Rating Schedule

SECTION 3: MUSCULOSKELETAL — UPPER EXTREMITIES

THUMB

TABLE 1 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE INTERPHALANGEAL JOINT OF THE THUMB
TABLE 2 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE METACARPOPHALANGEAL JOINT OF THE THUMB
TABLE 3 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE CARPOMETACARPAL JOINT OF THE THUMB
TABLE 4 RELATIONSHIP OF IMPAIRMENT OF THE THUMB TO IMPAIRMENT OF THE HAND*

FINGERS

TABLE 5 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE DISTAL INTERPHALANGEAL JOINT OF ANY FINGER
TABLE 6 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE PROXIMAL INTERPHALANGEAL JOINT OF ANY FINGER
TABLE 7 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE METACARPOPHALANGEAL JOINT OF ANY FINGER
TABLE 8 RELATIONSHIP OF IMPAIRMENT OF THE DIGITS TO IMPAIRMENT OF THE HAND

WRIST JOINT

TABLE 9 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE WRIST JOINT—EXTENSION
TABLE 10 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE WRIST JOINT—FLEXION
TABLE 11 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE WRIST JOINT—RADIAL/ULNAR DEVIATION

ELBOW JOINT

TABLE 12 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE ELBOW JOINT—FLEXION/EXTENSION
TABLE 13 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE ELBOW JOINT—PRONATION/SUPINATION

SHOULDER JOINT

Flexion/Extension

TABLE 14 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE SHOULDER JOINT—FLEXION
TABLE 15 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE SHOULDER JOINT—EXTENSION
TABLE 16 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE SHOULDER JOINT—ABDUCTION-ADDUCTION

Internal/External Rotation

TABLE 17 IMPAIRMENT DUE TO ABNORMAL MOTION AND ANKYLOSIS OF THE SHOULDER JOINT—ROTATION

DISORDERS OF THE UPPER EXTREMITY

Derangements not previously described can contribute to impairments of the hand and upper extremity and should be considered in the final impairment determination. These include bone and joint disorders, presence of resection or implant arthroplasty, musculotendinous disorders, and loss of strength.

NOTE: It must be stressed that impairments secondary to these disorders are usually rated by other parameters. The following disorders are to be rated only when other factors have not adequately rated the extent of impairment. Whether to consider these disorders separately is left to the discretion of the examiner.

Table 18 shows relative impairment values for loss of function of the digits, hand, wrist, elbow, and shoulder due to the conditions described below and impairment values for the larger units. This table differs from figures 1 and 2 (p. 41), which show values for amputation at these levels.

TABLE 18 RELATIVE IMPAIRMENT VALUES

BONE AND JOINT DEFORMITIES

Joint Crepitation with Motion—Joint crepitation with motion can reflect synovitis or cartilage degeneration. The impairment degree is multiplied by the relative value of the joint (Table 18).

The evaluator must use judgment and avoid duplication of impairments when other findings, such as synovial hypertrophy, carpal collapse with arthritic changes, or limited motion are present. The latter findings may indicate a greater severity of the same underlying pathological process and take precedence over joint crepitation, which should not be rated in these instances.

Joint Crepitation Severity ... % Joint Impairment*

    • Mild: Inconstant during active ROM** ... 10
    • Moderate: Constant during active ROM ... 20
    • Severe: Constant during passive ROM ... 30

*Use table 18 (previous page) to find the relative value of each joint.

**ROM: Range of Motion

Joint Swelling due to Synovial HypertrophyThis condition would usually be rated through loss of motion and is to be considered for impairment only when there is full range of motion of the joint. The percent of impairment is multiplied by the relative value of the joint (Table 18).

Joint Swelling Due to Synovial Hypertrophy ... % Joint Impairment*

    • Mild ... 10
    • Moderate ... 20
    • Severe ... 30

*Use Table 18 to find the relative value of each joint.

Digit Lateral Deviation—The longitudinal alignment of each of the finger joints is measured in degrees during maximum active extension. Since lateral deviation at any level affects the longitudinal arch of the digit, deviation affects the entire digit. If lateral deviation is the sole impairment, it is multiplied by the relative value of the digit to the hand to calculate hand impairment (Table 18). If the digit has other impairments, the lateral deviation impairment value is combined with them using the Combined Values Chart, in Section 15.

Ulnar or Radial Deviation ... % Digit Impairment*

    • Mild: Less than 10° ... 10
    • Moderate: 10° to 30°... 20
    • Severe: Greater than 30°... 30

*Use Table 18 to find the relative value of each digit.

Digit Rotational Deformity—Rotational Deformity of the distal, middle, or proximal phalanx is measured during maximum active flexion of the finger and expresses a malrotation of the normal axial alignment of the phalanx. Rotational deformity at any level affects the function of the entire digit, and the impairment percentage is applied to the entire digit. If other impairments of the same digit are present, rotational-deformity impairment is combined with them using the Combined Values Chart.

Rotational Deformity ... % Digit Impairment*

    • Mild: Less than 15° ... 20
    • Moderate: 15° to 30°... 40
    • Severe: Greater than 30°... 60

*Use Table 18 to find the relative value of each digit.

Persistent Joint Subluxation and DislocationWhen persistent joint subluxation or dislocation results in restricted motion, impairment percentages are given for lack of motion in order to avoid duplication in the rating. If there is no restricted motion, the following table is used to determine the degree of joint impairment. The percentage of impairment is multiplied by the relative value of the joint (Table 18).

Persistent Joint Subluxation or Dislocation ... % Digit Impairment

    • Mild: Can be completely reduced manually ... 20
    • Moderate: Cannot be completely reduced manually ... 40
    • Severe: Cannot be reduced ... 6

*Use Table 18 to find the relative value of each joint.

Joint Instability—Excessive passive joint motion is evaluated by comparing it with normal joint stability and graded according to the degree of severity. Then the percentage of impairment is multiplied by the relative value of the joint (Table 18). If other impairments of the same joint are present, the values are combined using the Combined Values Chart.

Joint Instability ... % Joint Impairment

    • Mild: Less than 10° ... 20
    • Moderate: 10° to 20°... 40
    • Severe: Greater than 20°... 60

*Use Table 18 to find the relative value of each joint.

Wrist and Elbow Joint Lateral Deviation—These angles are measured with the wrist or elbow in maximum active extension. The degree of severity is multiplied by the relative value of the joint to the upper extremity to obtain upper extremity impairment due to lateral deviation (Table 18). If other impairments of the same joint are present, they are combined using the Combined Values Chart. After all impairments for either the wrist or elbow joint have been calculated, they are combined with any other upper-extremity impairment using the Combined Values Chart.

Lateral Deviation Severity ... % Joint Impairment*

    • Mild: Less than 20° ... 10
    • Moderate: 20° to 30°... 20
    • Severe: Greater than 30°... 30

*Use Table 18 to find the relative value of the wrist and elbow joints.

Carpal Instability—Carpal instability patterns resulting from lunate or scaphoid pathology can be classified as mild, moderate, or severe, based on the severity of the radiographic findings (Table 19, below). The proximal carpal row represents half of the value of the wrist, or 30% of the upper extremity. Therefore the grades of mild (20%), moderate (40%), and severe (60%) represent upper- extremity impairments of 6%, 12%, and 18%, respectively. These values may be combined with other upperextremity impairments due to wrist abnormalities using the Combined Values Chart.

In using Table 19, apply only the greatest impairment value determined by the radiographic findings. Do not combine or add the impairment values shown on Table 19. These radiographic parameters are to be used only when all other factors including range of motion and grip strength are normal.

TABLE 19 IMPAIRMENT OF UPPER EXTREMITY DUE TO CARPAL INSTABILITY PATTERNS

Arthroplasty—Simple resection arthroplasty is given 40% impairment of the joint value due to loss of function; implant arthroplasty is given 50% impairment of the joint value due to loss of function. Table 20 provides impairment ratings for the upper extremity for arthroplasty of specific joints, based on these values.

TABLE 20 IMPAIRMENTS OF UPPER EXTREMITY FOLLOWING ARTHROPLASTY OF SPECIFIC BONES OR JOINTS

Musculotendinous Impairments and Intrinsic Tightness—Intrinsic tightness in the hand may be demonstrated by a test described by Bunnell. Hyperextension of the metacarpophalangeal (MP) joint in a normal hand still allows passive flexion of the proximal interphalangeal (PIP) joint. If the intrinsic muscles are tight or contracted, the available stretch of these muscles is taken up by the hyperextended position of the MP joint, and passive flexion of the PIP joint will be difficult.

If there is already restriction in active range of motion at the MP or PIP joint, then no additional rating is given for intrinsic tightness.

Intrinsic tightness impairment is combined with other impairments of the same digit using the Combined Values Chart. Finger impairment is converted to hand impairment using Table 21.

Intrinsic Tightness Severity (Passive flexion of PIP Joint with MP Joints hyperextended) ... % Digit Impairment*

    • Mild: PIP flexion 80° to 60° ... 20
    • Moderate: PIP flexion 59° to 20° ... 40
    • Severe: PIP flexion less than 20° ... 60

*Use Table 18 to find the relative value of each digit.

Constrictive Tenosynovitis—Impairment due to constrictive tenosynovitis is combined with other impairments of the digit using the Combined Values Chart. The digit impairment is converted to hand impairment with Table 21.

If there is already restriction in active range of motion, no additional rating is given for constrictive tenosynovitis.

Constrictive Tenosynovitis Severity ... % Digit Impairment*

    • Mild: inconstant triggering during active ROM** ... 20
    • Moderate: Constant triggering during active ACM ... 40
    • Severe: Constant triggering during passive ROM ... 60

*Use Table 18 to find the relative value of each digit.

**ROM: Range of Motion

Extensor Tendon Subluxation at MP Joint—The severity of extensor tendon subluxation at the metacarpophalangeal (MP) joint is combined with other impairments of the same digit using the Combined Values Chart. The finger impairment is converted to hand impairment with Table 21.

When persistent extensor tendon subluxation results in restricted range of motion, impairment is given only for lack of motion.

Extensor Tendon Subluxation Severity ... % Digit Impairment*

    • Mild: Ulnar subluxation on MP joint flexion only ... 10
    • Moderate: Reducible tendon subluxation in the intermetacarpal groove ... 20
    • Severe: Nonreducible tendon subluxation in the intermetacarpal groove ... 30

*Use Table 18 to find the relative value of each digit.

UPPER EXTREMITY—CONVERSION TABLES

TABLE 21—Relationship of Impairment of the Digits to Impairment of the Hand
TABLE 22—Relationship of Impairment of the Thumb to Impairment of the Hand
TABLE 23—Relationship of Impairment of the Hand to Impairment of the Upper Extremity
TABLE 24—Relationship of Impairment of the Upper Extremity to Impairment of the Whole Person

AMPUTATION—FINGER, THUMB, HAND, UPPER EXTREMITY

Figure 1. Impairment of upper extremity from amputation at various levels.

Figure 2. Impairments of the digits (percents outside digits and of hand (percents inside digits) for amputations at various levels.

Figure 3. Impairment of finger due to amputation at various lengths (top scale) and total transverse sensory loss impairments correspond to 50% of amputation impairments.

Figure 4. Impairment of thumb due to amputation at various levels (top scale) or total transverse sensory loss (bottom scale). Total transverse sensory loss impairments correspond to 50% amputation values.