The employee appeals the compensation judge’s finding that the preponderance of the evidence fails to show that the employee suffered a personal injury to his low back on April 7, 2014.  We affirm.

The employer Carley Foundry^[1] employed Charles Moore, the employee, beginning November 5, 2003.  The employee worked for the employer for 11 years before he claimed a work related injury on April 7, 2014, to his low back.  Describing the job as heavy, the employee claimed that he lifted multiple parts weighing 60 pounds and moved wheeled carts weighing in excess of 500 pounds.  The employee testified that he stands 6 feet 6 inches tall and weighs 345 pounds.

In 1999, a few years before the employee worked for the employer, he suffered a significant low back injury resulting in surgery with post-surgical complications.  He was medically released to work on October 6, 2000, with no restrictions.  The employee’s low back pain flared on multiple occasions, but no ongoing significant treatment of his low back occurred until April 2014 when he claimed a work-related low back injury.

In addition to the prior low back issues, the employee also developed foot pain which he believed was due to ill-fitting boots.  He wears a size 15 EEE.  Before the claimed work injury, multiple emails were sent describing the need to find better fitting boots.

On April 7, 2014, the employee reported to his supervisor that he had low back pain.  He completed an accident form and wrote that he attributed the pain to “wearing poor boots (too small) my left foot was hurting due to this, so I was favoring that leg and it effected by back now (sic).”  The employee’s supervisor Brent Bliese reported that “the employee has gout - and boots are too tight and making feet and back sore (sic).”  There is no reference on either form to any other activity the employee may have performed at work which resulted in low back pain.

The employee worked a full day on April 7, 2014.  He returned to work the next day and worked one hour.  Then he left work to seek medical treatment for his low back pain.  He saw Dr. Daryn Collins at Fairview Eagan Clinic.  Dr.  Collins reported that the employee’s low back pain started the day before “at work.”  Dr. Collins noted that the employee would like to pursue workers’ compensation for this problem.  Dr. Collins recorded that the employee was wondering if ill-fitted boots could cause low back pain.  Noting that the employee would “pour steel and aluminum, pushes an autoclave cart which is very heavy, over 100 pounds on wheels,” Dr. Collins made a working diagnosis of a “lumbar strain due to overuse injury.”  Two days later, on April 10, 2014, the employee’s pain was so severe that he sought emergency room treatment at Unity Hospital.  Complaining of back and flank pain, the employee underwent diagnostic testing for kidney stones.  Eight stones were discovered, but none in the ureters.  Clarifying the medical treatment, it was later noted on May 6, 2014, by Dr. David Yehl at Fairview Eagan Clinic that the employee “suffers from back pain as a direct result of disc herniation that he suffered from lifting at work.  Unrelated (and incidentally discovered during his work up) he also has a kidney stone which is asymptomatic.”

On April 13, 2014, the employee underwent an MRI at Fairview Ridges Hospital which showed a herniated disc compressing a nerve root at two levels and stenosis.  While the notes reflect that the pain began seven days prior, there is no reference in the office notes stating that the employee had a work related injury.  He was referred to an orthopedic surgeon at Twin Cities Spine Clinic.  On April 23, 2014, sixteen days after the alleged work injury, the employee sought treatment with Dr. Christine Schmitz who recorded that the “injury occurred April 7th, gradual onset of back pain at work while lifting pieces out of an autoclave cart.”

The employee next sought treatment at Twin Cities Spine Clinic.  He saw Dr. Pinto’s physician’s assistant on May 13, 2014, but did not see Dr. Pinto until June 10, 2014, at which time Dr. Pinto recommended surgery.  Dr. Pinto agreed that the history given to his assistant on May 13, 2014, “was of a specific event, that being his onset of low back pain while lifting parts out of an autoclave.”^[2]  The employee underwent surgery in the nature of laminectomy, decompression, and foraminotomy on August 15, 2014, by Dr. Pinto with poor surgical results.^[3]  While the surgery was performed four months after the alleged date of injury, the history given in the operative report is that the employee had symptoms for “over a year.”

The employer and insurer denied primary liability.  The employee filed a claim petition alleging that a low back injury occurred at work on April 7, 2014, and requested medical benefits and wage loss benefits.  Multiple providers also intervened.

The employer and insurer retained Dr. Eric Deal for the purpose of an independent medical examination (IME).  Dr. Deal opined that the employee’s original claim of tight fitting boots would not have caused the employee’s low back condition.  However, he agreed that if the employee was at work lifting when he injured his back, lifting could have caused the employee’s low back condition.  Concerning the causal history, Dr. Deal wrote:

The compensation judge agreed with Dr. Deal noting that the employee’s story appeared to have changed.  While there was no finding on credibility, the compensation judge wrote in the memorandum to the findings and order that he could not find the employee’s account of his onset of low back pain credible, describing the employee’s accounts as “inconsistent and unconvincing.”  The employee appeals from the compensation judge’s denial.

The compensation judge found that the employee failed to establish by a preponderance of the evidence that he suffered an injury to his low back on April 7, 2014.  The employee argues this is simply a case involving a misinformed man who lost his workers’ compensation claim because he initially thought his tight work boots caused his low back pain.  Because he was misinformed, he did not understand the cause of his low back pain.  On April 7, 2014, the employee told his supervisor that his tight boots caused low back pain because they caused an altered gait.  On April 23, 2014, the employee said it was the lifting at work that caused his low back pain.  And in May, 2014, Dr. Pinto testified that the history given was low back pain occurring after a specific event at work.  The employee argued that while he was misinformed as to the true cause of his low back pain, the medical records were constant in describing that the low back pain began at work.

The employer and insurer denied liability because the employee’s story changed.  They argued that no advanced medical or legal training is necessary to tell a doctor the source and cause of one’s pain.  They argue that the employee simply failed to meet his burden of proof as the compensation judge determined.

The employee had the obligation to prove entitlement to benefits by a preponderance of the evidence.  Minn. Stat. § 176.021, subds. 1 and 1a.  The employee first said the pain was due to his boots, then to what appears to be a specific lifting event, and then it appears that the employee attempted to show that it was due to overuse.  In the confusion of causes, the compensation judge reasonably concluded that the employee failed to prove that any of these possible events occurred, let alone caused the low back pain.  The compensation judge noted that he did not find the employee’s accounts of the employee’s onset of low back pain credible.  We conclude that substantial evidence supports the compensation judge’s decision.

The employee’s low back pain may first have occurred at work, but the employee did not carry his burden to prove that the work activities were a substantial contributing factor to the development of herniated discs, need for surgery, and resulting wage loss.  This is often accomplished through the use of medical expert reports or testimony regarding the physical nature of the job and the mechanism of injury.  Neither was adequately explored here.  In the short deposition of Dr. Pinto,^[5] there was no discussion about how the work activities resulted in the employee’s injury.  We agree with the compensation judge that the employee failed to show by a preponderance of the evidence that the employee suffered an injury to his low back on April 7, 2014.

The compensation judge found the opinion of Dr. Deal, the IME, more persuasive than that of Dr. Yehl and Dr. Pinto.  The employee argues that the Dr. Deal’s report actually supports the employee’s claim of a work related injury on April 7, 2014.  The employer and insurer argue that both the employee’s medical experts relied on faulty information.  Both Drs. Pinto and Yehl assumed that the employee’s injury arose from a specific lifting accident.

At first impression, it indeed appears that Dr. Deal’s opinion supports the employee’s claim.  Dr. Deal wrote that “if one were to believe Mr. Moore’s reported history of his lower back symptoms arising out of lifting casting materials (no one specific lifting incident) out of the autoclave at Carley Foundry on April 7, 2014, then one could opinion, Mr. Moore sustained a Gillette-type injury culminating out of his employment with Carley Foundry on April 7, 2014.”  But, Dr. Deal endorses the version which makes sense to him.  He opined,

Dr. Deal weighs three versions of what caused the low back pain as reported by the employee.  Putting all three versions into perspective, the compensation judge apparently chose the course which made the most sense to him based on the record as a whole, but especially based on the employee’s accounts described as “inconsistent and unconvincing.”

“As the trier of fact, the compensation judge is to resolve conflicting expert testimony.”  Nord v. City of Cook, 360 N.W.2d 337, 342 W.C.D. 364, 372-73 (Minn. 1985).  When the facts assumed by the expert in rendering an opinion are not supported by the evidence we will, as a general rule, reverse.  Id.  Here, there is no indication that the facts assumed by Dr. Deal were not supported by the evidence.  We affirm the compensation judge’s Findings and Order.