305The following tables assess impairments to range of motion of the shoulders, including ankylosis:

305     The following tables assess impairments to range of motion of the shoulders, including ankylosis:

a)      Table 9.11.1a: Shoulder – flexion/extension;

b)      Table 9.11.1b: Shoulder – internal/external rotation; and

c)       Table 9.11.1c: Shoulder – abduction/adduction.

306     Loss of range of motion in each functional plane is measured from the neutral position. The range of motion is expressed as the two achievable limits of active motion in each direction through the normal range of motion. It is possible that the only motion that can be achieved is between two points on one side of the neutral position.

307     The WPI rating for restriction of motion in one direction is assessed according to the active motion than can be achieved in that direction. It is then added to the WPI rating for the active motion in the reverse direction.

308     Add the abnormal motion WPI ratings for each direction of motion for shoulder flexion/extension, abduction/adduction and internal/external rotation. Where there is ankylosis, including after an arthrodesis procedure, the assessment should only be made under the ankylosis scale.

309     Where an arthroplasty procedure has been undertaken, refer to the AMA5. Assess the upper extremity impairment rating for abnormal motion and the upper extremity impairment rating for arthroplasty in accordance with the AMA5, then convert each of those ratings into WPI ratings using Table 16-3 of AMA5. Combine those WPI ratings obtained from the AMA5 using the combined values chart (see Appendix 1).

310     For ankylosis, the optimal or functional position is 20°-40° of flexion, 20°-50° of abduction and 30°-50° of internal rotation. Unless the shoulder has been arthrodesed, an assessment for ankylosis under this table would be rare.