Pain in the arm, leg, and lower back are very common work-related musculoskeletal complaints. In the arm, the cause is often either inflammation of the structures in the rotator cuff, also called impingement syndrome; lateral epicondylitis, also called tennis elbow; or compression neuropathy of the median nerve, or carpal tunnel syndrome. In the lower extremity, there are strains of the ankle and of the knee, with or without internal derangement. In the lower back, there are mechanical and neurologic issues.
Often, the first response of many clinicians to a musculoskeletal work injury is to order an X-ray. However, X-rays and other diagnostic imaging modalities are only rarely of value in work-related injury, unless there are specific red flags raised in the history or physical. In the absence of mechanical trauma or clear, relevant neurologic findings, or a history of osteoporosis or cancer, imaging the injured area is likely to reveal nothing or to find a non-work-related issue that will muddy the waters. When an X-ray identifies old and unrelated conditions, such as degenerative changes that may be irrelevant to the work injury, it can become a legal point of contention.
The most important tools in handling a musculoskeletal injury are a detailed history and a careful physical exam. Work-related injuries often occur in the context of other physical problems and can mask the presence of confounding issues. It is helpful to expand the history to look for other processes that may be referring symptoms to the area in question. ACOEM provides excellent guidelines for the diagnosis and treatment of work-related issues within their Practice Guidelines (https://www.acoem.org/PracticeGuidelines.aspx).
The History and Physical Examination
A clear understanding of the mechanism of injury directs further history gathering and focuses the health care provider on the requirements of the physical exam. It is an important tool for sorting out which symptoms are relevant to the injury and which may not be.
Not all patients presenting with work-related injuries will be able to name the incident that immediately preceded the onset of symptoms. When there is a complaint of pain or other symptoms in the absence of a clear injury, repetitive motion injury (cumulative trauma) is often considered. However, the medical literature has not adequately delineated the causes of cumulative trauma and repetitive motion injury, and thus it should be diagnosed with considerable caution.
The history should be comprehensive, including documentation of past diagnoses and injuries, current or past surgeries, and present diagnoses and medications taken. Many past or concurrent diagnoses will affect the diagnosis and treatment of a work-related injury and may also shed light on whether a complaint is truly related to work. Findings in the history may suggest the presence of a previously undetected process that may either complicate the diagnosis and treatment of the work-related complaint or explain it completely.
Examining a worker with an injury requires attention to the area of the complaint, but it should never be restricted to it. Symptoms are often referred to an area of the body from a process in another area, as can be the case in a bladder or prostate infection or in a subtle cervical disc herniation. Carefully examining areas of the body that may refer symptoms to the one in question can go a long way toward making an accurate diagnosis and returning the injured individual to productivity.
Treatment of the Injured Worker
Maintaining function, perhaps with restriction, should be the most important result that medical providers seek. In building a therapeutic approach to an injured worker, the priority is to focus on function rather than feeling. But despite the beliefs of the past, pain is not a reason to stay home from work; in general, being back at work and understanding that work is therapeutic will do more to relieve than aggravate the pain. To aim to eliminate all pain before returning to work is irrational and, in the long run, counterproductive.
It is the primary care provider’s role to determine an injured individual’s capabilities and return the person to the work environment with appropriate restrictions. If the workplace cannot find a job that will qualify under these restrictions, it is the employer that needs to take the injured individual out of the workforce, not the medical provider. A worker should be removed only from duties that will cause hazard to life or limb or put others at risk. It is worth noting that fewer than one- quarter (20 to 22%) of treatments for most work injuries have any support in the evidence-based medical literature.
Opioids should be used only for analgesia in very rare circumstances. Aside from the risk of addiction, it also appears that they prolong the duration of disability. Nonsteroidal anti-inflammatory drugs have been shown to be equivalent for pain relief, and in many circumstances, especially for lower back pain, to be superior to opioids in keeping pain at a level that permits function.
Common Work-Related Musculoskeletal Injuries
Upper Extremity Issues
Shoulder impingement, occasionally known as “swimmer’s shoulder,” is characterized by pain in the affected shoulder that occasionally radiates down to the mid-bicep region, with increased pain reaching above the shoulder or behind the back. Physical examination will most often show a complaint of discomfort with palpation in the lateral portion of the subclavicular space, though other areas of tenderness, including the acromioclavicular joint, may be noted. The Neer sign and the Hawkins- Kennedy test are useful to document that the issue is in the shoulder but are not specific to impingement. Initial treatment should be with anti-inflammatory medication, often for four or five weeks, with an initial restriction of lifting or reaching above the shoulder with the affected arm that is progressively reduced during the treatment. Local injection with corticosteroids has been suggested but is generally best reserved until after a trial of oral agents has shown inadequate results for three to four weeks. More recalcitrant impingement syndromes may require physical therapy.
Unless there is a history of an impact that may have caused a fracture or a history of a potentially metastatic malignancy, there is little initial use for plain films. If conservative treatment fails after several weeks, imaging to seek spurring is reasonable. The diagnosis should be confirmed by MRI of the shoulder if arthroscopic surgery is under consideration.
Lateral epicondylitis or tennis elbow is characterized by pain in the lateral aspect of the elbow, aggravated by gripping, resisted dorsiflexion of the wrist, and resisted supination of the forearm. There is generally no actual inflammation involved; the condition represents a degenerative change in the associated tendons, with disorganized collagen deposition; it would be wiser to call it a lateral epicondylopathy. Diagnosis is through a relevant history and physical examination; imaging is not needed initially.
The treatment should focus on physical or occupational therapy; anti-inflammatory medication is of limited usefulness, except as an analgesic. Local steroid injection, once a popular approach to this diagnosis, has been found to impoverish results at one year, compared to no injection. Although restricting the use of the affected elbow can produce resolution in a few days to a week in many cases, it can take up to six months or more for some individuals to fully resolve this condition. If there is little or no improvement after about a week of restricted activity, physical therapy is the next step. Forearm straps provide some relief, presumably by unloading the affected tendon. Night time wrist supports are helpful as they eliminate extensor activation while sleeping.
Carpal Tunnel Syndrome
Carpal tunnel syndrome is a compression neuropathy of the median nerve, occurring as the nerve passes under the ligament forming the roof of the carpal tunnel at or near the base of the thumb. Pain or numbness in the palmar surface of the thumb, index finger, and lateral part of the middle finger, and of the lateral portion of the palm, sparing the thenar eminence, is characteristic; but, it is not uncommon for only a portion of the area for which the median nerve provides sensation to be involved. Occasionally, the median nerve may supply sensation to whole palmar surface of the hand, again sparing the thenar eminence.
Phalen’s and Tinel’s signs are often positive on physical examination. Notably, carpal tunnel syndrome can be a result of hypothyroidism, obesity, rheumatoid arthritis and diabetes mellitus rather than work activities. Even if the work activity is the cause of the syndrome, these other conditions can and do aggravate the syndrome and potentially delay recovery. If any of these comorbidities is present, it is important to ensure that they are well controlled. Unless the carpal tunnel syndrome is severe, nighttime splinting may resolve the problem, often combined with an oral anti-inflammatory. Local corticosteroid injection has been suggested, as well, though its effect is generally short term. If nocturnal splinting fails to resolve the symptoms after three to four weeks, physical therapy is often quite effective. If these approaches do not produce good results, a nerve conduction test can be considered; surgical intervention should be suggested only after a failure of more conservative measures.
Ankle strains characteristically occur after trauma, such as forceful inversion or eversion of the ankle, and show local pain and swelling. Technically, a sprain involves stretching of a tendon or ligament without significant tearing; a sprain is associated with tearing. Unless there is instability of the ankle, differentiating the two is difficult and generally does not change the treatment. Imaging is not likely to be of value unless 1) there is point tenderness on palpation of the posterior aspect of the distal 6 centimeters of the fibula or tibia or at the tip of the malleolus, 2) the patient cannot take four steps immediately or at the time of exam, 3) there is point tenderness at the base of the fifth metatarsal or the navicular, or 4) the patient is elderly or has potentially metastatic cancer or osteoporosis. The RICE acronym applies: rest the affected area, ice it for the first 24 to 36 hours, externally compress it with either an elastic bandage or support it with a stirrup or clamshell splint, and elevate it.
Knee Strain With and Without Internal Derangement
Knee strains occur after trauma, through falls or lateral or twisting force, resulting in stretched tendons or ligaments and local pain and swelling. Imaging is generally not useful unless there is 1) tenderness of the head of the fibula, 2) isolated tenderness of the patella, 3) inability to flex the knee more than 90º, 4) inability to bear weight for four steps immediately and at the time of exam, or 5) if the worker is over 55 years of age. Signs of laxity of the knee are of concern, possibly indicating ligamentous tears, as is a history of the knee locking, possibly indicating a meniscal tear. Pulses in the foot are an important sign: in dislocations, the popliteal artery can be occluded, which requires more emergent intervention. Presence of an effusion is worthy of note but may not be of great help diagnostically. Rest and ice for the first 24 to 36 hours, followed by intermittent heat and support, is the best treatment. Toe or foot pumping exercises are suggested during this time frame to reduce the risk of deep venous thrombosis. If there is concern about knee stability, bracing may be of some value. Acetaminophen or an anti-inflammatory medication is generally all that is needed for the pain, and careful follow-up with reassessment of the knee function and stability is important. Instability or locking demonstrated on examination and lasting more than four weeks raises the potential of a complete ligament tear and may call for an MRI. Unless surgical repair is under consideration, there is little reason for further imaging.
Mechanical Versus Neurological Problems
Back pain, particularly lower back pain, is among the most common work-related complaints. It is also potentially among the most expensive. A careful history of the injury is important but does not always produce a clear mechanism of injury. Several findings are “red flags” that may indicate a more serious disorder. The popular mnemonic TUNAFISH indicates potentially more serious disorders that call for imaging:
T – Trauma
U – Unexplained weight loss
N – Neurologic symptoms (dermatomally distributed pain, or loss of bowel/bladder control)
A – Age > 50
F – Fever
I – IV-drug use
S – Steroid use
H – History of cancer
Back pain that does not show a dermatomal pattern, or that does not extend below the elbow or the knee, is generally not neurologic in origin. Certainly, the physical examination should screen for disc disease with a careful neurologic exam, including LeSègue’s sign, Spurling’s maneuver, and screen for meningismus as well as muscle strength and deep tendon reflexes. Unless there is a clearly palpable muscle spasm, treatment should consist of initial cold compresses for 20 minutes or so every four hours while awake for the first 24 to 36 hours, followed by moist heat in the same rotation; acetaminophen or an anti-inflammatory for pain; and continued work with reduced lift, twist, push-pull, and bending. Close follow-up is important, with progressive reduction of the restrictions. If these conservative measures fail to produce improvement in two weeks, the next step is to initiate physical therapy. Only after four weeks of conservative treatment, with at least two weeks of physical therapy, have failed to produce adequate results should imaging be considered, unless the “red flags” above appear. Unless there is clearly palpable muscle spasm, muscle relaxants appear to have little or no value, and even when there is active spasm noted, they are rarely of value for more than about 7 to 14 days.
The SPICE Model: A Guide to Treatment
In handling an injured worker, remember the acronym SPICE, and let it be a guide in diagnosis and treatment.
Keep the treatment and diagnosis simple; the simpler the label and the focused the treatment, the more likely and sooner the worker will be able to return to full duty. A complicated diagnosis or complex treatment regimen generally delays returning to work and decreases the chance that the worker will return. Prolonged periods of time completely off work tend to generate both physical and mental issues that ultimately inhibit a return to gainful employment.
Keep the individual as close to the work environment as possible. Ideally, limited duty should be assigned near the location of normal duty, if not at the usual workstation. Physical therapy or other interventions should be planned to allow the injured worker to be at the workplace when he or she is not being treated. Those who share the workplace often form important social networks, and keeping a worker in that environment provides support toward recovery. This support improves the injured worker’s morale and motivation, and often that of coworkers.
The injured worker should be seen and treated promptly. The more time that elapses before treatment, the more time the worker has to become focused on the problem, potentially adding psychological barriers to returning to work. It also weakens or breaks emotional and social bonds with the others in the workplace, reducing the will to return. Psychosocial issues can be major roadblocks to returning to work.
One individual health care provider should be the central person responsible for care of the worker’s injury and ensure that all involved share the common goal of restoring the injured worker to full function. The health care provider is uniquely able to fill this role but must be willing to communicate clearly with all parties involved.
All too often, injured workers see their situation as a catastrophe that will end their ability to work. This is only rarely the case, and from the start, the injured worker should be coached to see the goal as a return to full duty at the same, or perhaps even better, capacity as before the injury.
Setting that expectation can go a long way toward building a worker’s confidence in his or her
ability to return to work. Equally important, the clinician needs to realize that occupationally related injuries will often require longer periods to achieve full recovery, but the clinician also needs to be alert to excessive prolongation of therapy, which often indicates the possibility of an unnoticed, additional confounding problem.
Encouraging Return to Work
Research shows that worker injuries compensated by workers’ compensation take longer to heal compared to injuries whose cost falls on the patient. The reasons are several. First, the patient may take on a victim mentality: upset at the injury, he or she may feel that he or she has a “right” to be taken care of. Second, the compensation system itself encourages worker to stay injured: light-duty assignment may pay the worker less than his or her income staying at home. This pay for reduced or no work sets up a strong disincentive to return to regular work. Therefore, the treating medical provider should be aware of these built-in factors and encourage the patient, supervisor, and all involved to expect the worker’s return to work as soon as is medically prudent.