LISA J. MANTY, Employee/Appellant, v. MINER’S, INC., and SFM RISK SOLUTIONS, Self-Insured Employer/Respondent, and N. MINN.-WIS. AREA RETAIL FOOD HEALTH AND WELFARE FUND, ESSENTIA HEALTH, and CLOQUET CMTY. MEM’L HOSP., Intervenors.

The employee appeals the compensation judge’s determination that she did not sustain a work-related specific or Gillette injury to her low back on August 13, 2021.  We affirm.

Lisa Manty, the employee, started working for the self-insured employer, Miner’s, Inc., in 1983.  On December 21, 1988, the employee injured her low back while twisting to lift a case of candy.  (Ex. A.)  The employee treated with chiropractor Dr. John Benson for the injury beginning on January 10, 1989.  Dr. Benson diagnosed the employee with an acute traumatic lumbar sprain-strain with discogenic nerve root compression resulting in bilateral hip pain.  The employee received treatment from Dr. Benson until discharged from care on March 29, 1989.  At discharge, the employee was released to return to work without any ratable permanent partial disability.  (Ex. P.)

The employee returned to work for the employer as a cashier.  In 2017, the employee began working as a wrapper in the employer’s meat department, and in August 2019, she began training as an apprentice meat cutter.  The physical requirements for working in the employer’s meat department included carrying up to 50 pounds continuously, 51 to 74 pounds frequently, and up to 100 pounds occasionally.  The position also required continuous lifting up to 34 pounds and frequent lifting up to 100 pounds.  (Ex. I.)  As a meat cutter, the employee used a grocery cart to move boxes of meat from the cooler to her work area.  Once in the work area, the employee would remove meat from the boxes and cut or grind it.

On March 11, 2021, the employee saw Dr. Victoria P. Heren at Community Memorial Health (CMH) Raiter Family Clinic for her annual physical examination.  The medical record from that day notes that the employee had left-sided sacroiliac (SI) joint dysfunction, chronic back pain, and osteoarthritis involving multiple joints, for which she had been prescribed a nonsteroidal anti-inflammatory.  The record also indicates that the employee intended to try chiropractic treatment for her SI joint dysfunction.  (Ex. E.)

The employee returned to Dr. Benson for assessment of her chronic left-sided low back pain on March 15, 2021, reporting recent worsening of her symptoms.  On examination, the employee’s lumbar range of motion was decreased and degenerative disc changes were noted at L5-S1.  Dr. Benson diagnosed a segmental and somatic dysfunction of the sacral region with muscle spasm.  The employee received chiropractic care from Dr. Benson until April 8, 2021. (Ex. G.)

On Friday, August 13, 2021, the employee lifted a box of pork weighing between 90 and 120 pounds at the beginning of her shift.  She testified that when she moved the box a couple of feet, she felt a strange discomfort in her lower back.  The employee completed her shift without any change in her work activity and left work when her shift ended at 2:00 p.m.

After completing her work shift, the employee went home to plan and organize for a cabin vacation scheduled for the following week. She testified that initially she did not “know anything was wrong . . . until when the numbness started.”  (T. 79-80.)  Specifically, while shopping at Walmart on Sunday, August 15, 2021, the employee’s legs suddenly went numb.  The employee was able to complete her purchase and drive herself home.  The numbness continued, and on August 16, 2021, the employee was seen by Lisa Hay, an advanced practice registered nurse, in the CMH emergency department.  The employee stated that her legs began going numb the day before and gave a history of right-sided SI issues without prior numbness or tingling in her legs, for which she had been seeing a chiropractor.  The employee also reported that, four days before, she was lifting boxes of meat ranging from 60 to 80 pounds without pain.  Examination of the employee’s back, hips, and legs was normal with no evidence of injury or tenderness.  A CT scan of the employee’s lumbar spine demonstrated a normal lordotic curve, normal bulk and contour of the paraspinous muscles, normal height and hydration of the lumbar intervertebral discs, and congruent SI joints.  In addition, chronic bulging and endplate degenerative changes narrowed the neural foramina at L5-S1 with bilateral L5 ganglionic impingement.  (Ex. D).

The employee was referred to the emergency department at Essentia Health – St. Mary’s Medical Center (Essentia) for an MRI scan and further evaluation, where she treated later the same day.  There, she complained of a sudden onset of numbness down both legs starting a day earlier, and of chronic low back pain with sciatica on the left side, which was not a new issue.  The employee also reported that her discomfort started after lifting a 100-pound box at work and that a few days before, she had been painting her house, which required going up and down a ladder.  A lumbar spine MRI showed multilevel degenerative changes with disc bulging at L4-5 and L5-S1 and a left paracentral protrusion abutting the left S1 root sleeve with possible impingement.  These findings did not seem to explain the employee’s neurologic symptoms.  A thoracic MRI scan revealed multilevel discogenic disease but no cord pathology.

The employee was admitted to Essentia without a clear etiology for her symptoms. Comments in the employee’s records note that her degenerative lumbar spine disease was not considered severe enough to cause her reported symptoms.  On August 19, 2021, the employee was discharged from Essentia at her own request.  At discharge, the employee was provided with a letter stating she could not report to work until being evaluated by her primary care provider.

A first report of injury dated August 19, 2021, was the employer’s initial notice of the employee’s claimed injury.  The employee reported that the injury to her SI joint and low back occurred when she was lifting a box weighing 90-100 pounds.  The employee’s back was subsequently sore but she “didn’t think anything about it until [the] numbness started.”  (Ex. 11.)

The employee returned to Dr. Heren on August 26, 2021.  Dr. Heren recorded that the employee’s history included back pain, degenerative disc disease, degenerative joint disease, and sciatica, and that prior episodes of the employee’s leg pain and numbness had been treated by a chiropractor.  The employee told Dr. Heren that she had lifted a heavy box on August 13, 2021, which potentially hurt her back, and that a few days later, she had a sudden onset of numbness from the waist down with difficulty walking, for which she had sought medical care.  Dr. Heren assessed the employee with lumbar disc disease with radiculopathy, lumbar disc disorder with myelopathy, weakness of the lower extremities, and sacral plexus neuropathy.  (Ex. E.)

The employee returned to Dr. Benson for a chiropractic evaluation for her low back and leg symptoms on September 1, 2021.  (Ex. G.)  The employee reported she had a sudden loss of sensation in her perineum and lower extremities while shopping on August 15, 2021.  Evaluations at CMH and Essentia had failed to disclose a clear cause of the employee’s symptoms.  The employee stated that her leg symptoms were now 80 percent improved.  Dr. Benson diagnosed the employee with segmental and somatic dysfunction of the lumbar and sacral regions and muscle spasm of the back.  The employee continued treating with Dr. Benson.  At a visit on September 16, 2021, she reported continued numbness in her lower extremities but that she was not experiencing back pain.

On September 9, 2021, the employee asked Dr. Heren for a return-to-work note.  Dr. Heren returned the employee to work with lifting restrictions for the next four weeks.

On December 15, 2021, the employee was evaluated by Dr. Jacob Hvidston, a neurologist at Essentia.  The employee reported that she had lifted a 120-pound object at work before treating at Essentia and that she had continued bilateral lower extremity numbness following her discharge from Essentia in August.  An EMG and nerve conduction study was performed, which showed the employee had chronic left L3-4 radiculopathy and chronic right L5 radiculopathy. Dr. Hvidston considered the employee’s symptoms likely related to her lumbar spine degenerative disease.  He further noted that the EMG findings did not correlate with the employee’s symptoms or imaging.  He referred the employee to physical medicine and rehabilitation for treatment of her lumbar spine condition.  (Ex. F.)

The employee returned to Dr. Benson for chiropractic treatment on February 1, 2022, with complaints of left-sided low back tightness, soreness, and stiffness.  She reported that bending, standing, twisting, and working worsened her symptoms.  The employee treated with Dr. Benson on February 4, 7, 11, and 15, 2022.  At each visit, Dr. Benson diagnosed employee’s condition as segmental and somatic dysfunction of the lumbar and sacral regions and muscle spasm of the back. (Ex. G.)

On May 25, 2022, the employee filed a claim petition alleging injuries to the spine on December 21, 1988, and August 13, 2021.  The employee also asserted a possible “Gillette injury^[1] with an unknown culmination date.”  She sought wage loss, medical, and rehabilitation benefits associated with the alleged injuries.

The employee saw Dr. Heren for an annual physical examination on June 7, 2022, and complained of chronic low back pain, saddle numbness, and bilateral leg pain and numbness.  Upon examination, the employee had SI joint pain on palpation and lumbosacral radiculopathy at S1.  On June 21, 2022, the employee again returned to Dr. Heren, reporting that she had returned to work after a week off and that pain symptoms in the left SI joint had become severe by the end of her first day back at work.  Dr. Heren added chronic pain and sacroiliac joint dysfunction of left side to the employee’s previous diagnosis of lumbosacral radiculopathy at S1 and referred her for an SI injection.  The employee had further follow-ups with Dr. Heren on August 16, September 14, and October 14, 2022, for her ongoing low back pain and bilateral leg numbness and weakness.  At the August visit, the employee expressed frustration that there was as yet no definitive diagnosis that explained her symptoms.  Dr. Heren noted that the employee suffered from degenerative disc disease but that this did not explain her symptoms.

At the request of the employer, the employee was seen for an independent medical examination (IME) on September 27, 2022, by Dr. David Fey.  In his report dated October 11, 2022, Dr. Fey opined that the employee’s December 21, 1988, injury was a temporary lumbar sprain/strain which resolved without ongoing sequelae and stated that there was no reasonable medical basis to support that the employee has any complaint, condition, or diagnosis related to her 1988 or 2021 injuries.  Further, Dr. Fey concluded that the employee did not sustain a Gillette injury as a result of her work activity at the employer.  He noted that the etiology of the employee’s neurologic complaints did not fit any objective or anatomic orthopedic condition.  In his view, the employee’s degenerative spine disease and low back pain were pre-existing and unrelated to the claimed work injury on August 13, 2021.  Finally, Dr. Fey noted that, had the employee suffered a low back lifting injury on that day, her neurologic symptoms would have appeared acutely rather than spontaneously two days later.  (Ex. 1.)

At the request of the employee’s counsel, Dr. Heren issued a report dated October 12, 2022.  Dr. Heren opined that the medical care received by the employee was reasonable and necessary to evaluate her low back and leg numbness symptoms.  She stated that the employee would benefit from work restrictions based upon a functional capacity evaluation, and recommended the employee receive ongoing rehabilitation, including physical therapy and chiropractic treatment. Dr. Heren commented that the exact etiology of the employee’s symptoms had never been defined, making it difficult to determine a cause of her condition.  However, Dr. Heren suggested that because the employee’s symptoms occurred within days of a heavy awkward lift, that incident “may have substantially contributed to the onset of her current medical problems.”  (Ex. S.)  Dr. Heren also opined that the employee’s repetitive heavy lifting had contributed to her degenerative disc disease.

On October 19, 2022, the employee saw Bryan Hunter, a certified registered nurse anesthetist (CRNA), at CMH for complaints of chronic low back pain and perineal numbness.  He diagnosed the employee with “lumbago” of the lumbar region with sciatica.  He scheduled the employee for an epidural steroid injection at L5-S1, which was performed on November 16, 2022, and reduced the employee’s pain by 90 percent.  A second injection was done on June 7, 2023.  On July 7, 2023, CRNA Hunter provided an opinion at the request of the employee’s attorney.  He opined that the employee’s work activities at the employer more than likely contributed to her low back and bilateral leg symptoms and that the medical treatment received by the employee had been reasonable and necessary.  (Ex. T.)

The employee’s claims were heard by a compensation judge on February 12, 2024. The issues for determination listed by the judge at the hearing included: “Did the employee sustain a work-related injury to her low back on August 13, 2021?”  (T. 5).  Counsel for the parties agreed that this was a correct statement of that issue.  Following the hearing, the compensation judge determined that the employee did not sustain an injury on August 13, 2021, whether specific or Gillette.  In reaching this determination, the compensation judge found the employee’s testimony to be unreliable and adopted the opinions of Dr. Fey as persuasive.  The employee appeals, contending the decision is erroneous and unsupported by substantial evidence.

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 erred by failing to make findings as to whether the employee’s 1988 work injury contributed to the employee’s condition and by failing to sufficiently address or consider the employee’s detailed testimony regarding her job duties.  She also argues that the compensation judge erred in not adopting the opinions of Dr. Heren and CRNA Hunter over those of Dr. Fey, and that there is substantial evidence to support a finding of either a specific or Gillette work-related injury sustained or culminating on August 13, 2021.  We are not persuaded.

The employee’s claim petition lists her dates of injury as December 21, 1988, and August 13, 2021.  At the hearing, the compensation judge listed the issues being presented, including whether the employee sustained a work-related injury to her low back on August 13, 2021.  The judge did not mention the 1988 injury and the parties agreed that the statement of issues was correct.  In her opening statement, the employee’s attorney mentioned both dates of injury, but noted that one was the primary date at issue.  (T. 23.)  The employee agreed on cross-examination that she was not claiming that her condition was related to the 1988 injury and stated, “I would say it’s from [the] August 13th injury.”  (T. 122.)  The compensation judge did not err by failing to address an injury that was not raised as an issue to be determined at the hearing.

Regarding the employee’s contention that the compensation judge did not adequately address the employee’s job duties, our review of the testimony and the record shows that the compensation judge considered her testimony about her job duties and the physical aspects of her work during the decades she worked for the employer.  In the decision, the compensation judge specifically addressed the employee’s physical work and job duties, finding that her work as a meat cutter with the employer involved repetitive heavy lifting and required her to move and lift boxes of meat while twisting and turning.  Although the judge did not explicitly discuss the employee’s earlier work duties for the employer, as we have frequently stated, a compensation judge is not required to explicitly refer to or discuss all the evidence introduced at a hearing.  See Regan v. VOA Nat’l Housing, 61 W.C.D. 142, 149 (W.C.C.A. 2000), summarily aff’d (Minn. Apr. 6, 2001); see also Ruby v. Casey’s Gen. Store, 71 W.C.D. 535, 550 (W.C.C.A. 2011), summarily aff’d (Minn. Sept. 28, 2011); Lowell v. Lee Stamping, 63 W.C.D. 304, 308 (W.C.C.A. 2003), summarily aff’d (Minn. Apr. 29, 2003).

The employee also argues that Dr. Fey’s IME opinion lacked adequate factual foundation and should not have been adopted by the compensation judge.  In workers’ compensation cases involving medical causation issues, the employer and insurer may have the employee examined by a doctor of their choice.  See Minn. Stat. § 176.155, subd. 1.  An IME doctor establishes sufficient competence to render an expert opinion where the doctor has made an examination of the employee and has reviewed the employee’s relevant medical records and medical history.  Relying on this information, the IME doctor provides a medical opinion to the employer.   See Grunst v. Immanuel-St. Joseph Hosp., 424 N.W.2d 66, 68, 40 W.C.D. 1130, 1132-33 (Minn. 1988).  An employer’s attorney is allowed to rely on an IME doctor’s opinion and an employee’s medical records in defending against workers’ compensation claims.  “An expert opinion lacks adequate foundation when the opinion does not include the facts upon which the expert is relying in forming the opinion, there is no explanation of the basis for the opinion, or the facts assumed by the expert are not supported by the evidence.”  Erickson v. Grand Itasca Clinic & Hosp., No. WC21-6413 (W.C.C.A. Nov. 16, 2021) (citing Hudson v. Trillium Staffing, 896 N.W.2d 536, 540, 77 W.C.D. 437, 442 (Minn. 2017)).  Here, Dr. Fey examined the employee, reviewed her relevant medical records as requested by the employer, and had an adequate factual background for his opinion.  Therefore, his opinion does not lack foundation.

The employee argues that the compensation judge should have rejected Dr. Fey’s opinion because he did not reference all the medical records in his report.  She further argues that Dr. Fey’s examination and knowledge of the employee’s condition was not as comprehensive as that of her treating doctors, and thus should have been given less weight in deciding whether she had sustained a specific or a Gillette injury.  In the absence of Dr. Fey’s opinion, the employee asserts that the compensation judge should have found that she had sustained a specific or a Gillette injury based on the opinions of Dr. Heren and CRNA Hunter.

A Gillette injury is a result of repeated trauma or aggravation of a preexisting condition which results in a compensable injury when the cumulative effect is sufficiently serious to disable the employee from further work.  Gillette v. Harold, Inc., 257 Minn. 313, 101 N.W.2d 200, 21 W.C.D. 105 (1960).  To establish a Gillette injury, an employee must prove a causal connection between the employee’s ordinary work and the resulting disability.  Steffen v. Target Stores, 517 N.W.2d 579, 581, 50 W.C.D. 464, 467 (Minn. 1994).  The decision of whether an injury was caused by repetitive minute trauma from the performance of work-related duties is an ultimate question of fact for the compensation judge to determine.  Gunderson v. McNeilus Cos., 73 W.C.D. 401, 409 (W.C.C.A. 2013).  The determination of a Gillette injury depends predominantly upon medical evidence based on adequate foundation.  Steffen, 517 N.W.2d at 581, 50 W.C.D. at 467; see also Marose v. Maislin Transp., 413 N.W.2d 507, 512, 40 W.C.D. 175, 182 (Minn. 1987).  However, this determination is not solely dependent on medical testimony, and the judge should consider the nature and extent of the employee’s work duties in deciding whether those activities caused the disability.  Gunderson, 73 W.C.D. at 409.

It is the employee’s burden to establish a causal connection between the work activities and the ensuing disability.  The employee’s testimony alone is generally not sufficient to prove this connection.   Id.  While the employee’s testimony can be a factor, the compensation judge found the employee’s testimony was unreliable^[2] in this case and was insufficient evidence to demonstrate a connection under a Gillette injury theory.  Assessment of witness credibility is the unique function of the trier of fact and findings based on that assessment will generally not be reversed.  Brennan v. Joseph G. Brennan, M.D., P.A., 425 N.W.2d 837, 41 W.C.D. 79 (Minn. 1988); see also Tolzmann v. McCombs-Knutson Assocs., 447 N.W.2d 196, 198, 42 W.C.D. 421, 424 (Minn. 1989).

The compensation judge, as the trier of fact, has discretion in weighing medical evidence and in choosing between competing expert opinions.  Gianotti v. Indep. Sch. Dist. 152, 889 N.W.2d 796, 803, 77 W.C.D. 117, 126 (Minn. 2017); see also Schuette v. City of Hutchinson, 843 N.W.2d 233, 237, 74 W.C.D. 169, 173 (Minn. 2014).  When the opinion relied upon by the compensation judge has adequate factual support, this court will not reverse the compensation judge on that issue.  See Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985); Smith v. Quebecor Printing, Inc., 63 W.C.D. 566, 573 (W.C.C.A. 2003), summarily aff’d (Minn. Aug. 15, 2003).  The judge was not required to accept the diagnoses and impressions of Dr. Heren or CRNA Hunter over Dr. Fey’s medical opinion, which was based on adequate foundation and provides substantial evidence for the judge’s determination.  See Carda v. State of Minn./Dep’t of Human Servs., 79 W.C.D. 649, 655 (W.C.C.A. 2019).

In reviewing the submitted medical reports, the judge was not presented with any medical opinion that the employee’s low back condition in 2021 was related to the injury in 1988 nor attributable to work activities resulting in a Gillette injury culminating in August 2021.  The employee did not substantiate her Gillette injury claim with a corroborating medical opinion.  It was within the discretion of the compensation judge to rely on Dr. Fey’s opinion.  As noted above, Dr. Fey’s medical opinion was adequately founded, and the compensation judge did not err in adopting that opinion.

Substantial evidence supports the compensation judge’s finding that the employee’s work activities did not cause a work-related specific or Gillette injury sustained or culminating on August 13, 2021.  The compensation judge’s decision is affirmed.