The employee appeals from the judge’s finding that the employee did not sustain Gillette-type injuries^[1] to her fingers as claimed.  We affirm.

The employee began work for Control Data, predecessor to Polar Semiconductor Inc. [the employer], in 1972.  She worked for many years in the test floor department in jobs requiring her to use tweezers to pinch, to handle test tubes, and to pull and push on a stopper.  It was during this work that she first experienced problems with her hands, including soreness in her fingers, requiring cortisone injections, and problems with her thumbs, leading to fusion surgeries.  She has treated with Dr. Mark Urban for these conditions since 1993.^[2]

In February of 2006 the employee was assigned to the employer’s wafer fabrication department, working three 12-hour shifts one week and four 12-hour shifts the next.  Her work involved carrying boxes of wafers.  Each box weighed 5-6 pounds and contained one cassette containing 25 wafers.  The employee handled about 40 boxes per 12-hour shift.  Once she arrived at her work station, she would unlatch the box, remove the cassette, and place the cassette into a machine that manipulated the wafers.  During the time that she worked in this job she redeveloped symptoms in the right index and middle fingers.

On November 21, 2008,^[3] Dr. Urban reviewed an August 29, 2008, right hand x-ray and confirmed that the employee had end-stage osteoarthritis of the right index and middle finger proximal interphalangeal [PIP] joints.  He also noted that he had administered steroid injections into those fingers in June and August and that the latest injection had helped for only two weeks.

On January 9, 2009, Dr. Urban saw the employee, in part, for recurrent pain in both little fingers, and he injected both fingers.  His diagnosis at that time was “recurrently symptomatic osteoarthritis.”

On May 29, 2009, Dr. Urban took new x-rays of the employee’s right hand, which revealed “essentially no residual joint cartilage of the index, middle and little finger PIP joints.”  He recommended that PIP arthroplasties of those three joints to be performed at the same time.

On September 11, 2009, Dr. Urban treated the employee for recurrent pain in the left index and little finger PIP joints by injecting those joints.

The employee underwent PIP joint arthroplasty on the right index, middle, and little fingers on April 22, 2010, performed by Dr. Urban, and the employee was off work from April 22, 2010, to December 20, 2010.  During that period she continued to treat with Dr. Urban, in part, for symptoms in her left index and little fingers.

The employee underwent a functional capacity evaluation [FCE] on December 3, 2010.^[4]  On December 20, 2010, after reviewing the FCE, Dr. Urban noted that the employee should do no firm grasping with her right hand.  It was his opinion that the employee “can perform all of the normal activities of her regular job within these limitations,” and he released the employee to return to work in the wafer fabrication department.  She began treating with Dr. Urban again in April 2011, complaining of recurrent pain in her left little finger.  Several months later, on September 30, 2011, Dr. Urban recommended a fusion of the left index finger and a PIP arthroplasty of the left little finger, which he performed on May 17, 2012.

An amended claim petition was filed on July 18, 2011, involving eight dates of injury.  In a second amended claim petition, filed January 13, 2012, the employee listed ten dates of injury and alleged entitlement to permanent total disability benefits, undetermined permanent partial disability benefits, out-of-pocket medical expenses, and approval for arthroplasty of the left little finger and fusion of the left index finger.  A compensation judge issued an order in July of 2012, limiting the claims to be considered at the scheduled hearing that month to claimed Gillette injuries to the employee’s left little finger on January 9, 2009; left index finger on September 11, 2009;  the right index and middle fingers on November 21, 2008; and right index, middle, and little fingers on May 29, 2009; and the employee’s entitlement to surgeries, permanent partial disability benefits, and out-of-pocket medical expenses related to those injuries.^[5]

When the matter proceeded to hearing, a claim for temporary total disability benefits was included.  Medical records and reports from Dr. Urban and reports from independent medical examiners Drs. David Falconer, Jeffrey Husband, Lawrence Donovan, and William Call were introduced as evidence.  In findings and order filed on September 13, 2012, the compensation judge determined that the employee had not sustained the claimed injuries, and all claims for benefits were denied.  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).

The employee first contends that the compensation judge erred as a matter of law by requiring the employee to establish that her work activities were the only cause of her condition.  We are not persuaded.  The judge phrased the issue as whether work activities “substantially contributed to and/or accelerated or aggravated” the employee’s finger symptoms, “culminating in a Gillette-type injury.”  As such, the compensation judge clearly understood that, if the employee’s employment substantially contributed to an aggravation or acceleration of a preexisting condition, the employee would have sustained a compensable injury.  Wallace v. Hanson Silo Co., 305 Minn. 395, 235 N.W.2d 363, 28 W.C.D. 79 (Minn. 1975).  In addition, the judge noted that he accepted the opinion of Dr. Husband, and he quoted Dr. Husband as stating that the  employee’s “work activities did not cause, aggravate or accelerate the osteoarthritis of her hands.”

As proof of her Gillette injury claim, the employee points to her testimony indicating that she experienced the symptoms while performing work activities, that, with the passage of time, her symptoms increased, and that, by the end of the week, her symptoms were worse than at the beginning of the week.  An employee’s testimony alone, however, is not sufficient to establish a causal connection between her work activities and ensuing disability.  Barros v. Scimed Life, slip op. (W.C.C.A. May 4, 2004).  Proving a Gillette injury “primarily depends on medical evidence.”  Steffen v. Target Stores, 517 N.W.2d 579, 50 W.C.D. 464 (Minn. 1994).

The employee also contends that Dr. Urban, as her treating doctor, had proper foundation for his opinions and that the judge should therefore have accepted his opinions.  Again we are unpersuaded.  A judge need not accept the opinion of a treating doctor even if that doctor has foundation for his opinion.

Dr. Urban opined that the employee’s work activities in the wafer fabrication department “would require grasp and use of the fingers in a repetitive nature” and that such activities caused a permanent aggravation of the employee’s underlying arthritis, which eventually required surgical treatment.  Dr. Falconer, on the other hand, opined that the employee had preexisting arthritis that was “not aggravated by work significantly.”  Dr. Falconer subsequently reviewed an 18-minute DVD analysis of the employee’s work duties, and he was also provided with cassette boxes, a cassette holder, and individual samples of the wafer.  He then reported that the employee’s work activities “were not sufficiently intense, forceful or strenuous enough to accelerate, aggravate or provide contributory worsening of her generalized inflammatory osteoarthritis.”  He disagreed with Dr. Urban’s opinion that the work activities involved “forceful pinch, grasp, push motions sufficient enough to aggravate or worsen her generalized inflammatory osteoarthritis.”  Similarly, Dr. Husband concluded that the employee’s work activities “did not cause, aggravate or accelerate the osteoarthritis of her hands.”

A judge’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.  Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985).  Drs. Urban and Falconer disagreed as to whether the employee’s work activities in the wafer fabrication department required repetitive grasping and pinching of the fingers.  The judge chose Dr. Falconer over Dr. Urban, and the employee has pointed to no unsupported facts assumed by Dr. Falconer.  We also note that Dr. Urban had released the employee to return to work in the wafer fabrication department in December of 2010 in spite of restricting the employee from firm grasping with the right hand.  This would seem contrary to his subsequent opinion that grasping was aggravating her hand conditions.  We find no basis to reverse the judge’s choice of expert opinion, and we affirm the judge’s findings and order in their entirety.^[6]