Judge Petty referred to the Escobedo case (Escobedo v. Marshalls (2005) 70 CCC 604). This case was not only important for the ruling of Apportionment but also framing what constitutes Substantial Medical Evidence.

“To be substantial medical evidence on the issue of apportionment, “a medical report must be framed in terms of reasonable medical probability, it must not be speculative, it must be based on pertinent facts and on an adequate examination and history, and must set forth reasoning in support of its conclusions.”

A more exhaustive iteration on substantial medical evidence comes from Robert Rassp in a presentation at a DWC Educational conference (the following is a portion of that presentation)

1. WHAT DOES “SUBSTANTIAL EVIDENCE” MEAN?

   “A MEDICAL REPORT MUST BE BASED UPON REASONABLE MEDICAL PROBABILITY.” McALLISTER vs. WCAB (1968) 69 Cal.2d 408, 33 Cal. Comp. Cases 660.

2. A MEDICAL OPINION IS NOT SUBSTANTIAL EVIDENCE IF IT IS BASED ON:

   • FACTS NO LONGER GERMANE.
   • AN INADEQUATE MEDICAL HISTORY.
   • AN INADEQUATE MEDICAL EXAMINATION.
   • INCORRECT LEGAL THEORIES.
   • SURMISE, SPECULATION, CONJECTURE OR GUESS.

   HEGGLIN vs. WCAB (1971) 4 Cal.3d 162, 36 Cal. Comp. Cases 93, PLACE vs. WCAB (1970) 3 Cal.3d 372, 35 Cal. Comp. Cases 525; ZEMKE vs. WCAB (1968) 68 Cal.2d 794, 33 Cal. Comp. Cases 358.

3. 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 vs. WCAB (1968) 69 Cal.2d 399, 33 Cal. Comp. Cases 647.

4. A MEDICAL REPORT MUST BE BASED UPON REASONABLE MEDICAL PROBABILITY, IT MUST NOT BE SPECULATIVE, IT MUST BE BASED ON PERTINENT FACTS AND ON AN ADEQUATE EXAMINATION AND HISTORY AND IT MUST SET FORTH REASONING IN SUPPORT OF ITS CONCLUSIONS.

   MARLENE ESCOBEDO vs. MARSHALLS (2005) 70 Cal. Comp. Cases 604 at 621.

5. SECTION E OF THE ESCOBEDO DECISION APPLIES TO ALL MEDICAL LEGAL ISSUES AND NOT JUST APPORTIONMENT.

   • IN AMA GUIDES CASE, DID THE PHYSICIAN PERFORM THE CORRECT MEASUREMENTS?
   • WHO PERFORMED ROM TESTING?
   • WAS A COMPUTER USED?
   • ACTIVE ROM OR ASSISTED OR PASSIVE ROM TESTING? (ONLY ACTIVE IS VALID).
   • SHOULDER INJURY IS GOOD EXAMPLE (FLEX‐EXT ‐50 TO 180 DEGREES NORMAL;

6. PEOPLE vs. BASSETT (1968) 69 Cal.2d 122, 70 Cal. Rptr. 193

   “THE CHIEF VALUE OF AN EXPERT’S TESTIMONY RESTS UPON THE MATERIAL FROM WHICH HIS OR HER OPINION IS FASHIONED AND THE REASONING BY WHICH HE OR SHE PROGRESSES FROM THE MATERIAL TO THE CONCLUSION, AND IT DOES NOT LIE IN THE MERE EXPRESSION OF THE CONCLUSION; THUS THE OPINION OF AN EXPERT IS NO BETTER THAN THE REASONS UPON WHICH IT IS BASED.”