The employee appeals from the judge’s decision that he did not injure his low back as a result of his work activities.  We reverse and remand the matter for reconsideration.

The employee has an extensive history of low back symptoms and treatment dating back to his time in the Navy in the late 1970s, when he suffered a strain while moving a fuel tank, and he has treated for low back pain repeatedly over the years.  In some instances, the employee connected his condition to a specific incident, such as lifting or playing softball or football; at other times, he was not aware of any particular injury or other cause for his symptoms.  Diagnoses included SI joint strain, musculoskeletal pain, strain/sprain, myofascial strain, sacroiliac dysfunction, and degenerative disc disease.  The employee underwent medical care, including physical therapy, as well as chiropractic treatment, for flare-ups, and he eventually began receiving what he characterized as maintenance chiropractic care from either Dr. Eric Zeiszler or Dr. Mike Ameli.

The employee started working for Malt-O-Meal [the employer] in 1995.  Medical records indicate that he received treatment on numerous occasions for low back symptoms that he tied to occurrences or accidents at work, including several lifting incidents and falls.

On June 20, 2011, a machine in the employer’s packaging department malfunctioned and poured twelve-ounce bags of cereal onto the floor.  The employee helped clean up the spill, bending to pick up the bags to discard or put them into boxes.  The employee testified that this work involved repetitive bending for at least five and possibly as long as ten minutes.  He further testified that, as he straightened up, he noticed stiffness and tight muscles on the left side of his low back.  He reported the incident to the employer and sought care from Dr. Ameli the following day.  According to Dr. Ameli’s records, the employee had experienced sharp pain the day before after “lifting many bags of materials off the floor.”  Dr. Ameli treated the employee several times a week for the next month or so.  He released the employee to work without restrictions on August 1, 2011, but administered more chiropractic treatments through mid-September 2011.  Subsequently the employee returned to Dr. Zeiszler for ongoing maintenance care.^[1]

The employee claimed entitlement to expenses for treatment he received from June 21, 2011, to September 13, 2011, and the matter came on for hearing before a compensation judge on July 13, 2012.  Evidence included certain treatment records and a report from Dr. Jeffrey Dick, who had evaluated the employee on behalf of the employer and insurer on March 1, 2012.  In a decision issued August 24, 2012, the compensation judge concluded that the employee’s chiropractic care from June 21, 2011, to July 25, 2011, was reasonable and necessary to treat the employee’s low back condition, but the judge denied the employee’s claim for treatment expenses based on his conclusion that the employee did not sustain an injury on June 20, 2011, arising out of and in the course of his employment.  The employee appeals.

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).

“[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).

Dr. Ameli did not issue a formal opinion on the issue of causation, but it is evident from his records that he believed the employee’s low back symptoms after June 20, 2011, to be causally related to the employee’s work activities on that date.^[2]  Furthermore, an athletic trainer apparently employed by the employer evaluated the employee on the date of the alleged work injury and reported that the employee’s “bending into an awkward position to lift something up” was a contributing factor in the employee’s condition.  The compensation judge, however, accepted the contrary opinion of Dr. Dick, the employer and insurer’s independent examiner.

Dr. Dick diagnosed the employee as suffering from “[c]hronic intermittent low back pain.”  In response to a question from the employer and insurer’s attorney,^[3] Dr. Dick wrote,

On appeal, the employee contends that the compensation judge erred in accepting the opinion of Dr. Dick in that Dr. Dick based his opinion on an erroneous interpretation as to what constitutes an injury under Minnesota workers’ compensation law.  In response, the employer and insurer maintain that the judge simply chose between conflicting expert opinions, that the opinion of Dr. Dick was well-founded, and that the judge properly evaluated the employee’s claim under appropriate case law standards.  We conclude that the matter must be remanded for reconsideration and further explanation.

It is well settled that if an employee’s work activities substantially aggravate or accelerate a preexisting condition, the resulting disability is compensable.  Vanda v. Minnesota Mining and Mfg. Co., 300 Minn. 515, 218 N.W.2d 458, 27 W.C.D. 379 (1979).  The opinion of Dr. Dick can easily be interpreted as contrary to this established precedent, in that it appears that Dr. Dick does not characterize activity-related aggravations as injuries.^[4]  Therefore, to the extent that the compensation judge relied on an erroneous view by Dr. Dick as to what constitutes a compensable injury, the judge erred.^[5]

It is possible, however, that the compensation judge interpreted the opinion of Dr. Dick in some other way that is not apparent to us on appeal.  Just as important, the judge made no express findings as to the employee’s credibility and, contrary to the employee’s contention, the record, even excluding the opinion of Dr. Dick, does not necessarily compel the conclusion that the employee did in fact sustain a compensable injury.  We therefore remand the matter to the compensation judge for reconsideration and further findings on the issue of whether the employee sustained an injury on June 20, 2011, arising out of and in the course of his employment.  If so, the judge should order the employer and insurer to pay for the employee’s treatment to July 25, 2011, consistent with the judge’s finding as to the reasonableness and necessity of that care.