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.

Dislocation, Acromioclavicular Joint


Related Terms

  • AC Separation
  • Shoulder Dislocation
  • Shoulder Separation

Differential Diagnosis

Specialists

  • Occupational Therapist
  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Sports Medicine Physician

Comorbid Conditions

Factors Influencing Duration

Duration is determined by the grade of AC separation, whether the injury occurred on the dominant or the non-dominant side, and the presence of other injuries. For non-dominant injuries, individuals may return to work earlier if duties can be performed with one hand. Dominant-side injuries may require longer disability, because individuals are not able to use their arm above the waist until healing is complete.

Disability may be longer for occupations that require manual dexterity, lifting, carrying, throwing, or overhead work. Surgical repair/reconstruction may increase the duration of disability.

Medical Codes

ICD-9-CM:
831.04 - Dislocation of Glenohumeral Joint (Shoulder), Closed, Acromioclavicular Joint
831.14 - Dislocation of Glenohumeral Joint (Shoulder), Open, Acromioclavicular Joint (Clavicle)

Overview

© Reed Group
Acromioclavicular dislocation (more commonly called AC separation) refers to separation of the collarbone (clavicle) from the highest point (acromion) of the shoulder blade (scapula). This injury is often confused with a dislocation of the shoulder (glenohumeral dislocation), which is actually a separation of the bone of the upper arm (humerus) from the socket in the shoulder blade (glenoid cavity of the scapula). The acromioclavicular (AC) joint capsule is made up of several groups of ligaments that stabilize the joint and allow motion.

Dislocation of the AC joint is usually the result of a downward force applied to the acromion (top of the shoulder) from a fall directly onto the shoulder or onto an outstretched arm. In this type of injury, the clavicle remains in place while the scapula is driven down, resulting in a tear to one or more ligament groups in the AC joint capsule. Injuries to the AC joint are graded from I to VI depending on the degree of ligament damage and the resulting separation of the joint. Grades I and II are more commonly called sprains of the AC joint, incomplete dislocation, or subluxation. Grade I injuries typically involve stretched or partially torn AC ligaments and joint capsule. Grade II injuries are caused by more significant forces, and the AC ligament and joint capsule may rupture. Grades III, IV, V, and VI constitute a true dislocation. Grade III injuries involve tearing of all ligaments, resulting in complete AC joint dislocation. Grades IV through VI also involve a complete dislocation, and may additionally include injury to the surrounding muscles (muscle strains or muscle tears). The clavicle can pierce the muscle around the shoulder (trapezius) when dislocated. An AC separation disrupts shoulder function, limiting arm motion. Instability of the joint may cause deformity when the lateral end of the clavicle rises higher than the acromion.

Other injuries sustained from a fall or blow directly on the shoulder may include tears in deltoid and trapezius muscles attached to the clavicle; fracture of the acromion, clavicle, or scapula; and disruption of the articular cartilage of the AC joint. Shoulder injury from falling onto an outstretched arm is more likely to result in a humeral neck fracture or glenohumeral joint dislocation, and a heavy object falling on the shoulder is more likely to result in a fracture than dislocation.

Incidence and Prevalence: In the general population, AC separations are most common during the third decade of life. Among athletes, AC separations occur most often between ages 10 and 20 (Malone). Incomplete injuries to the AC joint are 2 to 3 times more common than complete dislocations. AC separations account for approximately 12% of all shoulder dislocations (Malone).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Individuals who participate in contact sports (football, soccer, rugby, hockey), cycling, or who do heavy, one-armed lifting are most at risk for this injury. Men are at greater risk than women for AC separations, which occur with a male-to-female ratio of about 5:1 (Prybyla).

Source: Medical Disability Advisor



Diagnosis

History: A thorough history will help establish the mechanism of injury and rule out other processes. In older individuals, it is important to distinguish AC separation from rotator cuff injuries, impingement syndrome (adhesive capsulitis), and glenohumeral arthritis. Individuals usually report a direct blow to the lateral shoulder area, either from a fall (e.g., landing on the side of the shoulder in a football tackle), or from a push or stumble (e.g., being checked into a wall when playing hockey). Individuals complain of pain, tenderness, swelling on the top of the shoulder, and decreased shoulder range-of-motion. Pain may be worse at night, particularly when rolling onto the injured shoulder. Athletes who do weight training may report difficulty with a specific exercise.

Physical exam: Observation may reveal asymmetry of the two shoulders with a noticeable deformity on the affected side. Deformity is most obvious with an injury above grade II or with a clavicle fracture. Loss of the normal shoulder contour and prominence of the clavicle can be accentuated in grade I and II injuries by having the individual hold a 10 to 15 pound weight in the hand of the affected side. There may be an abrasion on the shoulder as well as swelling and bruising (ecchymosis) at the site of the injury. The individual may hold the arm across the chest and apply upward pressure to the elbow.

Gentle examination of the AC joint with the fingers (palpation) may reveal tenderness. There is limited active range of motion and painful assisted (passive) range of motion of the shoulder. The cross-body (or crossover) adduction test is the most reliable physical exam technique for AC joint pathology. In grade III injuries, the high riding end of the clavicle may be rocked front to back (anterior-posterior) if examined shortly after the injury. Pain can be elicited over the coracoclavicular space. In grades IV through VI, the end of the clavicle may be depressed, aimed behind (posterior), above (superior), or below (inferior) the normal position. Comparison to the opposite shoulder is important when determining position. The nerves to the arm and circulation to the extremity should be examined by testing reflexes, sensation, pulses, and capillary filling time.

Tests: X-rays of the AC joint help confirm the diagnosis. Stress radiographs may be used to assess the degree of instability and distinguish grade III separations. The individual holds a weight in the hand on the affected side to show the joint separation more clearly on x-ray (stress radiograph). In rare situations, a computed tomography (CT) or magnetic resonance imaging (MRI) may be needed to evaluate injury to soft tissues surrounding the shoulder. A nerve conduction velocity (NCV) study and electromyogram (EMG) study may be used to assess nerve damage.

Source: Medical Disability Advisor



Treatment

Grade I and II injuries respond well to non-surgical (conservative) treatment with ice, analgesics, and immobilization. Early physical therapy (between days 4 and 14 contingent on the amount of pain and swelling) will help the individual regain full range-of-motion.

There is controversy about the role of surgery in grade III dislocations. Conservative treatment of grade III dislocation begins with closed reduction. Historically this was followed by application of a sling or harness (Kenny-Howard sling) to keep the clavicle and acromion in proper alignment. Unfortunately, this sling resulted in frequent skin breakdown as is seldom used today. Ice and analgesics help control pain, and early physical therapy helps the individual regain full range-of-motion. Usually, surgical intervention is considered only when the individual has failed to heal with conservative treatment, is a professional athlete, or performs heavy lifting or overhead work.

Grade IV through VI injuries are treated surgically with open reduction and internal fixation (ORIF), a surgical procedure that realigns the bones and reconstructs the ligaments. Screws, wires, or non-absorbable sutures may be used to hold the joint in place while the reconstructed ligaments heal. During the healing phase, shoulder motion is increased gradually to restore full range of motion. The individual usually regains full use of the shoulder about 10 weeks after surgery. ORIF usually leaves a scar about 2 inches long over the AC joint.

Any surgical procedures for AC separation must accomplish three objectives: (1) expose and remove any damaged tissue from the AC joint (débridement), (2) repair torn and damaged ligaments, and (3) achieve a stable reduction of the AC joint. Arthroscopic techniques using fiber-optic instruments and a smaller incision have been used for AC joint fixation with good results (Canale), but most orthopaedic surgeons prefer open procedures.

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.*
 
Shoulder Disorders
 
* 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

Early repairs achieve satisfactory results in 96% of cases, whereas late reconstruction achieves satisfactory results in 77% of cases (Canale). Individuals with grade III injuries treated conservatively without surgery may return to normal function and activity without restriction in approximately 6 to 8 weeks. Grade III injuries, however, do not always respond to conservative therapy, especially if there has been damage to the disc of cartilage between the acromion and clavicle, damage to capsular ligaments, of if there are fragments of articular cartilage between the acromion and the clavicle. Recovery from grade IV to VI injuries occurs more slowly due to associated injuries to surrounding structures.

Injury to the AC joint may be accompanied by loss of strength in the shoulder joint. This may not restrict the activities of most individuals but can have serious consequences for individuals whose jobs require heavy lifting or overhead work, as well as for athletes who participate in contact sports and / or throwing.

While the predicted treatment outcome is good, chronic pain and decreased joint function from degenerative arthritis develop in a small percentage of individuals as they age. If AC joint arthritis becomes disabling, it may be treated by a Mumford procedure, in which the distal clavicle is surgically resected to remove the diseased joint (arthropathy).

Source: Medical Disability Advisor



Rehabilitation

Rehabilitation of individuals with AC separation depends greatly on the severity of injury. The treatment of a minor AC separation may consist of a sling for comfort for several days. Even if the AC joint is not to be exercised, it becomes important to exercise the fingers, hands, and elbows to prevent stiffness. The use of modalities such heat and cold can help in the control of pain and inflammation (Salter). Once the initial pain and swelling subside, usually about 2 weeks after the injury, the rehabilitation process may warrant the observation and guidance of a physical therapist or occupational therapist until the individual progresses to an independent exercise program (Dlaback). Horizontal abduction and other painful positions are generally avoided initially and with an emphasis on restoring shoulder flexion and abduction (Rizzo). The individual may be instructed in a home exercise program to continue daily in conjunction with supervised treatment. The progression of all exercise is based on the healing of the involved soft tissue.

Rehabilitation of an individual with AC separation begins with range of motion exercises to the shoulder in all pain-free movements. Individuals may progress to strengthening exercises, using pain as a guide, avoiding motions that may compromise the integrity of the joint (Buss). Care should be taken to strengthen all muscles surrounding the shoulder.

Heavy weight lifting activities should be avoided for approximately 6 to 12 weeks, until the ligaments heal. At this point, the strengthening program advances, as tolerated (Canale; Rizzo).

The therapist may need to modify the exercise program for individuals with arthritis or other joint irritations. If the AC separation requires surgical repair, some restrictions may be placed on the progression of the range of motion and strengthening in certain movements. These restrictions vary depending on the degree of dislocation or type of surgery performed. Surgery is not usually performed on AC separations unless there is significant inferior or posterior displacement, or severe displacement (Type IV) (Dlaback).

Additional information may provide greater insight into the rehabilitation needs of these individuals (Clarke; Rockwood).

FREQUENCY OF REHABILITATION VISITS
Nonsurgical
SpecialistDislocation, Acromioclavicular Joint
Occupational or Physical TherapistUp to 6 visits within 4 weeks
Surgical
SpecialistDislocation, Acromioclavicular Joint
Occupational or Physical TherapistUp to 12 visits within 8 weeks
The table above represents a range of the usual acceptable number of visits for uncomplicated cases. It provides a framework based on the duration of tissue healing time and standard clinical practice.

Source: Medical Disability Advisor



Complications

Skin abrasions are common with this type of injury and should be monitored for signs of infection. Pressure from a sling or harness can lead to skin ulceration and potential for infection. Muscle weakness, chronic pain, and chronic deformity of the shoulder may occur. Acute injury to the brachial plexus or blood vessels may be associated with grades IV through VI injuries. Development of osteoarthritis in the affected joint is a late complication.

Complications of surgery may include infection, hematoma formation, scar formation, recurrence of deformity, loosening or migrating screws or wires, and need for subsequent surgery.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Individuals may need to wear a sling or harness during the recovery period and this may limit manual dexterity. Lifting, carrying, overhead work, and participation in sports is usually restricted for up to 8 weeks. Time off may be needed for physical therapy appointments. In some cases, individuals may be permanently restricted from heavy lifting and overhead work. Company policy on medication usage should be reviewed to determine whether or not pain medication use is compatible with job safety and function.

Risk: Most injuries occur from trauma and in a younger age group.

Capacity: Capacity is dependent upon the grade (severity) of the injury and the treatment provided. Surgery could provide for earlier return to light work.

Tolerance: Tolerance is limited by both pain and capacity which are dependent on the severity of the AC separation and on the treatment provided.

Accommodations: Return to work is dependent on job demands, injury severity, and treatment required. If an individual performs a light work (office desk job) early return is possible. For manual labor with lifting, accommodations will be required to allow the individual an earlier return to work.

Source: Medical Disability Advisor



Maximum Medical Improvement

60 to 90 days post surgery.

Continued improvement is possible over 540 days (18 months), but the amount of improvement is limited.

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:

  • What was the mechanism of injury?
  • Has diagnosis of AC separation been confirmed?
  • Was joint deformity present?
  • Did x-rays confirm a shoulder separation?
  • Was there a fracture in addition to dislocation? Other injuries?

Regarding treatment:

  • Did non-surgical treatment include strapping, bracing, splinting, or a sling?
  • Was surgery performed? Open reduction and / or internal fixation? Did individual experience any complications from surgical procedure?
  • Has individual received physical therapy?
  • Is individual actively participating in a home exercise program?
  • Has heavy lifting been avoided for 4 to 8 weeks? Have contact sports been avoided for at least 8 weeks?
  • Did conservative treatment fail?
  • Has late reconstructive surgery been recommended?

Regarding prognosis:

  • Has pain resolved?
  • Has function been restored? If not completely, to what degree?
  • How does this impact the individual's ability to perform daily activities or job requirements?
  • Would further rehabilitation increase functional ability?
  • Has individual experienced any complications?
  • Does individual have an underlying condition that may affect recovery?

Source: Medical Disability Advisor



References

Cited

Buss, D. D., and J. D. Watts. "Acromioclavicular Injuries in the Throwing Athlete." Clinics in Sports Medicine 22 2 (2003): 327-341, vii. National Center for Biotechnology Information. National Library of Medicine. 3 Oct. 2013 <PMID: 12825534>.

Canale, S. Terry, and James H. Beaty, eds. "Acromioclavicular Joint." Campbell's Operative Orthopaedics. 11th ed. Philadelphia: Mosby Elsevier, 2008. 3586-3587.

Clarke, H. D., and P. D. McCann. "Acromioclavicular Joint Injuries." Orthopedic Clinics of North America 31 2 (2000): 177-187. National Center for Biotechnology Information. National Library of Medicine. 3 Oct. 2013 <PMID: 10736388>.

Dlaback, Jeffrey A. "Chapter 57 - Acute Dislocations." Campbell's Operative Orthopaedics. Eds. S. Terry Canale and James H. Beaty. 11th ed. Philadelphia: Mosby Elsevier, 2008.

Malone, Terry R., Thomas Mcpoil, and Arthur J. Nitz, eds. Orthopedic and Sports Physical Therapy. St. Louis: Mosby-Year Book, Inc., 1997.

Prybyla, David, et al. "Acromioclavicular Joint Separations." eMedicine. Eds. Lynn A. Crosby, et al. 7 Feb. 2012. Medscape. 3 Oct. 2013 <http://emedicine.medscape.com/article/1261906-overview>.

Rizzo, Thomas, et al., eds. "Chapter 9 - Acromioclavicular Injuries." Essentials of Physical Medicine and Rehabilitation. 2nd ed. Philadelphia: Saunders, Elsevier, 2008.

Rockwood, C. A., Gerald Williams, and Christopher Young. "Disorders of the Acromioclavicular Joint." The Shoulder. Eds. C. A. Rockwood and Frederick A. Matsen. 2nd ed. Philadelphia: W.B. Saunders, 1998. 483-554.

Salter, Robert, ed. Textbook of Disorders and Injuries of the Musculoskeletal System. 3rd ed. Philadelphia: Lippincott, Williams & Wilkins, 1999.

Source: Medical Disability Advisor






Feedback
Send us comments, suggestions, corrections, or anything you would like us to hear. If you are not logged in, you must include your email address, in order for us to respond. We cannot, unfortunately, respond to every comment. If you are seeking medical advice, please contact your physician. Thank you!
Send this comment to:
Sales Customer Support Content Development
 
This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is published with the understanding that the author, editors, and publisher are not engaged in rendering medical, legal, accounting or other professional service. If medical, legal, or other expert assistance is required, the service of a competent professional should be sought. We are unable to respond to requests for advice. Any Sales inquiries should include an email address or other means of communication.