There are a few basic rules to follow when determining impairment ratings for the upper and lower extremities. When evaluating range of motion of a specific joint such as the wrist, elbow, shoulder, ankle, knee, or hip, the values are added. When multiple joints are involved (i.e., shoulder and elbow or hip and knee), the total value from each joint must be combined using the Combined Values Chart.
SPECIFIC DISORDERS
Upper extremity — Specific disorders of the upper extremity (i.e., persistent joint subluxation, joint swelling, etc.) are converted to impairment of upper extremity and then combined with all other upperextremity values.
Lower extremity — Specific disorders of the lower extremity (i.e., hip disorders, specific disorders of the knee, etc.) are combined with all other lower- extremity values.
Using the specific guidelines for motor and sensory impairment, these values will also be determined separately and combined with all other values of the involved extremity.
The evaluator is cautioned to combine all the values of one extremity before conversion to whole person. (Only one conversion to whole person should be done per extremity.)
When both upper and lower extremities are involved, each extremity should be evaluated separately and converted to whole person. Then the two whole-person values (both the upper and lower extremities) should be combined to produce a single whole-person rating.
PREFERRED OR NONPREFERRED EXTREMITY
Since the basic tasks of everyday living are more dependent upon the preferred upper extremity than the nonpreferred one, dysfunction of the nonpreferred extremity results in less impairment. Therefore, when an impairment of an upper extremity has been determined, the value should be reduced by 10% if the impairment is of the nonpreferred extremity.
Example: 40% of the (upper) nonpreferred extremity
10% of 40% = 4%
40% minus 4% = 36% upper extremity
There is no dominant or preferred lower extremity. Most conditions of the lower extremity relative to the dominant side refer to the employability of the patient and determine disability, not physical impairment.
Ankylosis
Ankylosis is defined as absence of joint motion. Since no joint motion can be measured, ankylosis cannot be considered range of motion. Therefore ankylosis values are combined with all other values of the extremity. Since there can be many planes of movement of a joint, there can be multiple ankyloses. When multiple ankyloses occur in the same joint, the evaluator should utilize the largest value for impairment rating.
Example: Wrist joint ankyloses at 20 degrees palmar flexion and 10 degrees ulnar deviation.
20 degrees palmar flexion ankylosed = 47% upper-extremity impairment
10 degrees ulnar deviation ankylosed = 50% upper-extremity impairment
SOLUTION: 50% impairment for upper extremity (higher value).
Example: Hip joint ankyloses at 20 degrees flexion and 10 degrees internal rotation
20 degrees flexion ankylosed = 54% lower-extremity impairment
10 degrees internal rotation ankylosed = 78% lower-extremity impairment
SOLUTION: 78% impairment for lower extremity (higher value).
ADDITIONAL RATABLE DISORDERS OF THE EXTREMITIES
Painful Organic Syndrome — A musculoskeletal condition characterized by pain with use of the affected member, which may or may not limit the voluntary active range of motion, with or without any limitation of passive range of motion, and attributed to a lesion in the soft tissues (capsule, ligament, tendon, fascia, muscle), and documented by clinical findings.
Upper Extremity
Shoulder.............................. 3% U E
Elbow .................................. 3% U E
Wrist/Hand.......................... 3% U E
Lower Extremity
Hip........................................4% L E
Knee.....................................4% L E
Ankle/Foot............................4% L E
Reflex Sympathetic Dystrophy — A condition characterized by disproportionate pain, disuse and apprehension associated with changes to bone and soft tissue documented by multiple diagnostic studies.
Upper Extremity ................................................ 15%—25%
Lower Extremity .................................................. 5%—25%
This condition must not be rated for at least one year after onset and should not be explained by any other ratable diagnoses.
These conditions (P.O.S. and R.S.D.) should not be rated until MMI and should not be secondary to any other ratable diagnosis.
These values must be combined with all other values.