The Ontario Rating Schedule

Policy

The WSIB has adopted the Ontario Rating Schedule (O.R.S.) as a clinical guide to evaluation, for consistency of medical assessment under the provisions of Sections 45(1), 45(3) and 13 of the Workers' Compensation Act. The Ontario Rating Schedule is used only as a guide for minimum rating levels for specified disabilities. It shows, in percentage, the approximate impairment of earnings capacity in an average unskilled worker. In every case, emphasis is placed on the individual factors being appraised and appropriate allowances are made.

Guidelines

Hand ratings

Four charts are provided for the rating of hand injuries. Each chart includes a diagram of a hand to identify the percentage of disability with the injured part.

Chart 1 shows values for individual fingers and thumb when the disability involves more than one phalanx and the disability pertains to a single finger.

Charts 2, 3, and 4 are used if the disability pertains to more than one finger.

Thumb or Single Finger - Chart 1

Single Distal Phalanx

When the only disability involves a single distal phalanx of a finger or thumb, half the value in the following chart and illustration is used.

If less than a quarter of the second phalanx is lost, the rating is carried out as if the amputation was a distal phalanx only. The exception to this guideline is the thumb: In this case, judgment must be used to arrive at a reasonable figure having regard to the whole value of the digit, i.e., in the 5% to 10% range.

Metacarpals

The diagram which accompanies Chart 1 also provides disability rating values for metacarpals. The values shown do not include the thumb. The medical consultant uses the values shown as a minimum guide only, and assesses the function of the whole hand when establishing a disability rating.

More than one finger (Same hand) - Charts 2, 3, and 4

When calculating these, remember to apply the multiple only to those phalanges which are amputated or seriously impaired in common.

Percentage rating calculation

  • 2 Finger Disability = Sum of single digit value x 1.5
  • 3 Finger Disability = Sum of single digit value x 2
  • 4 Finger Disability = Sum of single digit value x 2.5

NOTE

When the thumb is involved on the same hand, the formula is:

finger(s) assessment + thumb assessment.

There is no multiple applied to a thumb rating, and a thumb disability does not increase the multiple factor applied in the finger(s) assessment.

Following from the application of these formulae, the percentage ratings for multiple finger injuries are provided and illustrated in charts 2 to 4.

Chart 1
Hand
Amputation Percentage
Thumb, including metacarpal 20.
Thumb, both phalanges 15.
Thumb, one phalanx 10.
Finger, index 5.
Finger, index at P.I.P. 4.
Finger, index at distal 2.
Finger, middle 4.
Finger, middle at P.I.P. 3.2
Finger, middle at distal 1.6
Finger, ring 3.
Finger, ring at P.I.P. 2.4
Finger, ring at distal 1.2
Finger, little 2.
Finger, little at P.I.P. 1.6
Finger, little at distal .8

NOTE

When the only disability involves a single distal phalanx the value is half that shown.

 

This diagram accompanies Chart 1

Skeletal image of the right hand with disability ratings of respective bones
Chart 2 (single value x 1 ½)
Hand — Two Finger Disability
Amputation Percentage
Index & middle at distal 5.4
Index & ring at distal 4.8.
Index and little at distal 4.2
Middle & ring at distal 4.2
Middle & little at distal 3.6
Ring & little at distal 3.
Index & middle at P.I.P. 10.8
Index & ring at P.I.P. 9.6
Index & little at P.I.P. 8.4
Middle & ring at P.I.P. 8.4
Middle & little at P.I.P. 7.2
Ring & little at P.I.P. 6.
Index & middle at metacarpal 13.5
Index & ring at metacarpal 12.
Index & little at metacarpal 10.5
Middle & ring at metacarpal 10.5
Middle & little at metacarpal 9.
Ring & little at metacarpal 7.5

This diagram accompanies Chart 2

Skeletal image of the right hand with disability ratings of respective bones
Chart 3 (single value x 2)
Hand — Three Finger Disability
Amputation Percentage
Index & middle with ring at distal 9.6
Index & middle with little at distal 8.8
Index & ring with little at distal 8.
Middle & ring with little at distal 7.2
Index & middle with ring at P.I.P. 19.2
Index & middle with little at P.I.P. 17.6
Index & ring with little at P.I.P. 16.
Middle & ring with little at P.I.P. 14.4
Index & middle with ring at metacarpal 24.
Index & middle with little at metacarpal 22.
Index & ring with little at metacarpal 20.
Middle & ring with little at metacarpal 18.

This diagram accompanies Chart 3

skeletal image of the right hand with disability rating of respective bones
Chart 4 (single value x 2.5)
Hand — Four Finger Disability
Amputation Percentage
Index, middle, ring, & little at distal 14.
Index, middle, ring, & little at P.I.P. 28.
Index, middle, ring, & little at metacarpal 35.

This diagram accompanies Chart 4

Skeletal image of the right hand with disability rating of respective bones

Ankylosis of Joints

Fixation of a joint in the position of optimum function would warrant an award equal to one-half the value of the phalanx or phalanges distal to it. A finger or portion of a finger ankylosed in a very poor position may be assessed as if it were amputated.

The medical consultant estimates the loss of any portion of the movement range in between the two extremes cited in the preceding paragraph, using a value which is proportional to the disability rating for amputation.

Immobility of joints Percentage
Thumb, both joints 7.5
Thumb, distal joint 2.5
Finger, all joints up to value of finger

Multiples between hands or limbs - bilateral disability

If a worker is bilaterally disabled (e.g., disability to both knees) the formula applied is the sum of the disabilities in the individual limbs plus half the value of the lesser disability.

In calculating the rating for any permanent disability award, however, the decision-maker or WSIB medical consultant also considers the presence of any pre-existing condition which the worker had. The WSIB may include an enhancement factor in the worker's award, see 14-05-03, Second Injury and Enhancement Fund (SIEF).

Ratings for the upper extremity
Amputations Percentage
Proximal third of humerus or disarticulation of shoulder 70
Middle third of humerus 65
Distal third of humerus to biceps insertion 60
Biceps insertion to wrist (depending on usefulness of stump) 50-60
Immobility of joints Percentage
Shoulder, without either articular or scapula movement (the totally "frozen" shoulder) 35
Shoulder joint (gleno humeral) ankylosed but with full scapular movement 15
Shoulder, abduction limited to 90 degrees but with good rotation and pivotal movement 5
Elbow 20
Wrist 12.5
Pronation and supination complete in mid-position 10
Pronation alone lost 3
Supination alone lost 5
Denervation  
Median, complete at elbow 40
Median, complete at wrist 20
Ulnar, complete at elbow 10
Ulnar, complete at wrist 8
Ratings for the lower extremity
Amputations Percentage
Hip disarticulation or short stump requiring an ischial bearing prosthesis 65
Thigh, site of election 50
End bearing knee, or short below-knee stump, not suitable for a conventional below knee prosthesis 45
Leg, suitable for B.K. prosthesis 35
Leg, at ankle, end bearing 25
Through foot 10-25
All toes 5
Toe, great 2.5
Toe, great at distal 1
Toes, other than great, each 0.5
Immobility of joints Percentage
Hip 30
Knee 25
Knee, flexion limited to 90 degrees 5
Ankle 12
Great toe, both joints 2.5
Great toe, distal joint 0.5
Shortening of Lleg Percentage
1 inch 1.5
2 inches 6
3 inches 15
Denervation Percentage
Peroneal, complete 12
Ratings for the spine
Location Percentage
Total immobility of spine (usual distribution) 60
Cervical and/or thoracic 30
Lumbar and/or lumbosacral 30
Rating for kidney injury
Location Percentage
Loss of one kidney 10

Permanent disability rating is done following optical correction with spectacles/contact lenses.

Ratings for impaired vision
Impairment of vision Percentage
Enucleation 18
Sight of one eye 16
Cataract 12
Hemianopia, right field 25
Hemianopia, left field 20
Diplopia, all fields 10
Scotomata, depending on location and extent Up to 16
Aphakic Eye Percentage
20/20, 20/30 6
20/40 7
20/50 8
20/60 9
20/80 10
20/100 11
20/200 12
Partial Visual Loss Snellen Test Result* Percentage
20/30 0
20/40 1
20/50 2
20/60 4
20/80 6
20/100 8
20/200 12
20/400 14

*NOTE

Results of Snellen test for distance are after correction with conventional eye glasses.

If one eye is enucleated, the WSIB adds 2% to the degree of permanent disability obtained, since the loss of sight in one eye is 16% and the enucleation is 18%.

When a worker, already blind in one eye, also becomes blind in the remaining sighted eye for a compensable reason, the WSIB awards a disability rating of 100%. For information concerning accident cost charges, see 14-05-03, Second Injury and Enhancement Fund (SIEF).

Table of permanent disability concerning loss of vision in one eye or both, following correction
Loss of sight in one eye 16% For loss of vision in both eyes following correction
Enucleation 18% 1. For one eye, find level of visual acuity on vertical axis.
Loss of sight in both eyes 100% 2. For the other eye, find level of visual acuity on horizontal axis.
    3. The intersection of both axes equals the percentage of permanent disability.
     
    For loss of vision in one eye following correction
    1. Find level of visual acuity on vertical axis.
    2. Look in next column to find the percentage of permanent disability.
Snellen Scale

20/30

6/9

20/40

6/12

20/50

6/15

20/60

6/18

20/80

6/24

20/100

6/30

20/200

6/60

20/400

6/120

Blind

20/30

6/9

0 1 2 4 6 8 12 14 16

20/40

6/12

1 6.3 7.3 9.3 11.3 13.3 17.3 19.3 21.3

20/50

6/15

2 7.3 12.5 14.5 16.5 18.5 22.5 24.5 26.5

20/60

6/18

4 9.3 14.5 25 27 29 33 35 37

20/80

6/24

6 11.3 16.5 27 37.5 39.5 43.5 45.5 47.5

20/100

6/30

8 13.3 18.5 29 39.5 50 54 56 58

20/200

6/60

12 17.3 22.5 33 43.5 54 75 77 79

20/400

6/120

14 19.3 24.5 35 45.5 56 77 87.5 89.5
Blind 16 21.3 26.5 37 47.5 58 79 89.5 100

Application date

This policy applies to all decisions made on or after October 1, 1989, for accidents prior to January 2, 1990.

Document History

This policy replaces 05-03-03 dated August 1, 2003.

References

Legislative Authority

Workers' Compensation Act, R.S.O. 1980, as amended
Sections 13, 45(1), 45(3)

Minute

Board of Directors
8(XLV), June 10, 2004, Page 6623