Current Diagnosis & Treatment of Pain, 1st Edition

6. Rehabilitation Issues: Pain Control

Steven P. Stanos DO

Mark D. Tyburski MD

Essential Criteria

  • The ultimate goal of a rehabilitation-based approach to acute and chronic pain is reduction of pain and restoration of function.
  • Chronic pain states may represent a more integrated biologic, psychological, and social constellation of problems including environmental and social context as well as the patient's emotions, personal meaning, beliefs, and attitudes.
  • A unidimensional biomedical model approach to pain focuses on pain as a sensory event reflecting underlying disease or tissue damage.
  • Multidisciplinary pain treatment programs embody a biopsychosocial approach to assessment and treatment and may be a more appropriate setting for management of complex chronic pain conditions.
  • Realistic treatment goals for patients with acute and chronic pain are essential.

General Considerations

The subjective experience of pain results from a complex interaction of physical, emotional, and social factors. For example, two patients with similar diagnostic findings on lumbar magnetic resonance imaging (degenerative disc disease, small annular tear) may have significantly different levels of pain and functional disability. One patient may complain of localized lumbar pain with minimal effect on daily activities. The other patient may be more impaired, reporting elevated pain scores and affective distress, functional decline, and disturbed nonrestorative sleep. Although functional restoration is a goal for both patients, the treatment approaches may differ drastically. In addition to a general understanding of pain as an individual experience, a general working knowledge of common clinically used pain terms is essential for appropriate assessment, documentation, and treatment (Table 6-1). Rehabilitation professionals are frequently involved in the care of patients suffering from both acute and persistent pain conditions. For patients with acute pain resulting from discrete posttraumatic tissue injury or surgery, treatment may include a short course of physical or occupational therapy combined with oral pain medications. For patients complaining of persistent pain, coordinated, multidisciplinary assessment and management may be required.

The Rehabilitation Team

The physiatrist plays a critical role in assessing and treating patients with acute and chronic pain and leads the team of health care professionals. Physical and occupational therapists are the principal members of the rehabilitation team; they help restore structure and function to injured patients suffering from painful conditions (Table 6-2). Physical and occupational therapists use passive and active exercises and passive modalities to guide patients through the process of recovery and rehabilitation. Targeted therapeutic exercises are used to address specific deficits in posture, flexibility, strength, balance, neuromuscular coordination, and endurance. Passive modalities such as cryotherapy, heat, and electrical stimulation are commonly used to address pain, alter tissue distensibility, and control inflammation (see Treatment section).

Occupational therapists focus on educating patients regarding proper posture and ergonomics related to functional activities. Family and caregiver education may be an additional component of the long-term rehabilitation program.

Pain psychologists focus on both cognitive and behavioral factors related to pain. A person's thoughts may impact mood, behavior, and function. Psychological intervention focuses on unlearning maladaptive responses and reactions to pain while fostering wellness, improving coping and perceived control, as well as decreasing catastrophic thoughts.

Therapeutic recreation therapists are important members of the rehabilitation team. They evaluate and plan leisure activities that serve to promote mental and physical health. Recreational therapists help patients establish and incorporate strategies learned from various disciplines of treatment into social and community functions. Application of these techniques (ie, correct biomechanics, pacing, relaxation techniques) leads to the reduction of stress, fear of movement, and depression

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while fostering a feeling of self-efficacy and confidence. In addition, therapeutic recreation therapists facilitate the recovery of motor function and reasoning skills, increase social awareness, and promote integration of patients with disabilities back into the community.

Table 6-1. Common Clinical Terms Used to Describe Pain.

Term

Description

Allodynia

Pain due to a stimulus that does not normally provoke pain

Analgesia

Absence of pain in response to stimulation that would normally be painful

Anesthesia dolorosa

Pain in an area or region that is anesthetic

Central pain

Pain initiated or caused by a primary lesion or dysfunction in the central nervous system

Dysesthesia

An unpleasant abnormal sensation, whether spontaneous or evoked

Hyperalgesia

An increased response to a stimulus that is normally painful

Hyperesthesia

Increased sensitivity to stimulation, excluding the special senses

Hyperpathia

A painful syndrome characterized by an abnormally painful reaction to a stimulus, especially a repetitive stimulus, as well as an increased threshold

Hypoalgesia

Diminished pain in response to a normally painful stimulus

Hypoesthesia

Decreased sensitivity to stimulation, excluding the special senses

Neuropathic pain

Pain initiated or caused by a primary lesion or dysfunction in the nervous system

Neuropathy

A disturbance of function or pathologic change in a nerve: in one nerve, mononeuropathy; in several nerves, mononeuropathy multiplex; if diffuse and bilateral, polyneuropathy

Nociceptor

A receptor preferentially sensitive to a noxious stimulus or to a stimulus that would become noxious if prolonged

Noxious stimulus

A noxious stimulus damages normal tissues

Pain threshold

The least experience of pain that a person can recognize (subjective experience of the individual)

Pain tolerance level

The greatest level of pain that a person is prepared to tolerate (subjective experience of the individual)

Paresthesia

An abnormal sensation, whether spontaneous or evoked

Peripheral neuropathic pain

Pain initiated or caused by a primary lesion or dysfunction in the peripheral nervous system

Reprinted, with permission, from Classification of Chronic Pain, 2nd ed. IASP Task Force on Taxonomy. Merskey H, Bogduk N (editors). IASP Press, Seattle. 1994:209-214.

Rehabilitation Framework

Acute Pain

In cases of acute pain, in which the type of injury has been accurately determined, the rehabilitation plan progresses through three major stages as the injury heals: acute, recovery, and functional (Table 6-3). The framework for rehabilitation is intimately related to the injury cycle. The injury cycle comprises the following categories: method of presentation, clinical symptom complex, tissue overload complex, functional biomechanical deficit complex, and subclinical adaptation complex. While this rehabilitation framework is commonly applied to sports injuries, it is applicable to general acute musculoskeletal injuries (such as shoulder impingement syndrome and discogenic low back pain with radicular leg pain) sustained by nonathletes.

Care must be taken to ensure that the focus is not principally applied to the acute stage of rehabilitation, in which the patient is experiencing acute pain from the tissue injury complex. Failure to remain dedicated to the recovery and functional stages of rehabilitation may lead to maladapted biomechanical alterations and continuation of the injury cycle, resulting in chronic injury and persistent pain conditions.

Chronic Pain

Multidisciplinary functional restoration programs based on cognitive and behavioral principles have been increasingly used in the treatment of patients with

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chronic pain and related psychosocial dysfunction. Members of these comprehensive teams include physiatrists; physical, occupational, and recreational therapists; pain psychologists; biofeedback specialists; social workers; nursing educators; and vocational counselors (Table 6-4). These comprehensive programs have shown clear benefits over conventional management in regard to decreasing pain behavior, improving mood, and restoring function. Scope and intensity varies, with most outpatient-based centers offering part time (2 days per week) or full-time (5 days per week, 6-8 hours per day) programs lasting 4-6 weeks. Goals of treatment include reduction in pain, maximal restoration of function, return to leisure activities, reduction in medication and health care resources, return to work, and possible vocational retraining.

Table 6-2. Rehabilitation Professionals and Their Areas of Expertise.

Therapist

Areas of expertise

Physical

Cervical spine
Lumbar spine
Lower extremity
Upper extremity (large joint)
Gait analysis and training
Lower extremity bracing
Provide adaptive equipment
Instruct family and caregivers

Occupational

Upper extremity (large and small joint)
Fine motor skills
Vision
Memory and reasoning skills
ADL evaluation and training
Work site evaluation
Fabrication of upper extremity splints
Provide adaptive equipment
Instruct family and caregivers

Recreational

Evaluation and application of leisure
interests
Group or individual based therapy
Community reintegration and function
Encourage functional independence
Pacing during activities
Relaxation strategies
Use of adaptive equipment

Frontera WR. Exercise and musculoskeletal rehabilitation: restoring optimal form and function. Phys Sports Med. 2003;31(12):39.

Turner-Stokes L et al. Outpatient cognitive behavioral pain management programs: a randomized comparison of a group-based multidisciplinary versus an individual therapy model. Arch Phys Med Rehabil. 2003;84:781.

Table 6-3. The Three Stages of Rehabilitation for Musculoskeletal Injury.

ACUTE

Treatment focus
   Clinical symptom complex
   Tissue injury complex

Tools
   Rest or immobilization, or both
   Physical modalities
   Medications
   Manual therapy
   Initial exercise
   Surgery

Criteria for advancement
   Pain control
   Adequate tissue healing
   Near-normal range of motion
   Tolerance for strengthening

RECOVERY
Treatment focus
   Tissue overload complex
   Functional biomechanical deficit complex

Tools
   Manual therapy
   Flexibility
   Proprioception/neuromuscular control training
   Specific, progressive exercise

Criteria for advancement
   No pain
   Complete tissue healing
   Essentially full, pain-free range of motion
   Good flexibility
   75-80% or greater strength compared with uninjured side
   Good strength balance

FUNCTIONAL
Treatment focus
   Functional biomechanical deficit complex
   Subclinical adaptation complex

Tools
   Power and endurance exercises
   Sports or activity-specific functional progression
   Technique/skills instruction

Criteria for return to play/previous recreational activity/activities of daily living
   No pain
   Full, pain-free range of motion/normal flexibility
   Normal strength and strength balance
   Good general fitness
   Normal sports/activity mechanics
   Demonstration of sport- or activity-related skills

Kibler WB et al. Functional rehabilitation of sports and musculoskeletal injuries. Aspen Publishers. 1998.

Table 6-4. Members of a Comprehensive Multidisciplinary Pain Treatment Team.

Physiatrist

Physical therapist

Occupational therapist

Pain psychologist

Biofeedback and relaxation training specialist

Therapeutic recreation therapist

Social worker

Vocational counselor

Nurse facilitator/educator

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Assessment

The diverse nature of any pain condition requires a comprehensive assessment in order to direct a tailored treatment plan. Identification of the injury type and method of presentation is the first step in the treatment of pain and rehabilitation of injury, since appreciably different approaches may be required for successful intervention. Understanding the injury cycle will help facilitate this process (see above section Rehabilitation Framework).

Injuries are typically classified as acute, subclinical adaptation to repetitive activity, chronic, or acute exacerbation of chronic injury. Table 6-5 compares acute and chronic pain. Most acute musculoskeletal injuries are generally identified and successfully treated before they progress to a subacute or chronic phase. Acute pain generally results from posttraumatic injuries, such as muscle strain, ligament sprain, muscular contusion, or fracture.

Subclinical adaptation to repetitive activity is a type of injury that may not produce significant symptoms in patients but should be identified and addressed in order to avoid future injury. Adaptations include postural abnormalities, joint contractures, and muscle weakness. For example, many athletes who throw a ball overhand display strength imbalances (weak external rotators) and alterations in flexibility (glenohumeral internal rotation deficit) before seeking medical attention for shoulder pain. Functional exercises to address these biomechanical abnormalities may decrease the risk of future rotator cuff injury.

The assessment and treatment of patients with chronic pain complaints is much more complex. In many cases, chronic pain is not a simple biomedical problem, and isolated unimodal medical and surgical treatment interventions may be unsuccessful. Since complete alleviation of pain is usually not possible, treatment strategies must focus on functional restoration and psychosocial distress.

Therefore, the practitioner should use a comprehensive assessment that focuses on functional impairments

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of the musculoskeletal system as well as appropriate psychosocial screening tools (Table 6-6). In addition to the standard components of the physical examination (Table 6-7), the physiatric assessment includes the directed examination of the suspected tissue injury complex, a comprehensive functional kinetic chain evaluation, and identification of postural imbalances.

Table 6-5. Comparison of Acute and Chronic Pain.

Acute pain

Chronic pain

Result of acute macrotrauma

Result of microtrauma, secondary adaptions with injury to other tissues

Focused diagnosis

Complex diagnosis

Responds to biomedical treatment model

Requires biopsychosocial assessment and management model

Minimal psychosocial interference

Comorbid depression, anxiety, avoidance behavior, maladaptive cognitions

Medications target pain and inflammation

Multimodal pharmacologic treatment addresses pain, affective distress, and disturbed sleep

NSAIDs, nonopioid and opioid analgesics, muscle relaxants

Nonopioid analgesics, judicious use of opioids, antidepressants, anticonvulsants

Low addiction risk

Polyaddiction risk

Complete resolution of pain likely

“Cure” unlikely; adjust expectations to management with reduced pain levels

Focused functional rehabilitation approach

Multidisciplinary approach incorporating functional restoration and cognitive behavioral interventions

NSAIDs, nonsteroidal anti-inflammatory drugs.

Table 6-6. General Psychosocial Screening Tools.

Category

Screening tool

Psychosocial history

Comprehensive pain questionnaire
CAGE questionnaire
Michigan Alcoholism Screening Test (MAST)
Self-Administered Alcohol Screening Test (SAAST)
Structured Clinical Interview for DSM-IV (SCID)

Pain intensity

Numerical rating scales (NRS)
Visual analogue scales (VAS)
Verbal rating scales (VRS)
Pain drawings

Mood and personality

Minnesota Multiphasic Personality Inventory (MMPI)
Symptom Checklist 90 (SCL-90)
Millon Behavioral Health Inventory (MBHI)
Beck Depression Inventory (BDI)
McGill Pain Questionnaire (MPQ)
Jung-Myers-Briggs Typology Test

Functional capacity

Sickness Impact Profile (SIP)
Short Form Health Survey (SF-36)
Multidimensional Pain Inventory (MPI)
Pain Disability Index (PDI)

Pain beliefs and coping

Coping Strategies Questionnaire
Pain Management Inventory (PMI)
Pain Self-Efficacy Questionnaire (PSEQ)
Survey of Pain Attitudes (SOPA)
Inventory of Negative Thought in Response to Pain (INTRP)

Observation of pain behavior is an important part of the multidimensional assessment. Pain behaviors include verbal complaints (eg, moaning), motor behaviors (eg, guarding affected body part, limping), and help seeking (eg, requesting medications and rest). Pain behaviors serve to communicate to others the pain and suffering that is being experienced and is based on contingencies of positive and negative reinforcement.

Table 6-7. Comprehensive Physical Assessment.

Pain behavior

Postural abnormalities

Gait assessment

Motor strength

Muscle stretch reflexes

Range of motion

Sensory exam

Soft tissue assessment

Selection of appropriate psychosocial tools may be patient specific. For the young, athletic patient with an obvious acute musculoskeletal injury due to macrotrauma (ie, ankle sprain), the use of a visual analogue scale and pain drawing may be sufficient when combined with social history, medical and surgical histories, medication history, and general review of systems. Alternatively, a more in-depth psychological assessment may be required for a 35-year-old physical laborer who has had several episodes of back pain over the course of 1 year, who reports depression and increased fear of reinjury, who has poor compliance with his active home exercise program, and who requests early refills for pain medication.

Hills CE. Adult physiatric history and examination. http://www.eMedicine.com2003http://www.emedicine.com/pmr/topic146.htm.

International Association for the Study of Pain IASP Pain

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Terminology http://www.iasp-pain.org/terms-p.html

Keefe FJ et al. Psychological aspects of persistent pain: current state of the science. J Pain. 2004;5:195.

Kibler WB. A framework for sports medicine. Phys Med Rehabil Clin North Am. 1994;5:1-8.

Stanos SP, Muellner PM, Harden RN. The physiatric approach to low back pain. Semin Pain Med. 2004;2:186-196.

Turk DC et al. Psychological factors in chronic pain: evolution and revolution. J Consult Clin Psych. 2002;70:678.

Treatment

Passive Physical Modalities

Physical modalities are an integral part of the management and rehabilitation of both acute and persistent pain conditions. A modality is a physical agent used to produce a physiologic response in a targeted tissue. Commonly prescribed passive physical modalities for the treat-mentofacute and chronic pain include cryotherapy, heat, and electrical stimulation. Modalities are initially incorporated into therapy sessions by physical or occupational therapists, with a goal of educating the patient on appropriate application and use at home. Depending on the specific pain complaint, modalities may be used as part of a daily treatment regimen (cryotherapy for osteoarthritic knee after exercise, electrical stimulation for low back pain resulting from prolonged upright postures) or as a rescue treatment for flare-ups.

Cryotherapy

  1. Physiology

Most forms of cryotherapy (eg, ice, cold packs, cold whirlpool baths, cryotherapy-compression units, vapocoolant spray) provide transfer of thermal energy by conduction, with the exception of vapocoolant sprays (evaporative cooling) and whirlpool baths (convective cooling). The physiologic effects of cold application include immediate vasoconstriction with reflexive vasodilation, decreased local metabolism and enzymatic activity, and decreased oxygen demand. Cold decreases muscle spindle fiber activity and slows nerve conduction velocity, therefore it is often used to decrease spasticity and muscle guarding.

  1. Patient Selection
  2. Indications—

Because connective tissue stiffness and muscle viscosity are increased with cold application, cryotherapy should be used during the first 48 hours after a musculoskeletal injury. In addition, cryotherapy plays an important role in the management of many persistant pain problems such as osteoarthritis. Other indications include edema, hemorrhage, muscle spasm, spasticity, and reduction of metabolic activity (Table 6-8).

Table 6-8. Indications for Cryotherapy.

Acute trauma

Edema

Hemorrhage

Pain (eg, osteoarthritis)

Muscle spasm

Spasticity

Reduction of metabolic activity

  1. Contraindications—

Cryotherapy should be avoided in patients with cryoglobulinemia, paroxysmal cold hemoglobinuria, cold hypersensitivity, ischemia, and Raynaud disease or phenomenon (Table 6-9).

  1. Precaution—

Cryotherapy may be considered in patients with arterial vascular disease, impaired sensation, cold intolerance, peripheral neuropathy, and cognitive deficits (ie, inability to report pain) but must be used cautiously (Table 6-9).

  1. Technique

Care must be taken when considering the application of cold therapy to areas overlying superficial nerves and areas of reduced or absent sensation. Cold application should not exceed 30 minutes, and peripheral nerves should be protected in the area of treatment. Cold packs and ice massage applied over 20 minutes have been shown to

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cool muscle by 4 to 5°C at a depth of 2 cm. Cryostretch and cryokinetics are approaches used by therapists to facilitate joint motion. By decreasing pain and muscle guarding, improvements in flexibility and function may be achieved.

Table 6-9. Contraindications and Precautions for Cryotherapy.

Contraindications

Cryoglobulinemia

Paroxysmal cold hemoglobinuria

Cold hypersensitivity

Ischemia

Raynaud disease or phenomenon

Precautions

Arterial vascular disease

Impaired sensation

Cold intolerance

Peripheral neuropathy

Cognitive deficits/inability to report pain

  1. Complications

Cryotherapy accounts for the majority of complications reported due to the use of passive physical modalities. The most common complications include local skin allergic reactions, burns, and intolerance. Other potential complications include exacerbation of Raynaud phenomenon, frostbite, and diaphoresis.

Heat

  1. Physiology

Commonly used mechanisms of heat transfer include conduction, convection, and conversion. Conduction is the transfer of heat directly from one surface to another; examples include hydrocollator packs and paraffin baths. Convection is the transfer of heat due to movement of air or water across a body surface; examples include hydrotherapy and fluidotherapy. Conversion involves the transformation of energy to heat; examples include infrared lamps, electromagnetic microwaves, and most commonly ultrasound.

The heating of a structure results in both local and distant effects. Vasodilation, increased capillary permeability, and increased metabolic demands promote increased blood flow with the delivery of oxygen and leukocytes.

  1. Patient Selection
  2. Indications—

Heat therapy is used to treat pain, contracture, hematoma, chronic inflammation, muscle spasm, and arthritis. It is also used to increase collagen extensibility before a stretching program (Table 6-10).

  1. Contraindications—

Avoid heat therapy under the following clinical circumstances: acute trauma and inflammation, hemorrhage, and bleeding diathesis (Table 6-11).

Table 6-10. Indications for Heat Therapy.

Pain

Contracture

Hematoma

Chronic inflammation

Muscle spasm

Increase collagen extensibility prior to stretching program

Arthritis

Table 6-11. Contraindications and Precautions for Heat Therapy.

Contraindications

Acute trauma and inflammation

Hemorrhage

Bleeding diathesis

Precautions

Impaired sensation

Altered thermal regulation (eg, spinal cord injury, traumatic brain injury, multiple sclerosis)

Malignancy

Ischemia

Atrophic or scarred skin

Cognitive deficits (ie, inability to report pain)

  1. Precautions—

Heat therapy may be considered in patients with impaired sensation, altered thermal regulation, malignancy, ischemia, atrophic or scarred skin, and cognitive deficits (inability to report pain) but should be used with caution.

  1. Benefits

Heat therapy is beneficial for assisting with pain control, facilitating muscle relaxation, and promoting collagen extensibility.

  1. Technique

The heat modalities are generally classified as either superficial or deep.

  1. Superficial heat—

Direct heat penetration is greatest at a depth of 0.5 to 2 cm from the skin surface and depends on the amount of adipose tissue. The most commonly used superficial heat modalities for musculoskeletal rehabilitation include hydrocollator packs, hydrotherapy, paraffin baths, and fluidotherapy.

  1. Hydrocollator packs—

Available in three standard sizes and are heated in stainless steel containers in water at temperatures between 65 and 90°C. The highest tem peratures found during the use of packs are at the surface of the skin. Towels are applied between the skin and pack to minimize skin trauma and maintain heat insulation. Common duration of treatment sessions ranges from 20 to 30 min.

  1. Hydrotherapy—

Treatment entails submerging small or large body surface areas. The risk of elevating core body temperature increases with the amount of surface area heated. Water temperature should not exceed 40°C for large body surfaces and 43°C when a limb is submerged. Hydrotherapy provides a gravity-eliminated

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environment that facilitates joint range of motion. Agitation provided by water flow provides sensory input.

  1. Paraffin baths—

A mixture of paraffin and mineral oil deliver heat to small joints such as those in the hand. Mineral oil creates a lower melting point for the paraffin, providing increased thermal release when compared with water. Temperatures are maintained at 52 to 58°C for upper limb applications and 45 to 52°C for lower limb treatments. Paraffin baths are contraindicated for patients with open wounds and severe peripheral vascular disease.

  1. Fluidotherapy—

This modality is dry heat therapy. It involves placing an extremity into a fluidotherapy unit in which Cellex medium (a dry powder of glass beads) is circulated using hot air, resulting in warm massage. Mechanical stimulation is thought to augment the heat for increased pain control.

  1. Deep heat

The process of conversion is used to heat deep tissue structures. These modalities include ultrasound (most common), phonophoresis, and short wave and microwave diathermy.

  1. Ultrasound (US)—

Ultrasound therapy may be used in the treatment of contractures, tendinitis, degenerative arthritis, and subacute trauma (Table 6-12).

Ultrasound is defined as acoustic vibration with frequencies above the audible range of 20,000 Hz. The production of heat occurs by applying an electric current to a quartz crystal (or synthetic ceramic), which produces vibration at a specified frequency. The ultrasonic energy is absorbed by the tissue and ultimately converted to heat. Selective heating is greatest when acoustic impedance is high, such as at the bone-muscle interface. Conversely, ultrasonic energy is readily conducted through homogeneous structures such as subcutaneous adipose or metal implants with minimal thermal effects due to rapid removal of heat energy.

Table 6-12. Indications and Precautions for Ultrasound Therapy.

Indications

Contractures (muscular, tendinous, capsular)

Tendinitis

Degenerative arthritis

Subacute trauma

Precautions

Malignancy

Open epiphysis

Pacemaker

Near spine, laminectomy site

Radiculopathy

Near brain, eyes, or reproductive organs

Pregnant or menstruating women

Arthroplasties, which often use methyl methacrylate or high-density polyethylene

General heat therapy precautions

Ultrasound can be used safely near metal implants. However, in the presence of methyl methacrylate and high-density polyethylene, which are often used in total joint replacements, a higher amount of ultrasound energy is absorbed, contributing to a potential for overheating (Table 6-12). Ultrasound can heat to depths of 5 cm below the skin surface, providing a therapeutic benefit to bone, joint capsule, tendon, ligament, and scar tissue.

In addition to thermal transfer, ultrasound produces other physiologic effects. Gaseous cavitation involves gas bubbles created by high frequency sound or turbulence, which may cause pressure changes within tissues leading to mechanical distortion, changes in cellular function, and cell death. Acoustic streaming causes movement of material due to pressure asymmetries produced by sound as it passes through the medium. Ultrasound physiology effects have the potential to creat plasma membrane damage and acceleration of metabolic processes. Standing waves are produced by superimposition of sound waves and can cause heating at tissue interfaces at different densities.

Ultrasound dosage is measured in W/cm2. Intensities of 0.8 to 3.0 W/cm2 are most commonly used. Application is started at approximately 0.5 W/cm2 and gradually increased while the practitioner monitors patient response. Treatment duration of 5 to 10 min is common and is based on the size of treatment area.

  1. Phonophoresis—

Medication is delivered into the deeper layers of the skin using US. Phonophoresis is helpful in treating postinjury conditions (eg, dislocations, distortions of joints), pain caused by rheumatic diseases, and low back pain that has a neurologic origin (eg, root pain, discopathies).

  1. Short wave and microwave diathermy—

Short wave diathermy uses an oscillating electromagnetic field of high frequency to heat large areas of the body surface. It heats to a tissue depth of 2 to 3 cm. Microwave diathermy uses electromagnetic radiation by microwaves and heats to a greater tissue depth than short wave diathermy. It is particularly useful in heating tissues with high water content, such as muscles, subcutaneous fat, and fluid-filled cavities.

Electrical Stimulation

The most commonly applied electrical modalities in the treatment of pain include transcutaneous electrical nerve

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stimulation (TENS) and interferential current therapy (ICT). TENS and ICT involve the transmission of electrical energy to the peripheral nervous system via an external stimulator and conductive gel pads on the skin.

  1. Physiology

There are multiple presumed mechanisms of action at the peripheral, spinal, and supraspinal levels. Stimulation of large myelinated fibers may block nociceptive transmission at the level of the spinothalamic tract cell bodies via stimulation of inhibitory interneurons (gate control theory). The three routes of neuromodulation include presynaptic inhibition of the spinal cord, direct inhibition of excited abnormally firing nerves, and facilitation of afferent input. Other postulated mechanisms of analgesia include direct peripheral effects of stimulation as well as increased release of endogenous opioids within the central nervous system with suppression of transmission and perception of noxious stimuli from the periphery. The indications for the use of TENS and ICT are similar, and the decision to use one form of electrical stimulation over another is largely based on clinical preference.

  1. Technique
  2. TENS

This treatment is typically applied in two manners: low-intensity, high-frequency “conventional” TENS (1 to 2 mA, 50 to 100 Hz) and high-intensity, low-frequency “dense-disperse” TENS (15 to 20 mA, 1 to 5 Hz).

High-frequency TENS is used to achieve quick analgesia for acute pain states. Treatment duration is 1 to 20 minutes for rapid analgesia and 30 minutes to 2 hours for short analgesia. Treatment should occur as frequently as needed to maintain a pain free state. Adaptation commonly occurs, so an increase in amplitude or pulse width may be necessary to maintain paresthesia.

Table 6-13. Indications for Electrical Stimulation Therapy.

Rheumatoid and osteoarthritis pain

Myofascial pain

Dysmenorrhea

Visceral pain

Deafferentiated pain syndromes (phantom limb)

Sympathetically mediated pain

Tension headache

Acute postoperative pain

Raynaud disease

Ischemic pain

Urogenital dysfunction

Table 6-14. Contraindications and Precautions for Electrical Stimulation Therapy.

Contraindications

TENS and ICT

Demand-type cardiac pacemaker

Avoid carotid sinus, laryngeal or pharyngeal muscles, eyes, and mucosal membranes

Incompetent patients

Myocardial disease or arrhythmias without proper monitoring

ICT

Should not be used over rib-cage in children with small body mass

Arterial or venous thrombosis or thrombophlebitis

Abdominal, lumbosacral, or pelvic areas of pregnant women

Precautions

TENS

Safety during pregnancy has not been established

Skin irritation (avoid by rotating treatment area)

ICT

Skin irritation (avoid by rotating treatment area)

Can increase metabolism and may exacerbate fever, infection, tuberculosis, neoplasm

Avoid areas of extreme edema

Avoid open wounds

TENS, transcutaneous electrical nerve stimulation; ICT, interferential current therapy.

Low-frequency TENS is more commonly used for chronic pain conditions. Treatment times range from 30 minutes for slower analgesia effect to 2 to 6 hours for long duration analgesia. Adaptation is minimal and treatment frequency is typically once daily. TENS has shown beneficial effects in numerous conditions and has been shown to decrease the amount of analgesic medication needed after surgical procedures. Indications and precautions are summarized in Tables 6-13and 6-14.

  1. ICT

A variant of TENS, ICT involves the mixing of two unmodulated sine waves with different frequencies (one at 4 kHz, and a second within a variable range) to generate frequencies between 4 and 250 Hz. This allows for the stimulation of deeper tissues with decreased

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discomfort. The proposed mechanism of action involves the direct stimulation of muscle fibers, as opposed to nerve fibers, to achieve improved muscle blood flow and promotion of the healing process. Variable frequency helps prevent adaptation. Compared with TENS, there is less scientific evidence for the use of ICT. Indications and precautions are similar to those for TENS (Tables 6-13 and 6-14).

Brosseau L et al. Thermotherapy for treatment of osteoarthritis. Cochrane Database Syst Rev. 2003;(4):CD004522.

Cheing GLY et al. Analgesic effects of transcutaneous electrical nerve stimulation and interferential currents on heat pain in healthy subjects. J Rehabil Med.2003;35:15.

Klein MJ. Deep heat. eMedicine. 2001 http://www.emedicine.com/pmr/topic203.htm

Klein MJ. Superficial heat and cold. eMedicine 2004. http://www.emedicine.com/pmr/topic201.htm

Nadler SF et al. Complications from therapeutic modalities: results of a national survey of athletic trainers. Arch Phys Med Rehabil. 2003;84:849.

Active Adjunctive Therapies

  1. Mind-Body Techniques

Mind-body techniques play an important role in the management of persistent pain conditions and are often incorporated into comprehensive multidisciplinary treatment programs. Biofeedback is often used in acute pain conditions. For example, biofeedback training following surgery to repair the anterior cruciate ligament may help improve motor recruitment of the vastus medial is muscle in an attempt to improve patellofemoral joint stability and function. Patients can be trained in mind-body techniques by health care providers who are certified in the specific field or by licensed therapists (ie, physical, occupational, or recreational therapists and psychologists).

Biofeedback

  1. Physiology

Biofeedback is most concisely defined by Olton and Noonberg as “any technique [that] increases the ability of a person to control voluntarily physiological activities by providing information about those activities.” Commonphysiologic target responses include muscle tension, heart rate, blood pressure, skin temperature, and skin conductance. Through the use of specific instrumentation and computers, these physiologic responses are brought closer to conscious awareness and control by their conversion into auditory or visual feedback.

  1. Benefits

The beneficial actions of biofeedback stem from the ability to decrease overall arousal and muscle tension, improve blood flow to tissue, and promote a generalized state of relaxation. The numerous clinical approaches described for biofeedback training apply equally to relaxation therapy and include diaphragmatic breathing, imagery, and autogenic training. Biofeedback has been shown to be effective in low back pain, upper extremity disorders, headache, temporomandibular disorders, and fibromyalgia. Regardless of the technique used, successful incorporation of relaxation techniques into a patient's treatment plan, offers the patient more active self-management tools. The techniques are applicable to daily self-management of chronic pain, as well as during more problematic periods of flare-ups.

Relaxation Therapy

  1. Patient Selection

Patients with persistent pain and elevated levels of anxiety and related muscle tension may find relief in relaxation therapy.

  1. Benefits

Relaxation therapies are easy to learn, use minimal health care resources, and have no side effects.

  1. Technique

The two chief methods of relaxation therapy are categorized as deep and brief. Deep methods include autogenic training and progressive muscle relaxation; brief methods include paced respiration and self-control relaxation.

  1. Autogenic training—

The patient imagines being in a peaceful place with pleasant body sensations. Breathing is centered and the pulse is regulated. The patient focuses on his or her body and attempts to make differing parts of the body feel heavy, warm, or cool.

  1. Progressive muscle relaxation—

The patient focuses on contracting and relaxing each of the major muscle groups in an attempt to better understand the feeling of tension, which can then facilitate subsequent relaxation.

  1. Self-control meditation—

This can be best described as a shortened form of progressive muscle relaxation (see above).

  1. Paced respiration—

The patient breathes slowly and deliberately for a specific time period.

  1. Deep breathing—

The patient takes a deep breath, holds it for 3 to 5 seconds, then slowly releases it. The sequences may be repeated several times to achieve a more relaxed state.

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Meditation

Common forms of meditation include mindfulness meditation, transcendental meditation, yoga, and walking meditation.

  1. Patient Selection

Patients with chronic pain can perform meditation daily to help maintain a basal level of pain control. It can also be useful in the management of flare-ups.

  1. Technique

The ultimate goal is mind-body relaxation and the passive removal of harmful thought processes.

  1. Mindfulness meditation—

Involves the concentration on body sensations and thoughts that occur in the moment. The patient learns to observe these sensations and thoughts without judging them.

  1. Yoga and walking meditation—

Both are derived from Zen Buddhism and use controlled breathing and slow, deliberate movements and postures to focus the body and mind.

  1. Transcendental meditation—

Involves focusing on a sound or thought and the repetition of a word, mantra, or sound.

Guided Imagery

  1. Patient Selection

Patients with persistent pain typically use guided imagery on a daily basis and may need to increase the number of sessions during acute pain flare-ups.

  1. Technique

Guided imagery involves the generation of specific mental images with the goal of evoking a general psychophysiologic state of relaxation. Examples of these visualizations include imagining the immune system attacking cancer cells or the performance of specific daily activities without pain. The visualizations are initially directed by a practitioner, with the goal of eventual self-guidance.

Hypnosis

  1. Patient Selection

Studies support the use of hypnosis in the treatment of patients with chronic pain, postoperative pain, anxiety, and tension headache.

  1. Technique

Medical hypnosis involves an altered state of consciousness in which the patient assumes a state of heightened awareness and attentive focal concentration, with a relative decrease in peripheral awareness. The three main phases of hypnotherapy include presuggestion, suggestion, and postsuggestion.

The goal of the presuggestion phase is to achieve an altered state in which the patient is relaxed and the mind is susceptible to suggestion. Techniques include distraction, imagery, and relaxation therapy. During the suggestion phase, the practitioner introduces specific goals related to their pain state. The postsuggestion phase occurs when the patient returns to the normal state of consciousness and at this time may practice the new behaviors that were introduced in the suggestion phase.

Techniques used for pain relief include direct and indirect suggestion, interpersonal techniques, hypnoanesthesia, guided imagery, and regression to cause. Typical goals in the treatment of pain states include transformation, alteration or displacement of pain, directly addressing pain and suggesting it to decrease, and the ability of the patient to direct attention away from their pain.

Astin JA et al. Mind-body medicine: state of the science, implications for practice. J Am Board Fam Pract. 2003;16:131.

  1. Movement-Based Therapy

Reduction of movement in acute pain is initially thought to serve as a protective function. With the development of chronic pain, reduced movement and guarding the affected extremity or body part serves no adaptive purpose and may contribute to ongoing disability and pain. Two important components are altered biomechanics (secondary to guarding) and fear avoidance behaviors. Guarding the affected limb may lead to compensatory postural imbalances, stressing related muscles and joints most commonly proximal to the original site of injury. These changes may cause an additional source of pain and contribute to a reduction in movement and loss of function.

Important maladaptive psychological aspect of chronic pain syndromes include fear avoidance behaviors and related elevated levels of anxiety. Fear avoidance behavior results in a cyclic cascade of reduced mobility and function. This reduced movement is likely to contribute to an overall decrease in range of motion, muscle strength, and aerobic fitness as well as heightened central nervous system functioning characterized by hypervigilance and increased autonomic arousal. Hypervigilance may predispose patients to attend more closely and self-monitor minor somatic events that would normally be ignored.

Movement-based therapies are instrumental in returning specific subsets of persistent pain patients to more active lifestyles. Through the use of low-level exercise therapies, patients can slowly reintroduce movement back into their lifestyle. These techniques improve

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balance and teach more efficient ways to use injured joints or muscles to offset loads; improve biomechanical function; and decrease pain, anxiety, and fear of movement or activity.

There are relatively few contraindications for the following movement-based therapies because programs are tailored to the individuals' abilities. Patients with severe osteoporosis or acute joint injuries or fractures should proceed with caution. Pregnant women, those with abdominal or inguinal hernias, and those recovering from recent abdominal surgery should avoid downward straining or holding prolonged postures. Less active patients who do not routinely exercise should avoid overworking when starting a movement-based therapy program. Potential risks include, but are not limited to, muscle soreness, muscle strains, ligament sprains, and back pain.

Yoga

The word yoga is derived from the Sanskrit “yug,” which means “to join.” The Indian sage Patanjali, who is considered the father of classical yoga philosophy, compiled the Yoga Sutra, a philosophical guidebook for the practice of yoga.

The Yoga Sutra describes the eight major branches of the philosophy:

  1. Pranayama (breathing exercises)
  2. Asana (physical postures)
  3. Yama (moral behavior)
  4. Niyama (healthy habit)
  5. Dharana (concentration)
  6. Pratyahara (sense withdrawal)
  7. Dhyana (contemplation)
  8. Samadhi (higher consciousness)

There are numerous variations of yoga that are currently practiced, each having different weightings of the eight branches.

  1. Benefits

Through consistent practice, yoga programs have been reported to reduce blood pressure, heart rate, and anxiety while improving range of motion, muscular endurance, and lung capacity.

  1. Technique

At its root, yoga consists of the performance of various postures, stretches, and controlled breathing. Yoga can be practiced in groups or on an individual basis.

Tai-Chi

The origins of T'ai Chi Chuan, commonly referred to as Tai-chi, predate the seventeenth century. While T'ai Chi Chuan translates as “supreme ultimate boxing,” the method incorporates both a Chinese martial art as well as a health regimen with a common set of principles and movements.

  1. Patient Selection

Recently, Tai-chi has gained more focus in the Western world as a method to improve balance and well-being in various populations, including the elderly and the disabled.

  1. Benefits

Studies evaluating short-term Tai-chi programs have reported improvements in balance, strength, flexibility, and overall quality of life as well as decreases in pain secondary to osteoarthritis, anxiety, depression, anger, and general pain perception.

Due to the slow, low impact nature of Tai-chi, it can be applied to all categories of pain conditions, especially those in which patients suffer from significant anxiety and fear-avoidance behaviors. Tai-chi aims to establish balance between the mind and the body.

  1. Technique

Tai-chi is known for its rhythmic, slow, coordinated, dance-like movement sequences performed with sharp mental focus.

Feldenkrais Method

The Feldenkrais method is a system of body retraining that was created by Moshe Feldenkrais, a physicist. The goal is to improve body awareness and psychological well-being through gentle stretching, reaching, and postural change sequences.

  1. Patient Selection

The Feldenkrais method is an appropriate movement-based therapy for the physical rehabilitation of patients with acute or persistent pain.

  1. Technique

The two complementary components of the Feldenkrais method, awareness through movement and functional integration, may be practiced together or independently of each other. Both components attempt to achieve the same results of improved function, comfort, body awareness, anxiety reduction, and mood improvement.

  1. Awareness through movement

Involves group-based sessions led by a Feldenkrais practitioner who guides patients through slow, sequenced movements that include normal activities of daily living as well as abstract

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patterns. As patients improve body awareness, they are able to adjust and find patterns and motions of comfort that allow them to perform activities of daily living more efficiently and with reduced discomfort.

  1. Functional integration—

These sessions are private classes with the Feldenkrais practitioner. Sequenced movements are instructed with hands-on input and feed back from the practitioner, with the goal of finding functional, mechanically efficient ways to perform activities of daily living with less discomfort.

Alexander Technique

This method was developed in the late 1800s by F. M. Alexander, a Shakespearean orator who suffered from recurrent laryngitis. Through careful observation of himself, he realized that poor habitual patterns of posture and movement were the reason for his vocal dysfunction. Through committed reeducation of posture and movement, he was successfully able to solve his vocal problem. He later refined and developed his technique of identification and correction of biomechanical deficits to help others alter poor postural habits and detrimental movement patterns.

Instructors in the Alexander technique use verbal instructions and light touch to guide patients through various movements with the goal of correcting postural and biomechanical imbalances. The position of the head and spine is thought to be important in the determination of overall functioning, and recognition that when a change is made in one body part, the rest of the body is then affected. Through repetition of movements, functional benefits can be achieved through reeducation of mechanics.

Cotter AC. Western movement therapies.Phys Med Rehabil Clin North Am. 1999;10:603.

Garfinkel M et al. Yoga. Rheum Dis Clin North Am. 2000;26:125.

  1. Aquatic Therapy

Aquatic therapy is generally provided by physical therapists, occupational therapists, or athletic trainers. Therapy prescriptions should include general safety precautions and one of three categories: “wet to dry” transition, “dry to wet” transition, or “wet only” therapy. Protocols generally are adapted to the functional level of the patient, and home aquatic-based exercise programs can be taught to patients and their caregivers.

  1. Patient Selection

The physical properties of water allow it to be a plausible alternative medium for rehabilitation of selected patients.

While aquatic therapy has classically been promoted for patients with rheumatoid arthritis and osteoarthritis, patients with a wide range of functional impairments are now involved in water-based therapy. Diagnoses include, but are not limited to fibromyalgia, postorthopedic surgery, generalized deconditioning, multiple sclerosis, stroke survivors, and brain injury patients.

  1. Benefits

The advantages of performing physical and occupational therapy in a pool-based environment are related to the buoyancy and viscosity provided by water. Due to the buoyant force of water, the effective weight of the patient is proportionally decreased as the depth increases. Weight-bearing loads are reduced to 40% of total body weight when standing in chest deep water. And, when floating, the effects of gravity are eliminated. Thus, therapy programs can introduce increased loads to tissue by gradually decreasing the depth at which therapy is performed.

The viscosity of water provides resistance to movement equal to that of the force exerted by the patient. This resistance also varies with the speed of movement performed.

In many cases, patients experience reduced levels of pain while performing passive and active range of motion as well as strengthening exercises in an aquatic environment. Patients can perform closed kinetic chain activities when pain or weight-bearing precautions prohibit land-based therapy. Other benefits include muscle relaxation, improved body awareness, cardiorespiratory fitness, balance, and coordination.

Prins J et al. Aquatic therapy in the rehabilitation of athletic injuries. Clin Sports Med. 1999;18:447.

Medications

A complete review of the medications used in treating various pain states can be found in Chapter 3. In this section, the role of medication in the setting of rehabilitation of acute and chronic pain will be discussed briefly. A rational polypharmacologic approach focuses on analgesia, inflammation reduction, relief of muscle spasm, reduction of affective distress, and improved sleep. The scope of medication use may vary depending on chronicity and related medical conditions.

Drugs for Managing Acute Pain

Analgesia and reduction of related muscle spasm and guarding are critical initial steps in the treatment of acute musculoskeletal conditions. Effective use of medications and modalities during the acute phase of rehabilitation may facilitate achieving optimal functional recovery.

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  1. Analgesic Drugs

Analgesia may be achieved through the judicious use of nonopioid analgesics, such as nonsteroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase (COX-2) inhibitors, acetaminophen, opioid analgesics, muscle relaxants, and tricyclic antidepressants. Practitioners should not hesitate to prescribe a short course of opioid analgesics for acute pain conditions, especially during the acute phase of rehabilitation. Caution should be reserved for those patients with a history of prior substance addiction or abuse. Close monitoring of patients is necessary to avoid or detect adverse sequelae of analgesic medication therapy (ie, bleeding, ulcer, renal or hepatic injury).

  1. Anti-Inflammatory Drugs

NSAIDs are commonly prescribed medications for acute pain states involving musculoskeletal injury. The rationale stems from the analgesic and anti-inflammatory properties of NSAIDs. However, judicious use is recommended, since inflammation is a necessary component of the healing process during the acute phase of injury. Therefore, excessive reduction of inflammation may be undesirable. In addition, there is insufficient data to support the notion that NSAIDs provide any significant anti-inflammatory action in the setting of acute injury or postoperative swelling. The most significant benefit to patients is likely due to their analgesic properties. Modalities such as ice and compression may be more important in the reduction of edema during the acute phase of injury.

  1. Muscle Relaxant Drugs

Reflex guarding of injured musculoskeletal structures is manifest as the production of local muscular spasm. Short-term use of muscle relaxants (metaxalone and methocarbamol), during the acute rehabilitation phase is appropriate when combined with analgesic medications. Nighttime dosing of more sedating agents (eg, cyclobenzaprine and tizanidine) may also help induce sleep. Prolonged benzodiazepine use is discouraged and may impair sleep architecture as well as lead to the development of tolerance and dependence.

Drugs for Managing Chronic Pain

Drug therapy is a critical component in the treatment of all persistent pain states. The importance of treatment targets may vary considerably from those in acute pain treatment paradigms. While acute pain treatment focuses on analgesia and inflammation control, medication therapy in persistent pain states may need a more comprehensive focus to include related affective distress (depression, anxiety, and anger) and disturbed sleep. A rational polypharmacy approach incorporates the use of various medications including newer generation and traditional antidepressants, anticonvulsants and sleep agents and, in more carefully selected cases, long-term opioid therapy.

Chronic pain-related depression may respond to a number of antidepressants. In general, tricyclic antidepressants help augment serotonin and norepinephrine levels in the brain and may offer both antidepressant and analgesic effects. More selective medications, such as selective serotonin reuptake inhibitors (SSRIs), may have better side-effect profiles but have demonstrated less promising analgesic effects. Tricyclic antidepressants may be taken at night in order to improve sleep and prescribed in conjunction with daily SSRIs for depression. Serotonin-norepinephrine reuptake inhibitors (SNRIs) (eg, venlafaxine and duloxetine) may also provide antidepressant and analgesic effects with less anticholinergic and cardiac side effects as tricyclic antidepressants.

The use of long-term opioid analgesic therapy in chronic pain management should incorporate the use of longer acting medications (sustained release oral medications and transdermal delivery systems) and a more judicious use of short-acting medications for breakthrough pain episodes. Steady serum levels with long-acting agents may help maintain consistent opioid serum levels offering a number of practical advantages including convenient dosing schedules, more sustained analgesia, and uninterrupted sleep, while limiting frequent episodes of breakthrough pain and over-reliance of excessive daily use of short-acting opioids.

Control of inflammation may be less important in the treatment of chronic pain. Numerous studies have shown that chronic musculoskeletal injuries such as those involving the extensor carpiradialis brevis, Achilles tendon, patellar tendon, and rotator cuff tendons have minimal inflammatory properties. Biopsies reveal degeneration and the lack of inflammatory cells. Thus, the long-term use of NSAIDs in these conditions are not recommended, and the benefit in pain reduction is likely through the analgesic properties of NSAIDs. Long-term NSAID and COX-2 inhibitor (celecoxib) therapy may decrease the pain and joint stiffness associated with chronic osteoarthritis pain conditions. Recent reports of cardiac and renal effects associated with long-term use of COX-2 inhibitors may limit their use in this population. Careful patient selection and consideration of comorbid medical conditions may need to be considered.

Curatolo M et al. Pharmacologic pain treatment of musculoskeletal disorders: current perspectives and future prospects. Clin J Pain. 2001;17:25.

Stovitz SD et al. NSAIDs and musculoskeletal treatment. What is the clinical evidence? Phys Sports Med. 2003;31:35.

Worsowicz GM et al. Rehabilitative management of pain. Arch Phys Med Rehab. 1998;79:S60.

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Pain Concernsin Selected Rehabilitation Conditions

Acute and chronic pain are common comorbidities in rehabilitation patients. It has been speculated that patients with disabilities may be at higher risk for developing persistent pain states when compared with the general population. The following section highlights some basic issues to consider when managing pain in these specific groups.

Stroke

Common pain conditions in stroke survivors include hemiplegic shoulder pain (38 to 84%) and central post-stroke pain (2 to 8%). Hemiplegic shoulder pain is usually musculoskeletal in nature and may be secondary to subacromial impingement syndrome, glenohumeral subluxation, and adhesive capsulitis. Other causes of shoulder pain include myofascial pain, spasticity, and complex regional pain syndrome (formerly called reflex sympathetic dystrophy).

Careful examination is critical because myofascial pain and central poststroke pain can mimic or present concurrently with pure musculoskeletal etiologies of shoulder pain. Musculoskeletal pain complaints in stroke survivors appear to be less common in patients with longer poststroke duration, and symptoms are typically aggravated by passive and active movements of the affected limb. Treatment of musculoskeletal shoulder pain involves taping or bracing for joint positioning, physical therapy for range of motion, stretching and scapular stabilization, and oral analgesic medications. Effective treatment of related myofascial pain in proximal muscle groups may help differentiate true musculoskeletal shoulder pain and guide appropriate treatment. Spasticity is managed by bracing, oral medications, and local botulinum toxin injections to the affected muscles.

More debilitating central poststroke pain can occur from months to years after stroke. It appears to be a deafferentation syndrome due to damage associated with spinothalamocortical pathways, usually accompanied by pain and temperature sensory deficits. Pain is typically constant and can affect the entire hemiparetic side. Treatment includes oral anticonvulsant medications, deep brain or motor cortex stimulation, and TENS.

Spinal Cord Injury

The disability caused by spinal cord injury varies significantly. Functional disability is related to the level as well as the completeness of the injury sustained. Patients with spinal cord injury typically suffer from both neuropathic and musculoskeletal pain. Neuropathic pain is common at the level of the injury (transitional zone pain) as well as below the level of the injury. Musculoskeletal pain commonly occurs above the injury. Estimates of the prevalence of chronic pain have been reported as high as 94%.

The most common pain sites include hip and buttock region, legs and feet, shoulder, arm and hand, and transitional zone. Musculoskeletal pain is common in the upper extremities and tends to increase with age. Overuse injury to the scapular stabilizers and rotator cuff musculature occurs with wheelchair usage, reliance on upper extremities for transfers, as well as other activities of daily living. This is especially true for patients with low cervical lesions, since they may suffer from more significant muscular imbalances in the scapulothoracic and glenohumeral joints.

Treatment for pain in spinal cord injury is relatively empiric. Shoulder pain typically benefits from scapular stabilization exercises, kinesiotaping, massage, heat modalities, and drug therapy. Related myofascial pain may respond to local injections and active strengthening programs. Treatment of central pain is challenging. Primary strategies consist of oral anticonvulsant and an-tidepressant medications as well as more comprehensive multidisciplinary treatment programs. Long-term opioid therapy, spinal cord stimulation, and surgical procedures such as dorsal root entry zone lesioning may be of benefit in selected cases.

Amputation

Amputee patients suffer from various types of both acute and chronic pain. As with spinal cord injury, the pain can be both neuropathic and musculoskeletal in nature. In addition to postoperative pain in the residual limb, a large number of patients experience residual limb pain long after the amputation has healed. Up to 85% of amputee patients experience phantom limb pain, which manifests as sharp, tingling, shooting, and stabbing pain in the portion of the limb that was amputated. This must be distinguished from phantom limb sensation, which is not painful and typically does not interfere with normal activities of daily living. In addition to pain directly related to the amputation site, many patients (up to 71%) develop back pain due to inactivity and alteration in biomechanics of ambulation. Upper extremity pain can result from excessive wheelchair locomotion or ambulation with an assistive device. These secondary pain etiologies may interfere more with activities of daily living than phantom limb pain or residual limb pain.

Treatment strategies for amputee patients are geared toward the type of pain experienced. Musculoskeletal pain complaints are best addressed with physical therapy, passive physical modalities, and oral analgesics. While

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there is minimal literature that describes successful treatments for phantom limb pain, antidepressants and anticonvulsants are the most commonly used oral medications. A current focus on more aggressive perioperative pain management, including preemptive analgesia, as a strategy for prevention of phantom limb pain has revealed inconsistent results.

Multiple Sclerosis

Acute and chronic pain are both possible sequelae of multiple sclerosis, occurring in 53 to 82% of affected patients. Acute pain is typically neuropathic in nature and can occur during a multiple sclerosis exacerbation as a result of active inflammatory processes. Chronic pain accounts for approximately 90% of cases. It may be neuropathic or musculoskeletal and presents with symptoms dependent on the location of the lesions. Paresthesias and Lhermitte sign are reported to occur with lesions located in the dorsal horn, while trigeminal neuralgia has been associated with lesions in the trigeminal entry zone in the brainstem. Demyelination in the brainstem or spinal cord can lead to muscle spasms that cause painful cramping. Lesions affecting the corticospinal, corticobulbar, or bulbospinal tracts can lead to spasticity with subsequent biomechanic and postural abnormalities resulting in back and extremity pain.

While there are few controlled clinical trials in the treatment of multiple sclerosis-related pain, there are a number of commonly addressed treatment targets. Newer generation anticonvulsant medications such as gabapentin, lamotrigine, oxcarbazepine, tiagabine, topiramate, and zonisamide are routinely prescribed “off-label” for neuropathic pain complaints. Spasticity is managed by both medication and therapy. Oral medications for spasticity management include baclofen, dantrolene, tizanidine, and diazepam. Injection therapies include botulinum toxin into muscle and phenol nerve blocks. They may be used independently or in conjunction with active physical therapy and bracing. Physical and occupational therapy is used to address spasticity and other biomechanical deficits related to abnormal positioning.

Ehde DM et al. Chronic pain secondary to disability: a review. Clin J Pain. 2003;19:3.

Jensen MP et al. Pain site and the effects of amputation pain: further clarification of the meaning of mild, moderate, and severe pain. Pain. 2001;91:317.

Kong KH et al. Prevalence of chronic pain and its impact on health related quality of life in stroke survivors. Arch Phys Med Rehabil. 2004;85:35.

Lidbeck J. Central hyperexcitability in chronic musculoskeletal pain: A conceptual breakthrough with multiple clinical implications. Pain Res Manage.2002;7:81.

Siddall PJ et al. Pain report and the relationship of pain to physical factors in the first 6 months following spinal cord injury. Pain. 1999;81:187.