in-the-matter-of-the-workers-compensation-claim-of-michael-j-hurt-an ( 2015 )


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  •                 IN THE SUPREME COURT, STATE OF WYOMING
    
    2015 WY 106
    APRIL TERM, A.D. 2015
    August 14, 2015
    IN THE MATTER OF THE WORKER’S
    COMPENSATION CLAIM OF
    MICHAEL D. HURT, AN EMPLOYEE
    OF TILTON READY MIX, INC.:
    MICHAEL D. HURT,
    Appellant
    (Petitioner),
    S-14-0266
    v.
    STATE OF WYOMING, ex rel.,
    DEPARTMENT OF WORKFORCE
    SERVICES, WORKERS’ SAFETY AND
    COMPENSATION DIVISION,
    Appellee
    (Respondent).
    Appeal from the District Court of Laramie County
    The Honorable Thomas T.C. Campbell, Judge
    Representing Appellant:
    Bernard Q. Phelan of the Phelan Law Firm, Cheyenne, Wyoming.
    Representing Appellee:
    Peter K. Michael, Wyoming Attorney General; John D. Rossetti, Deputy Attorney
    General; Michael J. Finn, Senior Assistant Attorney General; and Samantha Caselli,
    Assistant Attorney General.
    Before BURKE, C.J., and HILL, KITE*, DAVIS, and FOX, JJ.
    * Justice Kite retired from judicial office effective August 3, 2015, and pursuant to Article 5,
    § 5 of the Wyoming Constitution and 
    Wyo. Stat. Ann. § 5-1-106
    (f) (LexisNexis 2015) she was
    reassigned to act on this matter on August 4, 2015.
    NOTICE: This opinion is subject to formal revision before publication in Pacific Reporter Third.
    Readers are requested to notify the Clerk of the Supreme Court, Supreme Court Building,
    Cheyenne, Wyoming 82002, of typographical or other formal errors so correction may be made
    before final publication in the permanent volume.
    KITE, Justice.
    [¶1] The Medical Commission sustained the Wyoming Workers’ Safety and
    Compensation Division’s (Division) permanent partial impairment (PPI) rating of
    Michael D. Hurt’s lumbar spine condition. The Medical Commission ruled Mr. Hurt
    failed to prove he was entitled to a PPI rating greater than the 9% whole body rating
    assigned by the Division, and the district court upheld the Medical Commission’s
    decision. We conclude the Medical Commission’s decision is supported by substantial
    evidence and, therefore, affirm.
    ISSUE
    [¶2]   The issue for our review is:
    1.     Was the Medical Commission’s decision that Mr. Hurt did not prove he
    was entitled to a higher impairment rating under the AMA Guides to the Evaluation of
    Physical Impairment supported by substantial evidence and otherwise in accordance with
    the law?
    FACTS
    [¶3] Mr. Hurt worked as a concrete truck driver for Tilton Ready Mix, Inc. On
    September 7, 2006, he was helping unload concrete from a truck when he slipped on a
    large hose and fell onto his back and buttocks. Steven Beer, M.D. performed surgery on
    Mr. Hurt’s back on December 19, 2006, including an L4-5 and L5-S1 interbody fusion,
    an L3 to S1 posterior instrumentation using various types of hardware, and an L3-S1
    intertransverse fusion using autologous bone.
    [¶4] Although Mr. Hurt generally had good results from the first surgery, he received
    permanent partial impairment (PPI) benefits as a result of the work-related injury. On
    September 15, 2008, Michael Kaplan, M.D. rated Mr. Hurt, using the AMA Guides to the
    Evaluation of Permanent Impairment (6th ed. 2008), as having 7% whole body
    impairment. Mr. Hurt accepted the Division’s award of PPI benefits based upon that
    rating.
    [¶5] Over time, Mr. Hurt began to experience additional problems with his back,
    including pain, weakness and numbness. On August 31, 2010, Dr. Beer performed a
    second surgery on Mr. Hurt’s back, removing the hardware installed in the first surgery
    and extending the lumbar spine fusion to L2 and L3. Mr. Hurt’s back was, therefore,
    fused from L2 to S1. The second surgery improved his condition, but he could not return
    to work.
    1
    [¶6] On August 2, 2011, Dr. Kaplan performed a second PPI rating. He concluded Mr.
    Hurt’s impairment placed him in Class 1 for Motion Segment Lesions and assigned an
    impairment rating of 9% of the whole body, a 2% increase over the previous rating and
    award. On September 26, 2011, Mr. Hurt was evaluated in Dr. Beer’s office by physician
    assistant Andy Beguin. The physician assistant placed Mr. Hurt in Class 4 for Motion
    Segment Lesions and assigned him a 25% whole body PPI rating. Given the disparity
    between the two ratings, the Division asked a third physician, Anne MacGuire, M.D., to
    review them. 1 She did not examine Mr. Hurt; however, she did review his medical
    records and the rating reports from Dr. Kaplan and Dr. Beer’s office under the AMA
    Guides. Although Dr. MacGuire agreed with Dr. Kaplan that Mr. Hurt belonged in Class
    1, she stated that he was only entitled to an 8% PPI rating.
    [¶7] After considering the three rating reports, the Division issued a final determination
    assigning Mr. Hurt a 9% impairment rating. He objected and the Division referred the
    matter to the Medical Commission for a contested case hearing. Mr. Hurt was the only
    witness to testify at the hearing, but the evidence included his medical records and the
    deposition testimony of Dr. Beer. The Medical Commission ruled that Mr. Hurt had not
    met his burden of establishing he was entitled to a PPI rating higher than the 9% assigned
    by the Division.
    [¶8] Mr. Hurt petitioned the district court for review of the Medical Commission
    decision. The district court affirmed, and Mr. Hurt appealed to this Court.
    STANDARD OF REVIEW
    [¶9] When an appeal is taken from a district court’s review of an administrative
    agency’s decision, we examine the case as if it came directly from the agency, giving no
    deference to the district court’s decision. Guerrero v. State ex rel. Wyo. Dep’t of
    Workforce Servs., Workers’ Comp. Div., 
    2015 WY 88
    , ¶ 11, 
    352 P.3d 262
    , 265 (Wyo.
    2015). See also Dale v. S & S Builders, LLC, 
    2008 WY 84
    , ¶ 8, 
    188 P.3d 554
    , 557 (Wyo.
    2008). 
    Wyo. Stat. Ann. § 16-3-114
    (c) (LexisNexis 2015) governs judicial review of
    administrative decisions:
    (c) To the extent necessary to make a decision and when
    presented, the reviewing court shall decide all relevant
    questions of law, interpret constitutional and statutory
    provisions, and determine the meaning or applicability of the
    terms of an agency action. In making the following
    determinations, the court shall review the whole record or
    1
    In Pohl v. Bailey Co., 
    980 P.2d 816
    , 821 (Wyo. 1999), overruled on other grounds, Torres v. State ex
    rel. Wyo. Workers’ Safety & Comp. Div., 
    2004 WY 92
    , 
    95 P.3d 794
     (Wyo. 2004), we approved the
    Division’s practice of engaging a third medical professional to assist in evaluating two conflicting
    impairment ratings.
    2
    those parts of it cited by a party and due account shall be
    taken of the rule of prejudicial error. The reviewing court
    shall:
    (i) Compel agency action          unlawfully    withheld   or
    unreasonably delayed; and
    (ii) Hold unlawful and set agency action, findings and
    conclusions found to be:
    (A) Arbitrary, capricious, an abuse of discretion or
    otherwise not in accordance with law;
    (B) Contrary to constitutional right, power, privilege or
    immunity;
    (C) In excess of statutory jurisdiction, authority or
    limitations or lacking statutory right;
    (D) Without observance of procedure required by law; or
    (E) Unsupported by substantial evidence in a case reviewed
    on the record of an agency hearing provided by statute.
    [¶10] In accordance with § 16-3-114(c), we review the agency’s findings of fact by
    applying the substantial evidence standard. Dale, ¶ 22, 188 P.3d at 561. Substantial
    evidence means “‘such relevant evidence as a reasonable mind might accept as adequate
    to support a conclusion.’” Guerrero, ¶ 12, 352 P.3d at 266, quoting Bush v. State ex rel.
    Wyo. Workers’ Comp. Div., 
    2005 WY 120
    , ¶ 5, 
    120 P.3d 176
    , 179 (Wyo. 2005) (citation
    omitted). “Findings of fact are supported by substantial evidence if, from the evidence
    preserved in the record, we can discern a rational premise for those findings.” Kenyon v.
    State ex rel. Wyo. Workers’ Safety & Comp. Div., 
    2011 WY 14
    , ¶ 11, 
    247 P.3d 845
    , 849
    (Wyo. 2011) (citation omitted).
    If the hearing examiner determines that the burdened party
    failed to meet his burden of proof, we will decide whether
    there is substantial evidence to support the agency’s decision
    to reject the evidence offered by the burdened party by
    considering whether that conclusion was contrary to the
    overwhelming weight of the evidence in the record as a
    whole. If, in the course of its decision making process, the
    agency disregards certain evidence and explains its reasons
    for doing so based upon determinations of credibility or other
    3
    factors contained in the record, its decision will be sustainable
    under the substantial evidence test. Importantly, our review of
    any particular decision turns not on whether we agree with
    the outcome, but on whether the agency could reasonably
    conclude as it did, based on all the evidence before it.
    Dale, ¶ 22, 188 P.3d at 561 (citations omitted). “We review an agency’s conclusions of
    law de novo, and will affirm only if the agency’s conclusions are in accordance with the
    law.” Middlemass v. State ex rel. Wyo. Workers’ Safety & Comp Div., 
    2011 WY 118
    , ¶
    13, 
    259 P.3d 1161
    , 1164 (Wyo. 2011) (citation omitted).
    DISCUSSION
    [¶11] The workers’ compensation law applicable to PPI benefits is set out in 
    Wyo. Stat. Ann. § 27-14-405
     (LexisNexis 2015), which states in pertinent part:
    (f) An injured employee suffering an ascertainable loss may
    apply for a permanent partial impairment award as provided
    in this section.
    (g) An injured employee’s impairment shall be rated by a
    licensed physician using the most recent edition of the
    American Medical Association’s guide to the evaluation of
    permanent impairment. The award shall be paid as provided
    by W.S. 27-14-403 for the number of months determined by
    multiplying the percentage of impairment by sixty (60)
    months.
    ****
    (m) If the percentage of physical impairment is disputed, the
    division shall obtain a second opinion and if the ratings
    conflict, shall determine the physical impairment award upon
    consideration of the initial and second opinion. Any
    objection to a final determination pursuant to this subsection
    shall be referred to the medical commission for hearing by a
    medical hearing panel acting as hearing examiner pursuant to
    W.S. 27-14-616.
    [¶12] When a worker’s compensation claimant contests the Division’s PPI rating, he has
    the burden of proving he is entitled to a higher rating. Green v. State ex rel. Dep’t of
    Workforce Servs., Workers’ Safety & Comp. Div., 
    2013 WY 81
    , ¶ 28, 
    304 P.3d 941
    , 950
    (Wyo. 2013). See also Himes v. Petro Eng. & Constr., 
    2003 WY 5
    , ¶ 16, 
    61 P.3d 393
    ,
    4
    398-99 (Wyo. 2003). The Medical Commission ruled that Mr. Hurt did not prove he was
    entitled to a higher PPI rating than the 9% assigned by the Division.
    [¶13] Mr. Hurt challenges the Medical Commission’s decision on various grounds.
    First, he claims the Medical Commission incorrectly applied the AMA Guides. This
    Court provided a general explanation of the use of the AMA Guides for impairment
    ratings in State ex rel. Wyo. Workers’ Safety & Comp. Div. v. Singer, 
    2011 WY 57
    , ¶ 18,
    
    248 P.3d 1155
    , 1160-61 (Wyo. 2011):
    According to 
    Wyo. Stat. Ann. § 27
    –14–405(g), an
    impairment “shall be rated by a licensed physician using the
    most recent edition of the American Medical Association’s
    guide to the evaluation of permanent impairment.” The
    Guides explain that an “impairment rating enables the
    physician to render a quantitative estimate of losses to the
    individual as a result of their health condition, disorder, or
    disease. Impairment ratings are defined by anatomic,
    structural, functional, and diagnostic criteria.” AMA
    Guides, at 5. The Guides use the concept of “whole person
    impairment,” which takes into account “the severity of the
    organ or body system impairment and the resulting functional
    limitations of the whole person.” 
    Id. at 21
     (emphasis in
    original).
    [¶14] Everyone involved in this case agreed that Mr. Hurt suffered from alteration of
    motion segment integrity [AOMSI], making the “Motion Segment Lesions” grid in the
    AMA Guides applicable to him. The dispute is whether Mr. Hurt’s level of impairment
    was properly classified as Class 1 or Class 4 under the Motion Segment Lesions grid.
    The grid includes classes ranging from 0 to 4, with the severity of the impairment
    increasing in accordance with the class numbers. Table 17-4 of the AMA Guides
    describes Class 1 lumbar spine impairments involving AOMSI as:
    Intervertebral disk herniation(s) or documented AOMSI,
    at a single level or multiple levels with medically documented
    findings; with or without surgery and for disk herniation(s)
    with documented resolved radiculopathy or nonverifiable
    radicular complaints at clinically appropriate level(s), present
    at the time of examination. [Footnote]: Or AOMSI in the
    absence of radiculopathy, or with documented resolved
    radiculopathy or nonverifiable radicular complaints at the
    clinically appropriate levels present at the time of
    examination.
    5
    Class 4 lumbar spine impairments involving AOMSI include:
    Intervertebral disk herniations and/or AOMSI, at multiple
    levels, with medically documented findings; with or without
    surgery and with documented signs of residual bilateral or
    multiple-level radiculopathy at the clinically appropriate
    levels present at the time of examination (see Table 17-7 to
    grade radiculopathy).
    [¶15] After the contested case hearing, the Medical Commission concluded:
    15. Hurt was rated for his permanent impairment by Dr.
    Kaplan and in Dr. Beer’s office utilizing the most recent
    edition of the AMA Guides [6th ed.]. On August 2, 2011, Dr.
    Kaplan rated Hurt’s permanent partial impairment at 9%
    whole body. Following Hurt’s objection to the IME rating by
    Dr. Kaplan, on September 26, 2011, Hurt’s permanent
    impairment was rated by Physician Assistant, Andy Be[g]uin
    at 25% whole body. This rating was apparently reviewed
    after the fact by Dr. Beer who concurred with the rating. . . .
    16. Dr. MacGuire did not examine Mr. Hurt. However,
    Dr. MacGuire reviewed the medical records and commented
    on the two impairment rating opinions of Dr. Kaplan and Dr.
    Beer’s office, applying her knowledge of the Guides, 6th
    edition. The value of her opinion is in helping the Hearing
    Panel evaluate the relative merit of the impairment ratings of
    Dr. Kaplan and Dr. Beer’s office. Pohl v. The Bailey
    Company, 
    980 P.2d 816
    , 821 (1999).
    17. Dr. Beer’s office incorrectly placed Hurt into class 4
    on Table 17-4 on page 570 of the Guides, with alteration of
    motion segment integrity at multiple levels with documented
    signs of bilateral radiculopathy at the clinically appropriate
    levels.    However, in order to properly document a
    radiculopathy placing Hurt in grade 4, Hurt must have only
    slight contraction of motor strength then [sic] no movement
    or no contraction: an inability to move. Hurt does not have
    documented evidence of residual bilateral or multilevel
    radiculopathy at the clinically appropriate levels; Table 17-9
    specifies EMG [electromyographic testing] evidence
    consistent with multiple nerve root radiculopathy. Guides,
    6
    Chap. 17, Table 17-9, p. 581. EMG and NCV studies have
    never been completed for Hurt.
    Hurt does not fall under class 4 either on table 17-4 or
    with the required use of table 17-7 to document
    radiculopathy. Placement in class 4 requires not only the
    “documented signs of bilateral or multiple-level
    radiculopathy at the clinically appropriate levels present at the
    time of evaluation” but also requires the “inability to
    ambulate without assistive devices.” Guides, Chap. 17, Table
    17-4, p. 572. Hurt is able to walk, sit, stand, and drive. His
    motor strength is essentially intact and he falls appropriately
    under the grade modifier 1.
    18. Hurt failed to meet his burden of proof to show by a
    preponderance of the evidence that on August 2[], 2011 he
    had a permanent impairment greater than the 9% rating upon
    which he was awarded PPI benefits; he needed to show that
    he was entitled to more than a 9% whole person permanent
    impairment rating using the AMA Guides to the Evaluation of
    Permanent Impairment (6th ed. 2008). The Hearing Panel
    finds that Dr. Kaplan correctly applied the AMA Guides, 6th
    edition to assign the 9% whole person impairment rating,
    while Andy Be[g]uin, a Physician Assistant, incorrectly
    placed Hurt in class 4 of the Table 17-4. His rating of 25%
    permanent impairment was in error, and not credible based
    upon the medical evidence. The Division properly awarded
    Hurt PPI benefits based on the 9% permanent impairment
    rating by Dr. Kaplan.
    (footnote and some citations omitted).
    [¶16] Mr. Hurt claims, under the AMA Guides, the Medical Commission incorrectly
    used criteria from grade 4 in Table 17-7, which is entitled “Physical Examination
    Adjustment: Spine,” in determining that he belonged in Class 1. He asserts the
    commission’s statement that he did not have “only slight contraction of motor strength
    then [sic] no movement or contraction: an inability to move,” improperly mixed grade
    criteria with class criteria. To support his argument, Mr. Hurt refers to some instructions
    on how to use the AMA Guides which apparently dictate that a class be assigned first and
    then a grade may be assigned within a class. He claims, therefore, that the Medical
    Commission erred when it referred to Table 17-7 in determining his class designation.
    7
    [¶17] By insisting that Table 17-7 can be used only to assign a grade within a class, not
    to determine the class, Mr. Hurt ignores the statement in Table 17-4 which specifically
    directs the use of Table 17-7 when radiculopathy is present (see Para 14, supra). More
    importantly, the medical evaluators did not apply the procedure advocated by Mr. Hurt in
    arriving at their ratings. In fact, Dr. MacGuire’s report specifically referred to the grade 4
    radiculopathy factors when she concluded Mr. Hurt’s impairment fell within Class 1. Mr.
    Hurt did not offer any medical evidence to show that Dr. MacGuire’s interpretation of the
    AMA Guides was incorrect.
    [¶18] The legislature was clear when it directed that impairment ratings be assigned by
    licensed physicians using the most recent version of the AMA Guides. That instruction
    confirms medical training and analysis are necessary to the proper interpretation and
    application of the AMA Guides. It would be improper for us to disregard the expert
    opinions and conduct our own ratings analysis based upon our interpretation of the AMA
    Guides and medical records.
    [¶19] Furthermore, while Mr. Hurt conducts an interesting exercise in applying the AMA
    Guides, we do not find it to be very helpful in determining whether the Medical
    Commission’s decision is supported by substantial evidence. In the end, the difference
    between Class 1 and Class 4 is determined by whether the person suffers from
    radiculopathy or nonverifiable radicular complaints. The AMA Guides define those terms
    as follows:
    Radiculopathy.        For the purposes of the Guides,
    radiculopathy is defined as significant alteration in the
    function of a single or multiple nerve roots and is usually
    caused by mechanical or chemical irritation of one or several
    nerves. The diagnosis requires clinical findings including
    specific dermatomal distribution of pain, numbness, and/or
    parasthesias. Subjective reports of sensory changes are more
    difficult to assess; therefore, these complaints should be
    consistent and supported by other findings of radiculopathy.
    There may be associated motor weakness and loss of reflex.
    A root tension sign is usually positive. The identification of a
    condition that may be associated with radiculopathy (such as
    a herniated disk) on an imaging study is not sufficient to
    make a diagnosis of radiculopathy; clinical findings must
    correlate with radiographic findings in order to be considered.
    Nonverifiable Radicular Complaints.          Nonverifiable
    radicular complaints are defined as chronic persistent limb
    pain or numbness, which is consistently and repetitively
    recognized in the medical records in the distribution of a
    8
    single nerve root that the examiner can name and with the
    following characteristics: preserved sharp vs. dull sensation
    and preserved muscle strength in the muscles it innervates, is
    not significantly compressed on imaging and is not affected
    on electrodiagnostic studies (if performed). Although there
    are subjective complaints of a specific radicular nature, there
    are inadequate or no objective findings to support the
    diagnosis of radiculopathy.
    [¶20] A diagnosis of true radiculopathy is required for a Class 4 rating. In order to meet
    the requirements for that diagnosis, a claimant must have significant alteration of nerve
    function. A Class 4 impairment requires documented signs of residual bilateral or
    multiple level radiculopathy at the clinically appropriate levels. By contrast, a patient
    with a Class 1 impairment may have radicular complaints that are “inadequate” to be
    classified as true radiculopathy. The AMA Guides’ use of terms like “significant” and
    “inadequate” recognize that medical judgment is required in applying the AMA Guides
    and determining the level of radicular problems a person is experiencing. Mr. Hurt
    would have the Court conduct its own analysis of the meaning and significance of the
    clinical findings without regard to the medical evaluators’ and the Medical Commission’s
    application of medical judgment. That is not the Court’s role in performing a substantial
    evidence review of an agency’s decision.
    [¶21] The second aspect of Mr. Hurt’s challenge to the Medical Commission’s decision
    is based upon the evidence actually presented at the hearing and the medical evaluator’s
    analysis of that evidence. Mr. Hurt claims the Medical Commission failed to properly
    recognize the existence and/or severity of his radiculopathy when it accepted Dr.
    Kaplan’s opinion that he belonged in Class 1 rather than Class 4 as surmised by Dr.
    Beer’s physician assistant. Mr. Hurt asserts the report from Dr. Beer’s office establishes
    bilateral radiculopathy because the physician assistant noted that reflexes were absent in
    both of Mr. Hurt’s knees and ankles.
    [¶22] The AMA Guides state that when radiculopathy is present there may be a loss of
    reflexes. However, the definition of radiculopathy does not state that a finding of loss of
    reflexes automatically establishes the condition. The AMA Guides specifically note that
    not all radicular symptoms or conditions are severe enough to qualify as true
    radiculopathy. As the definition of Class 1 states, a patient may have radicular
    complaints and still fall within that range of impairment. Medical examiners use their
    judgment in determining the degree of radicular problems.
    [¶23] Furthermore, Dr. Beer’s physician assistant’s finding of loss of reflexes is
    contradicted by other medical records. Another physician in Dr. Beer’s office, Radu
    Segal, M.D., examined Mr. Hurt in the months following the second surgery and
    preceding the impairment rating and consistently found reflexes bilaterally at the knees
    9
    and ankles. When Dr. Beer was asked about the apparent contradiction between Dr.
    Segal’s and the physician assistant’s findings, he acknowledged they were significantly
    different. Dr. Beer did not explain the discrepancy or relate the loss of reflexes to any
    deterioration in Mr. Hurt’s condition. Dr. Kaplan, who examined Mr. Hurt just a few
    weeks before the physician assistant, did not note any loss of reflexes.
    [¶24] Mr. Hurt also asserts the physical findings in Dr. Kaplan’s report establish that he
    suffers from radiculopathy. He directs us to Dr. Kaplan’s finding that “[w]ith sensory
    examination, there was some apparent decrease to pinwheel in the right L4 through S1
    dermatomes. 2 This also included his right lateral thigh.” It is true that a radiculopathy
    diagnosis under the AMA Guides requires “clinical findings including specific
    dermatomal distribution of pain, numbness, and/or parasthesias.” However, as we said
    above there are other indicators of true radiculopathy and the diagnosis depends on the
    severity of the symptoms. Dr. Kaplan noted the dermatomal findings, but he did not
    conclude that those findings mandated a diagnosis of radiculopathy for a Class 4
    designation. Dr. MacGuire analyzed Mr. Hurt’s medical records and Dr. Kaplan’s and
    the physician assistant’s ratings and ultimately agreed with Dr. Kaplan that under the
    AMA Guides, Mr. Hurt was properly placed in Class 1 despite the dermatomal findings.
    [¶25] In addition, although Mr. Hurt is relying upon Dr. Beer’s physician assistant’s
    evaluation to support the Class 4 rating, the physician assistant’s report did not include
    any dermatomal findings. When questioned about the report during his deposition, Dr.
    Beer testified:
    Q.      And then in terms of the dermatomal
    distribution of any radiculopathy, what was the dermatomal
    distribution in this case?
    A.      If I – I don’t see it documented clearly here. I
    would say it’s an L2-L3 distribution.
    Q.      It’s not documented in the report in terms of
    findings at the time of the impairment evaluation, correct?
    A.      Andy’s indication [sic] does not specify exactly
    where the loss was at, no.
    [¶26] To determine whether the Medical Commission’s decision on an impairment
    rating is supported by substantial evidence, we recognize:
    2
    Dermatome is defined as “an area of skin that is supplied with the nerve fibers of a single, posterior,
    spinal root.” Webster’s Third New Int’l Dictionary 608 (2002).
    10
    “It is the obligation of the trier of fact to sort through and
    weigh the differences in evidence and testimony, including
    that obtained from medical experts.” In re Worker’s Comp.
    Claim of David v. State ex rel. Wyo. Workers’ Safety and
    Comp. Div., 
    2007 WY 22
    , ¶ 15, 
    151 P.3d 280
    , 290
    (Wyo.2007). Further, we have noted that “The Commission is
    in the best position to judge and weigh medical evidence and
    may disregard an expert opinion if it finds the opinion
    unreasonable or not adequately supported by the facts upon
    which the opinion is based.” Spletzer v. Wyo. ex rel. Wyo.
    Workers’ Safety & Comp. Div., 
    2005 WY 90
    , ¶ 21, 
    116 P.3d 1103
    , 1112 (Wyo.2005).
    Willey v. State ex rel. Wyo. Workers’ Safety & Comp Div., 
    2012 WY 144
    , ¶ 18, 
    288 P.3d 418
    , 426 (Wyo. 2012).
    [¶27] In choosing to reject Dr. Beer’s physician assistant’s rating and accept Dr.
    Kaplan’s rating as supported by Dr. MacGuire’s analysis, the Medical Commission
    explained that, under § 27-14-405(g), a “licensed physician,” rather than a physician’s
    assistant was supposed to perform the rating. The Medical Commission noted the
    irregularity but apparently did not completely disregard the physician assistant’s rating.
    Instead, the commission decided that Dr. Kaplan’s and Dr. MacGuire’s opinions were
    more credible. The Medical Commission’s decision to accept Dr. Kaplan’s rating is not
    against the overwhelming weight of the evidence. Dr. Kaplan’s rating was consistent
    with Mr. Hurt’s other medical records and supported by Dr. MacGuire. The physician
    assistant’s rating did not include an analysis of the dermatomal distribution and his
    finding of loss of reflexes was contradicted by the other medical records. Thus, the
    Medical Commission’s determination that Mr. Hurt’s radicular problems fell within the
    definition of nonverifiable radicular complaints in Class 1 instead of true radiculopathy
    for Class 4 was not against the overwhelming weight of the evidence.
    [¶28] One more matter bears mention in our review of this case. The Medical
    Commission referenced language from Table 17-4 regarding a patient’s inability to
    ambulate without assistive devices. The Division concedes that criterion did not apply to
    Mr. Hurt’s AOMSI condition but asserts any error in that regard was harmless. We
    agree. The medical experts did not refer to the factor or use it in determining Mr. Hurt’s
    impairment rating. The Medical Commission’s conclusion as to that factor was,
    therefore, extraneous to the analysis of Mr. Hurt’s degree of impairment and its error in
    referring to it was harmless. See W.R.A.P. 9.04 (“any error, defect, irregularity or
    variance which does not affect substantial rights shall be disregarded by the reviewing
    court”).
    11
    [¶29] Affirmed.
    12