The employer and insurer appeal the compensation judge’s finding that the employee’s September 15, 2008, injury arose out of and in the course of her employment and that the claimed medical expenses were reasonable and necessary.  We affirm in part and vacate in part.

On September 15, 2008, Shannon Stans, the employee, was working as a medical records clerk for Long Prairie Memorial Hospital & Home, the employer, which was insured for workers’ compensation liability by SFM Mutual Companies, the insurer.  The employee was performing her regular job duties, scanning medical records into a computer system, which required the employee to retrieve a chart, remove staples from the records, and feed the records into a scanner.  The employee would then go to her work station to verify that the records had scanned properly.  The employee would flip through the records with her left hand and use her right hand to operate the mouse on her computer to verify that the records had scanned.  If not, the employee would scan them again in a scanner at her desk.  The employee’s desk was adjustable to a seated or standing position.  The employee would perform these job duties for about 80 percent of her eight hour shift.  About two hours into her shift, the employee’s neck and shoulders felt stiff and sore, so she stretched her arms over her head and leaned side to side.  The employee experienced sudden severe pain in her neck and left shoulder. 

The employee was treated that day by Dr. Paul VanGorp at CentraCare Clinic, who reported that the employee stretched both arms over her forehead and had sudden pain in her neck that radiated into the left trapezius muscle.  Dr. VanGorp assessed probable pulled muscle or ligamentous strain, but noted that cervical radicular or impingement problems were possible.  He recommended a soft cervical collar and medication, and indicated that if her symptoms did not improve, he would order imaging.  The employee was off work the rest of the day and half the next day.  She returned to Dr. VanGorp on September 24, 2008, reporting some improvement but continued neck and shoulder pain.  He indicated that he did not think it was cervical radiculopathy but muscle strain and spasm, and that if the employee failed to improve, physical therapy might be recommended.  The employee underwent physical therapy from October 15 through November 14, 2008.

The employee had limited prior medical treatment for her neck.  Although there are no medical records of a previous car accident, the employee reported to a medical provider that she had been involved in a car accident and injured her neck in the past.  In March 2007, she treated on one day for neck pain at CentraCare Clinic.  Dr. Hans Bjellum assessed trapezius pain and recommended rest, heat, and ibuprofen.

The employee’s neck and shoulder pain began to increase in January 2009.  The employee sought treatment at the Long Prairie CentraCare Clinic in March and April 2009.  On April 6, 2009, the employee was evaluated by Dr. Ronald Brown, who diagnosed cervical neck strain and ordered a cervical x-ray, which indicated some straightening of the cervical lordosis and muscle spasm.  The employee underwent physical therapy in April and May 2009.  The employer and insurer initially accepted liability for the employee’s injury and assigned the employee a QRC, Mary Merchlewicz.  Disability case management services started on May 13, 2009, and continued in a limited capacity through June 3, 2011.  The employee continued to work through the date of the hearing.

In May 2009, the employee started seeing Dr. Philip Prosapio, an orthopedic specialist at Little Falls Orthopedic.  Dr. Prosapio noted that the employee’s neck and shoulder pain began with a stretching incident at work, and that he thought her symptoms were related to her neck, not her shoulder.  He recommended a cervical spine MRI scan, which was performed on September 4, 2009.  The MRI scan showed a right-sided intravertebral disc paracentral protrusion and/or tear at C5-6.  Dr. Prosapio did not think this was causing the problems on her left side.

On September 16, 2009, the employee was evaluated by Dr. Nolan M. Segal at the employer and insurer’s request.  Dr. Segal reviewed the employee’s medical records, took a medical history, and examined the employee, but did not have the MRI scan to review.  Dr. Segal concluded:

In October 2009, the employee sought treatment at the Long Prairie CentraCare Clinic for left shoulder pain.  An October 16, 2009, x-ray of her left shoulder indicated no evidence of acute injury.  The employee returned to the clinic in November 2009.  Dr. Rene Eldidy, Jr., suspected thoracic outlet syndrome and recommended an MRI scan of the left shoulder.  The insurer denied payment for the MRI scan based on Dr. Segal’s report.  In January 2010, the employee agreed to an MRI scan of her left shoulder covered by her health insurer.  The scan indicated mild tendinosis with no subacromial fluid, mild osteoarthritis of the acromioclavicular joint with no spurs, and a small glenohumeral joint effusion.  In February 2010, Dr. Prosapio reviewed the MRI scan and indicated that it was difficult to determine whether the employee’s pain was coming from her shoulder or her neck.  A differential injection did not provide much relief.

In April 2010, Dr. Prosapio referred the employee to a cervical specialist, Dr. Joel Shobe at St. Cloud Orthopedic Associates.  On April 21, 2010, Dr. Shobe evaluated the employee, reviewed the 2009 cervical MRI scan, and ordered a left C5-6 foraminal injection.  The employee reported no improvement after the injection on April 28, 2010.  The employee returned to Dr. Shobe on May 19, 2010, reporting continued neck and left arm pain.  Dr. Shobe recommended another MRI to try to determine the source of the employee’s left arm pain.  On May 25, 2010, the employee underwent another cervical MRI scan.  Dr. Shobe reviewed the second cervical spine MRI scan and noted that the employee had a significant disc bulge with right-sided extrusion at C5-6, minimal disc bulging at C6-7, and no significant narrowing of the foramen extending off to the left side that would correlate with her left arm symptoms.  Based on the results of the scan, Dr. Shobe determined that he would not recommend surgery and referred the employee for physical therapy and to the Center for Pain Management.

On June 9, 2010, the employee was evaluated by Dr. Timothy Olson at the Center for Pain Management.  Dr. Olson assessed chronic axial neck and left shoulder pain, cervical degenerative disc disease, myofascial pain syndrome, rotator duff tendinosis, and mild AC joint arthritis.  Dr. Olson treated the employee with trigger point and steroid injections in her shoulder and neck, which provided some relief.  The employee was treated at the CentraCare Clinic emergency department on September 23, 2010, for bilateral posterior neck pain and was diagnosed with a trapezious strain.  In October 2010, Dr. Olson opined that the employee’s condition was multifactorial in that she had a component of degenerative disc disease that was causing her intermittent radicular symptoms and neck pain, superimposed on a left rotator cuff strain.  He recommended physical therapy.  The employee was evaluated for physical therapy on November 16, 2010; three to four weeks of physical therapy, two to three days a week, were scheduled.

In December 2010, Dr. Segal reviewed additional medical records of the employee, including the MRI scans, and prepared a supplemental report.  He found that the employee has mild multilevel degenerative disc disease of the cervical spine, mild degenerative cuff disease of the left shoulder, and a non-work related tension myalgia syndrome.  Dr. Segal stated that his opinions from the November 2009 report remained unchanged.^[2]

In January 2011, the employee returned to St. Cloud Orthopedic Associates for her left shoulder pain and was treated with a trigger point injection.  A nerve block injection provided relief and a repeat nerve block reduced her pain.  At this time, the employee first reported being involved in a car accident and injuring her neck in the past.  In February 2011, a diagnostic facet block indicated that the employee’s neck pain was not facet related.  Dr. Olson referred the employee to Physician’s Neck & Back Clinic (PNBC).  As of June 24, 2011, the employee reported no improvement to Dr. Olson from her sessions at that clinic.  The employee’s QRC noted in her June 3, 2011, report that the employee had completed the PNBC cervical strengthening program with some improvement.

In his April 23, 2011, report, Dr. Olson opined that the employee’s symptoms were the result of a myofascial pain syndrome which stems from the September 15, 2008, injury.

The employee filed a claim petition on January 11, 2010, for medical expenses.  A hearing was held on September 27, 2011.  At the hearing, the employee testified that the employer encouraged stretching for its employees.  When she worked in the nursing home, the employees would stretch as a group before starting their shift.  Her supervisors in the medical records department also encouraged stretching numerous times.  In July 2009, a newsletter included in the employee’s paycheck included information on stretching and its benefits.^[3]  The employee also testified that stretching helped her to do her work and to be productive.  The compensation judge’s found that the employee’s September 15, 2008, injury arose out of and in the course of her employment and that the claimed medical expenses were reasonable and necessary.  The employer and insurer 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.^[4]  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.^[5]  Fact findings are clearly erroneous if the reviewing court, looking at the entire evidence, is left with a definite and firm conviction that a mistake has been committed.^[6]  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 the evidence or not reasonably supported by the evidence as a whole.”^[7]

The employer and insurer argue that the compensation judge’s finding that the employee’s September 15, 2008, injury arose out of and in the course of her employment is erroneous as a matter of law, and also that substantial evidence does not support the finding.  We disagree.

Employers are “liable to pay compensation in every case of personal injury . . . arising out of and in the course of employment without regard to the question of negligence.”^[8]  The phrase “in the course of” refers to the time, place, and circumstances of the incident causing the employee’s injury.^[9]  Here, there is no dispute that the employee was in the course of her employment when the work injury occurred since she was on the employer’s premises, performing her regular job activity of scanning documents, during her regular working hours.  The issue is whether the injury arose out of her employment.

For an injury to “arise out of” the employee’s employment, there must be a causal connection between the employee’s injury and the employment.^[10]  The requisite causal connection “exists if the employment, by reason of its nature, obligations or incidents may reasonably be found to be the source of the injury-producing hazard.”^[11]  The Minnesota Supreme Court has stated that the “ ‘arising out of’ requirement requires a showing of some hazard that increases the employee’s exposure to injury beyond that of the general public.”^[12]  Under the “increased risk” test, the employee must show that the injury was caused by an increased risk to which the employee was subjected by his or her employment beyond that experienced by the general public.^[13]  The increased risk need not be unique to the employment.^[14]  The increased risk test is met if the injury followed “as a natural incident of the work . . . as a result of the exposure occasioned by the nature of the employment.”^[15]  Whether the employee met the burden of proving that the injury arose out of employment is a question of fact for the compensation judge.^[16]

The employer and insurer argue that the compensation judge did not address the applicable “increased risk test” to determine whether the employee’s injury arose out of her employment.  The compensation judge found that the employee was engaged in an activity beneficial to the employer while at work for the employer, and concluded that the employee’s stretching activity on the date of injury was “ ‘incidental to the employment relationship.’ ”^[17]  The employer and insurer assert that the compensation judge erred since he made this finding while citing a case involving whether an employee’s injury had occurred in the course of his employment.^[18]  We disagree.  The increased risk test to determine whether an injury “arose out of” employment considers “if the injury has its origin with a hazard or risk connected with the employment, and flows therefrom as a natural incident of the exposure occasioned by the nature of the work,”^[19] and if so, then the injury arose out of the employment.  The compensation judge’s finding that the employee’s stretching activity was “incidental to the employment relationship” addresses the increased risk test.

The compensation judge distinguished this case from Polz v. Jackson County Sheriff’s Dep’t,^[20] cited by the employer and insurer, where the employee had an extensive pre-existing history of medical treatment for his right hip, and a right hip dislocation which occurred when he was leaning against a wall during a break from work was found not to arise out of his employment.  In this case, the employee has one medical record indicating neck treatment a year before the stretching incident and reported having a neck injury from a car accident in the past.^[21]  The employer and insurer argue that the presence or lack of pre-existing medical history is not the determinative factor in deciding whether the employee’s injury arose out of her employment, and that the Polz case is an example of an employee not presenting evidence proving the requisite causal connection, similar to this case.  We agree that pre-existing medical history is not the determinative factor in deciding whether the employee’s injury arose out of her employment, but do not agree that Polz is in any way controlling in this case.  Under our standard of review, cases affirming a compensation judge on substantial evidence grounds have limited precedential value.^[22]

We have noted that “[n]o one comprehensive definition can be fashioned to fit all cases addressing whether an injury arises out of and in the course of employment”^[23] and that “each case stands on its own facts.”^[24]  In this case, the employee felt stiff and sore after working for a few hours in a repetitive activity, so she stretched her arms over her and leaned side to side.  The employer encouraged its employees to stretch.^[25]  The employee testified that she had done this type of stretching in the past to help her continue working.^[26]  This activity is reasonably incidental to her employment.^[27]  The compensation judge could reasonably conclude that the employee established that the “injury was caused by an increased risk to which the claimant, as distinct from the general public, was subjected by . . . her employment.”^[28]

The employee began treating for her work injury on the day that it occurred, and she has experienced symptoms since that time.  Dr. Olson opined that the employee’s symptoms were caused by a myofascial pain syndrome which resulted from the September 15, 2008, injury.  The compensation judge also chose to rely on the part of Dr. Segal’s opinion that indicated the stretching incident was a substantial contributing factor to her current symptoms.^[29]  Based on our review of the evidence as a whole, we conclude that the judge did not err as a matter of law in finding that the employee’s September 15, 2008, injury arose out of and in the course of her employment, and that substantial evidence supports that finding.  Accordingly, we affirm.

The employer and insurer also argue that substantial evidence does not support the compensation judge’s finding that the claimed medical treatment was reasonable, necessary, and causally related to the employee’s work injury.  An employer and insurer are required to furnish medical treatment as may reasonably be required at the time of the injury and at any time thereafter to cure or relieve the employee from the effects of a work‑related injury.^[30]  The employee has the burden of proving that medical expenses were reasonable, necessary, and causally related to the work injury.^[31]  Generally, the reasonableness and necessity of medical treatment is a question of fact for the compensation judge.^[32]

The employer and insurer argue that Dr. Segal’s opinion regarding the reasonableness and necessity of the claimed medical expenses was unopposed and that the judge was not free to reject his opinion on this issue.  We disagree.  In some situations, a compensation judge “is not free to disregard unopposed medical testimony because such testimony concerns issues not within the realm of knowledge of the fact finder.”^[33]  There is a difference between disregarding an unopposed medical opinion, however, and rejecting it on other grounds.^[34]  A compensation judge may base his or her conclusions on other reliable evidence in the record.^[35]  A compensation judge is not obligated to accept an unopposed expert medical opinion, just to consider it along with other evidence.^[36]  In this case, the employee’s treating physicians prescribed the disputed medical treatment.  Medical records may also be considered as medical evidence.^[37]  The compensation judge could reasonably conclude that the medical treatment was reasonable and necessary based on the employee’s medical records.  The compensation judge did not err by disregarding an unopposed medical opinion.

The employer and insurer argue that the second cervical spine MRI scan on May 25, 2010, was duplicative, and therefore not reasonable or necessary since the employee did not have any new objective findings or neurological symptoms.  The employee’s first cervical spine MRI scan was on September 4, 2009.  In April 2010, Dr. Prosapio referred the employee to a cervical specialist, Dr. Shobe.  On April 21, 2010, Dr. Shobe evaluated the employee, reviewed the 2009 MRI scan, and ordered a left C5-6 foraminal injection.  The injection did not improve the employee’s symptoms.  The employee returned to Dr. Shobe on May 19, 2010, reporting continued neck and left arm pain, and Dr. Shobe recommended another MRI to determine the source of the employee’s left arm pain.  After reviewing the second cervical spine MRI scan performed on May 25, 2010, Dr. Shobe determined that he would not recommend surgery and referred the employee for physical therapy and to the Center for Pain Management.  The compensation judge could reasonably conclude that the second cervical MRI, as recommended by Dr. Shobe, was reasonable and necessary medical treatment, and therefore, we affirm.

The employer and insurer also argue that there is no supporting documentation for medical expenses claimed for Physician’s Neck and Back Clinic (PNBC) for treatment between February 23 and April 27, 2011, and therefore no evidence that the treatment at that clinic was reasonable, necessary, and causally related to the employee’s work injury.  Treatment records from PNBC were not included in the employee’s medical records exhibit.  Invervenor Twin City Iron Workers included the medical expenses for PNBC in its itemized list exhibit along with other medical expenses that it had paid for the employee.  The employee did not testify regarding any treatment at PNBC.  The employer and insurer argue that there is no evidence to support a finding that the treatment is reasonable, necessary, and causally related to the employee’s injury.  We agree, and vacate the compensation judge’s award of claimed medical expenses from PNBC.