LINDA LUDFORD, Employee/Cross-Appellant, v. HONEYWELL, INC., SELF-INSURED, Employer/Appellant, and BLUE CROSS/BLUE SHIELD OF MINN. and CENTER FOR DIAGNOSTIC IMAGING, Intervenors.
WORKERS= COMPENSATION COURT OF APPEALS
MARCH 17, 2004
PERMANENT TOTAL DISABILITY - SUBSTANTIAL EVIDENCE. Where the employee was subject to an extreme multitude of nonwork-related diagnosed maladies in addition to her work-related injuries, where the judge=s decision was supported by expert medical opinion, and where the judge=s decision was not unreasonable in light of the employee=s age, training, and experience, the compensation judge=s conclusion that the employee remained permanently and totally disabled and had not received benefits fraudulently or in bad faith was not clearly erroneous and unsupported by substantial evidence.
CAUSATION - SUBSTANTIAL EVIDENCE. Where it was supported by expert medical opinion, the compensation judge=s conclusion that the employee=s work injury was limited to her right and left shoulders was not clearly erroneous and unsupported by substantial evidence.
Determined by: Pederson, J., Johnson, C. J., and Stofferahn, J.
Compensation Judge: Gary Hall
Attorneys: Michael J. Patera, Buffalo, MN, for the Appellants. Lorrie L. Bescheinen, Borkon, Ramstead, Mariani, Fishman & Carp, Minneapolis, MN, for the Cross-Appellant. Thaddeus V. Jude, St. Paul, MN, for the Special Compensation Fund.
WILLIAM R. PEDERSON, Judge
The self-insured employer appeals from the compensation judge's conclusion that the employee is permanently and totally disabled and has not received benefits in bad faith. The employee cross-appeals from the judge=s conclusion that the employee sustained work injuries only to her shoulders on the date at issue. We affirm.
On January 27, 1972, Linda Ludford sustained a work-related injury when she fell over backward in her chair in the course of her employment as a factory line worker with Honeywell, Inc., which was self-insured at the time against workers= compensation liability. Ms. Ludford [the employee] was twenty-four years old on that date and was earning a weekly wage of $141.60. The employee evidently received treatment from Honeywell doctors immediately following the injury, and eventually, on April 10, 1972, she commenced treatment for continuing pain in specifically her right shoulder with Dr. Rodney Peterson, who temporarily restricted her from working. Honeywell, Inc. [the employer], admitted liability for a right shoulder injury and commenced payment of benefits. By May 2, 1972, the range of motion in the shoulder was essentially normal, and Dr. Peterson released the employee to return to work with restrictions.
On October 24, 1972, the employee was seen by Dr. W. B. Park, who characterized the nature and extent of her injury as A[s]welling over right clavicle.@ Subsequently, on November 20, 1972, the employee was examined also by orthopedist Dr. Paul Gustafson, who eventually performed surgery on the shoulder in January of 1973. Subsequent to that surgery, sometime before May 7, 1973, the employee began to experience pain also in her left shoulder. Her condition gradually improved, however, through the course of the summer, and on October 2, 1973, Dr. Gustafson wrote to the claims adjuster opining that the employee was capable of doing Asome type of work in front of her on a sit down basis,@ although it remained the doctor=s Afirm opinion at the present time that [the employee] is disabled@ from performing Aher whole job in a repetitive form.@ By December 4, 1973, the employee was complaining of Ahaving pains in all her joints, in both shoulders, in both knees which have been swollen before as well as in her left dorsum of her foot.@ The employee has apparently not worked since 1973.
In the years subsequent to her work injury, the employee=s physical and emotional condition grew increasingly complex. On May 23, 1974, she returned to Dr. Gustafson, complaining now that her left shoulder pain was worse than the right shoulder pain. Five months later, however, on October 31, 1974, Dr. Gustafson rated the employee=s right shoulder permanent partial disability at 25% and restricted the employee from performing any repetitive motion with the arm, especially above shoulder level, characterizing the employee=s left shoulder symptoms as Amigratory pains which are not related to her right shoulder injury.@ By the time the employee saw Dr. Gustafson again, on April 15, 1975, her right thumb was also becoming very painful, as was a bump on her left wrist, both of which Dr. Gustafson injected with Xylocaine. By September 16, 1975, the employee=s pain had moved into both elbows, and she had pain also in her right wrist and thumb.
On September 17, 1976, the employee was examined for the employer by neurologist Dr. Brian Krasnow, who diagnosed exogenous obesity, hypertension, low back syndrome, right upper extremity pain, and either cervical radiculopathy or entrapment neuropathy. Dr. Krasnow concluded, however, that there was no evidence of any neurological deficit that could account for the employee=s complaints and that the employee was therefore retrainable without limitation from a neurological point of view.
On March 2, 1977, the employee was examined by rheumatologist Dr. Daniel Hathaway, to whom the employee complained that her work injuries on January 27, 1972, included injuries to both wrists, both elbows, both knees, her low back, the base of her thumbs, and her right hand, in addition to injuries to her shoulders. Dr. Hathaway indicated that he was unable to make a rheumatologic diagnosis of the employee and that he could not find any arthritis or other reason why she should not be able to utilize her hands in normal fashion.
On June 20, 1979, the employee commenced treatment with rehabilitation specialist Dr. A. V. Anderson, complaining primarily of right and left shoulder pain. Dr. Anderson diagnosed minimal right shoulder post-surgical residuals, moderate post-traumatic right and left shoulder residuals, chronic pain syndrome, residuals of cervical strain and thoracic sprain, endogenous obesity, endogenous depression, bilateral carpal tunnel syndrome, and extreme deconditioning. On July 8, 1979, the employee was admitted into a chronic pain program with Dr. Anderson. Upon her discharge on August 10, 1979, her diagnosis was improved but very similar, and Dr. Anderson released her to return to work restricted from sustained positions involving the cervical spine and repetitive bending of the neck. The employee apparently did not subsequently obtain suitable work.
On October 16, 1980, the employee was examined on referral from Dr. Anderson by orthopedic surgeon Dr. Robin Crandall with regard to her left shoulder pain. On October 20, 1980, Dr. Crandall diagnosed probable acromioclavicular impingement syndrome, and the following day he performed an acromioplasty of the left shoulder with rotator cuff repair. Upon discharging the employee on October 24, 1980, Dr. Crandall also diagnosed probable mild superficial phlebitis of the right leg, and about a month later, on December 3, 1980, he apparently performed also an A-1 pully release of the left thumb and injected a steroid into the left long finger. In a physician=s report on that same date, December 3, 1980, Dr. Crandall related the employee=s left shoulder condition to her injury at the employer in 1972. In a letter to the claims adjuster on February 10, 1981, Dr. Crandall stated that, although Athere does seem to be some resistance regarding returning to work,@A[o]verall, I think [the employee] is the type of person that certainly could get back into the work force and I hope she will be able to do this.@
The employee=s back complaints continued, however, and the employee did not apparently return to work. On June 28, 1985, on referral from Dr. Anderson, the employee underwent a CT scan of her lumbar spine, which was read to reveal mild hyperlordosis, mild disc space narrowing at L4-5, mild degenerative central bulging of the disc annulus at L5-S1, and evidence of spina bifida occulta at S1, although there was no evidence of thecal sac or nerve root impingement and no herniation. A couple of years later, on January 21, 1988, again on referral from Dr. Anderson, the employee underwent also an MRI scan of her lumbar spine, which was read to reveal a slight nuclear dehydration and vertical disc narrowing at L3-4 and L4-5. There was also noted some minor facet joint asymmetry at L4-5 and L5-S1, but there was no evidence of any lumbar disc herniation, nerve root compression, or bony stenosis. Eventually, on May 19, 1988, Dr. Anderson concluded, however, that he had Asevere doubts as to whether or not [the employee] would be gainfully employable,@Ataking into consideration the physical limitations and also her mental and emotional state.@
On June 27, 1988, the employee was examined for the employer by orthopedic surgeon Dr. Nolan Segal, who diagnosed chronic myofacial pain syndrome of the neck and back, status post bilateral rotator cuff surgery. Noting the employee=s normal EMG and unremarkable CT scan, MRI scan, and cervical x-rays, Dr. Segal concluded that the employee could not be considered totally disabled from gainful employment based only on objective findings. However, noting that there appeared to be "a significant psychological component to her problem," Dr. Segal concluded finally that Abased on the overall psychologic picture she would be a poor candidate to go through vocational rehabilitation and the prospects of her returning to gainful employment are bleak. In that respect I feel she is disabled from gainful employment.@ On August 10, 1988, Dr. Anderson reiterated that he was Adoubtful that [the employee] would be able to qualify for competitive gainful employment.@ Four years later, on October 5, 1992, Dr. Anderson went further in stating, ABased on my medical evaluation of [the employee] at this office, it is my opinion . . . that she is totally disabled from gainful employment. This disability is expected to last at least 12 months from the present date.@ Finally, on March 22, 1996, in a letter to AThe Travelers Company@ regarding its Apolicy holder,@ Dr. Anderson indicated unequivocally that it was his Aopinion that [the employee] will never be able to return to any type of gainful employment@ and that A[t]hroughout the time that I have seen [her], she has been permanently and totally disabled from any type of gainful employment.@
The employee was evaluated two months later, on May 20, 1996, by Dr. Gary Robinson, who noted that he had seen the employee several months earlier in the emergency room for severe congestive heart failure, prior to her undergoing a coronary artery bypass. Dr. Robinson diagnosed longstanding hypertension, coronary artery disease, diabetes mellitus, reflux esophagitis, and probable chronic personality disorder and anxiety, with a possible history of sleep apnea and seizure disorder and chest, neck, and shoulder problems, for which Dr. Robinson recommended heat, stretch, massage, and Aspercreme therapy.
From September 1997 through January 2003, the employee received treatment also from Dr. Larry Grong, for various problems, including the following: chronic sinusitis/bronchitis, dizziness, hyperlipidemia, migraine headaches, hypothyroidism, coronary artery disease, hypertension, tobacco abuse, renal insufficiency, seizures, depression, diabetes, degenerative joint disease, asthma, bilateral knee pain, leg swelling, chronic back pain, chest pain, right elbow pain and synovitis, trigger finger, bilateral plantar fasciitis, anxiety, emphysema, neck strain and spasm, right hip pain, bilateral sciatica, right corneal abrasion, right arm swelling, bursitis, right shoulder pain, left elbow epicondylitis, restless leg syndrome, chronic arthralgias, thumb laceration, allergic rhinitis, fatigue, and left wrist and hand pain.
On February 26, 1998, the employee was seen at the Northeast Orthopaedic Center in Watertown, South Dakota, where she began treatment for various problems over the course of the next two years. Upon examination on that date, she was diagnosed with a bony contusion of the left patella, with neuritis of the saphenous nerve and a possible but unlikely medial meniscal tear in that knee, and with a possible medial meniscal tear in the right knee. X-rays of her knees on that same date also revealed mild patellofemoral and tibiofemoral osteoarthritis in both knees. The following month, on March 10, 1998, she underwent an MRI scan of the right knee, which proved negative, and two days later, on March 12, 1998, her knee diagnosis was revised to probable patellofemoral catching of the right knee and degeneration of the left knee. On that same date, the employee was also diagnosed with a Atriggering@ left index finger, and several months later, on November 23, 1998, she underwent oblique-view x-rays of a painful right elbow. The x-rays were read to reveal no acute findings, but the radiologist recommended obtaining lateral-view x-rays for complete evaluation, and in December of that year the employee was diagnosed with probable traumatic synovitis of the right elbow, together with left carpal tunnel syndrome. Two weeks later she was diagnosed also with medial epicondylitis/flexor pronator strain of the left elbow. In January of 1999, the employee underwent left index finger trigger release surgery. On July 15, 1999, she was diagnosed with moderate osteoarthrosis of the left knee, and three months later, on October 14, 1999, she was diagnosed with plantar fascitis at both heels.
On December 30, 1999, the employee underwent x-rays of her cervical spine and right elbow, which were read to reveal a possible nondisplaced fracture in the neck but no acute findings in the elbow. On March 28, 2000, the employee underwent an MRI scan of her low back, which was initially read by Dr. Albert Ruhe to reveal no specific abnormalities. On April 10, 2000, she underwent x-rays of her right elbow, which were read to reveal a probable Abone island@ in the trochlea of the distal humerus in that joint, but no evidence of joint effusion, fracture, or significant degenerative changes. On April 20, 2000, the employee was diagnosed with right olecranon bursitis in the right elbow and right long finger trigger problems, for which she underwent release surgery in May of that year. The following month, on May 18, 2000, she underwent further x-rays of the elbow, which were read to reveal no abnormalities.
On February 14, 2001, the employee underwent a lumbar MRI scan, which was read to reveal multilevel degenerative disc disease of the lumbar spine, with a moderate-sized extruded foraminal disc herniation at L4-5 on the left, with moderate compression of the left L4 nerve root ganglion. Two days later, she also underwent x-rays of her pelvis and neck, which were read to reveal mild degenerative changes of the SI joints, severe degenerative disc disease at C6-7 with probable neuroforaminal stenosis, and moderate degenerative changes of the lower cervical spine. On March 13, 2001, Dr. Anderson reported to the employee his opinion that she was subject to a 20% permanent partial disability of the spine related to cervical and lumbar injuries that she had sustained Ain the accident of January 5, 1972,@ and that she was subject also to an additional 3% rating related to her thoracic spine.
On September 9, 2002, the employee filed a claim petition, alleging entitlement to compensation for a 20% permanent partial disability of the spine related to her neck and low back and for an additional 3% permanent partial disability of the spine related to her mid back, all consequent to her work injury on January 27, 1972. On October 10, 2002, the employee=s March 28, 2000, lumbar MRI scan was reread, this time by Dr. Ugur Camli, to reveal a left foraminal disc herniation at L4-5.
On February 18, 2003, the employee was examined for the employer by internal medicine specialist Dr. Jeff Luther, who noted in part the employee=s history of progressive multi-level degenerative disc disease, bilateral shoulder decompression surgeries, diabetes mellitus, hypertension, thyroid disorder, seizure disorder, chronic pain syndrome, depression, questionable somatization disorder, post right-sided carpal tunnel surgery, and several injections into the shoulders and elbows to relieve various pain complaints. Dr. Luther concluded the following in response to queries of the employer=s attorney: (1) that on January 27, 1972, assuming the mechanism of injury described by the employee, the employee sustained a contused shoulder on the right and possibly on the left, although A[i]t is nearly impossible after this many years to determine exactly what type of injury she sustained on that date,@ and that none of the employee=s nonshoulder maladies could be causally related to that injury; (2) that the employee sustained a 25% impairment of her right shoulder and a 15% impairment of her left shoulder as a result of her January 1972 work injury; (3) that the employee was not subject to any Asignificant@ restrictions consequent to her work injury; (4) that it was Apossible@ that treatment for the employee=s shoulders bilaterally was reasonable and necessary treatment for her work injury but that it was Ahighly unlikely@ that the injections of her elbows and her carpal tunnel surgery were reasonable and necessary treatment for that injury; (5) that the employee=s current symptoms were related to a degenerative process, and any ongoing treatment would be related to aging rather than to the work injury; and (6) that the employee=s mild shoulder impinging and degenerative spinal changes were not related to her work injury.
On April 24, 2003, the employer filed a petition to discontinue wage loss benefits, on grounds that the employee Adoes not need significant physical restrictions and is physically capable of performing employment,@ including Aher pre-injury job and many other jobs at [the employer].@ In support of its petition, the employer cited expert medical opinion and attached income tax records to support the assertion that the employee had Abeen earning an income from the operation of a do[g] kennel for at least 6 years.@ Asserting also that the employee=s actual Aearning capacity exceeds her pre-injury wage,@ the employer alleged that the employee had Abeen fraudulently receiving wage loss benefits from the Employer since at least 1997 and Employer is entitled to reimbursement of the same from Employee,@ in addition to discontinuance of benefits.
On June 10, 2003, the employee=s claim petition and the employer=s petition to discontinue benefits were consolidated for hearing, and the matter came on for hearing on June 19, 2003. Issues at hearing included (1) the nature of the employee=s January 27, 1972, work injury, (2) the employee=s entitlement to additional permanent partial disability benefits related to her back, (3) the employer=s liability for certain disputed outstanding medical expenses, (4) the employer=s entitlement to discontinue permanent total disability benefits, and (5) whether the employee had accepted wage loss benefits fraudulently or in bad faith, entitling the employer to reimbursement of benefits paid in error. Evidence introduced at hearing included surveillance videotape and a report of Sedgwick investigators purporting to show that, between Tuesday January 14, 2003, and Sunday January 19, 2003, the employee negotiated and contracted with them to board a small dog over the weekend, in a manner implying that she was an agent of one Shaw Kennels, operating out of her home, although she was at that time purportedly totally disabled from employment. Also admitted into evidence was a kenneling agreement, dated January 16, 2003, between Shaw Kennels, signed for by one Bruce Shaw, and the investigator, purporting to be the dog=s owner. At the hearing, Bruce Shaw, who lives with the employee, testified that Shaw Kennels is his business, that he handles all material aspects of the work related to the business, and that the employee is not an employee of the business, although she has invested some capital in it. Also introduced into evidence at the hearing were the employee=s tax records from 1997 through 2001, on which the employee had identified herself as a Adog breeder@ by occupation and had reported business losses against her alimony income. The employee declined to testify as to these records, citing the Fifth Amendment=s protection against self-incrimination.
By findings and order filed August 18, 2003, the compensation judge concluded in part the following: (1) that, on the date alleged, the employee sustained an injury to both shoulders but not to any other part of her body; (2) that the permanent partial disability alleged by the employee was not causally related to her work injury; (3) that the employer was liable for medical expenses related to treatment of both of the employee=s shoulders but not for any other treatment or any claimed mileage expenses; (4) that intervenors Blue Cross/Blue Shield of Minnesota and the Center for Diagnostic Imaging were entitled to reimbursement for expenses paid for treatment to the employee=s shoulders; (5) that the employee was entitled to continuation of her permanent total disability benefits, due in substantial part to her work-related shoulder injuries; (6) that, due in substantial part to her work injuries, the employee was medically restricted from any employment, including her pre-injury job; (7) that the employee=s current earning capacity did not exceed her date-of-injury weekly wage; (8) that the employee continued to have restrictions on the use of both of her shoulders, which, together with her numerous nonwork-related disabilities, prevented any chance of her return to gainful employment; and (9) that the employee had not received any workers= compensation benefits fraudulently or in bad faith and the employer was not entitled to reimbursement of any benefits on this basis. On those findings, the compensation judge denied the employee=s claims for permanent partial disability benefits and for payment of medical expenses other than those related to her shoulders, and he denied the employer=s petition to discontinue benefits and for reimbursement of benefits allegedly paid in error. The employer appeals, and the employee cross appeals.
STANDARD OF REVIEW
In reviewing cases on appeal, the Workers= Compensation Court of Appeals must determine whether Athe 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 (1992). Substantial evidence supports the findings if, in the context of the entire record, Athey 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, A[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 Food 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, Aunless 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.
1. The Employer's Appeal - Permanent Total Disability and Discontinuance
At Finding 1, the compensation judge concluded that the employee sustained work injuries to both of her shoulders on January 27, 1972, and at Finding 2 the judge concluded that the employee continues to be permanently and totally disabled due in substantial part to those injuries. In his memorandum, the judge supported these conclusions by noting that the employee=s right shoulder problems have been admitted as work related, that the February 18, 2003, report of Dr. Luther supports the work-relatedness of the employee=s left shoulder problems as well, and that the employee is subject also to various other nonwork-related ongoing cervical, thoracic, and lumbar conditions. The judge explained,
The employee is 56 years old and has not worked since 1973. Her ongoing disability from the bilateral shoulder injuries and surgeries, together with her non work-related disabilities, her age, her education, and the length of time she has been out of the workforce, combine to support a finding of permanent total disability.
With regard to the employee=s alleged demonstrated ability to work with Shaw Kennels, the judge stated that Aeven assuming the employee=s answers to those questions [regarding her tax records in this regard, to which she pleaded the Fifth Amendment] would be against her interests, there still is no real evidence of gainful employment.@ On appeal, the employer contends that there is no vocational opinion indicating either that the employee=s shoulders-related restrictions would significantly impact her ability to work or that her age, education, training, and experience would be vocationally significant. Moreover, the employer argues, the employee has not performed a job search and has evidently been engaged in self-employment activities since at least 1997 to the extent that she has identified herself as a Adog breeder@ on her income tax returns ever since that year. We are not persuaded.
The testimony of both the employee and Mr. Shaw was that the employee was not employed in or otherwise actively involved in Shaw Kennels except to the extent that she had a financial investment in it, and the judge was clearly entitled to accept that testimony as an assertion of fact. See Brennan v. Joseph G. Brennan, M.D., 425 N.W.2d 837, 839-40, 41 W.C.D. 79, 82 (Minn. 1988), citing Spillman v. Morey Fish Co., 270 N.W.2d 781, 31 W.C.D. 187 (Minn. 1978) (assessment of the credibility of witnesses is the unique function of the trier of fact). Moreover, we have observed the videotape of the employee=s activity in her home at the times of the investigator=s dropping off and picking up of the dog, and we conclude that it would not have been unreasonable for the compensation judge to conclude that the employee as observed on that tape was substantially disabled physically from meaningful employment, particularly in light of other information contained in the employee=s very substantial medical records in evidence. Already in 1988 Dr. Segal concluded that Athe prospects of [the employee=s] returning to gainful employment are bleak.@ And Dr. Anderson, who directed the employee=s treatment for over twenty-one years, also became increasingly convinced that the employee would never work again, finally concluding unequivocally in 1996 that the employee was permanently and totally disabled and had been since 1979. Nor was it unreasonable for the judge to conclude that a viable earning capacity was not demonstrated by the employee=s tax records, notwithstanding that the employee had represented herself on them as a dog breeder. The tax records at issue reveal only business losses to the employee from Shaw Kennels, and there is no evidence that the employee=s represented activity in dog breeding was anything more than a financial investment in Bruce Shaw=s business. Indeed, there is affirmative testimonial evidence to the contrary.
In light of the opinions of Drs. Segal and Anderson, in light of the extreme multitude of nonwork-related diagnosed maladies to which the employee is subject in addition to her work-related injuries, and in light of the employee=s age, training, and experience, we conclude that it was not unreasonable for the compensation judge to find the employee permanently and totally disabled at the time of the hearing. Because that finding was not unreasonable, we affirm the judge=s denial of the employer=s petition to discontinue wage replacement benefits. See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239. Because we are affirming the judge=s finding that the employee is entitled to continuing permanent total disability benefits, the employer=s allegation that the employee has received benefits fraudulently or in bad faith is moot.
2. The Employee's Cross Appeal - Nature and Extent of Injury
The compensation judge found only the employee=s shoulder conditions to be causally related to her January 27, 1972, work injury, and he denied the employee=s claims for additional permanent partial disability benefits or payment of medical expenses related to any other condition. The employee contends that this conclusion is unsupported by substantial evidence. She argues that she Atestified credibly that at the time of her injury she sustained injuries to . . . her neck and back,@ that her right shoulder was the sole object of her initial medical attention only Abecause it was so painful,@ and that Aas her shoulder pain decreased, she noticed the pain in her neck, low back and left shoulder.@ She argues that Dr. Anderson opined that her need for medical care and treatment to her neck and low back were also related to the work injury, that independent examiner Dr. Segal, in his 1988 report, did not say that they weren=t related, that the only medical evidence discounting that causal relationship was Dr. Luther=s 2003 independent medical evaluation, and that A[s]ubstantial evidence, including medical records as well as the Employee=s testimony, supports a finding that the Employee did indeed sustain injuries to her cervical and lumbar spine as a result of the work-related injury.@ We are not persuaded.
We would reiterate initially, as we often have in the past, that the factual issue on appeal is not whether substantial evidence may or may not exist to support a conclusion other than that reached by the compensation judge but whether substantial evidence exists to support the conclusion actually reached by the judge. Nor is the employee=s own opinion as to the source of the neck and back pain that eventually superseded her shoulder pain determinative in this case. As we reiterated above, assessment of the credibility of witnesses is the unique function of the trier of fact, see Brennan, 425 N.W.2d at 839-40, 41 W.C.D. at 82, and, even to the extent that the employee might be deemed to have testified credibly as to her own perceptions, the judge was not obligated to agree with the employee=s opinion as to the cause of her nonshoulder maladies in the face of contrary medical opinion. The causation issue in this case appears to have come down to a choice between medical experts, and the compensation judge implicitly appears to have chose to accept the opinion of Dr. Luther over that of Dr. Anderson on this issue. A trier of fact's choice between experts whose testimony conflicts is normally 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, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985). Concluding that Dr. Luther=s opinion does not appear to have been based on any false premises, we affirm the judge=s conclusion that the employee=s work injury was limited to her right and left shoulders, in keeping with the opinion of Dr. Luther.
The decision of the compensation judge is affirmed in its entirety.
 See Schulte v. C. H. Peterson Constr., 278 Minn. 79, 83, 153 N.W.2d 130, 133-34, 24 W.C.D. 290, 295 (1967) ("a person is totally disabled if his physical condition, in combination with his and the type of work available in his community, causes him to be unable to secure anything more than sporadic employment resulting in an insubstantial income").