Authorities as the decision cited them, with how this panel applied each one.
South Coast Framing v. Workers' Comp. Appeals Bd. (Clark) (2015) 61 Cal.4th 291
The employee bears the burden of proving the injury arose out of and in the course of employment (AOE/COE) by a preponderance of the evidence.
The Board applied this standard to assess the burden of proof for injury causation.
From the decision · page 5I.
The employee bears the burden of proving the injury arose out of and in the course of
employment (AOE/COE) by a preponderance of the evidence. (South Coast Framing v. Workers'
Comp. Appeals Bd. (Clark) (2015) 61 Cal.4th 291, 297-298, 302 [80 Cal.Comp.Cases 489]; Lab.
Code, § 3600(a), 3202.5.) An injury may be either "specific," occurring as the result of one
incident or exposure which causes disability or need for medical treatment; or "cumulative,"
occurring as repetitive mentally or physically traumatic activities extending over a period of time,
the combined effect of which causes any disability or need for medical treatment. (Lab Code § 3208.1.) "In any given situation, there can be more than one injury, either specific or cumulative
or a combination of both, arising from the same event or from separate events." (Western Growers
Ins. Co. v. Workers' Comp. Appeals Bd. (1993) 16 Cal.App.4th 227, 234, citing Chevron U.S.A.,
Inc. v. Workers' Comp. Appeals Bd. (1990) 219 Cal.App.3d 1265, 1271.) The number and nature
of the injuries suffered are questions of fact for the WCJ or the Appeals Board to determine.
(Western Growers Ins. Co. v. Workers' Comp. Appeals Bd. (1993) 16 Cal.App.4th 227, 234-235.)
Labor Code section 3208.21 provides:
Lab. Code § 3208.2
When disability results from combined effects of two or more injuries, all questions of fact and law shall be separately determined with respect to each such injury, including apportionment.
The Board considered this statute in evaluating cumulative injury and apportionment issues.
From the decision · page 5When disability, need for medical treatment, or death results from the combined
effects of two or more injuries, either specific, cumulative, or both, all questions
of fact and law shall be separately determined with respect to each such injury,
including, but not limited to, the apportionment between such injuries of
liability for disability benefits, the cost of medical treatment, and any death
benefit.
Lab. Code § 5500.5(a)
Liability for cumulative injury or occupational disease shall not be apportioned to prior or subsequent years; evidence of disability due to specific injury or nonindustrial causes may be admissible for apportionment.
The Board referenced this statute regarding apportionment of cumulative injury liability.
From the decision · page 8Section 5500.5 was enacted in 1951 to codify the holding in Colonial Ins. Co. v. Industrial
Acc. Com. (1946) 29 Cal.2d 79 [11 Cal.Comp.Cases 226] that an employee who sustains an injury
as a result of a progressive occupational disease may obtain an award for the entire amount of
permanent disability from any one employer or insurer and the defendant held liable will have the
burden of seeking contribution from other employers. Section 5500.5 states
McAllister v. Workmen's Comp. App. Bd. (1968) 69 Cal.2d 408
A medical opinion must be predicated on reasonable medical probability and set forth the reasoning behind the opinion to constitute substantial evidence.
The Board applied this standard to evaluate the sufficiency of medical opinions presented.
From the decision · page 8be predicated on reasonable medical probability. (McAllister v. Workmen's Comp. App. Bd. (1968)
69 Cal.2d 408, 413, 416-417, 419 [33 Cal.Comp.Cases 660].) Also, a medical report is not
substantial evidence unless it sets forth the reasoning behind the physician's opinion, not merely
his or her conclusions. (Granado v. Workmen's Comp. App. Bd. (1968) 69 Cal.2d 399, 407 [33
Cal.Comp.Cases 647].) "Medical reports and opinions are not substantial evidence if they are
known to be erroneous, or if they are based on facts no longer germane, on inadequate medical
histories and examinations, or on incorrect legal theories. Medical opinion also fails to support
the Board's findings if it is based on surmise, speculation, conjecture or guess." (Hegglin v.
Workmen's Comp. Appeals Bd. (1971) 4 Cal.3d 162, 169 [36 Cal.Comp.Cases 93].)