California Labor Codes 4750

Ashley v. WCAB

Note: Employer need not compensate a worker for a disability from a preexisting perm. disability.

King v. WCAB

Note: Apportionment to preexisting disability must be based on evidence that preexisting condition was labor disabling.

Wilkinson v. WCAB

Note: Whenever a worker sustains successive industrial injuries to the same part of his body while working for the same employer, and these injuries become permanent at the same time, the board should render a single award for the combined disability.

Dept. of Education v. WCAB (Gill)

Note: Method of converting PD rating to a number of weeks of workers' comp.

Fuentes v. WCAB

Note: 4658 is limited by 4750 only where employee had preexisiting disability.

Ditler v. WCAB

Note: Doctor's testimony that worker would ultimately suffer disability was too speculative.

Morgan v. WCAB

Note: Objection to reopen waived by failure to recon; Board must describe all disability, up to evaluator to decide MDT vs duplication.

Gay v. WCAB, Guarantee Collection Co.

Note: Dr's report must demonstrate legal basis for apportionment under principle of reasonable medical probability.

Mihesuah v. WCAB

Note: The MDT is only a guide and the disability evaluator may rely on his expertise only.

Parker v. WCAB

Note: Injuries cannot be combined for rating if no common body part though P&S at same time.

Fresno Unif. School Dist. v. WCAB

Note: Unrelated noncompensable injury means a disabling event which, had it been work-related, would be compensable under the worker's compensation laws; Apportionment requires pre-existing labor disability.

Welcher, Strong, Lopez, & Williams v. WCAB

Note: The Legislature did not intend to alter the old apportionment method with the 2004 amendments.

Mercier vs. WCAB, City of Los Angeles

Note: Where factors of disability from different injuries overlap apportionment is applicable.

Benson vs. WCAB

Note: Courts must separately rate successive injuries to the same body part that simultaneously become permanent and stationary.

Kopping v. WCAB

Note: If section 4664(b) is understood as representing the Legislature�s common sense recognition that there can be no recovery from a permanent disability, then there is no inconsistency between that statute and section 4664(a).

Mills v. WCAB

Note: The new apportionment provisions in Senate Bill No. 899 became effective immediately and must be applied to all pending cases 'not yet final at the time of the legislative enactment on April 19, 2004, regardless of the earlier dates of injury and any interim decision.'

Benson v. The Permanente Medical Group

Note: The rule in Wilkinson is not consistent with the new requirement that apportionment be based on causation and, therefore, Wilkinson is no longer generally applicable.

Amico vs. WCAB

Note: Prior rating or award does not necessarily evidence prior level of disability.

Brodie v. WCAB

Note: The Fuentes formula remains the correct one to apply in apportioning compensation between causes of disability.

Davis v. WCAB and Allied Security, et al., and Torres v. WCAB and Williams Tank Lines et al.

Note: When an employee's overall permanent disability is subject to apportionment for a preexisting disability the calculation of compensation is to be made by subtracting the preexisting percentage of permanent disability from the overall percentage of permanent disability.

E&J Gallo Winery v. WCAB (Dykes)

Note: Employee sustaining multiple disabling injuries while working for the same selfinsured employer is entitled to compensation for the total disability above any percentage of permanent disability previously awarded.