Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Crush Wounds


Related Terms

  • Crush Injury
  • Crush Syndrome
  • Rhabdomyolysis
  • Traumatic Crush Syndrome

Specialists

  • Emergency Medicine Physician
  • General Surgeon
  • Neurologist
  • Neurosurgeon
  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Vascular Surgeon

Comorbid Conditions

Factors Influencing Duration

Factors influencing duration of disability include loss of limb, age and overall health of the individual, and any associated complications.

Medical Codes

ICD-9-CM:
925.1 - Crushing Injury of Face and Scalp; Cheek; Ear
925.2 - Crushing Injury of Neck; Larynx; Throat; Pharynx
926.0 - Crushing Injury of External Genitalia; Labium (Majus) (Minus); Penis; Scrotum; Testis; Vulva
926.11 - Crushing Injury of Back
926.12 - Crushing Injury of Buttock
926.19 - Crushing Injury of Trunk, Other
926.8 - Crushing Injury of Multiple Sites of Trunk
926.9 - Crushing Injury of Trunk, Unspecified Site
927.00 - Crushing Injury of Shoulder Region
927.01 - Crushing Injury of Scapular Region
927.02 - Crushing Injury of Axillary Region
927.03 - Crushing Injury of Upper Arm
927.09 - Crushing Injury of Shoulder and Upper Arm, Multiple Sites
927.10 - Crushing Injury of Forearm
927.11 - Crushing Injury of Elbow
927.20 - Crushing Injury of Hand(s), Except Finger(s) Alone
927.21 - Crushing Injury of Wrist
927.3 - Crushing Injury of Finger(s)
927.8 - Crushing Injury of Multiple Sites of Upper Limb
927.9 - Crushing Injury of Upper Limb, Unspecified Site
928.00 - Crushing Injury of Thigh
928.01 - Crushing Injury of Hip
928.10 - Crushing Injury of Lower Leg
928.11 - Crushing Injury of Knee
928.20 - Crushing Injury of Foot, Excluding Toe(s) Alone
928.21 - Crushing Injury of Ankle
928.3 - Crushing Injury of Toe
928.8 - Crushing Injury of Multiple Sites of Lower Limb
928.9 - Crushing Injury of Lower Limb, Unspecified Site
929.0 - Crushing Injury of Multiple Sites, Not Elsewhere Classified
929.9 - Crushing Injury of Unspecified Site

Overview

Crush wounds or injuries are the result of the body or a body part being forcefully compressed between two hard surfaces. Compression of the muscle mass blocks the flow of blood and oxygen to tissues (ischemia), resulting in tissue death (necrosis) within a few hours. These injuries most commonly are the result of an accident caused by pressure of entrapment in equipment/machinery, a fall, an automobile vs. pedestrian accident, industrial or transportation accident. Natural disasters such as earthquakes and landslides, manmade accidents such as building collapses, or acts of war can also result in multiple cases of crush injury. Damage that can be caused by a crush injury includes laceration, fracture, bleeding, loss of vascular integrity, and bruising (ecchymosis). Compartment syndrome, a complex series of clinical events that may occur when a portion of an extremity is isolated by injury, is a common complication of crush injury. Crush injuries result in damage to the overlying soft tissue envelope, the neurovascular structures, and the bony ligamentous supportive structures.

If the crush injury is severe enough, the body releases cellular byproducts and electrolytes (e.g., myoglobin and potassium, respectively) from the affected muscles and damaged tissue into the bloodstream. This physiologic response, called crush syndrome (rhabdomyolysis), can lead to acute kidney (renal) failure and heart arrhythmias, sometimes resulting in permanent disability or death.

Incidence and Prevalence: Crush injury is an uncommon injury, and the overall incidence is 0.1 per 10,000 individuals (Sahjian). Mortality from crush injury is estimated to be 5% but varies with cause. An estimated 20% of victims of natural disasters and 40% of victims of building collapse are reported to have crush injuries (Sahjian).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Risk of crush injury is not predictable since the source of injury is typically a non-predictable accident.

Source: Medical Disability Advisor



Diagnosis

History: An individual with a crush injury may complain of pain, swelling (edema), bleeding, damaged skin, and numbness or loss of sensation (sensory deficit) in the affected area. A detailed account of the accident or source of injury is needed if the individual is conscious or from witnesses if the individual is unconscious.

Physical exam: Examination of the crushed limb or body part may reveal edema, bleeding, hematoma, and fracture. The entire body will be examined for signs of multiple injuries, including possible head injury. Vital signs (blood pressure, heart rate, and respiration) are closely monitored. Injuries to the chest or abdomen may cause shallow, restricted breathing. Heart arrhythmias may be present. Degree and duration of compression, structure and make up of the crushing surface(s), and the number of injured extremities determines the severity of rhabdomyolysis. Dangerous signs that could lead to death from rhabdomyolysis are low fluid volume (extreme hypovolemic shock), high blood potassium concentrations (hyperkalemia), low blood calcium concentration (hypocalcemia), metabolic acidosis, acute myoglobinuric renal failure, increased intercompartmental pressure, compromised circulation, and compartment syndrome.

Tests: X-rays will be used to identify fractures. A combination of x-rays, MRI, and CT may identify more complex soft tissue injury and internal injuries. Routine hematology and blood chemistry parameters (especially serum bicarbonate, calcium, and electrolytes) will be measured to assess for blood loss and rhabdomyolysis. Laboratory confirmation of rhabdomyolysis may require determination of serum myoglobin and urinary red blood cell count (myoglobinuria). Peak serum concentration of creatine phosphokinase (CPK) is also diagnostic, as it is usually elevated with rhabdomyolysis that affects large muscle groups. Because rhabdomyolysis and compartment syndrome may evolve together, intercompartmental pressures may be measured by the simple needle, slit catheter, or side-ported needle technique. Pulse oximetry may be used to monitor tissue oxygenation.

Source: Medical Disability Advisor



Treatment

The objectives of treatment for crush injuries are to restore blood volume and flow of blood and oxygen, correct electrolyte and pH imbalances, and maintain renal function. Treatment for individuals with multiple crush wounds consists of early administration of intravenous fluids preferably given at the site where trauma occurred, followed by an osmotic diuretic (Mannitol) that prevents reabsorption of water by the kidney. This treatment can prevent shock and arrhythmias. With this regimen, survival of lives and limbs increases substantially as does prevention of acute myoglobinuric renal failure in individuals suffering from rhabdomyolysis. Ischemia, ischemic injury to nerves and muscles, compartment syndrome, heart arrhythmia, and cardiac function irregularities may be treated with continuous oxygen at high pressure (hyperbaric oxygen therapy). Fluid and electrolyte replacement may be necessary to correct arrhythmias and rhabdomyolysis.

Treatment of crush injuries varies according to the nature of the crush wound, the extent of damage, and the presence of other injuries such as fracture. Surgical treatment is often the only option. In an acute situation, it may be difficult to decide whether an attempt at a salvage procedure should be made or whether a primary amputation should be performed. In certain s situations such as interruption of blood flow, primary amputation of an extremity may be the treatment of choice. Penetrating artery injury from a concomitant open fracture may require orthopedic and vascular repair(s) to stabilize skeletal integrity and restoration of blood circulation.

A tetanus shot may be given and antibiotics will usually be administered to prevent infection.

Source: Medical Disability Advisor



ACOEM

ACOEM's Practice Guidelines, the gold standard in effective medical treatment of occupational injuries and illnesses, are provided in this section to complement the disability duration guidelines.*
 
Crush Injuries and Compartment Syndrome
 
* The relationship between the MDGuidelines (MDA) content and ACOEM's guidelines is approximate and does not always link identical diagnoses. The user should consult the diagnostic codes in both guidelines, as well as the clinical descriptions, before assuming an equivalence.

Source: ACOEM Practice Guidelines



Prognosis

Outcome varies with the extent of the crush wound and presence of other injuries. Outcome is excellent for otherwise healthy individuals who do not go into shock, with injuries that do not require mechanical ventilation or amputation, and if minor or no surgery is required.

When a crush wound to a limb is too severe to repair, the usual result is amputation of the crushed limb to prevent gangrene. Recovery after amputation is usually complete; however, death from other complications of rhabdomyolysis is still possible.

Crush injuries can be severe and devastating to the individual. Long-term impairment and disability may occur, and disability is sometimes permanent.

Source: Medical Disability Advisor



Rehabilitation

Crush wounds require a multilevel approach to rehabilitation since they involve damage to the muscle, bone, nerve, and soft tissue. Although usually confined to a general area of the body, crush wounds typically affect multiple body parts and may involve both legs and the pelvis or an arm and the chest. Severe deformity and psychological trauma can result from these types of injuries. In the mildest form, a crush wound may only affect a finger or toe and will require only a short rehabilitation period. However, complications from tissue or bone necrosis due to ischemia are always a possibility. For more severe cases, the rehabilitation process is arduous and requires the combined effort of many post-acute healthcare professionals including physical, occupational, and vocational therapists, as well psychiatric and/or psychological professionals.

Rehabilitation therapy does not begin immediately because of threat of kidney failure or embolism blockage. Kidney failure is of great concern when the crush wound involves the legs due to necrosis of muscle and increased renal burden. Rehabilitation begins when the individual is out of acute danger and stabilization of fractures has been assessed. One problem with delaying physical therapy is the complications that arise from disuse such as muscle atrophy, decreased joint range of motion, and insufficient circulation of blood through injured areas. The sequelae of these issues could lead to poor recovery outcomes, including amputation.

Pain management is also a concern since multiple operations and prolonged recovery may influence an individual's mental status. Psychological support services may help reduce anxiety and ease restlessness. Visualization techniques may help prepare individuals to accept themselves with the possible disability and/or deformity. Individuals may remain immobilized for the first 6 weeks post-trauma. A series of reparative surgeries may be needed during this time.

Exercise rehabilitation is progressed slowly in all cases. Therapy protocol varies greatly due to the wide range of possible outcomes. The individual may undergo treatments for both upper and lower body simultaneously. All treatments are performed to pain tolerance.

It should be noted that amputation of the affected limb may be a treatment necessity during early stages of treatment and rehabilitation. If the limb must be amputated, the individual should begin education on prosthetics. Rehabilitation protocol should be redesigned to teach daily living skills and functioning given the absence of the limb. If rehabilitation progresses, the individual advances to exercises that include an active range of motion where the individual moves the remaining part of the extremity or the entire extremity if amputation has not been performed. Rehabilitative therapies, however, must be based on the extent of injury and current level of function.

Another important aspect of rehabilitation is scar tissue care. The individual may use massage techniques to continue to break up scar tissue along the surgery site. The individual may experience extreme sensitivity at the site of surgery; therefore, it is important to initiate activities that decrease hypersensitivity (desensitization), such as applying various degrees of touch and gentle pressure, and exposing the site to different textures and sensations.

After temporary stabilizing orthopedic hardware (such as pins and rods) is removed from the limb, more functional exercises are performed. It may take as long as 2 to 3 months for the individual to attempt actual weight bearing on lower extremities. The individual is taught to use a wheelchair. Other therapy during this time may include participating in an aqua or whirlpool routine to increase blood flow throughout the body and to increase range of motion for the hips, legs, and arms. The exercise simulates normal movement and serves to improve aerobic conditioning. Individuals experiencing an amputated arm use the pool to regain body balance.

An occupational therapist may be needed to evaluate remaining function, particularly for those individuals who have lost a limb. It is critical to properly assess the physical and mental capabilities of the individual to understand vocational constraints. Psychological counseling also may be needed as the individual faces new physical challenges and permanent care.

Source: Medical Disability Advisor



Complications

Prolonged severe crush injury can result in severe systemic manifestation of trauma and ischemia involving soft tissues (skeletal muscle, nerves and vascular tissue). This leads to increased permeability of cell membranes and to the release of potassium, enzymes, and myoglobin from within cells. Ischemic renal dysfunction secondary to hypotension and diminished renal perfusion results in acute tubular necrosis, uremia, and sometimes renal failure, which can be fatal.

Other possible complications include increased clotting of blood (hypercoagulability) that can result in deep vein thrombosis and pulmonary embolism or stroke, immune suppression that results in infection at the wound site or systemically (sepsis), hemorrhagic shock, and lipid embolism that results in reduced levels of blood oxygen (acute hypoxia). Elevated intracompartmental pressure within a closed compartment (acute compartment syndrome) such as a portion of an injured limb or the entire abdomen is a serious complication of rhabdomyolysis that can lead to severe systemic complications.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Possible work restrictions and special accommodations are determined on an individual basis depending on degree of disability. For example, an individual whose legs have been amputated may no longer be able to work in an occupation that requires use of both legs such as a construction worker, roofer, or street police officer, whereas an individual with a sedentary job may return to work after appropriate access and workplace accommodations are put in place. Vehicles may need to be modified to allow an amputee to drive and maintain a profession that requires driving. Company policy on medication usage should be reviewed to determine if pain medication use is compatible with job safety and function.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Was individual involved in an accident that caused multiple crush wounds?
  • How long was the body part(s) compressed?
  • Did individual developed hypovolemic shock? Hyperkalemia or hypocalcemia?
  • Did individual have metabolic acidosis? Renal failure? Compartment syndrome?
  • Is individual's breathing shallow? Are cardiac arrhythmias present?
  • Did individual have x-rays, MRI, and CT? Was peak serum concentration of creatine phosphokinase done? Was myoglobinuria confirmed?

Regarding treatment:

  • Did individual receive intravenous fluids at the trauma site?
  • Was pulse oximetry done to determine tissue oxygenation?
  • Were ischemia, compartment syndrome, or arrhythmias treated with hyperbaric oxygen therapy?
  • Did individual receive fluid and electrolyte replacement?
  • Was the limb salvaged? Was a primary amputation done?
  • Was an amputation done later secondary to gangrene?
  • Did individual receive a tetanus shot?
  • Were antibiotics administered?
  • Was orthopedic intervention required to address skeletal integrity?

Regarding prognosis:

  • Is individual in a rehabilitation program?
  • Are the appropriate professionals on the rehabilitation team?
  • Can individual's employer accommodate any necessary restrictions?
  • Does individual have any pre-existing or additional injury related conditions that may affect ability to recover?
  • Have any complications occurred such as renal failure, deep vein thrombosis, or pulmonary embolism that may affect recovery?
  • Would individual benefit from psychotherapy? Additional vocational counseling?

Source: Medical Disability Advisor



References

Cited

Sahjian, Miachael, and Michael Frakes. "Crush Injuries: Pathophysiology and Current Treatment." Advanced Emergency Nursing Journal 29 2 (2007): 145-150. NursingCenter.com. 13 Mar. 2009 <http://www.nursingcenter.com/Library/JournalArticle.asp?Article_ID=717617>.

General

Annunziato, Amendola, and Bruce C. Twaddle. "Compartment Syndromes." Skeletal Trauma: Basic Science, Management, and Reconstruction. Eds. Bruce. D. Browner, et al. 3rd ed. 2 vols. Philadelphia: Elsevier, Inc., 2003. 272-273. MD Consult. Elsevier, Inc. 20 May 2005 <http://home.mdconsult.com/das/book/47361886-2/view/1217?sid=368797199>.

Source: Medical Disability Advisor






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