Canto Shadoan, Claudia, Applicant v. CITY OF SAN DIEGO, permissibly self-insured, Defendant

WORKERS’ COMPENSATION APPEALS BOARD
STATE OF CALIFORNIA
CLAUDIA CANTO SHADOAN, Applicant
vs.
CITY OF SAN DIEGO, permissibly self-insured, Defendant
Adjudication Numbers: ADJ11349806, ADJ11349617
San Diego District Office
OPINION AND DECISION
AFTER RECONSIDERATION
We previously granted reconsideration in order to further study the factual and legal issues.
This is our Opinion and Decision After Reconsideration.
Defendant seeks reconsideration of the “Findings and Award” (F&A) issued on February
19, 2021, by the workers’ compensation administrative law judge (WCJ). The WCJ found, in
pertinent part, that applicant sustained industrial injury to her back for a cumulative injury through
March 2, 2017, and that applicant’s injury caused 24% permanent partial disability. The WCJ
further found that applicant qualified for the duty-belt presumption of Labor Code1, section 3213.2,
and thus her disability was not subject to apportionment under section 4663(e). Finally, the WCJ
found that applicant’s prior specific injury to the back in 2010, which resulted in 9% permanent
partial disability, warranted apportionment under section 4664. However, the WCJ did not deduct
the percentage of disability, but instead deducted the monetary value of the prior disability due to
application of the non-attribution clause of section 4663(e).
Defendant contends that the WCJ erred because the opinion does not follow the California
Supreme Court’s holding in Brodie v. Workers’ Comp. Appeals Bd. (2007) 40 Cal. 4th 1313, 57
Cal. Rptr. 3d 644, 156 P.3d 1100 (Brodie), which mandates that when calculating apportionment
under section 4664, the percentage of disability is deducted and not the dollar value of the
disability.
1 All future references are to the Labor Code unless noted.

2
Defendant attached additional exhibits to its Petition in violation of WCAB Rule
10945(c)(2). (Cal. Code Regs., tit. 8, § 10945(c)(2).) Defendant is politely reminded to follow
proper procedure because exhibits must not be attached to petitions for reconsideration. To the
extent that defendant wishes to cite to the Legislative Counsel’s Digest in support of any
arguments, defendant should include citations in their brief. (Jessen, California Style Manual, 4th
ed., (2000), § 2:29, p. 69.) We have not considered the additional exhibits attached to the Petition
for Reconsideration.
We 	have 	received 	an 	Answer 	from 	applicant. 	The 	WCJ 	filed 	a 	Report 	and
Recommendation 	on 	Petition 	for 	Reconsideration 	(Report) 	recommending 	that 	we 	deny
reconsideration.
We have considered the allegations of the Petition for Reconsideration and the Answer,
and the contents of the WCJ’s Report. Based on our review of the record, as our Decision After
Reconsideration, we will rescind the WCJ’s February 19, 2021 F&A and substitute a new finding
that applicant’s disability after apportionment under section 4664 is 15% (24% - 9%). As a
precaution, we will issue an order deferring all issues in ADJ11349617.
FACTS
Per the WCJ’s Report:
Applicant is a police detective who has received a prior permanent
disability award of 9% for a specific low back injury of August 24,
2010. This award provided applicant with permanent disability
payments totaling $6,210. Thereafter, applicant filed two additional
low back injury claims: A specific injury and a cumulative trauma
claim, which are now the subject of the current dispute. The parties
have stipulated that applicant now has a 24% permanent disability
to the low back due to the combined effects of the prior August 24,
2010 injury and the cumulative trauma injury currently alleged in
ADJ11349806. 	The 	specific 	injury 	(ADJ11349617) 	has 	not
produced any disability.
The parties have stipulated that labor code section 3213.2 applies in
this case.
(WCJ’s Report, p. 3.)
In her Answer, applicant does not challenge the conclusion that apportionment under 4664
applies 	in 	this 	case. 	(See 	generally, 	Applicant’s 	Response 	to 	Defendant’s 	Petition 	for
Reconsideration, March 18, 2021.) Instead, the issue presented is purely one of law: does the non-

3
attribution clause of section 4663(e) affect the calculation of apportionment under section 4664 to
allow a dollar amount deduction, instead of subtraction of disability percentages per Brodie, supra?
For the reasons discussed below, we conclude that it does not.
DISCUSSION
a. 	The proper legal standard for establishing apportionment under section 4664.
Section 4663 requires 	any report addressing 	permanent disability to also address
apportionment of disability. Defendant carries the burden of proof on apportionment. (§ 5705.)
However, certain presumptive injuries are not subject to apportionment based upon causation due
to the non-attribution clause of section 4663(e), which states: “(e) Subdivisions (a), (b), and (c) do
not apply to injuries or illnesses covered under Sections 3212, 3212.1, 3212.2, 3212.3, 3212.4,
3212.5, 3212.6, 3212.7, 3212.8, 3212.85, 3212.9, 3212.10, 3212.11, 3212.12, 3213, and 3213.2.”
(§ 4663(e).)
Here, applicant’s injury was stipulated as presumptive under section 3213.2. Accordingly,
section 4663 does not apply, and we cannot apportion applicant’s disability based upon causation.
However, that is not the end of the analysis.
As we have explained in previous decisions, apportionment also exists under section 4664,
which allows apportionment to prior awards and precludes the accumulation of awards to certain
body regions from exceeding 100% over the course of one’s life. (§ 4664.) Before addressing the
interplay of sections 4663(e) and 4664, it is important to understand the history of section 4664,
which was previously discussed by the Appeals Board in dual en banc decisions as follows:
The apportionment of pre-existing permanent disability has been a fixture of
California workers’ compensation law since its inception. The original Workmen’s
Compensation, Insurance and Safety Act of 1917 (the 1917 Act) contained a
provision stating: “The percentage of permanent disability caused by any injury
shall be so computed as to cover the permanent disability caused by that particular
injury without reference to any injury previously suffered or any permanent
disability caused thereby.” (Stats. 1917, ch. 586, p. 839, § 9; see also, Stats. 1919,
ch. 471, p. 916, § 4; Stats. 1925, ch. 354, p. 643, § 1.) In 1929, the Legislature
amended the 1917 Act to provide:
““The fact an employee has suffered previous disability or received
compensation therefor shall not preclude compensation for a later
injury . . . ; . . . provided, however, that an employee who is suffering
physical impairment and shall sustain permanent injury thereafter
shall not receive compensation for a later injury in excess of the
compensation allowed for such injury when considered by itself and

4
not in conjunction with or in relation to the previous disability or
impairment. The employer shall not be liable for compensation to
such employee for the combined disability but only for that portion
due to the later injury as though no prior disability or impairment
had existed.” (Stats. 1929, ch. 222, p. 420, § 1.)”
In 1937, the 1917 Act and its amendments were codified in the Labor Code. At that
time, 	the 	Legislature 	adopted 	former 	section 	4750, 	whose 	language 	was
substantially similar to the 1929 law, supra. For the next 67 years, the language of
former section 4750 remained essentially unchanged, until its repeal on April 19,
2004 by SB 899. (Stats. 2004, ch. 34, § 37.) At the time of its repeal, former section
4750 provided:
““An employee who is suffering from a 	previous permanent
disability or physical impairment and sustains permanent injury
thereafter shall not receive from the employer compensation for the
later injury in excess of the compensation allowed for such injury
when considered by itself and not in conjunction with or in relation
to the previous disability or impairment.
“The employer shall not be liable for compensation to such an
employee for the combined disability, but only for that portion due
to the later injury as though no prior disability or impairment had
existed.” (Stats. 1937, ch. 90, p. 285; amended by Stats. 1945, ch.
1161, p. 2209, § 1.) ”
One long-standing purpose of former section 4750 was to encourage employers to
hire 	people 	with 	disabilities; 	the 	Legislature 	recognized 	that 	employers
might refrain from hiring the disabled if, upon a subsequent injury, the employer
would become obligated to compensate the employee for the pre-existing disability.
(Citations.) Thus, under former section 4750, when an employee who had pre-
existing permanent disability sustained an industrial injury that also resulted in
permanent disability, the employer or its insurer was not liable for the combined
disability, but only for that portion attributable to the subsequent industrial injury,
considered alone. (.)
(Sanchez v. County of Los Angeles (2005) 70 Cal. Comp. Cases 1440, 1444-1445 [Appeals Board
en banc] disapproved on another ground in Kopping v. Workers’ Comp. Appeals Bd. (2006) 142
Cal.App.4th 1099; see also Strong v. City and County of San Francisco (2005) 70 Cal. Comp.
Cases 1460 [Appeals Board en banc] disapproved on another ground in Kopping, supra.)
Under SB 899, section 4664 was added to the Labor Code in place of former section 4750
and it states, in pertinent part:

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(a) The employer shall only be liable for the percentage of
permanent disability directly caused by the injury arising out of and
occurring in the course of employment.
(b) If the applicant has received a prior award of permanent
disability, it shall be conclusively presumed that the prior permanent
disability exists at the time of any subsequent industrial injury. This
presumption is a presumption affecting the burden of proof.
Over the years since its enactment in 2004, multiple cases have interpreted how
apportionment is established pursuant to section 4664(b).
First, defendant must prove that a prior award of disability exists. (Pasquotto v. Hayward
Lumber (2006) 71 Cal. Comp. Cases 223 [Appeals Board en banc]; see Sanchez, supra; see also
Strong, supra.) This burden requires the production of a prior Stipulations with Request for Award,
or a prior Compromise and Release, where the parties agreed to applicant’s level of permanent
disability in the settlement. (Pasquotto, supra, at p. 230.)
Once a prior award of permanent disability is established, the disability in that award is
conclusively presumed to exist.
When the defendant has established the existence of any prior
permanent disability award(s) relating to the same body region, the
permanent disability underlying any such award(s) is conclusively
presumed to still exist, i.e., the applicant is not permitted to show
medical rehabilitation from the disabling effects of the earlier
industrial injury or injuries[.]
(Sanchez, supra, 70 Cal. Comp. Cases at p. 1442; Strong, supra, 70 Cal. Comp. Cases at p. 1462;
see also Brodie v. Workers’ Comp. Appeals Bd. (2007) 40 Cal.4th 1313, 1327 [“[S]ection 4664,
subdivision (b) was intended to reverse the rule based on former section 4750 that permitted an
injured employee to show rehabilitation of an injury for which a permanent disability award had
already been issued. (Citation.)”)
Section 4664 contains contradictory language, indicating that it operates as both a
conclusive presumption and a rebuttable presumption. In dual en banc opinions, the Appeals Board
initially interpreted this contradiction as a burden-shifting mechanism, which required defendant
to establish the existence of a prior award of disability, but permitted applicant to rebut the
conclusive presumption by proving that the prior award did not overlap with applicant’s current
disability. (Sanchez, supra, 70 Cal. Comp. Cases at p. 1442; Strong, supra. 70 Cal. Comp. Cases
at p. 1462.) However, the Court of Appeal rejected this burden-shifting approach, and instead

6
required that defendant prove both the existence of a prior award of disability and that the prior
award of disability overlaps with the current award of disability. (Kopping, supra, 142 Cal.App.4th
at p. 1115.)
Accordingly, and following the decisions in Sanchez and Strong as modified by Kopping,
where defendant proves that a prior award of disability exists and proves that the prior award of
disability overlaps with the current award, defendant is entitled to subtract the prior award of
overlapping permanent disability from applicant’s current award. (Brodie, supra, 40 Cal.4th at p.
1332 [deciding that the proper method of calculating apportionment is to subtract the prior
disability from the present].)
The Appeals Board noted in both Sanchez and Strong that the principles of proving overlap
are substantially the same principles of overlap applied prior to the enactment of SB 899. (Sanchez,
supra, 70 Cal. Comp. Cases at p. 1457; Strong, supra, 70 Cal. Comp. Cases at p. 1477.)
We state that apportionment shall be determined “substantially” in
accordance with historical overlap principles because we recognize
that, in future cases, the differences between how permanent
disability is determined under the April 1997 Schedule for Rating
Permanent Disabilities and how it is determined under the January
2005 Schedule for Rating Permanent Disabilities may present novel
overlap questions. None of these questions are presented here,
however, and we will not speculate on them.
(Sanchez, supra, 70 Cal. Comp. Cases at p. 1457; Strong, supra, 70 Cal. Comp. Cases at p. 1477.)
The Appeals Board explained the historical principles of overlap within its decisions in
Sanchez and Strong:
In applying former section 4750, when the permanent disability
resulting from a new injury included factors of disability that were
the same as ones that already existed as the result of a prior injury
or condition, the disabilities were said to “overlap.” (Citations.) If
all 	of 	the factors 	of 	permanent 	disability 	attributable to 	the
subsequent industrial injury already existed as a result of the prior
injury or condition, then there was “total” overlap, and the employee
was not entitled to any additional permanent disability indemnity;
if, however, the subsequent industrial injury caused some new
factors of permanent disability that were not pre-existing, then there
was “partial” overlap, and the employee was entitled to permanent
disability indemnity to the extent the subsequent industrial injury
further restricted his or her earning capacity or ability to compete.
(Mercier v. Workers’ Comp. Appeals Bd., supra, 16 Cal.3d 711

7
(employee had prior back disability precluding heavy lifting and
repetitive bending, and then sustained a new industrial injury to his
heart resulting in a limitation between light work and semi-
sedentary work 	and in a need to avoid strenuous activities and
severe emotional stress; held, all factors of disability attributable to
the back were included in or subsumed by the factors attributable to
the heart injury, resulting in total overlap, and it was proper to
deduct the rating for the back disability from the rating for the heart
disability); State 	Comp. 	Ins. 	Fund 	v. 	Industrial 	Acc.
Com. (Hutchinson), supra, 59 Cal.2d 45 (employee had prior neck
disability consisting of constant slight pain, becoming slight with
overhead work and climbing, and becoming moderate with lifting
over 30 pounds, and then sustained a new injury to his low back
resulting in disability consisting of minimal pain increasing to slight
pain on heavy work; held, disability from neck injury was held to
overlap the disability from back injury because the latter resulted in
pain when performing certain work activities); Edson v. Industrial
Acc. Com. (1928) 206 Cal. 134 [273 P. 572] [15 I.A.C. 193]
(employee had previously lost 30/50ths of the sight of each eye, and
then sustained new industrial injury resulting in an additional 17-
&1/2/50ths loss of the sight of his left eye; held, employee entitled
to 	compensation 	only 	for 	the 	latter 	impairment); Gardner 	v.
Industrial Acc. Com., supra, 28 Cal.App.2d 582 (employee had
prior left ankle disability resulting in partial stiffness of the ankle
joint, and then sustained a new industrial injury resulting in
amputation of left leg between knee and hip joint; held, rating for
loss of leg properly reduced by rating for ankle).) As can be seen
from these cases, it was not the part of the body involved in the
subsequent industrial injury that was important; rather, it was the
nature of the disability resulting from the new injury in relation to
the pre-existing disability that was determinative. (Citation.) Thus,
the fact that the pre-existing disability and the new disability
involved two different anatomical parts of the body, while relevant,
did not in itself preclude apportionment using the rules of overlap.
(Citations) The mechanics of rating overlap generally provided
that each separate factor of permanent disability for both the
new industrial injury and the pre-existing condition be set forth,
so it could be determined what elements, if any, of one disability
were included in the other. (State Comp. Ins. Fund v. Workers’
Comp. 	Appeals 	Bd. (Gaba), supra, 	72 	Cal.App.3d 	13 	(rating
instructions 	for 	subsequent 	industrial 	heart 	injury 	described
employee’s disability as “moderate” but omitted any heart-related
work restrictions; WCAB’s decision was annulled and the matter
remanded to delineate work preclusions for heart and to determine
extent, if any, to which employee’s heart disability overlapped pre-
existing back disability resulting in a limitation to light work).) The

8
issue of apportionment would be resolved by determining the
percentage of combined disability after the new injury, and then
subtracting the percentage of disability due to the prior injury which
overlapped—either partially or totally—the disability resulting
from the new injury. (Citations.)
If, 	however, 	successive 	injuries 	produced 	separate 	and
independent 	disabilities—i.e., if the disabilities did not fully or
partially overlap because they did not affect the same abilities to
compete and earn—then each was rated separately. (Mercier v.
Workers’ Comp. Appeals Bd., supra, 16 Cal.3d at p. 714; State
Comp. Ins. Fund. v. Industrial Acc. Com. (Hutchinson), supra, 59
Cal.2d 	at 	p. 	53; Fresno 	Unified 	School 	Dist. 	v. 	Workers’
Compensation Appeals Bd. (Humphrey) (2000) 84 Cal.App.4th
1295, 1310, fn. 3 [101 Cal. Rptr. 2d 569] [65 Cal.Comp.Cases
1232].) 	Thus, 	for 	example, 	where 	an 	employee, 	who 	had 	a
childhood disease that resulted in the amputation of one leg above
the knee, later sustained an industrially-related cerebral vascular
accident that resulted in hearing loss, loss of the use of his left arm,
decreased vision, loss of memory, and learning disabilities, the
employee was entitled to the full rating for the industrial disabilities
because they did not overlap the pre-existing loss of his leg.
(Newman v. Workers’ Comp. Appeals Bd. (1984) 152 Cal.App.3d
219, 223 [199 Cal. Rptr. 422] [49 Cal.Comp.Cases 126].)
(Sanchez, supra, 70 Cal. Comp. Cases at pp. 1445-1447, emphasis added; Strong, supra, 70 Cal.
Comp. Cases at pp. 1465-1468.)
Accordingly, in analyzing overlap we are looking at the factors of disability that constitute
the rating.
Under the 1997 Permanent Disability Rating Schedule (PDRS), impairment was assigned
through objective limitations, such as amputations, and through preclusions upon the ability to
work. (Cal. Dept. of Industrial Relations, Div. of Workers’ Comp., Schedule for Rating Permanent
Disabilities (1997) p. 1-2.) For example, a disability to the spine could be described through a work
restriction chart which progressively increased beginning with a preclusion from substantial work,
and ending with a limitation to sedentary work only. (Id. at p. 2-15.)
However, under SB 899 the mechanics of rating permanent disability significantly
changed. The Legislature adopted and incorporated the American Medical Association Guides to
the Evaluation of Permanent Impairment, 5th Edition (2001) (AMA Guides). Impairment under
the AMA Guides is designed to reflect how a disability affects a person's activities of daily living

9
(“ADLs”) (self-care, communication, physical activity, sensory function, non-specialized hand
activities, travel, sex, and sleep). (AMA Guides, pp. 2–9.) Unlike the prior PDRS, the AMA Guides
expressly excludes work from the impairment analysis. (Id. at p. 6.)
Impairment percentages or ratings developed by medical specialists are consensus-
derived estimates that reflect the severity of the medical condition and the degree
to which the impairment decreases an individual’s ability to perform common
activities of daily living (ADL),excluding work. Impairment ratings were designed
to reflect functional limitations and not disability. The whole person impairment
percentages listed in the Guides estimate the impact of the impairment on the
individual’s overall ability to perform activities of daily living, excluding work[.]
(Ibid.)
Thus, similar to the 1997 PDRS, overlap under the 2005 PDRS is shown on a legal basis
when the second impairment is simply a progression of the first impairment utilizing the exact
same chart or table within the AMA Guides.
In cases where the disability is not rated using a progression within the same chart or table,
overlap is a factual issue requiring medical evidence establishing overlap between the two
disabilities. In some cases, a doctor may deviate from using the same chart to rate the subsequent
injury. For example, a doctor may rate an injury by analogy using other charts or tables in the
AMA Guides. (Milpitas Unified School Dist. v. Workers’ Comp. Appeals Bd. (Almaraz-Guzman)
(2010) 187 Cal.App.4th 808, 822 [75 Cal.Comp.Cases 837].) Another example could occur where
a low back injury is rated disparately using a Diagnosis Related Estimate in one case, and the
Range of Motion method in another.
Where the disability is not rated using a progression within the same chart or table, overlap
may be shown when the medical evidence demonstrates the following:
1. 	The impacts to the ADLs from the prior award of disability are to the same body
region.
2. 	The impacts to the ADLs from the current award of disability overlap the impacts
to the ADLs measured in the prior disability.
The presence of factual overlap requires medical reporting. The requirement for expert
medical evidence exists throughout workers compensation proceedings, including determination
of temporary disability, permanent disability, apportionment, and causation of injury to name a
few. (See also, Escobedo v. Marshalls (2005) 70 Cal. Comp. Cases 604, 621 (Appeals Board en

10
banc) [wherein the Appeals Board required that apportionment under section 4663 be established
by substantial medical evidence].) “[T]he medical cause of an ailment is usually a scientific
question, requiring a judgment based upon scientific knowledge and inaccessible to the unguided
rudimentary capacities of lay arbiters.” (Peter Kiewit Sons v. Industrial Acci. Com. (McLaughlin)
(1965) 234 Cal. App. 2d 831, 839 [30 Cal.Comp.Cases 188] [“In a field which forces the experts
into hypothesis, unaided lay judgment amounts to nothing more than speculation”].) We see no
reason to deviate from this requirement when analyzing application of section 4664(b).
b. 	Defendant’s Petition for Reconsideration
With the above analysis in mind, we can now address the issues raised in this case.
Applicant does not challenge the WCJ’s finding that apportionment under section 4664 exists. The
only issue on reconsideration is how such apportionment should be calculated.
When apportionment is proven pursuant to section 4664, the correct method for calculating
apportionment was decided by the Supreme Court in Brodie, supra. The percentage of disability
attributable to the new injury is calculated by subtracting the old rating from the new rating, then
awarding the difference. (Brodie, supra 40 Cal. 4th 1322.) The Brodie court expressly rejected the
formula used by the WCJ in this case, which was to subtract the dollar amount of the prior
disability from the dollar amount of the present disability. (Ibid.)
The WCJ based their opinion, in part, upon the Appeals Board holding in Bates v. County
of San Mateo, 2019 Cal. Wrk. Comp. P.D. LEXIS 72.2 In Bates, the Appeals Board addressed a
novel argument raised by defendant, that apportionment based upon causation was allowed
notwithstanding section 4663(e) because section 4664(a) states: “(a) The employer shall only be
liable for the percentage of permanent disability directly caused by the injury arising out of and
occurring in the course of employment.” (§ 4664(a).) The employer argued that section 4664(a)
was outside section 4663 and thus apportionment based upon causation was permissible
notwithstanding 4663(e)’s non-attribution clause. The Appeals Board rejected this argument and
held that section 4664(a) states a general principle of apportionment and the more specific section
2 Unlike en banc decisions, panel decisions are not binding precedent on other Appeals Board panels. (See Gee v.
Workers’ Comp. Appeals Bd. (2002) 96 Cal. App. 4th 1418, 1425 fn. 6 [67 Cal.Comp.Cases 236].) However, panel
decisions are citeable authority and the Appeals Board may consider these decisions to the extent that their reasoning
is found persuasive, particularly on issues of contemporaneous administrative construction of statutory language. (See
Guitron v. Santa Fe Extruders (2011) 76 Cal. Comp. Cases 228, fn. 7 (Appeals Board En Banc); Griffith v. Workers’
Comp. Appeals Bd. (1989) 209 Cal. App. 3d 1260, 1264, fn. 2, [54 Cal.Comp.Cases 145].)

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of 4663(e) excluding apportionment based upon causation for certain presumed injuries was
controlling. (Bates, supra, at *17-19.)
The Appeals Board further noted that apportionment under Benson is also not permitted
when 	dealing 	with 	presumptive 	injuries 	as 	Benson 	apportionment 	necessarily 	involves
apportionment based upon causation under section 4663. (Id. at *12-13.)
We continue to find the holding in Bates persuasive. The inclusion of a general principle
of 	apportionment 	in 	section 	4664(a), 	does 	not 	override 	the 	more 	specific 	exclusion 	of
apportionment based upon causation contained in 4663(e). However, the Bates opinion did not
address the dispute in this matter. The question here is whether the non-attribution clause of section
4663(e) in any way impacts the apportionment calculation under section 4664(b) and Brodie. It
does not.
In reaching our conclusion, we must address another panel decision, Thomas Santiago v.
California Highway Patrol, which expanded our holding in Bates and found that presumptive
injuries contained in 4663(e) are not subject to apportionment under section 4664(b). (2022
Cal.Wrk.Comp. LEXIS 51; 87 Cal Comp.Cases 1011.) However, we do not find the holding in
Santiago persuasive as it does not adequately explain why section 4664(b) is preempted by section
4663(e).
Section 	4663(e) 	precludes 	apportionment 	based 	upon 	causation 	of 	disability.
Apportionment under 4664(b) is not apportionment based upon causation, but instead is
apportionment to a prior award of disability, which overlaps with the current award.
That is, like section 4663(e), section 4664 requires an analysis of whether the two
disabilities overlap, but that analysis does not involve causation of the disability. This is because
a prior award necessarily reflects only that portion of the disability that was found industrial. When
examining a prior award of disability, any analysis under section 4663 has already occurred.
As explained above, overlap analyzes the factors of disability. (Contra Costa County Fire
Protection District v. Workers' Comp. Appeals Bd. (Minvielle) (2010) 75 Cal.Comp.Cases 896
[2010 Cal. Wrk. Comp. LEXIS 144].) The factors of disability are the methods used in the AMA
Guides to rate an impairment. (See Hom v. City & County of San Francisco, 2020 Cal. Wrk. Comp.
P.D. LEXIS 124 [finding overlap where injuries are rated using the same edition of the AMA
Guides]; Robinson v. Workers' Comp. Appeals Bd. (2011) 76 Cal.Comp.Cases 847 [finding

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overlap where prior award was recalculated using the same metric as the current award and
constituted substantial medical evidence].)
As the basis for apportionment under section 4664(b) does not analyze the cause of the
disability, section 4663(e) does not preclude its application. When calculating apportionment
under section 4664(b), we find no reason to disregard the holding in Brodie, even where the injury
is subject to the anti-attribution clause of section 4663(e).
Accordingly, as our Decision After Reconsideration, we rescind the WCJ’s February 19,
2021 F&A and substitute a new finding that applicant’s disability after apportionment under
section 4664 is 15% (24% - 9%). As a precaution, we will issue an order deferring all issues in
ADJ11349617 as the case number was raised at trial; however, the parties entered into no
stipulations on that case and raised no issues related to that case and the WCJ made no findings
that appear linked to that case. It appears that the parties may have intended to dismiss that case as
it appears to have been subsumed as part of the cumulative trauma. If that is the case, the parties
may wish to submit a stipulation to that effect.
For the foregoing reasons,
IT IS ORDERED as the Decision After Reconsideration of the Workers’ Compensation
Appeals Board that the Findings of Fact and Award issued WCJ’s February 19, 2021, is
RESCINDED with the following SUBSTITUTED therefor:
FINDINGS OF FACT IN ADJ11349806
1. 	Claudia Canto Shadoan, while employed during the period
August 25, 2010 through March 2, 2017 as a detective,
occupational group number 490 at San Diego California by
the City of San Diego, sustained injury arising out of and in
the course of employment to her back.
2. 	At 	the 	time 	of 	injury, 	the 	employee’s 	earnings 	were
$1,533.60 per week.
3. 	Applicant is in need of further medical treatment to cure or
relieve from the effects of the industrial injury.
4. 	Applicant’s level of permanent disability to the low back is
24% before apportionment.
5. 	Applicant has received a prior award of permanent disability
to the low back in the amount of 9%.

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6. 	Labor Code section 3213.2 is applicable to this injury.
7. 	This 	injury 	caused 	permanent 	disability 	of 	15% 	after
apportionment under Labor Code section 4664.
8. 	Applicant requires further medical treatment to cure or
relieve from the effects of this injury.
9. 	Attorney’s fees of 15% of the benefits awarded herein are
reasonable.
AWARD IN ADJ11349806
AWARD IS MADE in favor of CLAUDIA CANTO SHADOAN,
against CITY OF SAN DIEGO of:
A. 	Permanent disability of 15% after apportionment under
Labor Code section 4664, which is all due and payable at the
rate of $290.00 per week for 50.5 weeks, for a total of
$14,645.00, less credit for permanent disability advances
made, if any, and less attorney’s fees of $2,196.75, payable
to the Law Offices of O’Mara & Hampton.
B. 	Further medical treatment in accordance with Finding No. 2,
above.
ADJ11349617
1. 	All issues are deferred.

14
IT IS FURTHER ORDERED that this matter is RETURNED to the trial level.
WORKERS’ COMPENSATION APPEALS BOARD
/s/ CRAIG L. SNELLINGS, COMMISSIONER
I CONCUR,
/s/ JOSÉ H. RAZO, COMMISSIONER
/s/ KATHERINE A. ZALEWSKI, CHAIR
DATED AND FILED AT SAN FRANCISCO, CALIFORNIA
DECEMBER 4, 2025
SERVICE MADE ON THE ABOVE DATE ON THE PERSONS LISTED BELOW AT
THEIR ADDRESSES SHOWN ON THE CURRENT OFFICIAL ADDRESS RECORD.
CLAUDIA CANTO SHADOAN
O’MARA & HAMPTON
OFFICE OF THE CITY ATTORNEY, CITY OF SAN DIEGO
EDL/mt
I certify that I affixed the official seal of
the Workers’ Compensation Appeals Board
to this original decision on this date.
KL