The employee appeals from the compensation judge’s denials of temporary total and temporary partial disability benefits and of payment of certain medical expenses.  We affirm.

Delores Peaches-Roy has had an extensive history of treatment for neck and left shoulder pain that predates the 2007 work injury here at issue, some of that pain apparently exacerbated by an incident in August of 1994 when a vehicle that she was driving was intentionally and repeatedly rear-ended by another vehicle.  Ms. Peaches-Roy [the employee] was eventually referred for related complaints to physiatrist Dr. Richard Timming, who, on June 25, 2004, diagnosed chronic neck and trapezius pain and headaches of over ten years’ duration, together with deconditioning syndrome and contributing psychological factors.  He ordered x-rays of the employee’s cervical spine and referred her for both physical therapy and chronic pain treatment.  On October 8, 2004, Dr. Timming reported that the ordered x-rays had revealed significant degeneration of the intervertebral discs at C5-6 and C7-T1.  About a year later, on October 7, 2005, with the employee’s pain continuing, Dr. Timming ordered a cervical MRI scan, which was conducted on October 14, 2005, and was read to reveal cervical spondylosis and loss of upper cervical lordosis, congenital central canal stenosis exacerbated by disc bulge osteophyte complexes most severe at C5-6, bilateral foraminal disc protrusions at C5-6 exacerbating moderately severe stenosis on the right, and a foraminal disc protrusion at C4-5 on the right.  On October 18, 2005, Dr. Timming reported to the employee that these findings were “consistent with your age,” and he recommended a comprehensive management program for her neck.  On November 10, 2005, Dr. Timming administered lidocaine injections for a flare-up in the employee’s neck pain, indicating that “the main thing I think is for her to get her stress under control and then to get on a fitness program.”  By December 15, 2005, the employee’s symptoms were extending down into her left wrist, and on January 9, 2006, noting that “[t]his is not a personal injury,” Dr. Timming ordered an MRI scan of the employee’s left shoulder and an EMG of her left upper extremity.  The scan was conducted on January 13, 2006, and was read to reveal lateral down-sloping of the acromion as well as enthesophyte formation at the acromial attachment, with no evidence of any rotator cuff tear.

Over the course of most of 2006, the employee continued to be treated periodically for chronic neck, shoulder, and low back pain, for which she continued to request refills of her medication.  On October 16, 2006, she returned to see Dr. Timming pursuant to the doctor’s concern that she understand well the potential risks and side effects of her pain medication.  The employee complained to Dr. Timming on that date of pain at level 7 on a scale of 1 to 10, but Dr. Timming concluded that she should not take the medication on a steady basis, suggesting injections as an alternative.  The employee declined the injections, and Dr. Timming released her to work with a restriction against lifting, carrying, pushing, or pulling over twenty pounds, requiring also that she be permitted to change positions as needed and to take five-minute stretch/strengthening breaks every thirty minutes.  About two months later, on December 19, 2006, on referral from Dr. Timming, the employee saw occupational medicine Dr. Paul Anderson regarding certain left wrist and arm pain.  Dr. Anderson diagnosed arm pain, left arm weakness, and degenerative spinal stenosis and referred the employee for an upper extremity EMG and a neurosurgical consultation.

On March 21, 2007, the employee reported a work-related injury to her left shoulder and left arm when she was bumped hard against a wall by a client in the course of her work as an Office Service Worker III with the Human Services and Public Health Department of Hennepin County.  At the time of her injury, the employee had worked for Hennepin County [the employer] for about ten years, most of that work part time as a Service Center Representative and most recently, for a little over four months, full time in her Office Service Worker III position, where she was still working in a six-month probationary status.  This position is described in an April 20, 2007, Employee Job Description, signed by the employee, as follows:  “This job is largely a sedentary one, greeting the clients, logging into computer[s] for information, completing registration form[s] by hand.  Employee gets up and carries papers to be processed further, walking to areas frequently.”  The employee completed her shift on the date of her injury, and she returned to work the following day to fill out a First Report of Injury to her left shoulder, leaving work thereafter with complaints of pain.  At the time of her injury, the employee was fifty-one years old and was earning a weekly wage of $703.00.  The employer, which was self-insured against workers’ compensation liability, acknowledged liability for the injury and commenced payment of benefits.

On March 23, 2007, two days after her injury, the employee sought treatment with family practitioner Dr. Charles Bass, who noted neck and left shoulder pain radiating into the left arm.  Dr. Bass diagnosed “[n]eck pain secondary to injury while going into work complicating her chronic neck pain,” noting, “Basically, this pain is in the same area as her more chronic neck pain, only it is much worse than it has been.”  He prescribed on that date Naprosyn and physical therapy and restricted the employee from working for one week, releasing her to return to work on April 2, 2007, for four hours a day, with no lifting, carrying, pushing, or pulling.  The employee returned to Dr. Bass on April 9, 2007, complaining of having had to leave work the previous Friday because of too much pain.  Dr. Bass assessed increasing pain with work, prescribed Naprosyn and continued physical therapy, and again restricted the employee from working for a week.  A week later, on April 16, 2007, noting that the employee’s neck pain was reportedly worse after therapy but that she currently appeared to be in no distress, Dr. Bass released the employee again to return to work four hours a day, three days a week, with no lifting, carrying, pushing, or pulling and with one rest day between each workday.  The employee’s pain was “mildly improved” by April 23, 2007, and on May 7, 2007, noting that her neck pain was chronic but stable, Dr. Bass referred the employee back to Dr. Timming.

By a memo dated April 30, 2007, and effective also on May 7, 2007, the employee’s probationary period in her Office Service Worker III position was extended “for a period of up to 1,040 worked hours.”  A Support Staff Employee Performance Review executed on that same date regarding the employee’s work rated the employee “Needs Improvement” in several areas on grounds that she had “missed a large amount of work due to unplanned absences.”  The memo certifying the extension identifies seven days, over the course of about fifteen-plus weeks beginning with November 28, 2006, and concluding with March 19, 2007, just before the employee’s work injury, on which the employee missed full, eight-hour days of work “due to call in’s.”

Unable to see Dr. Timming on schedule, the employee saw Dr. Bass again on May 21, 2007, on which date Dr. Bass found her “in no distress” and her “[p]ersistent neck and upper back pain, gradually improving.”  Dr. Timming saw the employee three days later, on May 24, 2007.  Upon examination, Dr. Timming noted that she was not in any acute distress, that her gait was normal, and that she had full range of motion in both her shoulders and her neck, with normal strength and tone in her upper extremities, symmetrical reflexes, and no sensory abnormalities.  An x-ray taken on that date proved normal, and Dr. Timming ordered a cervical MRI scan and an EMG of the left upper extremity, noting that the employee was “not at her maximum medical improvement but I think she should improve nicely.”  He thereupon released the employee to work four hours a day five days a week, restricted from lifting or carrying or pushing or pulling over ten pounds.  The recommended cervical MRI scan was conducted on June 1, 2007, and was read to reveal multi-level degenerative changes with reversal of the normal cervical lordosis, diffuse mild congenital canal narrowing exacerbated by disc osteophyte complexes at C4-5 and C5-6, and a prominent disc osteophyte complex at C5-6 resulting in moderate to severe bilateral neural foraminal narrowing.  On June 4, 2007, Dr. Timming informed the employee that these findings were similar to those of her 2005 MRI scan.  Physical therapy records indicated that the employee’s progress was poor, and, on June 14, 2007, Dr. Timming ordered a left shoulder MRI scan, in addition to her previous cervical MRI scan, and referred the employee for an orthopedic consultation.  The left upper extremity EMG, recommended on May 21, 2007, was conducted on June 18, 2007, and was read as normal.  The recommended left shoulder MRI scan was conducted on June 20, 2007, and was read to reveal in part mild tendinopathy in the supraspinatus and infraspinatus tendons but no evidence of focal rotator cuff tendon tear and “[o]verall, no significant change since the prior [January 13, 2006] examination.”  On June 21, 2007, Dr. Timming reported to the employee that the scan revealed “no evidence of a new injury.”

On June 25, 2007, on referral from Dr. Timming, the employee saw neurosurgeon Dr. David Chang, to whom she reported that she had never, prior to her work injury three months earlier, experienced her current symptoms.  In his report two days later, on June 27, 2007, Dr. Chang indicated that he had personally reviewed the employee’s MRI scan and had noted disc herniations at C4-5 and C5-6.  On those findings he restricted the employee to working only three days a week, four hours a day, and he recommended a cervical discectomy and fusion, which he reported the employee to have wanted to proceed with.  Eventually, on July 9, 2007, Dr. Timming restricted the employee from all work, in light of Dr. Chang’s recommendation of surgery and the employee’s report of “pain too severe to work.”

On July 10, 2007, the employee was examined for the employer by Dr. Mark Engasser, who reported a fifteen-year history of neck and upper extremity problems in the employee, which the employee told him she “knew . . . was going to set in” at the time of her March 21, 2007, work injury.  Dr. Engasser noted that the findings on the employee’s June 1, 2007, cervical MRI scan, subsequent to the work injury, were not significantly different from those on the previous study, in October of 2005, prior to the injury.  He noted also that the findings on the employee’s post-injury left shoulder MRI, on June 29, 2007, were also not significantly different from those on her pre-injury left shoulder MRI, on January 13, 2006.  He noted further that the employee had indicated to him that her current neck symptoms were the same as those that she had experienced after three incidents prior to her March 2007 work injury.  On examination, Dr. Engasser found no evidence of any spasm or tightness with active range of motion of the cervical spine, although there was self-limited and variable range of motion that he indicated was subjective, not objective.  On those findings, and after review of the employee’s medical records, Dr. Engasser diagnosed multi-level cervical degenerative disc disease, with spinal stenosis at C4-5 and C5-6, together with left shoulder pain, mild supraspinatus and infraspinatus tendinopathy, and nonorganic pain elements.  It was Dr. Engasser’s opinion that the employee was not a surgical candidate, and he expressed concern “that she has functional pain which would not be improved with cervical decompression and fusion.”  He found all of the employee’s current problems clearly present prior to her work injury, concluding that the neck and left shoulder injuries that she sustained on March 21 2007, were temporary aggravations that had resolved, at maximum medical improvement [MMI], no later than three months after the injury.  He saw “absolutely no reason why [the employee] could not perform” her Office Specialist III job, emphasizing that her symptoms were identical to those that she had prior to her work injury.

On July 24, 2007, the employee saw Dr. Timming again, with complaints of increasing pain.  Dr. Timming prescribed Vicodin and noted in his records as follows: “I discussed with [the employee] that the proposed surgery seems reasonable and is something she can consider if she feels it is necessary.  We could try epidural steroids as well.  She tells me very much she wants to proceed with the surgery.”  On August 8, 2007, the employer filed a Notice of Intention to Discontinue [NOID] the employee’s workers’ compensation benefits, on grounds, as supported by Dr. Engasser’s report of July 10, 2007, that the employee’s work injury was a temporary aggravation of a preexisting condition that resolved no later than June 21, 2007, that the employee was now able to return full time to her pre-injury job, and that the employee was not a candidate for surgery.

On August 23, 2007, the employee saw Dr. Timming for the last time, whose notes on that date indicate that he found “[n]o evidence of cervical radiculopathy.”  Nevertheless, on August 28, 2007, Dr. Chang performed a discectomy and fusion at C4-5 and C5-6 of the employee’s cervical spine.

After an initial postponement, the administrative conference on the employer’s NOID was eventually held on September 7, 2007, benefits having been paid through August 18, 2007, the date originally scheduled for the conference.  On September 14, 2007, Compensation Judge Jeanne Knight issued an order indicating her conclusion that the employer had met its burden of showing a reasonable basis for discontinuing benefits.  About three weeks later, on October 3, 2007, the employee filed a claim petition, alleging entitlement to temporary total disability benefits continuing from August 7, 2007, as well as payment of unspecified medical expenses, rehabilitation benefits, penalties, and attorney fees.

By October 17, 2007, the employee’s bilateral shoulder and arm pain had improved, x-rays of her cervical spine revealed no post-operative abnormalities, and the employee was referred for physical therapy.  On November 12, 2007, she was released to return to work on November 14, 2007, half days three days a week, restricted from lifting over thirty pounds.  X-rays taken on December 17, 2007, were again normal, and Dr. Chang released the employee to return to work the following day without restrictions.  In an intradepartmental memorandum dated January 16, 2008, the employer’s Administrative Support Services Leader, Sharon Reid, reported that the employee had missed work on short notice on at least six different occasions between December 19, 2007, and January 29, 2008, subsequent to her return to full time work without restrictions.  About two months later, by letter dated March 31, 2008, from her Senior Support Services Supervisor, the employee was informed that, “[d]ue to continued job performance issues during [her] extended probationary period,” she had failed her probationary period in her Office Service Worker III position and would be transferred back to her former half-time position as a Service Center Representative.

On July 14, 2008, in a letter to the employee’s attorney, Dr. Timming opined that the employee’s March 21, 2007, work injury “flared up a pre-existing neck and left shoulder, left upper extremity pain syndrome.”  Dr. Timming was unable to give an opinion as to whether the employee’s work-related aggravation was permanent or whether she would need any further medical treatment, in that he had not seen her in nearly eleven months.  About four months later, on November 12, 2008, Dr. Timming again wrote to the employee’s attorney in answer to certain queries.  In his letter, Dr. Timming opined in part that, prior to her March 21, 2007, work injury, the employee’s pre-existing neck pain had been steadily subsiding, she had not had any complaints of left shoulder pain, and “she was doing well.”  Subsequent to the work injury, he went on, the employee was left “with increasing neck pain, left shoulder and arm pain,” and “[s]he was no longer able to work full time at her job.”

The matter came on for hearing on December 10, 2008.  Issues at hearing included the following:  whether the employee’s March 21, 2007, work injury was ongoing after August 7, 2007, the date of the employer’s NOID, together with certain secondary issues relative to the employee’s entitlement to wage replacement benefits beginning August 18, 2007; whether the surgical procedure performed August 28, 2007, by Dr. Chang was reasonable and necessary; whether the employee’s other medical expenses were reasonable, necessary, and causally related to her March 21, 2007, work injury; and whether certain intervenors were entitled to reimbursement and/or payment.  The employer contended at hearing that the employee’s work injury was only a temporary aggravation of a pre-existing condition, which had resolved by July 10, 2007, and that the employee’s claim to the wage replacement and medical benefits at issue should be denied.

By findings and order filed May 18, 2009, Compensation Judge Cheryl LeClair-Sommer concluded in part, in reliance on the expert opinion of Dr. Engasser over that of Dr. Timming, that the employee’s work-injury-related neck and left upper extremity condition was a temporary aggravation of a pre-existing condition that had resolved by July 10, 2007, the date of Dr. Engasser’s independent medical examination.  Pursuant to that conclusion, the judge found that all claimed medical expenses up through July 10, 2007, were reasonable, necessary, and causally related to the work injury but that any expenses incurred after that date, including the fusion surgery performed by Dr. Chang, were not and that the employee was also not entitled to any wage replacement after that date.  The employee appeals.

In reviewing cases 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.  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, “[f]actfindings are clearly erroneous only if the reviewing court on the entire evidence is left with a definite and firm conviction that a mistake has been committed.”  Northern States Power Co. v. Lyon Foods Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).  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.”  Id.

The compensation judge found that the employee’s work injury had resolved by July 10, 2007, and she denied all of the employee’s claims other than claims for related medical expenses up through that date, the employee having already received wage replacement benefits through that date.  The employee contends on appeal (1) that the judge erred as a matter of law in placing the burden of proof on the employee in this matter, (2) that the judge erred as a matter of law in finding Dr. Chang’s opinions unpersuasive for foundational reasons, and (3) that substantial evidence does not support the judge’s conclusions “when the employer/insurer failed to show” (a) that the employee’s work injury was only temporary, (b) that Dr. Chang’s surgery was not reasonable and necessary, and (c) that the employee has not sustained a work-injury-related loss of earnings or conducted a reasonably diligent search for employment.

In Findings 2 and 3, the compensation judge concluded that “[t]he preponderance of the evidence fails to prove” that the employee’s March 21, 2007, work injury was ongoing after July 10, 2007, or was a substantial contributing factor in the employee’s loss of earning capacity after August 18, 2007.  In Findings 6 and 7, the judge concluded also that it “has not been proven” that the employee’s work injury is a substantial contributing factor in her physical restrictions or that Dr. Chang’s August 28, 2007, surgical procedure was reasonable and necessary.  In her memorandum, the judge stated, “The party seeking to receive benefits has the burden of proof.”  The employee contends that the judge’s imposition of the burden of proof on the employee in this case is contrary to law, in that the hearing below proceeded directly from an administrative hearing on the issue of the employer’s August 7, 2007, NOID, an issue relative to which the employer, not the employee, had the burden of proof.  We are not persuaded.

An employer/insurer in a discontinuance case has the initial burden of proving that discontinuance of benefits is warranted by a preponderance of the evidence.  Violette v. Midwest Printing, 415 N.W.2d 318, 322, 40 W.C.D. 445, 453 (Minn. 1987).  Thereafter, the burden of proof properly shifts to the employee to demonstrate ultimate entitlement to compensation.  King v. Farmstead foods, 45 W.C.D. 292 (W.C.C.A. 1991); Larsen v. Hauenstein and Burmeister, slip op. (W.C.C.A. Jun. 24, 1992) (after the employer and insurer had introduced sufficient evidence to support a conclusion that the employee’s work injury was only a temporary aggravation, the compensation judge properly shifted the  burden of proof to the employee to show entitlement to benefits).  In this case, whether the parties viewed the proceeding as a discontinuance hearing or an expanded hearing on the employee’s claim petition, evidence was introduced by the employer, in the form of substantial medical records and the independent medical opinion of Dr. Engasser, to the effect that the employee’s work injury was a temporary aggravation that ended by July 10, 2007.  It is evident from her comments prior to testimony at hearing that the judge viewed the burden of proof as resting on the employee to proved entitlement to benefits.  If there existed any uncertainty on this issue at the time of hearing, neither party raised a concern.  Ultimately, the issue for the judge in this case was whether the evidence supported a conclusion that the work injury was a temporary aggravation or a permanent aggravation of the employee’s pre-existing condition.  Both the employee and the employer offered substantial evidence on the issue.  We find no error in the judge’s placing of the burden of proof in this case.

Without specifying directly what opinion of Dr. Chang she is referencing, the employee contends that the compensation judge improperly “disregarded” the opinion of Dr. Chang when she “dismissed the opinion . . . based on lack of foundation.”  The employee argues that this was improper because the doctor’s “records had been admitted into evidence without objection, and . . . there was no evidence to support the [employer’s] accusation that Dr. Chang lack[ed] foundation to form an opinion.”  We are not persuaded.

First of all, it is clear that the compensation judge did not “ignore” the records and implicit opinions of Dr. Chang, in that she referenced them in some detail at no fewer than half a dozen different locations in her findings and order and memorandum.  We view any issue regarding the judge’s acceptance or rejection of Dr. Chang’s apparent opinions as one of weight rather than of competency, cf. Cull v. Wal-Mart Stores, Inc., 64 W.C.D. 262 (W.C.C.A. 2004); Burke v. Precision Eng’g, slip op. (W.C.C.A. Aug. 21, 1997); it is apparent to us that the judge considered and weighed the opinions and records of Dr. Chang.  More importantly, however, to the extent that this issue pertains to the temporary nature of the work injury and resolution of the injury’s causal relationship to any ongoing disability by July 10, 2007, we note that Dr. Chang clearly never issued or offered any opinion, regardless of whether or not he may have had proper foundation to do so.  The only “opinions” that he may be construed to have offered are his recommendation of surgery in the first place, based on his radiological and examination findings, and then his subsequent release of the employee to return to work unrestricted on December 18, 2007.

In that it is clear, by her reliance on it in Finding 5, that the judge did not “ignore” Dr. Chang’s opinion, whatever weight she may have attributed to it, and given this court’s often reiterated deference to compensation judges in the choice between expert medical opinions, we will not disturb the judge’s reliance on the opinion of Dr. Engasser, that the surgery performed by Dr. Chang was not reasonable and necessary.  See Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985) (a trier of fact's choice between experts whose testimony conflicts is usually upheld unless the facts assumed by the expert in rendering his opinion are not supported by the evidence).

The record in this case is replete with evidence that the employee was subject to not just intermittent but chronic neck and left upper extremity problems for over ten years immediately prior to her work injury.  The employee acknowledges that she has a long history of preexisting neck and left shoulder problems, but she contends that they became and stayed chronically worse as a consequence of her March 21, 2007, work injury.  It was Dr. Engasser’s opinion, however, that that work injury was only a temporary aggravation of the pre-existing condition, which had fully resolved no later than June 21, 2007, three months after its occurrence.  In reliance on that opinion, the compensation judge found that that injury was fully resolved no later than July 10, 2007, the date of Dr. Engasser’s opinion.  As we have indicated above, we will defer to the judge’s decision to rely on the opinion of Dr. Engasser, see id., and so we affirm her conclusion as to the date of resolution of the employee’s work injury.  That date is well in advance of both Dr. Chang’s cervical fusion surgery on August 28, 2007, and the first date of the periods for which the employee has claimed wage replacement benefits - - August 18, 2007.  Therefore we need not address the employee’s appeal from the judge’s denial of payment for Dr. Chang’s August 28, 2007, surgery, in that that surgery, whether or not reasonable and necessary, was on that date no longer causally related to the employee’s temporary work injury.  Nor do we need to address the employee’s appeal from the judge’s findings regarding the employee’s earning capacity and job search, since those findings are relevant only to the employee’s entitlement to the claimed wage replacement, which also is unavailable after full resolution of a work injury.  See Kautz v. Setterlin Co., 410 N.W.2d 843, 40 W.C.D. 206 (Minn. 1987) (wage replacement is not available to an employee who is medically able to return to work without restriction and has no residual disability).

Because the judge’s reliance on medical opinion and her imposition of the burden of proof in this case were not clearly erroneous as a matter of law, and because her factual conclusions were not unreasonable, we affirm the judge’s findings and order in their entirety.  See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.