TERRY M. ZEIMET, Employee/Appellant, v. METRO. COUNCIL ENVTL. SERVS. and METRO. COUNCIL, SELF-INSURED, Employer/Respondent, and SUPER CYCLE and CNA INS. CO. d/b/a VALLEY FORGE INS., Employer-Insurer/Respondent, and ABBOTT NW. HOSP., TWIN CITIES SPINE CTR., and MINN. DEP’T LABOR & INDUS./VOC. REHAB. UNIT, Intervenors.

The employee appeals from the compensation judge’s determination that he did not sustain a Gillette injury to his cervical spine while employed by the self-insured Metropolitan Council (hereinafter “Metro Transit”). We affirm.

On November 30, 1993, while in the employ of Super Cycle, Inc., insured by CNA Ins. Co. (hereinafter “Super Cycle”), the employee sustained an injury to his cervical spine when throwing cardboard into a truck while collecting curbside recycling. Therapy and injections did not resolve his symptoms. An MRI showed a right-sided disc herniation at C5-6 and fusion surgery was ultimately recommended by Dr. Timothy Garvey. On July 12, 1994, the employee underwent an anterior cervical decompression with discectomy and foraminotomy and anterior fusion at C5-6. Thereafter, the employee saw some reduction in symptoms, but continued to have pain and to need work restrictions. In the few years following the fusion surgery, Dr. Garvey repeated concerns about the employee’s work as a semi-truck and/or school bus driver and the risks related to whole body vibration and associated potential increase in cervical degeneration. In 1997, Dr. Garvey saw the employee for follow-up and noted that the employee was possibly developing early adjacent segment stenosis.

In 1996, the employee entered into a stipulation for settlement, which settled his claims related to the November 30, 1993, injury on a full, final, and complete basis, with the exception of reasonable and necessary medical expenses related to the work injury.

In October 1999, the employee began working for Metro Transit as a bus driver. In August 2006, he began operating a light rail train. The employee testified that while driving the train, he would experience jolting at particular places on the track and in certain weather conditions.^[1] The operator seat adjusted up and down and was padded, but was not an air-ride and did not bounce. He further testified that coming into or leaving a station required turning his head to look at either mirrors or monitors, depending on the type of train he was operating.

Subsequent to his 1994 fusion surgery and related follow-up, the employee did not seek medical treatment for ten years. He considered his 1994 fusion surgery to have been successful and had no symptoms following the surgery other than stiffness. The employee testified that his symptoms got progressively worse while working for Metro Transit.

On September 29, 2008, the employee presented to Dr. Garvey with complaints of neck and left arm pain that began months prior. X-rays showed spondylosis at the C6-7 level. Dr. Garvey recommended an MRI for likely nerve root compression as a result of adjacent segment process, which he believed was due in part to the employee’s previous work injury. An October 21, 2008, MRI scan revealed a disc herniation at C6-7 with moderate bilateral foraminal stenosis. A nerve root injection was administered which the employee found helpful. Dr. Garvey considered the employee to be a candidate for revision surgery. In a letter dated January 9, 2009, Dr. Garvey again opined that the prior work-related injury and 1994 fusion were contributing factors to the new disc herniations and degenerative changes. It appears that the employee did not treat for neck symptoms again until he requested and underwent another nerve root injection in December 2009. He reported that this injection caused more arm pain and did little to improve his symptoms overall. In February 2010, Dr. Garvey recommended non-operative care for the neck and upper extremity symptoms, but stated that surgery was an option should the employee be unable to tolerate his symptoms.

The employee next saw Dr. Garvey on April 29, 2013 with reports of increased difficulties with his neck, especially with rotation. According to the note, the employee’s pain was worst in the mornings but would improve with a shower. Dr. Garvey stated that surgery was an option should the employee’s symptoms deteriorate, but cautioned that it would be in the form of a multi-level fusion that would restrict motion and affect employment.

On September 8, 2014, the employee was seen by Dr. John Kipp at Minnesota Occupational Health for an evaluation of numbness and ‘electrical’ sensation in the left neck, shoulder, and arm. He reported that this had been occurring over the last ten to fourteen days and only when reaching to operate the controls of the railcar. Dr. Kipp opined that the symptoms were not related to the employee’s work at Metro Transit and referred him to return to Dr. Garvey.

The employee was seen by Dr. Garvey on October 15, 2014. He reported a flare up of left arm symptoms three weeks prior and stated that his symptoms increased after driving light rail for three hours. X-rays were performed and showed a solid C5-6 fusion, moderate spondylosis at C4-5 with loss of disc height, and retrolisthesis in extension that neutralized in flexion. Dr. Garvey recommended an MRI scan and expected pathology at the segments adjacent to the employee’s previous surgery, which he believed would be related to that surgery. A November 22, 2014, MRI showed minimal retrolisthesis with disc herniation at C4-5, moderate degenerative disc disease with disc herniation at C6-7, and disc protrusion at C3-4. According to Dr. Garvey, the C4-5 disc herniation was somewhat larger than before, and that with regard to the disc herniation, there was more contact with the cord than there had been in 2008. He again stated that surgery was an option. The employee testified that in 2014, his neck and shoulder pain were worse when operating the train at work.

On January 12, 2015, Dr. Garvey opined that an anterior cervical decompression and fusion was medically indicated at C4-5. Dr. Garvey believed that the 1993 injury was a significant factor in adjacent segment degeneration and that the employee’s current need for surgery was related to the 1993 injury. On February 13, 2015, the employee underwent an anterior fusion of levels C4-6. Following the surgery, the employee did not have a full resolution of symptoms. At the time of the hearing in this matter, he testified to feeling stable, but with pain shooting on both sides of his neck, as well as stiffness.

In the approximate six months following the employee’s C4-6 fusion surgery, Dr. Garvey repeated a recommendation that the employee minimize whole body vibration. He issued a narrative report dated February 28, 2015, wherein he stated that the 1993 injury and subsequent fusion at C5-6 placed an increased risk of degenerative change at the adjacent segments. He went on to state that the employee’s work activities as a light rail operator were a significant factor leading to a Gillette injury because whole body vibration is an increased factor for degenerative change. However, in correspondence to the employee’s QRC dated April 9, 2015, Dr. Garvey stated that while the employee should minimize whole body vibration in order to return to driving, he was not able to expound effects of whole body vibration caused by light rail specifically, as he was only aware of the effects from truck driving and railroad.

Dr. Garvey issued a follow-up narrative report dated October 17, 2015. Therein, Dr. Garvey definitively opined that the employee’s work-related activities driving bus and light rail accelerated the underlying risk factor of developing progressive degenerative change.

At the request of Super Cycle, Dr. David Florence saw the employee for an independent medical examination. In his report, Dr. Florence opined that the whole body vibration phenomenon the employee experienced while driving bus and light rail was a substantial contributing factor in the development of a Gillette injury to the cervical spine, which culminated on September 28, 2008. Dr. Florence was of the opinion that this was a permanent aggravation of the cervical spine condition accelerated by the employee’s work activities, and that the employee should no longer drive truck, bus, or a rail transit vehicle. Dr. Florence further opined that the employee’s disability from this type of work was equally apportioned between his November 30, 1993, injury at Super Cycle and the September 28, 2008, Gillette injury at Metro Transit.

At the request of Metro Transit, the employee was seen for an independent medical examination by Dr. Brian Konowalchuk on July 28, 2015. It was Dr. Konowalchuk’s opinion that the employee’s need for the 2015 fusion surgery was the result of inevitable progression due to everyday stressors, and that the employee would have needed the 2015 fusion surgery regardless of the 1994 fusion surgery, though the 1994 fusion surgery slightly increased his risk. It was his opinion that the employee’s work activities as a light rail operator were not a relevant factor in his progression.

Also submitted by Metro Transit was a Talas Engineering report, completed by mechanical engineering expert, Elaine Serina, Ph.D., P.E. In July 2015, inspections and vibration testing were conducted of the light rail vehicles on routes similar to those taken by the employee while an operator. The employee’s deposition testimony, select medical records, and various train operation documents were reviewed. Based upon vibration measurements taken, it was Dr. Serina’s conclusion that the whole body vibration exposure in a light rail vehicle is comparable to or less than that experienced in other vehicles, including cars, trucks, boats, and buses. She cited a critical review study that concluded the epidemiologic data was insufficient to provide support for the relationship between vibration and neck disorders. Based upon her testing, she found that the vibration levels of the light rail vehicle were well below the lower limit of the health guidance caution zones articulated by the international technical standard. Dr. Serina also noted that scientific research literature does not clearly document or objectively observe health effects of vibration at levels similar to those found in her testing of the light rail vehicles.

This matter came on for hearing on October 21, 2015, on the employee’s claim petition and a petition for contribution filed by Super Cycle. At issue was whether the employee sustained a Gillette injury to his cervical spine on or about September 28, 2008, and/or September 8, 2014, while in the employ of Metro Transit, to which date of injury his medical expenses were causally related, the employee’s entitlement to temporary total disability benefits and vocational rehabilitation benefits, apportionment, notice of the September 28, 2008, claimed injury, Super Cycle’s right to reimbursement, the right to reimbursement of the intervenors, and whether claims of some medical providers should be extinguished.

In her Findings and Order issued December 18, 2015, Compensation Judge Stacy Bouman declined to find that the employee sustained a Gillette injury while employed by Metro Transit, either on September 28, 2008, or September 8, 2014. She then denied the employee’s claim for temporary total disability and vocational rehabilitation benefits, and concluded that the employee’s medical treatment was causally related to the November 30, 1993, work injury sustained at Super Cycle. The employee appeals the denial of his claim.

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).

The employee appeals the compensation judge’s determination that he did not sustain a Gillette injury as a result of his work activities at Metro Transit. The employee claims that the compensation judge held him to an inappropriately high burden of proof with respect to establishing causation between whole body vibration and his cervical spine condition and need for surgery. We disagree.

The employee is correct in stating that application of the preponderance of the evidence standard was required in considering his claim. “Preponderance of the evidence means evidence produced in substantiation of a fact which, when weighed against the evidence opposing the fact, has more convincing force and greater probability of truth.” Minn. Stat. § 176.021, subd.1a. The employee argues that the compensation judge held him to a higher burden of proof than the preponderance of the evidence standard, thereby committing legal error. In support of his argument, the employee points to language used by the compensation judge in her Findings and Order. Therein, she outlined the report of Dr. Serina of Talas Engineering. In summarizing Dr. Serina’s conclusions, the compensation judge stated, “Dr. Serina further noted that the causal relationship between whole-body vibration and spinal disorders has not been clearly established.” The employee asserts that the compensation judge’s use of “clearly established” demonstrates that the compensation judge applied a burden of proof higher than the preponderance of evidence standard. It is his position that with regard to the issue of causation, a clear and convincing standard was applied.

Upon review of the evidence, the compensation judge’s use of “clearly established” appears to have been directly lifted from the report of Dr. Serina, where Dr. Serina cites to a critical review that showed that epidemiologic data was insufficient to provide support for a relationship between vibration and neck disorders. Dr. Serina stated, “[v]ibration has been identified as one of many risk factors for spinal problems, but the causal relationship between whole-body vibration and spinal disorders has not been clearly established.” It was this statement from the report which the compensation judge summarized in her Findings and Order.

The compensation judge found that the employee did not sustain a Gillette injury as a result of his work activities at Metro Transit, stating, “[t]he preponderance of the evidence fails to establish the employee sustained a Gillette-type work injury culminating in disability on or about September 28, 2008, and/or September 8, 2014.” In her supporting memorandum, the compensation judge states, “[t]he preponderance of the evidence failed to support a finding that the employee’s work as a bus driver and/or light rail driver for the Metropolitan Council was a substantial contributing factor in his cervical spine condition and ultimate need for surgery.” A reading of the compensation judge’s findings and supporting memorandum in their entirety shows that her citation to one of Dr. Serina’s conclusions and her use of the term “clearly established” was not reflective of the standard of proof to which the employee was held. Rather, as is outlined in her supporting memorandum, the compensation judge considered not only the report and conclusions of Dr. Serina, but also the opinions of Drs. Garvey and Florence and their acknowledged inability to address the effects of whole body vibration in light rail trains as opposed to other types of vehicles.

The employee further argues that had the compensation judge applied the preponderance of the evidence standard, the weight of the evidence would have required a finding that the employee experienced whole body vibration while working for Metro Transit and that the same is causally connected to his cervical spine condition and 2015 fusion surgery. Specifically, the employee relied upon the February 28, 2015, and October 17, 2015, opinions of Dr. Garvey to establish a causal connection.

Substantial evidence in the record supports the compensation judge’s determination that the employee did not sustain a Gillette injury while employed by Metro Transit. When Dr. Garvey saw the employee in 2008, a number of years had passed since his 1994 fusion surgery. At that time, Dr. Garvey stated that while not the sole cause, the 1993 work injury was related to the employee’s current condition. Dr. Garvey was aware of the employee’s employment as a light rail operator and was seeing the employee upon referral from Dr. Kipp. Yet, Dr. Garvey did not mention those work activities or possible whole body vibration as being a cause. Dr. Garvey did not make that connection until his narrative report dated February 28, 2015. Even so, in a letter to the employee’s QRC less than two months later, Dr. Garvey qualified his earlier opinion in that he was only familiar with the effects of whole body vibration from trucks and railroad, and could not speak to light rail trains. Similarly, Dr. Florence opined that the employee experienced whole body vibration as a light rail operator and that his current condition is causally related to the same. However, Dr. Florence’s expertise is limited to driving truck. Finally, the compensation judge found the opinions of Dr. Konowalchuk to be more persuasive than those of Dr. Garvey. A compensation judge’s choice of expert is affirmed so long as the accepted opinions have adequate foundation. Smith v. Quebecor, 63 W.C.D. 566 (W.C.C.A. 2003) (citing Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985)). The employee does not contend that the opinions of Dr. Konowalchuk lack foundation, nor would the evidence in the record support such a position.