LYDIA G. ANDERSON, Employee/Appellant, v. MENARD, INC. and XL INS. AM., INC./ GALLAGHER BASSETT SERVS., Employer-Insurer/Respondents, and BLUE CROSS AND BLUE SHIELD OF MINN. AND BLUE PLUS, MANKATO SURGERY CTR., ORTHOPAEDIC & FRACTURE CLINIC, and MAYO CLINIC, Intervenors.

The employee appeals the compensation judge’s determination that her work activities for the employer were not a substantial contributing cause of her claimed work injuries.  Substantial evidence supports the compensation judge’s finding, and we affirm.

Lydia Anderson, the employee, claimed to have sustained injuries to her low back and bilateral thumbs while working part time for the employer, Menard, Inc. (“Menards”).  In February 2015, the employee was hired to work part-time in the wallcovering department.  Within a few months, she transferred to the receiving department where she broke down pallets, lifted items weighing up to 65 pounds, and drove a forklift.  Her employment at Menards was in addition to the employee’s full-time position at a circuit board manufacturing company where she performed quality inspection, keyboarding, and labeling.  Outside of work, the employee engaged in exercise classes regularly lifting weights up to 70 pounds.

The employee alleged to have injured her low back while working at Menards on June 29, 2015.  She testified at the hearing that she was not sure when she injured her low back, but that she knew it was in the year 2015.  She also remembered that she lifted an item from the floor and felt a sharp pain in her back.  In August 2015, the employee sought treatment for low back pain with Wenger Physical Therapy.  The initial intake form showed the date of onset was the year 1986.  The physical therapist reported that the employee’s low back complaints began 20 years ago when lifting something during pregnancy.  It was noted that the employee’s low back symptoms flared in June 2015 when working at Menards lifting heavier items for two weeks.  The diagnosis was mechanical low back pain.

After a few physical therapy sessions, it was noted that she wanted to see a back surgeon since physical therapy had not worked.  She saw Curt Schultz, D.O., at the Mayo Clinic, who treated her and recommended that she continue physical therapy.  She sought care with Thomas R. Jones, M.D., at the Orthopedic and Fracture Clinic who ordered an MRI scan.  That scan showed degenerative disease changes at two facet levels and some mild pedicle edema at the L5 level.  Dr. Jones recommended medial branch facet blocks and more physical therapy.  The employee subsequently underwent additional physical therapy,^[1] multiple injections, a radiofrequency neurolysis in 2016 and a radiofrequency ablation in 2019.  While there was a reduction in pain short term, none of these treatments succeeded in alleviating her symptoms.  In his narrative report of March 11, 2019, Dr. Jones opined that the work injury of June 29, 2015, resulted in a permanent aggravation of a pre-existing asymptomatic condition.  Dr. Jones permanently restricted the employee to lifting no more than 35 pounds with limited bending and twisting.

The employer and insurer initially admitted primary liability for the employee’s low back injury and paid some benefits.  The employer and insurer retained Nolan Segal, M.D., who reviewed multiple medical records, took a medical history from the employee, examined her, and submitted a narrative report.  Dr. Segal concluded that the employee’s work injury of June 29, 2015, was not a substantial contributing factor to her low back complaints.  He explained that there were inconsistencies in the employee’s history and medical records.  He noted that at her initial office visit in August 2015, she reported symptoms for two weeks, but later reported an acute onset of symptoms on June 29, 2015.  He also noted that the employee was not seen between June 29 and August 10, 2015, which was inconsistent with a significant acute injury occurring on June 29, 2015.  Finally, he pointed out that the employee’s complaints of pain and weakness in the leg were not supported by the radiographic findings, which included the 2015 MRI findings.  Dr. Segal later reviewed findings from the 2018 MRI, and submitted an addendum narrative report in which he compared the 2015 and 2018 MRI findings.  Dr. Segal opined that there was no evidence to suggest any new structural injuries to the low back and diagnosed the employee with two-level degenerative disease with spondylolisthesis at the L4-5 level without evidence of neurologic deficit or significant radicular problem.  He restricted the employee’s lifting to a maximum of 50 pounds and recommended that she avoid high impact activities.

In January 2018, the employee claimed another work-related injury in the nature of bilateral trigger thumb.  She initially filed a claim for bilateral trigger thumb with her full-time employer, the circuit board manufacturing company.  That employer denied her claim.  The employee filed a claim for bilateral trigger thumb with Menards around the same time.  Menards’ local general manager testified that when the employee asked him to complete a workers’ compensation report, he had asked her when she was injured and what happened.  He testified that her response was that she was not sure, but that her other employer had denied the claim, so she needed to fill out a report at Menards.  Menards denied that this injury was related to the employee’s work activities.

The employee underwent treatment of her bilateral trigger thumb, including a release in April 2018 performed by Steven Curtis, M.D.  Dr. Curtis opined that the etiology of trigger finger was unknown.  It was his opinion that the employee’s work activities could not be proven to have caused trigger finger, but added that her job duties certainly contributed to her need for treatment.

The employer and insurer retained Jeffrey Husband, M.D., to assess the employee’s trigger thumb condition.  Dr. Husband reviewed multiple medical records, took a medical history from the employee, examined her, and submitted a narrative report.  It was Dr. Husband’s opinion that work was not a substantial contributing factor to the employee’s trigger thumb condition.  He explained that trigger digit is an idiopathic disorder which in most individuals occurs spontaneously without any relationship to work.  Dr. Husband concluded that the employee had reached maximum medical improvement on May 8, 2018, and that she needed no activity restrictions or additional medical treatment.

The employee filed a claim petition for benefits related to the bilateral thumb injury.  This claim for benefits was consolidated with the employee’s low back claim and was heard by a compensation judge on February 10, June 30, and July 2, 2020.  In Findings and Order filed September 2, 2020, the compensation judge concluded that the employee’s work activities at Menards were not a substantial contributing cause of her low back and bilateral trigger thumb conditions, assigning greater weight to the medical evidence and opinions of the medical experts on the causation issue.  The employee appeals.

On appeal, the Workers’ Compensation Court of Appeals must determine whether “the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.”  Minn. Stat. § 176.421, subd. 1(3).  Substantial evidence supports the findings if, in the context of the entire record, “they are supported by evidence that a reasonable mind might accept as adequate.”  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.  Id. at 60, 37 W.C.D. at 240.  Similarly, findings of fact should not be disturbed, even though the reviewing court might disagree with them, “unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of evidence or not reasonably supported by the evidence as a whole.”  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).

A decision which rests upon the application of a statute or rule to essentially undisputed facts generally involves a question of law which the Workers’ Compensation Court of Appeals may consider de novo.  Krovchuk v. Koch Oil Refinery, 48 W.C.D. 607, 608 (W.C.C.A. 1993), summarily aff’d (Minn. June 3, 1993).

On appeal, the employee argues that the compensation judge failed to address the claims she actually asserted, that her low back and trigger thumb conditions were compensable as permanent aggravations of her pre-existing conditions.  The employee also challenges the foundation upon which Dr. Husband relied, claiming that he did not understand the nature of the employee’s job activities at Menards in addressing the causation issue.  She asserts that because Dr. Husband lacked foundation, the judged erred in adopting that opinion.

Citing Fenton v. Murphy Motor Freight Lines, Inc., 297 N.W.2d 294, 33 W.C.D. 194 (Minn. 1980), the employee maintains that uncontroverted evidence overwhelmingly showed that the employee’s work activities at Menards were a substantial contributing cause that aggravated or accelerated her pre-existing low back and trigger thumb conditions.  In determining that the employee’s work activities did not cause the employee’s low back and trigger thumb conditions, the judge considered the employee’s claim that work had substantially aggravated her pre-existing conditions.  In the Findings and Order, the compensation judge specifically addressed the conclusions of the medical experts.  He explained that the employee’s orthopedist, Dr. Jones, appeared to simply accept the employee’s “attribution of responsibility to the alleged lifting incident at Menards.”  In determining that the work activities were not a substantial contributing cause of the low back condition, he adopted the opinion of Dr. Segal that the employee experienced a manifestation of a pre-existing condition, and not a permanent aggravation or discrete new injury.

It is clear that the judge did not accept the employee’s explanation for the injuries.  He notes the gap in treatment between the alleged lifting incident in June and medical attention almost two months later, reasoning that one “would not expect an individual experiencing a serious back injury as a result of such an incident to put off seeing a medical provider.”  (Mem. at 4.)  The compensation judge also found it difficult to accept that a single incidence of lifting a box, even one weighing 60 to 65 pounds, would have caused significant injury to a person who routinely engaged in rigorous physical exercise as the employee testified.  As a general rule, it is not the role of this court to evaluate the credibility of a witness.  Redgate v. Sroga’s Standard Serv., 421 N.W.2d 729, 734, 40 W.C.D. 948, 957 (Minn. 1988); see also Even v. Kraft, 445 N.W.2d 831, 835, 42 W.C.D. 220, 225 (Minn. 1989) (“Assessment of witnesses’ credibility is the unique function of the trier of fact.”)

With respect to the trigger thumb condition, the compensation judge accepted the opinion of Dr. Husband that this condition is commonly idiopathic and determined that the employee failed to sustain her burden that her condition was related to her work activities.  The compensation judge’s conclusion that the employee failed to establish causation was reasonable, whether for a new injury or an aggravation of a pre-existing injury.

The employee argues that the opinion of Dr. Husband lacked adequate factual foundation because Dr. Husband assumed the employee’s job did not require any forceful gripping or pinching and did not involve hard or sharp edges pressing down on the flexor sheaths in her hands.  The employee testified at the hearing that she used a utility knife to break down pallets and had to lift boxes weighing up to 60 pounds which pressed on her flexor sheaths.  Dr. Husband took a history from the employee and reviewed the employee’s deposition transcript regarding the onset of the employee’s symptoms.  He recorded her description of breaking down freight as requiring the employee to reach and move boxes and place shrink wrap around each pallet.  Dr. Husband noted her description of operating a forklift as using her left hand to steer the wheel and her thumbs to work the horn, and her thumbs and finger to move three different levers.  He indicated that she did not use hand tools.  Although he concluded the work activities were not a substantial contributing factor to the bilateral trigger thumb condition, he added that if work required the use of tools with hard or sharp edges which press down on the flexor sheaths, then this is could be a contributing factor to trigger finger or trigger thumb.  The employee contends that using a utility knife tool and carrying boxes with edges pressing on the flexor sheaths satisfied Dr. Husband’s causation opinion and because Dr. Husband’s opinion is based on an erroneous assumption to the contrary, the employee argues that his opinion is not reliable.

A compensation judge’s decision to adopt the opinion of an expert must be upheld if the opinion has adequate foundation.  Mattick v. Hy-Vee Foods Stores, 898 N.W.2d 616, 621, 77 W.C.D. 617, 624 (Minn. 2017).  The foundation for an expert’s opinion is not adequate if the opinion does not include the facts upon which the expert relied in forming the opinion, it does not explain the basis for the opinion, or the facts assumed by the expert in rendering the opinion are not supported by the evidence.  Id.  The expert need not be provided with every possible fact, only enough to form a reasonable opinion.  Gianotti v. Indep. Sch. Dist. 152, 889 N.W.2d 796, 77 W.C.D. 117 (Minn. 2017).  Here, the employee challenges the foundation of Dr. Husband’s opinion on the basis that the facts assumed by the expert are not supported by the evidence.  We disagree.

It is the employee’s burden to prove her claim.  See Minn. Stat. § 176.021, subd. 1.  Over the course of her claim, the employee had described a number of ways her thumbs may have been injured.  She initially claimed the thumb injury was related to her full-time work at the circuit board manufacturing company.  When that employer denied her claim, she made a report at Menards.  She testified at her deposition, which was reviewed by Dr. Husband, that she injured her thumbs breaking down freight.  During his independent examination, Dr. Husband took a history from the employee.  He reported that she said her injury related to breaking down freight and pushing the buttons on the forklift.  The employee’s testimony describing how she broke down freight differed than what was recorded by Dr. Husband.  We conclude that the opinion of Dr. Husband was based upon enough facts to form a reasonable opinion, and is not based upon speculation or conjecture.  See Gianotti, 889 N.W.2d at 802, 77 W.C.D. at 124.  Furthermore, Dr. Husband’s conclusion was consistent with the employee’s own medical expert, Dr. Curtis, who similarly opined that the employee’s work was not a substantial contributing factor to the trigger thumb condition.  It was reasonable for the compensation judge to assign greater weight to the medical experts’ opinions than to the employee’s testimony.

Findings of fact should not be disturbed, even though the reviewing court might disagree with them, “unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of evidence or not reasonably supported by the evidence as a whole.”  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).  Because the weight of the evidence does not support the employee’s claim, we will not disturb the compensation judge’s decision and, accordingly, affirm.