The employer and insurer appeal from the compensation judge’s decision that the employee’s 2011 work-related back injury substantially contributed to his need for treatment, including surgery.  We affirm.

The employee began working for Polaris Industries, Inc. [the employer], in 1979.  The employer is a manufacturer of snowmobiles and all-terrain vehicles, and the employee worked in many departments and held many different jobs during his 33 years of employment there.  The employee testified that much of the work required repetitive bending, stooping, and reaching, and the employee developed periodic neck, shoulder, and back pain that he attributed to his employment.  He sought intermittent chiropractic care for these symptoms but apparently missed little or no time from work, and he testified that, for most of his career, the employer did not require any formal reporting of incidents of this nature but would instead simply pay for the treatment.^[1]  Later, the employee testified, workers were required to “report a cut or anything that ever happened to you.”

On April 7, 2011, the employee sustained a work-related injury to his back after bending down to reach for a box beneath a bench.  As the employee described it, his back “tweaked” or “snapped” as he turned after picking up the box.  He reported the injury to the employer and then returned to his work.  He first sought treatment after the injury about a week later, when he saw Dr. David Verworn, one of several chiropractors who had treated him over the years.  After a second appointment with Dr. Verworn, the employee was seen on May 3, 2011, by Dr. Byron Vande Wege, a medical doctor.  Dr. Vande Wege advised the employee to limit bending and twisting and to avoid lifting more than 20 pounds.  He also prescribed physical therapy.  The employee continued to work for the employer without significant time off due to his back condition.^[2]

The employee underwent an MRI scan on June 16, 2011.  The scan showed degenerative disc disease and degenerative joint disease throughout the lumbar spine, particularly at L4-5 and L5-S1.  Following the scan, Dr. Vande Wege referred the employee to a surgeon, Dr. Maria Li.  Dr. Li diagnosed L4-5 right foraminal and central stenosis causing mild L4-L5 radicular symptoms, and she recommended injections.

The employee retired from his job with the employer in February 2012.  He testified that his objective had been to last at the employer until he was 62 and that he was sure he would not have been able to continue that kind of work until age 65.

On April 12, 2012, the employee was seen by Dr. Mickey Syrquin.  Injections had not been successful, and Dr. Syrquin recommended a repeat MRI.  Subsequent to that test, Dr. Syrquin indicated that the employee was not a surgical candidate at that time.

A year later, on May 21, 2013, the employee was evaluated by Dr. Sunny Kim.  After examining the employee, taking a history, and reviewing test results, Dr. Kim concluded that the employee would be a good candidate for a lumbar decompression with fusion, but he indicated that the employee should first undergo a CT scan.  That scan, performed in early June 2013, was read to reveal multilevel lumbar spondylosis, most severe at L4-5, with grade I anterolisthesis.

The employee was examined on July 8, 2013, by Dr. Daniel Randa, at the request of the employer and insurer.  Dr. Randa agreed that the surgery proposed by Dr. Kim would be appropriate to treat the employee’s back condition.  He also concluded, however, that the employee’s need for surgery was not necessitated either by the April 2011 work injury, which he characterized as a temporary aggravation, or by the employee’s work for the employer over the years.  Rather, according to Dr. Randa, the employee was suffering from a progressive spine disorder caused by the “sum total of any and all movements accumulated over one’s life,” unrelated to any specific occupation.  Dr. Randa further indicated that the employee’s condition had been aggravated by tobacco use.

In October of 2013, Dr. Kim completed a hand-written Workers’ Compensation Physician’s Report form, indicating that the employee’s back symptoms were causally related to an (undated) work-related accident as well as repetitive trauma from work.

When the matter came on for hearing before a compensation judge on January 7, 2014, the sole issue was whether the employee’s need for surgery and other treatment was causally related to the April 2011 work injury and/or the effects of cumulative trauma from the employee’s work activities over the years.^[3]  The compensation judge resolved the issue in the employee’s favor and ordered the employer and insurer to pay for the surgery recommended by Dr. Kim and other treatment rendered through the date of hearing.  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 (2012).  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).

The compensation judge concluded that the April 2011 work injury “continues to be a substantial contributing factor to [the employee’s] need for the surgical procedure recommended by Dr. Kim,” as well as other post-injury treatment expenses through the date of hearing.  On appeal, the employer and insurer contend that substantial evidence does not support the judge’s decision and also that the judge erred by relying on the causation opinion of Dr. Kim.  We are not persuaded.

As regards Dr. Kim, the employer and insurer maintain that Dr. Kim’s opinion “lacked foundation.”  This is clearly not the case.  Dr. Kim examined the employee, took his medical history, and was given a description of the employee’s work activities.  Dr. Randa may have had more details, but that fact goes to weight, not foundation.  Further, as a surgeon, Dr. Kim was clearly competent to render an opinion on causation.  See Drew v. Kohl’s, 55 W.C.D. 33 (W.C.C.A. 1996) (citing Reinhardt v. Colton, 337 N.W.2d 88, 93 (Minn. 1983)).  In fact, however, nowhere in his findings or in his memorandum did the compensation judge adopt the opinion of Dr. Kim.  Rather, noting that even Dr. Randa found the work injury to be an aggravation of the employee’s underlying condition, the compensation judge analyzed the facts under criteria relevant to determining whether an aggravation is temporary or permanent.

Factors that a judge may consider for purposes of determining whether an aggravation is temporary or permanent include the nature and severity of the preexisting condition and the extent of the medical treatment received prior to the aggravating incident; the nature and severity of the aggravating incident and the extent of restrictions and disability resulting therefrom; the nature of the symptoms and the extent of medical treatment following the aggravating incident; the nature and extent of the employee’s work duties and non-work activities during the relevant period; and medical opinions on the issue.  See McClellan v. Up North Plastics, slip op. (W.C.C.A. Oct 18, 1994).  In the present case, it is true, as the employer and insurer maintain, that the employee had received intermittent chiropractic treatment for back symptoms for years prior to the April 2011 work injury, and the employee himself characterized the April 2011 incident as being essentially the same as other incidents occurring at work over the same years.  However, prior to the April 2011 work injury, the employee had never sought care for back symptoms from medical doctors, providers had never recommended ongoing restrictions on his activities due to his back symptoms, he had apparently never undergone CT or MRI scans of his back, and surgery had never been proposed to treat his back condition.

As explained by the Minnesota Supreme Court,