CAUSATION – SUBSTANTIAL EVIDENCE. Substantial evidence, including expert medical opinion, medical records and the employee’s testimony, supports the compensation judge’s findings that the employee’s 2014 and 2015 work injuries were substantial contributing factors to the employee’s disc herniation and need for treatment.
Compensation Judge: Stephen R. Daly
Attorneys: Caroline Bell Beckman, Erickson, Bell, Beckman & Quinn, P.A., Roseville, Minnesota, for the Respondent. Timothy S. Crom, Jardine, Logan & O’Brien, P.L.L.P., Lake Elmo, Minnesota, for the Appellants.
Affirmed.
GARY M. HALL, Judge
The employer and insurer appeal from the compensation judge’s findings that the employee’s admitted work injuries on July 21, 2014, and March 16, 2015, were substantial contributing factors to his L5-S1 disc herniation and associated medical treatment. We affirm.
The employee was born in 1986 and is currently 30 years of age. He started working for the employer, St. Paul Linoleum & Carpet, in 2005 as a materials handler and truck driver. His job involved delivering carpeting, carpet tile, vinyl and linoleum, and carpet-laying supplies.
The employee’s medical history shows that he treated briefly with a chiropractor, Dr. Daniel Olien, for each of a few incidents of low back pain in 2004, 2007, 2008, and 2010, usually after playing softball or hockey. In 2012, the employee sustained a work injury to the low back when he felt a pull in his back while unloading carpet from a van. He treated briefly with Dr. Olien and recovered quickly with no time lost from work.
On July 21, 2014, the employee again sustained an admitted low back injury while lifting a roll of carpet. He was seen at Olien Family Chiropractic that same day complaining of low back pain along with tingling in the toes of his right foot but no leg pain. The employee testified that after two months of chiropractic treatment he made a good recovery from that injury, with no ongoing symptoms.
The employee sustained a further admitted low back injury on March 16, 2015. On that date, the employee was unloading a 6' 7'' tall roll of vinyl weighing about 400 pounds. The roll was on its end, and to get it out of the truck he had to rock and twist the roll, walking it to the back of the truck. While he was doing this, the roll began to tip over and he twisted to the right and tried to catch it. He felt a pop and experienced immediate low back pain. He left work and went for medical treatment.
He was seen that same day for back pain by James Stowell, M.D., at the Urgency Center complaining of back pain which started while he caught a heavy roll of vinyl while twisting. Examination showed mild right lumbar soft tissue tenderness but no spasm. His neurologic examination was normal. He was prescribed ibuprofen and Flexeril.
The employee returned to his chiropractor on March 19, 2015. He gave a history of right lower back pain that started when he was working with a heavy roll of vinyl. His pain was localized to the right lower back, right SI joint, and right hip. The employee continued regular treatment with his chiropractor for 17 visits between March 19 and June 15, 2015. Chart notes during April and May noted pain below the belt line on the right side whenever he stepped while walking. He was given work restrictions to avoid bending, lifting, and twisting, and was advised to regularly ice his back.
The employee initially was restricted to light duty but returned to full duty work about two weeks after the injury. He continued to ice his back at home and take ibuprofen. He testified that his symptoms gradually improved, although he continued to experience ongoing symptoms in the low back both above and below the belt line.
On June 15, 2015, Dr. Olien noted that the employee continued to improve, although he still had mild soreness/stiffness on waking. Dr. Olien felt that the employee needed to continue to work on posture and to strengthen his lower back. He released him from treatment, recommending he use ice as needed at home. Dr. Olien recorded that he would “give him a couple of weeks before closing the claim in case he has any setbacks.” The employee testified that he did not feel fully recovered on that date, but that he and the doctor had decided to halt treatment for a week and see how the employee felt. The employee testified that he continued to notice pain and continued to ice his back following that visit.
According to the employee’s testimony, he noticed increased pain while getting into and out of his truck at work on June 23, 2015, and later that day started to have “a little tingling in my right foot.” He did not associate this with any new incident. He was able to work at his regular duties the following day, Wednesday, June 24, 2015.
On Wednesday evening, the employee was scheduled to play in a softball game after work. He admitted on cross-examination that he went wearing his team jersey and brought his glove along. However, he testified that by the time he showed up to the game his right leg had become numb, and he did not play. That evening, he could not sleep due to pain in his lower back and down his right leg.
At about 4:30 a.m. on the following morning, June 25, the employee went to the emergency room at Westfields Hospital for severe back pain radiating into his right leg with right leg tingling. An MRI of his lumbar spine was read as showing a “degenerative disc extrusion on the right at L5-S1.” The employee was placed on light duty restrictions and provided with medications. The chart notes record that his symptoms “were precipitated by no known etiology” and with no specific activity, lifting, or trauma at the time of onset.
On June 25, 2015, the employee also followed up with Dr. Olien, his chiropractor, and described the flare up of his lower back as “[h]e started to feel discomfort Tuesday 6/23/15 and pain got worse last night. He states he now has pain shooting down his posterior right leg with tingling into his toes. He states he was up all night with pain and went to the ER today.” (Ex. H.)
The employee returned to the Westfields Hospital on June 29, 2015. He continued to have shooting pain into his right leg along with low back pain. His neurologic examination was unremarkable. He was given a Medrol Dosepak.
The employee also had some additional chiropractic treatment at Olien Family Chiropractic, with his last treatment taking place on June 30, 2015. He testified that the chiropractic adjustments did not provide much help and he continued to experience pain radiating down the right leg.
On July 6, 2015, the employee followed up at Westfields Hospital for sciatica and right foot drop. An MRI of the lumbar spine on July 10, 2015, showed a right-sided disk herniation at L5-S1 with a sequestered fragment causing nerve root impingement on the right.
On July 14, 2015, the employee was seen by Donna M. Koning, M.D., a neurologist at Stillwater Medical Group, who diagnosed L5 radiculopathy with right foot/leg weakness and right foot numbness. Dr. Koning recommended surgical decompression and referred the employee for a surgical consultation.
The employee was seen by Bruce Bartie, D.O., on July 16, 2015 at St. Croix Orthopaedics. Dr. Bartie recommended an L5-S1 discectomy. On August 7, 2015, the employee underwent a right sided L5-S1 microdiskectomy and excision of a disk fragment at High Pointe Surgery Center.
The employee was off work for several months following the surgery, during which time he received follow-up care with St. Croix Orthopedics and OSI Physical Therapy. The employee indicated that the surgery completely relieved his right foot weakness and right leg pain. He ultimately returned to work full time with a 50-pound lifting restriction.
On December 10, 2015, the employee was seen by Paul T. Wicklund, M.D., for an examination at the request of the employer and insurer. Dr. Wicklund’s diagnosis was of a right L5-S1 disk herniation, status-post laminectomy and disc excision with a good result. However, Dr. Wicklund opined that this problem was unrelated to either the July 21, 2014, or March 16, 2015, dates of injury. He considered the July 21, 2014, work injury to have been a low back strain which had fully resolved within six weeks based on the employee’s ability to return to work without restrictions. He considered the March 16, 2015, work injury to have also resulted only in a low back strain, based on the employee’s improvement and the absence of other symptoms than mild back soreness as of June 15, 2015, when his chiropractor had released him from care. In his view, the disk herniation seen on the MRI scan of July 10, 2015, had come on spontaneously without any specific trauma somewhere around June 23rd to 25th, and was consistent with the effects of degenerative disc disease at L5-S1 leading to an annular tear and ultimate disc herniation. Because there were no signs of disc herniation at the time of the March 2015 work injury, Dr. Wicklund concluded that it was unrelated to that injury.
Dr. Bartie provided a letter opinion, dated September 22, 2015, in which he expressed the opinion that both the 2014 and 2015 work injuries substantially contributed to the employee’s disc herniation and need for surgery. He noted that disc herniations often start with an internal tear which does not produce radicular symptoms until it progresses through the layers of the annulus peripherally to the outside. In his view, the final onset of radiculopathy is frequently insidious and occurs without additional trauma.
In a supplemental letter opinion dated November 10, 2015, Dr. Bartie stated that he had now reviewed the employee’s prior chiropractic records showing earlier treatment for low back conditions, after each of which the employee had shown substantial improvement. He considered these to have been typical musculoskeletal complaints and wrote that these records did not change his opinion regarding causation for the employee’s disc herniation or surgery. Dr. Bartie wrote a further supplemental letter opinion dated February 3, 2016, after having reviewed the report of Dr. Wicklund. He wrote that nothing in that report had changed his opinion regarding causation.
Relying on the opinion of Dr. Wicklund, the employer and insurer denied liability for medical treatment subsequent to June 15, 2015, the date by which they contend the employee’s injuries had resolved. On May 13, 2016, a hearing was held before a compensation judge of the Office of Administrative Hearings to determine the nature and extend of the 2014 and 2015 work injuries and whether the medical treatment after June 15, 2015, was causally related to those injuries. The parties stipulated that, should the medical treatment be found causally related, it was reasonable and necessary treatment. Following the hearing, the judge found that the employee’s work injuries of July 21, 2014, and March 16, 2015, were substantial contributing factors to the employee’s herniated disc at L5-S1 and that the claimed treatment expenses were causally related to these work injuries. The employer and insurer appeal.
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 central issue in this case was whether the employee’s admitted personal injuries to the low back on July 21, 2014, and March 16, 2015, were merely temporary, as opined by Dr.Wicklund, or were substantial contributing causes to the employee’s L5-S1 herniated disc as asserted by Dr. Bartie.
The employer and insurer argue that the timing of the employee’s symptoms suggest that the two admitted work injuries were not a substantial contributing cause of the employee’s disc herniation. They argue that the 2014 work injury could not be a contributing cause of the employee’s disc herniation in that the employee did not complain of radicular symptoms while treating for the 2014 work injury, his symptoms resolved after about two months of treatment, and he was able to return to work without restrictions within about two weeks of the injury. As to the 2015 work injury, they point out that the employee again did not initially have radicular symptoms immediately after the injury, had returned to work, and had shown a significant improvement in his symptoms to merely minor low back pain by June 15, 2015, such that his chiropractor was planning at that time to discontinue further treatment. They further note that the employee showed no radicular symptoms until about June 25, 2015.
The employer and insurer argue that, under these facts, the compensation judge should have accepted the opinion of their medical expert, Dr. Wicklund, who opined that, in the absence of signs of disc herniation in the medical records directly following either work injury, the employee’s disc herniation at L5-S1 was not related to those injuries, but instead came on spontaneously without any specific trauma somewhere around June 23rd to 25th from the effects of pre-existing degenerative disc disease at L5-S1 leading to an annular tear and ultimate disc herniation. Based on this evidence, the employer and insurer argue that the employee failed to meet his burden of proof that the disc herniation was related to either of his work injuries.
In his memorandum, however, the compensation judge noted that he had considered various factors bearing on the nature and extent of an injury set forth in Wold v. Olinger Trucking, slip op. (W.C.C.A. Aug. 29, 1994). The timing and nature of the employee’s symptoms are among those factors. However, the judge noted further aspects of the evidence which the judge found significant to his decision. These included the absence of ongoing low back symptoms prior to July 21, 2014; the nature of the March 16, 2015, work injury, which involved a sudden jarring movement with a 400-pound roll of vinyl and which resulted in an immediate onset of significant symptoms; the fact that the employee had constantly experienced low back symptoms after the 2015 work injury. The judge further noted that “the employee testified credibly regarding his work injuries and ongoing symptoms.” The judge stated that in light of those factors, he had accepted Dr. Bartie’s causation opinion as more persuasive that of Dr. Wicklund. (Mem.at 9.)
Resolution of conflicting medical expert opinion is the responsibility of the compensation judge, and the trier of fact’s choice between medical experts must be upheld so long as there is adequate factual foundation for the opinion accepted by the judge. See Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985). Dr. Bartie took a history from the employee, reviewed the employee’s MRI scan, personally examined the employee, and provided treatment to the employee for his back condition. As a general rule, this level of knowledge establishes a doctor’s competence to render an expert opinion. See Grunst v. Immanuel-St. Joseph Hosp., 424N.W.2d 66, 68, 40 W.C.D. 1130, 1132-33 (Minn. 1988).
The employer and insurer argue in their reply brief that Dr. Bartie’s opinion was defective in that the doctor “did not provide any medical opinion as to how or why the 2015 work injury would have contributed to or caused that internal tear and peripheral progression.” (Reply Brief at 10.) We note, however, that a failure to explain the mechanism of the injury or the underlying reasons for the opinion may go to the persuasiveness or weight that may be afforded the opinion by the compensation judge, but does not render the opinion without foundation. See, e.g., Goss v. Ford Motor Co., 55 W.C.D. 316 (W.C.C.A. 1996); Simons v. Ridgeview Med. Ctr., No. WC06-211 (Dec. 1, 2006); Midtling v. Schwan’s Sales Enters., slip op. (W.C.C.A. Sept. 22, 2003); Darnick v. Swett & Crawford, slip op. (W.C.C.A. Oct. 29, 2002). We, accordingly, conclude there was adequate foundation for Dr. Bartie’s opinion.
In addition to medical opinions, a judge may base his or her conclusions on other reliable evidence in the record. See Reimer v. Minnit Tool/M.I.T. Tool Corp., 520 N.W.2d 397, 51 W.C.D. 153 (Minn. 1994). The judge’s decision here was also based on the credibility of the employee’s testimony as to the continuity and nature of his symptoms over time. The employee is most familiar with the severity of his or her symptoms, and the judge did not err by relying on that testimony. See Brening v. Roto-Press, Inc., 306 Minn. 562, 237 N.W.2d 383, 28 W.C.D. 225, (Minn. 1975).
The appellants, however, argue that the compensation judge erred in accepting the employee’s testimony as credible. They contend that the employee’s testimony should have been discounted as self-serving. In particular, they point to the fact that the employee attended a softball game shortly before he went to the hospital with the onset of radicular symptoms. Although the employee testified that he only watched the game, and did not play, the appellants suggest that the employee’s testimony should not have been credited, especially in light of his admission that he had worn his jersey and brought along his glove and cleats. They further point to some discrepancies between the employee’s testimony and the phrasing of a few medical records. They ask that this court overturn the compensation judge’s acceptance of the employee’s testimony as credible.
We note that the assessment of a witness’s credibility is held to be the unique function of the trier of fact. See Brennan v. Joseph G. Brennan, 425 N.W.2d 837, 839-40, 41 W.C.D. 79, 82 (Minn. 1988) (citing Spillman v. Morey Fish Co., 270 N.W.2d 781, 31 W.C.D. 187 (Minn. 1978)); see also Hatch v. Langhoff Enters., No. WC09-195 (W.C.C.A. Jan. 25, 2010). It is not the role of this court to evaluate the credibility and probative value of witness testimony and choose different inferences from the evidence than the compensation judge. See Krotzer v. Browning-Ferris/Woodlake Sanitation Serv., 459 N.W.2d 509, 513, 43 W.C.D. 254, 260-61 (Minn. 1990); Redgate v. Sroga’s Standard Serv., 421 N.W.2d 729, 734, 40 W.C.D. 948, 957 (Minn. 1988).
The employer and insurer point out that it was only in the compensation judge’s memorandum that the judge mentioned his acceptance of the employee’s testimony as credible. They argue that this distinguishes this case from others in which we deferred to a judge’s credibility determinations, and that this court should review witness credibility de novo in the absence of a formal finding on credibility. We note that we have previously given the same deference to a judge’s implicit credibility determination despite the absence of a formal finding on credibility. See, e.g., Linder v. Regis Corp., No. WC13-5561 (W.C.C.A. Aug. 29, 2013). We continue to see no reason to apply a different standard of review based merely on whether the judge’s acceptance of witness testimony as credible was or was not embodied in a specific formal finding.
The compensation judge’s findings were supported by substantial evidence, and we affirm.