State by and Through Workforce Safety and Insurance v. Sandberg , 931 N.W.2d 488 ( 2019 )


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  •                  Filed 7/30/19 by Clerk of Supreme Court
    IN THE SUPREME COURT
    STATE OF NORTH DAKOTA
    
    2019 ND 198
    State of North Dakota, by and through
    Workforce Safety and Insurance,                                          Appellant
    v.
    John Sandberg,                                                            Appellee
    and
    Park Construction,                                                     Respondent
    No. 20180442
    Appeal from the District Court of Ramsey County, Northeast Judicial District,
    the Honorable Donovan J. Foughty, Judge.
    REVERSED AND REMANDED.
    Opinion of the Court by McEvers, Justice.
    Sean F. Marrin, Special Assistant Attorney General, Grand Forks, ND, for
    appellant.
    Dean J. Haas, Bismarck, ND, for appellee.
    WSI v. Sandberg
    No. 20180442
    McEvers, Justice.
    [¶1]   Workforce Safety and Insurance (“WSI”) appeals from a judgment affirming
    an administrative law judge’s (“ALJ”) decision that John Sandberg sustained a
    compensable injury because his repetitive work activities substantially worsened the
    severity of his preexisting degenerative disc condition. We conclude the ALJ’s
    findings are not sufficient to understand the basis for the decision, and we reverse and
    remand for further proceedings.
    I
    [¶2]   Sandberg worked as a truck driver in the oil industry in the 1970s and 1980s,
    and he began operating heavy equipment for various construction companies in the
    1980s and 1990s. Sandberg testified he operated heavy equipment as a seasonal
    employee for Park Construction from 2002 through September 28, 2015. According
    to Sandberg, he primarily operated a track hoe to unload and place rip rap along raised
    railroad grade. Sandberg testified that while operating the track hoe, he was required
    to wear a seatbelt holding him in a seat consisting of a board covered with a piece of
    half-inch foam, that he sat at an angle while operating the track hoe and maneuvering
    large irregularly shaped rocks into place over uneven terrain, and that there was
    frequent jarring, slipping, and twisting when he moved the track hoe over the rocks
    while manipulating the controls and rotating to see around the machine.
    [¶3]   Sandberg’s medical history included treatment for a non-work related incident
    resulting in a sore right neck and right lower back in March 1998, and a
    contemporaneous x-ray disclosed mild degenerative arthritis in his cervical spine.
    Sandberg also sought medical care for upper back and neck pain after a non-work
    related car accident in a parking lot in April 2006, and he was diagnosed with a soft
    tissue injury, consisting of an upper back and neck sprain.
    1
    [¶4]    In July 2003, Sandberg saw Dr. Michael Remmick for chiropractic adjustments
    for a stiff neck, pain down his right shoulder and arm, and numbness in his fingertips.
    Dr. Remmick’s treatment notes stated that Sandberg reported jarring and twisting
    from operating a track hoe at work. Sandberg received several adjustments from Dr.
    Remmick into September 2003, and after the last adjustment, Dr. Remmick noted
    Sandberg had responded favorably to the treatment and should return for further
    treatment only if needed.
    [¶5]    In November 2011, Sandberg again sought chiropractic treatment from Dr.
    Remmick, describing his work on heavy equipment and complaining of pain and
    discomfort in his upper back, neck, left shoulder, and arm, and numbness in his left
    hand.    Dr. Remmick performed a series of chiropractic adjustments between
    November 2011 and September 2012. Sandberg also saw Dr. Remmick for a series
    of chiropractic adjustments between March and September 2015. According to
    Sandberg, he could no longer perform his job for Park Construction because of back
    pain and he took an early seasonal layoff on September 28, 2015, which was his last
    day of work for Park Construction.
    [¶6]    In May 2016, Sandberg reported complaints of neck and upper back pain
    during a preoperative evaluation for cataract surgery, and x-rays and MRIs revealed
    multilevel degenerative disc disease. In July 2016, Sandberg filed a claim with WSI
    for a “[c]ervical (neck)” injury, identifying his last day of work with Park
    Construction on September 28, 2015, as the injury date. Sandberg’s claim described
    how the injury occurred:
    unloading and placing rock with excavator with continuous bouncing,
    slimming [sic], due to ruff [sic] terrain, with repetitive movement, arms
    and head continuous movement over long periods of time, arms at my
    side, hands running joysticks, head moving side to side, up and down,
    resulting in extreme neck, back and shoulder pain, with numbing in
    both arms and hands.
    [¶7]    WSI denied Sandberg’s claim and his request for reconsideration, determining
    that his upper and middle back issues were a preexisting condition of degenerative
    disc disease and that his employment acted only as a trigger to produce symptoms in
    2
    the preexisting condition and did not cause or increase the risk of his cervical
    degenerative disc disease. WSI determined Sandberg’s work activities did not
    substantially accelerate the progression or substantially worsen his preexisting
    condition.
    [¶8]   Sandberg requested an administrative hearing. An independent ALJ identified
    the issues for resolution at the hearing as whether Sandberg proved by a
    preponderance of evidence that his repetitive work activities: (1) were a substantial
    contributing factor to his cervical and thoracic degenerative conditions; or (2)
    substantially accelerated or worsened his preexisting cervical spine and thoracic
    spinal conditions.
    [¶9]   At the hearing, Sandberg relied on testimony and a letter from Dr. Remmick
    and a letter from another treating physician, Dr. Steven Schoneberg, to support his
    claim that his repetitive work activities substantially accelerated the progression or
    substantially worsened the severity of his preexisting cervical and thoracic condition.
    Dr. Remmick testified there was more than just pain from a preexisting degenerative
    disc disease and there was an “accumulative trauma type effect” to Sandberg’s soft
    tissues, supportive structures, and joint structures from his repetitive activities. Dr.
    Remmick testified there was a progression of significant physiological change in x-
    ray imaging from 2003 through the latest imaging. Dr. Schoneberg opined that
    Sandberg’s work could have substantially contributed to the development and gradual
    worsening of his condition and likely contributed to his chronic neck and mid-back
    pain. WSI’s medical consultant, Dr. Gregory Peterson, testified there was no
    significant clinical evidence demonstrating that Sandberg’s work activities accelerated
    changes in his condition or that his condition was caused by his work activities. Dr.
    Peterson opined that Sandberg’s work acted as a trigger to produce symptoms in his
    preexisting condition but did not cause or substantially accelerate the progression of
    his degenerative disc disease.
    [¶10] The ALJ issued a decision stating Dr. Peterson’s opinion that Sandberg’s work
    did not cause or substantially accelerate his condition was in conflict with the
    3
    opinions of Dr. Remmick and Dr. Schoneberg and finding Dr. Peterson’s opinion was
    more persuasive. The ALJ determined that Sandberg’s employment did not cause or
    substantially accelerate the progression of his degenerative disc disease. However,
    the ALJ also found that Sandberg’s employment substantially increased the severity
    of his pain and did not merely trigger symptoms but substantially worsened the
    severity of his degenerative disc disease. The ALJ decided Sandberg had met his
    burden of proving he sustained a compensable injury. The district court affirmed the
    ALJ’s decision.
    II
    [¶11] Under the Administrative Agencies Practice Act, N.D.C.C. ch. 28-32, courts
    exercise limited appellate review of a final order by an administrative agency.
    Davenport v. Workforce Safety & Ins. Fund, 
    2013 ND 118
    , ¶ 10, 
    833 N.W.2d 500
    ;
    Mickelson v. N.D. Workforce Safety & Ins., 
    2012 ND 164
    , ¶ 7, 
    820 N.W.2d 333
    .
    Under N.D.C.C. §§ 28-32-46 and 28-32-49, the district court and this Court must
    affirm an order by an administrative agency unless:
    1.     The order is not in accordance with the law.
    2.     The order is in violation of the constitutional rights of the
    appellant.
    3.     The provisions of this chapter have not been complied
    with in the proceedings before the agency.
    4.     The rules or procedure of the agency have not afforded
    the appellant a fair hearing.
    5.     The findings of fact made by the agency are not
    supported by a preponderance of the evidence.
    6.     The conclusions of law and order of the agency are not
    supported by its findings of fact.
    7.     The findings of fact made by the agency do not
    sufficiently address the evidence presented to the agency
    by the appellant.
    8.     The conclusions of law and order of the agency do not
    sufficiently explain the agency’s rationale for not
    adopting any contrary recommendations by a hearing
    officer or an administrative law judge.
    N.D.C.C. § 28-32-46.
    4
    [¶12] In reviewing an administrative agency’s factual findings, a court may not make
    independent findings of fact or substitute its judgment for the agency’s findings;
    rather, a court must determine only whether a reasoning mind reasonably could have
    determined the findings were proven by the weight of the evidence from the entire
    record. Davenport, 
    2013 ND 118
    , ¶ 11, 
    833 N.W.2d 500
    . When reviewing an appeal
    from an independent ALJ’s final order, similar deference is given to the ALJ’s factual
    findings because the ALJ had the opportunity to observe witnesses and the
    responsibility to assess the credibility of witnesses and resolve conflicts in the
    evidence. 
    Id.
     Similar deference is not given to an independent ALJ’s legal
    conclusions, however, and a court fully reviews an ALJ’s legal conclusions on
    questions of law, including the interpretation of a statute. 
    Id.
     Under N.D.C.C. § 28-
    32-39(1), an administrative agency “shall make and state concisely and explicitly its
    findings of fact.” We have said an agency’s findings are adequate if they enable a
    reviewing court to understand the agency’s decision. Pleinis v. N.D. Workers Comp.
    Bureau, 
    472 N.W.2d 459
    , 462 (N.D. 1991); F.O.E. Aerie 2337 v. N.D. Workers
    Comp. Bureau, 
    464 N.W.2d 197
    , 199-200 (N.D. 1990).
    III
    [¶13] WSI argues the ALJ’s decision misapplied the law, utilized inappropriate
    speculative evidence, is not supported by credible objective medical evidence, and is
    contrary to the ALJ’s prior finding about the persuasiveness of Dr. Peterson’s opinion
    that Sandberg’s work did not cause or substantially accelerate the progression of his
    degenerative disc disease. WSI argues the mere triggering of pain symptoms in a
    preexisting injury, disease, or other condition is not sufficient to establish a
    compensable injury and the medical evidence in this case does not establish Sandberg
    sustained a compensable injury.
    [¶14] Claimants have the burden of proving by a preponderance of evidence they
    have suffered a compensable injury and are entitled to workers’ compensation
    benefits. N.D.C.C. § 65-01-11; Bergum v. N.D. Workforce Safety & Ins., 
    2009 ND
                                         5
    52, ¶ 11, 
    764 N.W.2d 178
    . A claimant must prove the condition for which benefits
    are sought is causally related to a work injury. Bergum, at ¶ 11. To establish a casual
    connection, a claimant must demonstrate the claimant’s employment was a substantial
    contributing factor to the injury and need not show employment was the sole cause
    of the injury. Bruder v. N.D. Workforce Safety & Ins. Fund, 
    2009 ND 23
    , ¶ 8, 
    761 N.W.2d 588
    .
    [¶15] Section 65-01-02(10), N.D.C.C., defines a “compensable injury” for purposes
    of workers’ compensation law and provides, in relevant part:
    10.    “Compensable injury” means an injury by accident arising out
    of and in the course of hazardous employment which must be
    established by medical evidence supported by objective medical
    findings.
    ....
    b.     The term does not include:
    ....
    (7)    Injuries attributable to a pre-existing injury,
    disease, or other condition, including when the
    employment acts as a trigger to produce
    symptoms in the pre-existing injury, disease, or
    other condition unless the employment
    substantially accelerates its progression or
    substantially worsens its severity. Pain is a
    symptom and may be considered in determining
    whether there is a substantial acceleration or
    substantial worsening of a pre-existing injury,
    disease, or other condition, but pain alone is not a
    substantial acceleration or a substantial
    worsening.
    [¶16] The issue in this appeal involves the continuing efforts to apply the statutory
    delineation between work activities that merely trigger pain symptoms in a preexisting
    injury, disease, or other condition and are not compensable and work activities that
    substantially accelerate the progression or substantially worsen the severity of a
    preexisting injury, disease, or other condition and are compensable. See, e.g.,
    Parsons v. Workforce Safety & Ins. Fund, 
    2013 ND 235
    , ¶¶ 14-22, 
    841 N.W.2d 404
    ;
    Davenport, 
    2013 ND 118
    , ¶¶ 20-29, 
    833 N.W.2d 500
    ; Mickelson, 
    2012 ND 164
    , ¶¶
    9-23, 
    820 N.W.2d 333
    ; Johnson v. N.D. Workforce Safety & Ins. Fund, 
    2012 ND 87
    ,
    6
    ¶¶ 7-10, 
    816 N.W.2d 74
    ; Curran v. N.D. Workforce Safety & Ins., 
    2010 ND 227
    , ¶¶
    18-28, 
    791 N.W.2d 622
    .
    [¶17] In Mickelson, 
    2012 ND 164
    , ¶¶ 1, 10, 12, 
    820 N.W.2d 333
    , this Court
    considered a denial of a workers compensation claim based on an alleged substantial
    worsening of a latent preexisting degenerative disc disease under the prior version of
    N.D.C.C. § 65-01-02(10)(b)(7).1 A plurality of this Court discussed the disjunctive
    statutory language authorizing compensation for employment activities that
    substantially accelerate the progression or substantially worsen the severity of a
    preexisting injury, disease, or other condition and said:
    When those terms are considered together to give meaning to
    each term, they mean injuries attributable to a preexisting injury,
    disease, or other condition are compensable if the employment in some
    real, true, important, or essential way makes the preexisting injury,
    disease or other condition more unfavorable, difficult, unpleasant, or
    painful, or in some real, true, important, or essential way hastens the
    progress or development of the preexisting injury, disease, or other
    condition. In contrast, injuries attributable to a preexisting injury,
    disease, or other condition are not compensable if employment acts like
    a mechanical trigger in initiating a process or reaction to produce
    subjective evidence of a disease or physical disturbance or something
    that indicates the presence of a bodily disorder. We recognize . . . that
    pain can be a symptom, or subjective evidence, of an injury, disease or
    other condition. Under the ordinary meaning of those terms, however,
    employment can also substantially worsen the severity, or substantially
    accelerate the progression of a preexisting injury, disease, or other
    condition when employment acts as a substantial contributing factor to
    substantially increase a claimant’s pain. That conclusion is consistent
    with our decision in Geck [v. N.D. Workers Comp. Bureau], that pain
    can be a substantial aggravation of an underlying latent condition. 
    1998 ND 158
    , ¶ 10, 
    583 N.W.2d 621
    . . . . [W]e conclude part of the analysis
    1
    Section 65-01-02(10)(b)(7), N.D.C.C., was amended in 2013 after this Court’s
    decision in Mickelson to add the last sentence in subsection (7) that “Pain is a
    symptom and may be considered in determining whether there is a substantial
    acceleration or substantial worsening of a preexisting injury, disease, or other
    condition, but pain alone is not a substantial acceleration or a substantial worsening.”
    2013 N.D. Sess. Laws ch. 498, § 1. The 2013 amendment states that it applies to all
    claims regardless of the date of injury. Id. at § 2.
    7
    for assessing compensability of injuries attributable to a latent
    preexisting injury, disease, or other condition is whether or not the
    underlying preexisting injury, disease, or other condition would likely
    have progressed similarly in the absence of employment. See Pleinis,
    472 N.W.2d at 462-63. We decline to construe those terms so narrowly
    as to require only evidence of a substantial worsening of the disease
    itself to authorize an award of benefits. Rather, the statute also
    authorizes compensability if employment substantially accelerates the
    progression or substantially worsens the severity of the injury, disease,
    or other condition, which we conclude requires consideration of
    whether the preexisting injury, disease or other condition would have
    progressed similarly in the absence of employment. Under that
    language, employment substantially accelerates the progression or
    substantially worsens the severity of a preexisting injury, disease, or
    other condition when the underlying condition likely would not have
    progressed similarly in the absence of employment. That interpretation
    provides additional clarification and explanation for delineating
    between noncompensability when employment triggers symptoms in a
    preexisting latent injury, disease, or other condition and compensability
    when employment substantially accelerates the progression or
    substantially worsens the severity of the preexisting injury, disease, or
    other condition. That interpretation is also consistent with the purpose
    of workers compensation law to provide “sure and certain relief” for
    workers, see N.D.C.C. § 65-01-01, and with the principle that
    employment must be a substantial contributing factor for a
    compensable injury and need not be the sole cause of the injury.
    Bruder, 
    2009 ND 23
    , ¶ 8, 
    761 N.W.2d 588
    .
    Mickelson, at ¶¶ 20-21.
    [¶18] In Mickelson, 
    2012 ND 164
    , ¶ 23, 
    820 N.W.2d 333
    , the plurality remanded for
    further proceedings, concluding an ALJ misapplied the law by looking too narrowly
    at the claimant’s degenerative disc disease itself without considering whether the
    injury, disease, or other condition likely would not have progressed similarly in the
    absence of the claimant’s employment so as to substantially accelerate the progression
    or substantially worsen the severity of the claimant’s injury, disease, or other
    condition. A special concurrence agreed with the conclusion that pain could be an
    aggravation of an underlying arthritic condition and noted a dissatisfaction with the
    statutory failure to distinguish “those instances in which pain aggravates an
    underlying condition, i.e., substantially worsens the severity of the condition, from
    8
    those instances in which . . . pain is only a symptom of the condition triggered by
    employment.” Id. at ¶ 30 (VandeWalle, Chief Justice, concurring specially). The
    special concurrence concluded a remand for further consideration of the claim was
    necessary. Id.
    [¶19] In Davenport, 
    2013 ND 118
    , ¶ 20, 
    833 N.W.2d 500
    , this Court considered an
    ALJ’s determination that a claimant’s preexisting degenerative spine and lower back
    conditions were not a compensable injury under the pre-2013 version of N.D.C.C. §
    65-01-02(10)(b)(7). We discussed the Mickelson decision:
    Under Mickelson, depending on the specific facts and
    circumstances and the medical evidence supported by objective medical
    findings, pain can be a substantially worsening of the severity or a
    substantial acceleration of the progression of a preexisting condition
    and pain also can be a symptom of the condition which is triggered by
    employment. Id. at ¶¶ 20-23, 30. Under Mickelson, however, pain
    alone does not establish a substantial acceleration or a substantial
    worsening of a preexisting condition for purposes of a compensable
    injury. Id. at ¶ 30. Rather, Mickelson does not eliminate the
    requirement that there must be medical evidence supported by objective
    medical findings for a compensable injury. See N.D.C.C. § 65-01-
    02(10). In Mickelson, there was medical evidence supported by
    objective medical findings from the claimant’s treating providers which
    stated his latent condition was directly related to his employment. Id.
    at ¶¶ 3-4. On that record, a majority of this Court concluded to remand
    for further findings on whether the claimant’s underlying injury,
    disease or other condition would likely not have progressed similarly
    in the absence of employment which would indicate the employment
    situation substantially accelerated the progression or substantially
    worsened the severity of the underlying later condition. Id. at ¶ 23.
    Davenport, at ¶ 25.
    [¶20] In Davenport, 
    2013 ND 118
    , ¶ 26, 
    833 N.W.2d 500
    , we distinguished
    Davenport’s history of neck and lower back complaints hastened by his chronic
    smoking from Mickelson’s latent condition, and we discussed the medical evidence
    in that case in conjunction with the ALJ’s decision denying Davenport benefits. We
    affirmed the ALJ’s decision:
    The ALJ’s decision identifies Davenport’s prior problems with
    his lower back, left shoulder and cervical spine. Unlike the record in
    9
    Mickelson, Davenport’s treating physician’s notes and Dr. Van
    Norman’s agreement with Dr. Burton’s independent medical
    examination support the ALJ’s decision that medical evidence
    supported by objective medical findings does not establish a causal
    relationship between Davenport’s work injuries and the pain from his
    degenerative condition. Dr. Burton’s independent medical examination
    provides evidence Davenport’s condition, including his pain symptoms,
    would have progressed similarly in the absence of the work injuries.
    A claimant has the burden to provide medical evidence
    supported by objective medical findings to show a compensable injury.
    See N.D.C.C. § 65-01-02(10). On this record and under our deferential
    standard of review, a reasoning mind could reasonably conclude
    Davenport failed to sustain that burden. We conclude a reasoning mind
    could reasonably conclude the ALJ’s findings were proven by the
    weight of the evidence and support the ALJ’s conclusions. We
    therefore sustain the ALJ’s decision that Davenport failed to establish
    a compensable injury under N.D.C.C. § 65-01-02(10)(b)(7).
    Davenport, at ¶¶ 28-29.
    [¶21] Both Davenport, 
    2013 ND 118
    , ¶¶ 25, 28, 
    833 N.W.2d 500
    , and Mickelson,
    
    2012 ND 164
    , ¶¶ 21, 23, 
    820 N.W.2d 333
    , focused on the existence of medical
    evidence supported by objective medical findings which would show the injury,
    disease, or other condition likely would not have progressed similarly in the absence
    of employment and which would indicate the employment substantially accelerated
    the progression or substantially worsened the severity of the injury, disease, or other
    condition.
    [¶22] In 2013, the legislature amended the definition of “compensable injury” in
    N.D.C.C. § 65-01-02(10)(b)(7) to add the language that “[p]ain is a symptom and may
    be considered in determining whether there is a substantial acceleration or substantial
    worsening of a preexisting injury, disease, or other condition, but pain alone is not a
    substantial acceleration or a substantial worsening.” 2013 N.D. Sess. Laws ch. 498,
    § 1. See fn. 1, supra. As originally introduced, the proposed language provided that
    “[p]ain is a symptom and is not a substantial acceleration or substantial worsening of
    a preexisting injury, disease, or other condition.” According to a representative of
    WSI, the proposed language was in response to this Court’s decision in Mickelson to
    clarify that pain symptoms are not a substantial worsening or progression of a
    10
    preexisting condition. See Hearing on H.B. 1163, Before House Industry Business
    and Labor Comm., 63rd N.D. Legis. Sess. (Jan. 21, 2013) (written testimony of Tim
    Wahlin, WSI Chief of Injury Services). The language was amended during the
    legislative process to the current language.
    [¶23] The plain language of the 2013 amendment to N.D.C.C. § 65-01-02(10)(b)(7)
    is consistent with Mickelson and Davenport, and clarifies that pain is a symptom of
    a preexisting injury, disease, or other condition and may be considered in determining
    whether there is a substantial acceleration of the progression or a substantial
    worsening of the severity of the condition, but pain alone is not a substantial
    acceleration or a substantial worsening. Morever, the 2013 amendment did not alter
    the requirement in N.D.C.C. § 65-01-02(10), that a compensable injury must be
    established by medical evidence supported by objective medical findings. See
    Davenport, 
    2013 ND 118
    , ¶ 29, 
    833 N.W.2d 500
    . We have recognized that objective
    medical findings may include a physician’s medical opinion based on an examination,
    a patient’s medical history, and the physician’s education and experience. Swenson
    v. Workforce Safety & Ins. Fund, 
    2007 ND 149
    , ¶ 25, 
    738 N.W.2d 892
    .
    [¶24] Here, the ALJ identified the issues for resolution at the administrative hearing
    as whether Sandberg proved by a preponderance of evidence that his repetitive work
    activities: (1) were a substantial contributing factor to his cervical and thoracic
    degenerative conditions; or (2) substantially accelerated or worsened his preexisting
    cervical spine and thoracic spine conditions. The ALJ’s findings of fact and
    conclusions of law state:
    The medical opinion of Dr. Peterson as to whether Mr.
    Sandberg’s work caused his disc disease or caused it to substantially
    accelerate is in conflict with the opinions of Drs. Remmick and
    Schoneberg. . . . Dr. Peterson’s opinion is the more persuasive. The
    greater weight of the evidence does not establish that Mr. Sandberg’s
    work caused or substantially accelerated the progression of Mr.
    Sandberg’s degenerative disc disease.
    ....
    A preponderance of the evidence does establish that operating
    the track hoe moving rip rap caused Mr. Sandberg’s degenerative disc
    disease to become more painful. Prior to 2015, the pain lessened after
    11
    rest during seasonal layoff and chiropractic treatment. Following, and
    as a result of a period of pushing rip rap year round, in 2015 Mr.
    Sandberg’s work induced pain became worse and no longer responded
    favorably to rest and treatment.
    A preponderance of the evidence does establish that Mr.
    Sandberg’s jarring work over time has increased the severity of the
    symptom of pain produced by his pre-existing degenerative disc disease
    that has caused him to seek considerable medical treatment and
    ultimately prevented him from performing his lifelong occupation.
    ....
    Mr. Sandberg has met his burden of proving by a preponderance
    of the evidence that he has sustained a compensable injury in that he
    has proven by a preponderance of the evidence that his repetitive work
    activities did not merely trigger symptoms, but rather substantially
    increased his pain and thus substantially worsened the severity of his
    degenerative disc condition.
    [¶25] The ALJ found persuasive Dr. Peterson’s medical opinion that Sandberg’s
    work did not cause or substantially accelerate the progression of his degenerative disc
    disease and determined the greater weight of the evidence did not establish
    Sandberg’s work activities caused or substantially accelerated the progression of his
    preexisting degenerative disc disease. The ALJ also found, however, that Sandberg’s
    work activities caused his degenerative disc disease to be more painful and increased
    the severity of the symptom of pain from his condition. As the trier-of-fact, the ALJ
    may rely upon either party’s witnesses, and the ALJ has the responsibility to weigh
    the credibility of medical evidence and adequately explain its reasoning. See, e.g.,
    Workforce Safety & Ins. v. Auck, 
    2010 ND 126
    , ¶ 14, 
    785 N.W.2d 186
    . Here, the ALJ
    decided Sandberg had established a compensable injury by showing his work activity
    substantially worsened the severity of his condition. The ALJ’s decision states that
    Sandberg’s work activities increased the severity of the symptom of pain from his
    preexisting degenerative disc disease, but the language of N.D.C.C. § 65-01-
    02(10)(b)(7) states that “pain alone is not a substantial acceleration or a substantial
    worsening” of a preexisting injury, disease, or other condition. Pain may be
    considered in determining whether there is a substantial worsening of a preexisting
    injury, disease, or other condition but a compensable injury must be established by
    12
    medical evidence supported by objective medical findings. N.D.C.C. § 65-01-02(10).
    The ALJ explained Sandberg’s work-induced pain no longer responded favorably to
    rest and treatment and prevented him from performing his lifelong occupation.
    However, the ALJ did not cite any medical evidence supported by objective medical
    findings in the record to support a determination that Sandberg’s repetitive work
    activities did not merely trigger symptoms, but rather substantially worsened the
    severity of his degenerative condition.
    [¶26] On this record, we are unable to reconcile the ALJ’s decision with the statutory
    requirements for medical evidence supported by objective medical findings for a
    compensable injury in N.D.C.C. § 65-01-02(10). We reverse the judgment and
    remand to the ALJ for findings under those statutory requirements. Because of our
    resolution of the foregoing issue, we do not address WSI’s argument that any finding
    in favor of Sandberg should be limited to an award based on aggravation under
    N.D.C.C. § 65-05-15.
    IV
    [¶27] We reverse the judgment and remand for proceedings consistent with this
    opinion.
    [¶28] Lisa Fair McEvers
    Daniel J. Crothers
    Jerod E. Tufte
    Jon J. Jensen
    Gerald W. VandeWalle, C.J.
    13