Sign-in
(your email):
(case sensitive):



 
 

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.

Internal Derangement of Knee


Text Only Home | Graphic-Rich Site | Overview | Risk and Causation | Diagnosis | Treatment | Prognosis | Differential Diagnosis | Specialists | Rehabilitation | Comorbid Conditions | Complications | Factors Influencing Duration | Length of Disability | Duration Trends | Ability to Work | Failure to Recover | Medical Codes | References

Overview

Internal derangement is an old term that describes internal damage to the joint generally caused by trauma. It is a nonspecific term that usually must be further refined by history, physical exam, x-rays, and frequently MRI studies.

The knee joint is the largest of weight bearing joint in the body. It is a hinge joint that connects the rounded, bony ends (condyles) of the thigh bone (femur) and the shin bone (tibia) and is bounded in front by the knee cap (patella). Various ligaments, muscles, and tendons help confine joint motion within safe limits while the menisci and cartilage cushion the joint against considerable forces that bear on the knee. Damage from injury or chronic overuse to any of these stabilizing and cushioning structures results in pain and may lead to joint instability.

With the popularity of jogging and skiing and the vulnerability of major sports figures to career-ending knee injury, terms of joint pathology have come into common usage and in many cases have supplanted the term internal derangement. Ligament tears are especially common. The knee has four major ligaments and each is vulnerable to injury: the anterior cruciate ligament (ACL), the medial collateral ligament (MCL) the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL). Each ligament restricts certain abnormal movement of the knee. Motion beyond the limits of the ligaments will produce damage manifested by a partial or complete tear. Cartilage damage is another common problem. The specialized cartilage cushion between the femur and tibia (meniscus) can be damaged in the same manner as the ligaments and may even be damaged at the same time. Articular cartilage is the smooth layer that covers the joint surfaces in the knee. Damage to the articular cartilage is referred to as chondromalacia. The most common example of chondromalacia is the cracking and popping (crepitus) that many people feel under their knee cap (See Meniscus Disorders; Patella Chondromalacia; Fracture, Patella; and Sprains and Strains, Knee).

Incidence and Prevalence: Knee pain is reported by about 20% of adult Americans and accounts for nearly 3 million outpatient and emergency room visits in the US annually (Levy). Among workers, traumatic knee injury is the second most common occupational accident. The MCL is the ligament most commonly injured, but damage to the ACL is the most common source of chronic joint instability (Levy).

Source: Medical Disability Advisor