, lateral bending, but most importantly help to stabilize the lumbar spine. Pelvic muscles also play a role in the kinetic chain by acting on the lumbar spine and transmitting forces from the lower extremity to the trunk and upper extremities and include: the hip flexors such as the iliopsoas, and gluteal hip extensor, as well as abductor muscles.25


The lumbar spine and related structures including ligaments and muscles receive an extensive nerve supply. The vertebral bodies, the intervertebral disc, the zygapophyseal joints, and the ligaments are all innervated and have the capacity to be pain generators, making it difficult for the clinician treating axial back pain to identify the origin of a patient’s symptoms.



Pathophysiology of injury


Flexion of the lumbar spine, which involves sagittal rotation and translation, is well tolerated by the lumbar elements. Compression of the lumbar spine occurs by adding body weight, muscular contraction, and the loads that are lifted by the individual. Excessive compression may injure the anterior vertebral elements, particularly the endplates. When flexion and compression are combined with rotation, shear applied to the intervertebral disc results in injury to this structure. Vertebral extension is limited primarily by bony impaction of the spinal processes or the inferior articular facet against the lamina below, and repeated extension as well as rotation activities may lead to injury of the posterior elements such as the pars intercularis.26


Lumbar disc disease associated with axial back pain is multifactorial in origin. Aging, apoptosis, abnormalities in collagen, vascular ingrowth, loads placed on the disc, and abnormal proteoglycan all contribute to disc degeneration.27 Repetitive or continuous axial overloading, associated with disc fatigue, is key in the pathogenesis of lumbosacral degenerative disease.24 Vigorous occupational activity and competitive athletic participation associated with end-range flexion and frequent turning predispose the disc to herniation and accelerated degeneration.28


These changes in the disc, which progress from herniation to subsequent internal disruption and resorption, may affect more than one functional unit and compromise spinal motion. The combined changes in the posterior joint and discs lead to arthritis, lateral recess stenosis, and central stenosis.2931


Low back pain may result from compression of nerve tissue, inflammation of the nerve root, and the facet joint, as well as damage to the anulus fibrosus. Inflammatory mediators, such as prostaglandins and substance P, have been identified in patients with disc disease and are associated with pain in the absence of a compressive lesion.28,32


Increasing age has been associated with progressive disc degeneration which can be asymptomatic in some individuals. Changes in trabecular bone morphology and inappropriate disc matrix may be related to apoptosis, or programmed cell death, in the patient with disc disease.27,33



Clinical presentation


In the individual with axial back pain, the history and physical examination are very important in the planning of a functional rehabilitation program. Pertinent information that should be obtained from the history include: the type of pain, the mechanism of injury, exacerbating and mitigating factors, and previous injuries and response to treatment strategies. The physical examination should identify limitations of motion, direction of pain exacerbation, lack of flexibility, muscle weakness and imbalance, ligamentous laxity, and neurologic as well as proprioceptive deficits. This information combined with pain diagrams, diagnostic imaging, and injection procedures allows the clinician to recognize specific characteristics of different clinical subsets.34 Clinical subsets of axial back pain include patients with acute annular tears, intrinsic disc disease, facet joint degeneration, or posterior element injury.


Patients with axial back pain associated with disc disease may present with acute symptoms, chronic symptoms, or acute exacerbation of chronic symptomatology. The patient with an acute annular disc injury will present with axial pain, limited lumbar motion, intolerance to sitting, and exacerbation of symptoms with attempted flexion of the spine. The physical examination of these individuals may reveal a lateral trunk list, pain with flexion of the spine, normal neurologic examination, and typically no evidence of spinal nerve root irritation.


The patient with chronic discogenic disease will present with axial back pain, intolerance to sitting as well as pain upon arising from a chair, limited capability to lift, bend, or twist.35 Physical examination will reveal soft tissue inflexibility of paravertebral muscles, fascia and ligaments as well as some muscle spasm. There may be evidence of lumbar segmental hypomobility, loss of lumbar lordosis, and pain with flexion and rotation. The neurologic examination is usually normal with no evidence of root irritation.36 Individuals who present with an acute on chronic injury give the history of an excessive load or sudden trauma superimposed on previous discogenic symptoms. The physical examination is usually similar to patients that presents with an acute annular tear.


Patients who present with axial back pain may also have involvement of posterior elements such as the facet joints. These individuals may present with pain in the back which may radiate to the buttocks or thighs that could worsen with extension activities such as walking downhill, prone lying, and prolonged standing. Other patients may present with a different history such as pain with flexion that is not exacerbated by sitting and still have facet joint pathology. The physical examination may reveal inflexibility of the lumbar soft tissues, hypomobility of spine segments, and pain with extension or flexion as well as rotation maneuvers. The neurologic examination and special maneuvers to identify root irritation are usually normal, and injection procedures may be required to clearly identify the facet joint as the pain generator.37


In sports, the patterns of back injury will depend on several factors which include the patient’s age and sport-specific demands. Athletes involved in sports that require trunk rotation and hyperextension usually present with axial back pain associated to posterior element injury. Repeated stresses associated to gymnastics, diving, and wrestling places the athlete at increased risk of pars interarticularis injury such as spondylolisis. These athletes may present with acute or gradual onset of pain and limited motion which restricts activity.38


Older individuals who exercise vigorously or participate in sports will generally present with injuries of the vertebral endplate and the intervertebral discs. These individuals usually present with symptoms associated to repeated flexion and trunk rotation. They may present with episodes of axial back pain and limited motion which may be accompanied by leg symptoms.39




BASIC CONCEPTS OF REHABILITATION




Phases of rehabilitation


Musculoskeletal rehabilitation combines therapeutic modalities and exercise in order to return the individual to normal function. It should start early in the disease process in order to reduce the deleterious effects of inactivity and immobilization. A medical rehabilitation program should state the goals and objectives of treatment specific for each phase of rehabilitation. The treatment should focus on optimizing the healing process, restoring the biomechanical relations between the normal and injured tissue, and finally preventing recurrence of pain and chronic disability. A functional rehabilitation program emphasizes therapeutic exercise and physical activity while monitoring for exacerbation of symptoms. Rehabilitation of the patient with back pain can be divided into acute, recovery, and functional phases (Table 90.3).


Table 90.3 Goals in Rehabilitation of Musculoskeletal Injury















Acute Phase Recovery Phase Functional Phase
Treat clinical symptoms Allow tissue healing Correct abnormal biomechanics
Protect injured tissue Restore normal strength and flexibility Prevent recurrent injury

The acute phase addresses the clinical symptom complex and should focus on treating tissue injury. The goal at this stage should be to allow tissue healing while reducing pain and inflammation. Reestablishment of nonpainful range of motion, prevention of muscle atrophy, and maintenance of general fitness should be emphasized. Symptom control and patient education about the condition should be accomplished prior to progressing to the next rehabilitation phase.


The subacute or recovery phase should focus on obtaining normal passive and active range of motion, improving muscle control, achieving normal muscle balance, and working on core strength as well as proprioception. Biomechanical and functional deficits including inflexibilities and inability to bend or lift should begin to be addressed. Functional activities should be initiated in this stage and progression without recurrence of symptoms is required prior to advancing to the next stage.


The functional or maintenance phase should focus on increasing power and endurance while improving neuromuscular control. Rehabilitation at this stage should work on the entire kinematic chain, addressing specific residual functional deficits. The individual should be pain free, exhibit full range of motion, normal strength, and muscle balance prior to returning to full activity.


After return to activity, disease prevention and ‘prehabilitation’ strategies to avoid recurrence of symptoms in the previously injured individual should be developed. Exercise programs which combine flexibility, stabilization, dynamic strengthening, and balance training, as well as appropriate biomechanics should be encouraged in the patient who has recovered from low back pain.



REHABILITATION OF AXIAL BACK PAIN


The functional rehabilitation model of patient management should be implemented as soon as the patient presents for clinical evaluation of back pain. As previously discussed, identification of the pain generator should be attempted based on the information obtained from the history, physical examination, laboratory studies, imaging data, and diagnostic injections.41 However, in many instances, the pain generator cannot be definitely identified, and a functional approach to the rehabilitation should be undertaken after developing a working diagnosis. Patterns of pain provocation with motion, muscle weakness, inflexibility, abnormal biomechanics, and functional abnormalities can be identified, used as a starting point for treatment, and addressed in a progressive manner.



Acute phase


The acute phase of treatment is the period when pain should be addressed, and the injured tissue should be protected from further damage, with the purpose of optimizing the healing process and allowing the patient to progress in the rehabilitation program. It is important to understand that a balance must be achieved between treating the pain with medications, among other passive rehabilitation therapeutic interventions, and encouraging active patient participation in their treatment early in the recovery process (Table 90.4).


Table 90.4 Rehabilitation of Back Injury – Acute Phase






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Sep 8, 2016 | Posted by in PHYSICAL MEDICINE & REHABILITATION | Comments Off on Medical Rehabilitation – Lumbar Axial Pain

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