ADJ17215880 · September 18, 2026

The QME's apportionment opinion was found not to be substantial evidence because it relied on probability and mathematical division without adequate medical or factual support, and the parties stipulated to compensability of the left wrist injury as a specific injury, not cumulative. Defendant did not meet the burden of proof for apportionment.

From the decision · page 5Marshalls (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc).) The mere fact that a medical report assigns approximate percentages of industrial and nonindustrial causation does not make the report reliable medical evidence by itself. (E.L. Yeager Construction v. Workers' Comp. Appeals Bd. (Gatten) (2006) 145 Cal.App.4th 922, 927–928 [71 Cal.Comp.Cases 1687].) Rather, the report must disclose familiarity with the concepts of apportionment, describe in detail the exact nature of the apportionable disability, and set forth the basis for the opinion that factors other than the industrial injury at issue caused permanent disability. (Escobedo, at p.

The parties stipulated that the left wrist condition is the result of the specific injury, not cumulative.

Favours Applicant prevailed

This stipulation supports the finding that the left wrist injury is compensable as a specific injury, undermining the QME's apportionment analysis based on cumulative trauma.

From the decision · page 6condition or prior condition. There are no opinions or review of diagnostics, particularly the cervical MRI, that indicate that there was an asymptomatic condition that pre-dated the specific injury. The analysis for the bilateral entrapment condition is somewhat more complicated. The QME opines that the bilateral entrapment condition is the result of cumulative trauma and divides liability strictly on the basis of length of employment. However, the parties have stipulated that the left wrist condition is the result of the specific injury at issue here, and we see no reason to disturb that stipulation. (See Lab. Code, § 5702.) The parties knowingly stipulated to the left wrist as a compensable body part of the specific injury, not a cumulative injury. Further, in their Petition, defendant does not raise compensability of the left wrist.

The QME's apportionment opinion relied on probability and mathematical division without adequate medical or factual support.

Favours Applicant prevailed

The opinion was rejected as not substantial evidence, leading to denial of apportionment and favoring the applicant.

From the decision · page 5Marshalls (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc).) The mere fact that a medical report assigns approximate percentages of industrial and nonindustrial causation does not make the report reliable medical evidence by itself. (E.L. Yeager Construction v. Workers' Comp. Appeals Bd. (Gatten) (2006) 145 Cal.App.4th 922, 927–928 [71 Cal.Comp.Cases 1687].) Rather, the report must disclose familiarity with the concepts of apportionment, describe in detail the exact nature of the apportionable disability, and set forth the basis for the opinion that factors other than the industrial injury at issue caused permanent disability. (Escobedo, at p.

Diagnosed status post left shoulder arthroscopic surgery, adhesive capsulitis left shoulder, cervicalgia, rule out cervical radiculopathy vs. carpal tunnel syndrome left upper extremity, bilateral carpal tunnel syndrome status post left carpal tunnel release, and C5-6 spondylosis derangement disc disease. Found left shoulder and cervical conditions resulted from specific injury on October 12, 2022. Found bilateral peripheral entrapment conditions were cumulative trauma with 10% industrial apportionment and 90% nonindustrial. Found cervical condition 90% due to specific injury and 10% nonindustrial. Found no apportionment for left shoulder. Provided whole person impairment ratings and MMI dates.

The QME's apportionment opinion was evaluated and found not to be substantial evidence due to lack of medical support and reliance on probability and mathematical division.

From the decision · page 2Applicant was seen by QME Scott Graham, M.D., on June 7, 2023. (Applicant’s Exhibit 1.) The mechanism of injury was reported as “He stated he was laying boxes on a loading truck when he pulled the tie-down rope and felt a strain in the left shoulder” (Id. at p.2.) The report noted that prior to working for defendant, applicant worked for farms as a tractor driver for seven months, but did not specify the exact period of time. Prior to that he worked for twelve years as a tractor driver with another company. (Id. at p. 6.) Applicant was diagnosed with status post left shoulder arthroscopic surgery, adhesive capsulitis left shoulder, cervicalgia, and “rule out cervical radiculopathy vs. carpal tunnel syndrome left upper extremity.” (Id. at p.

Provided MMI reports for cervical spine and left carpal tunnel release.

QME reviewed MMI reports from PTP Kupperman as part of supplemental evaluation.

From the decision · page 2(Applicant’s Exhibit 3.) The QME reviewed reports including maximum medical improvement (MMI) reports from the Primary Treating Physician (PTP) Asher Kupperman, M.D., regarding the cervical spine and left carpal tunnel release on June 27, 2025, and September 24, 2024, respectively. (Id. at p. 2.) Applicant underwent carpal tunnel release on April 8, 2024. Dr. Graham amended his diagnoses to status post left shoulder arthroscopy debridement removal of loose bodies, subacromial decompression for left shoulder impingement and left shoulder osteoarthritis. (Id.) He did not change the diagnoses for the cervical spine, except that he added C5-6 spondylosis derangement disc disease as well as bilateral carpal tunnel syndrome status post left carpal tunnel release. (Id.) He found that the cervical condition as well as the left carpal tunnel syndrome was “precipitated” by the specific injury. He also found that the evidence of right carpal tunnel syndrome was the result of a cumulative trauma through the last date of employment. (Id.) Dr. Graham also found that applicant was MMI for the left carpal tunnel syndrome on September 24, 2024, for the right carpal tunnel and left shoulder on September 3, 2025, and for the cervical spine on June 27, 2025. (Id. at p.3) He provided 7% whole person impairment (WPI)

Escobedo v. Marshalls (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc)

A physician’s opinion on apportionment must rely on reasonable medical probability, cannot be speculative, must rely on pertinent facts and/or an adequate examination and history, and must set forth the reasoning in support of its conclusions.

The QME's opinion was found not to be substantial evidence because it relied on probability and mathematical division without adequate medical or factual support.

From the decision · page 5Marshalls (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc).) The mere fact that a medical report assigns approximate percentages of industrial and nonindustrial causation does not make the report reliable medical evidence by itself. (E.L. Yeager Construction v. Workers' Comp. Appeals Bd. (Gatten) (2006) 145 Cal.App.4th 922, 927–928 [71 Cal.Comp.Cases 1687].) Rather, the report must disclose familiarity with the concepts of apportionment, describe in detail the exact nature of the apportionable disability, and set forth the basis for the opinion that factors other than the industrial injury at issue caused permanent disability. (Escobedo, at p.

Benson v. The Permanente Medical Group (2007) 72 Cal.Comp.Cases 1620, 1622 (Appeals Board en banc)

Apportionment can include pathology, asymptomatic prior conditions, and retroactive prophylactic work preclusions, provided there is substantial evidence establishing that these other factors have caused permanent disability.

The QME did not properly address apportionment based on prior employment or conditions, so the opinion was not substantial evidence.

From the decision · page 7does not consider comparative contribution, apart from time, of each employment as there was no further inquiry into each job description and requirements. Of course, it is possible that prior industrial injuries or employment have contributed to the ultimate permanent disability award pursuant to Escobedo, supra 70 Cal.Comp.Cases 604, 611 and Benson v. The Permanente Medical Group (2007) 72 Cal.Comp.Cases 1620, 1622 (Appeals Board en banc.) Apportionment can include pathology, asymptomatic prior conditions, and retroactive prophylactic work preclusions, provided there is substantial evidence establishing that these other factors have caused permanent disability. Here, the QME does not properly address that type of apportionment. While he mentions that applicant previously worked as a tractor driver over many years, there is no additional discussion as to how that employment would cause applicant’s condition and whether the employment actually caused impairment.

The QME's apportionment opinion relied on probability and mathematical division without adequate medical or factual support.

From the decision · page 5Marshalls (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc).) The mere fact that a medical report assigns approximate percentages of industrial and nonindustrial causation does not make the report reliable medical evidence by itself. (E.L. Yeager Construction v. Workers' Comp. Appeals Bd. (Gatten) (2006) 145 Cal.App.4th 922, 927–928 [71 Cal.Comp.Cases 1687].) Rather, the report must disclose familiarity with the concepts of apportionment, describe in detail the exact nature of the apportionable disability, and set forth the basis for the opinion that factors other than the industrial injury at issue caused permanent disability. (Escobedo, at p.

Parties stipulated that the left wrist condition is the result of the specific injury, not cumulative.

From the decision · page 6condition or prior condition. There are no opinions or review of diagnostics, particularly the cervical MRI, that indicate that there was an asymptomatic condition that pre-dated the specific injury. The analysis for the bilateral entrapment condition is somewhat more complicated. The QME opines that the bilateral entrapment condition is the result of cumulative trauma and divides liability strictly on the basis of length of employment. However, the parties have stipulated that the left wrist condition is the result of the specific injury at issue here, and we see no reason to disturb that stipulation. (See Lab. Code, § 5702.) The parties knowingly stipulated to the left wrist as a compensable body part of the specific injury, not a cumulative injury. Further, in their Petition, defendant does not raise compensability of the left wrist.