MARTI VIKER, Employee/Appellant, v. WAL-MART and AIG/CLAIMS MGMT., INC., Employer-Insurer, and NORAN NEUROLOGICAL CLINIC and NORIDIAN ADMIN. SERVS., LLC/MEDICARE, Intervenors.
WORKERS= COMPENSATION COURT OF APPEALS
JANUARY 19, 2005
CAUSATION - TEMPORARY AGGRAVATION; CAUSATION - PRE-EXISTING CONDITION. Where the employee=s pre- and post-work-injury radiological studies were essentially unchanged, where the employee=s average symptom levels in the months immediately preceding the injury were very similar to his average symptom levels in the months immediately following the injury, and where the judge=s decision was supported by expert medical opinion, the compensation judge=s conclusion that the employee=s low back work injury was only a temporary aggravation of a significant preexisting low back condition was not clearly erroneous and unsupported by substantial evidence.
Determined by: Pederson, J., Johnson, J., and Wilson, J.
Compensation Judge: Bradley J. Behr
Attorneys: Steven S. Fuller, Fuller Law Firm, Rochester, MN, for the Appellant. Christopher E. Sandquist, Gislason & Hunter, Mankato, MN, for the Respondents.
WILLIAM R. PEDERSON, Judge
The employee appeals from the compensation judge's conclusion that the employee=s work injury was a temporary aggravation of a preexisting disability and was not a substantial contributing factor in the employee=s permanent total and permanent partial disability. We affirm.
The medical history in this case is lengthy and problematic with regard to the workers= compensation claim here at issue. Marti Viker has been subject since birth to degenerative scoliosis of the spine and nondegenerative cerebral palsy, the latter condition having resulted in a surgically shortened left leg and an antalgic gait. Mr. Viker graduated from high school in 1976 and subsequently obtained vocational training as a gunsmith, which he has since that time put to some use primarily in stocking of sporting goods and other retail employment. Between 1990 and 1992, Mr. Viker was treated for low back and right leg pain on a number of occasions subsequent to a motor vehicle accident and several different lifting incidents. A lumbar MRI scan conducted in June of 1992 was read to reveal a normal spine except for a bulging annulus at the L5 level, which was not impinging on the adjacent thecal sac or exiting nerve roots.
In October of 1994, Mr. Viker sustained further injury to his low back as a result of another motor vehicle accident. Subsequent to the latter injury, on October 14, 1994, Mr. Viker sought treatment with chiropractor Dr. Robert Jensen, who initially restricted Mr. Viker to four-hour working shifts. On February 3, 1995, on referral from Dr. Jensen, Mr. Viker was examined by neurologist Dr. Steven Noran, who diagnosed a low back injury with lumbosacral sprain/strain, noting, AObviously, his cerebral palsy is a predisposing factor to this condition but not a cause.@ Dr. Noran recommended continued treatment with Dr. Jensen and ordered a CT scan. The scan, which was conducted on that same date, was read to reveal a small disc herniation at L5-S1 without evidence of any nerve root compression or displacement or degenerative spurring or bony stenosis, together with bulging discs at L3-4 and L4-5.
On March 9, 1995, Mr. Viker saw Nurse Practitioner Charlotte Farmer at the Noran Neurological Clinic, Avery frustrated with the persistent back symptoms.@ He complained to Nurse Farmer that his symptoms were radiating across his back and out toward his hips, that he was sometimes experiencing some Amushy, Jello-like feeling@ in his left knee, though no shooting leg pains, and that he was Areally feeling it@ to be working, even limited to a four-hour shift. Nurse Farmer diagnosed status post low back injury with persistent spasm, together with mild cervical sprain/strain, and she prescribed pool therapy and referred Mr. Viker back to Dr. Jensen. On April 7, 1995, in a letter to attorney Ross Muir, who was apparently representing Mr. Viker in proceedings related to his October 1994 automobile accident, Dr. Jensen recommended that Mr. Viker be restricted from working more than twenty hours a week, that he avoid bending at the waist to pick up objects from the floor, that he avoid rapid spinal flexion/extension, rotation, or lateral bending, that he avoid lifting twenty pounds from desk height to desk height, that he avoid lifting more than five pounds from floor to desk height, and that he avoid lifting even five pounds more frequently than once every five minutes.
When she saw Mr. Viker again on May 11, 1995, Nurse Farmer noted that his back pain continued and that his left knee had given out again a couple of times in the interim. In addition to her previous diagnosis, Nurse Farmer noted moderate spasm bilaterally in the lumbar paravertebral region, and she outlined for Mr. Viker how to gradually try to increase his work hours by one hour every week or two. However, when he returned for follow-up on July 6, 1995, Mr. Viker was still Avery frustrated,@ in that he had Anot been able to increase his activities without immediate flare-ups, to the point he can hardly move.@ Noting that Mr. Viker Awants to work full time, but he has had such terrific pain@ that Ahe is becoming depressed,@ Nurse Farmer expressed A[c]oncern for progression into chronic pain syndrome.@ About September 8, 1995, in a report to Dr. Jensen, Dr. Noran referenced the employee=s reirritation of his low back a few weeks earlier, when the latter had bent over to pick up a fifty-five-pound package of rifles. Dr. Noran indicated that the employee=s work activities Aremain a four to five hour work day with limitation@ and that he Acontinues to have sacral pain.@ On those findings, Dr. Noran diagnosed A[l]umbar disc injury with lumbosacral myoligamentous sprain/strain syndrome superimposed on pre-existing scoliotic curvature related to [Mr. Viker=s] long standing CP.@
Mr. Viker evidently also sustained a number of other aggravations of his low back condition subsequent to his October 1994 motor vehicle accident, but he was gradually able to increase his hours at work. By March 14, 1996, according to Nurse Farmer=s records, he was having milder back pain and had been bringing his normal work schedule up to a regular full-time, eight-hour work day, although he was Astill frustrated with the whole system and that he cannot do all the activities he could do before.@ On April 22, 1996, Dr. Jensen reported to attorney Muir that Mr. Viker was subject to Asustained instability of the holding elements, particularly the muscles, ligaments, and fascia in the area of the thoracolumbar spine,@ and he opined that Mr. Viker had suffered permanent injuries as a result of his October 6, 1994, automobile accident.
During the summer and fall of 1996, while apparently back working full time at his job as a salesclerk in the sporting goods department at Wal-Mart, Mr. Viker evidently continued to experience ongoing low back pain that was evidently aggravated by lifting and extended walking, standing, or sitting. On September 25, 1996, while so employed, Mr. Viker sustained a work-related injury to his low back when he reached out to prevent a gun cabinet from falling over in the course of his work. Mr. Viker [the employee] was thirty-nine years old on the date of this injury and was earning a weekly wage of $268.00. Subsequent to his injury, the employee was treated by Dr. Jensen=s partner, Dr. Kevin Huelskamp, who evidently restricted the employee from all work on September 27, 1996. On October 10, 1996, the employee was examined also by Nurse Farmer, who diagnosed A[p]ost musculoligamentous sprain, acute in the past few weeks,@ with A[n]o new radicular symptoms.@ She prescribed medication and a TENS unit and recommended that the employee consult his chiropractor as to Ahow to gradually try to get back into light-duty work.@ On October 18, 1996, however, and without remark, Dr. Huelskamp continued the employee=s total restriction from working.
On January 17, 1997, the employee was examined again by Dr. Noran, who, noting that the employee had not been back to work since his September 1996 work injury, reported that the employee had recently Ahad an episode where he was leaning back to lean on a bean bag chair with his four-year-old daughter when he experienced [a] sudden onset of very severe pain in the right paraspinous lumbar muscles.@ Dr. Noran diagnosed A[w]ork-related injury with acute aggravation of pre-existing back injury,@ together with A[o]ngoing lumbar myoligamentous sprain/strain syndrome with underlying disc herniation at L5-S1 and congenital abnormality in the lumbosacral region on the right side.@ Dr. Noran ordered another CT scan, which was conducted and read on that same date to reveal no significant change in findings since the employee=s February 3, 1995, scan, prior to his work injury. On March 24, 1997, Dr. Huelskamp continued the employee=s total restriction from work again, Aas he has not reached MMI.@ On May 1, 1997, the employee was examined again by Nurse Farmer, who noted that A[o]verall, he is doing a little bit better,@ although the employee was unable to tolerate bending or turning quickly or prolonged sitting. Nurse Farmer diagnosed A[p]ost lumbar injury, related aggravation of September 1996,@ together with ongoing mechanical back pain symptoms, and she recommended continued follow-up at Dr. Jensen=s clinic.
On May 2, 1997, Dr. Huelskamp indicated in a memorandum ATo Whom It May Concern@ that the employee Aseems to have reached Maximum Medical Improvement with possible permanent disability@ and that the employee=s treatment, including the issuance of work restrictions, was now being referred to Dr. Noran. On that same date, May 2, 1997, the employee filed a claim petition, alleging entitlement to temporary total disability benefits continuing from September 25, 1996, to unknown permanent partial disability benefits, to penalties for the employer=s failure to make workers= compensation payments, to payment of $5,520.95 in medical and chiropractic bills, and to possible rehabilitation assistance. By May 21, 1997, the employee, still restricted from working, had received some eighty-eight treatments at the Jensen Chiropractic Clinic since the September 25, 1996, date of his work injury, in the records of which are noted several different exacerbations of symptoms associated with several different nonwork-related activities. Wal-Mart [the employer] and its workers= compensation insurer eventually accepted liability for a September 25, 1996, work injury and commenced payment of various benefits, including compensation for wage loss and payment of treatment expenses.
On July 2, 1997, on referral from Dr. Noran, the employee underwent a psychiatric examination at the Mayo Clinic with Drs. Steven Yost and Donald McAlpine, whose histories address in some detail both the employee=s 1994 motor vehicle accident and his 1996 work injury. In his separate report, Dr. Yost notes that the employee Aat one point stat[ed] that the accident has kept him from pursuing what he would like to do which is opening his own shop gunsmithing.@ In his separate report, Dr. McAlpine notes that the employee=s Amemory has been diminished he says since the motor vehicle accident in 1994. In general, he says since the motor vehicle accident >I just don=t feel right=.@ The doctors prescribed psychotherapy, concluding also that A[c]onsideration of [a] pain management approach might be given.@
On July 10, 1997, the employee was examined also, apparently with regard to his October 1994 motor vehicle accident, by orthopedic surgeon Dr. Paul Wicklund, who, in a July 14, 1997, report to Legal Assistant Kendrea Kim Moccia, diagnosed chronic back pain, chronic neck pain, and cerebral palsy involving the left lower extremity. It was Dr. Wicklund=s opinion that the October 1994 motor vehicle accident resulted in only a temporary flare-up of the employee=s preexisting condition, not in any permanent injury, and that the employee was currently off work because of his September 1996 work-related injury. About a week later, however, in a July 22, 1997, letter to attorney Muir, Dr. Noran rendered an opinion that the employee had sustained a 15% permanent partial disability of the spine consequent to the October 1994 motor vehicle accident. He stated that he was Aaware that [the employee] had some problems with his back off and on before that, but not on a regular basis and had only minor problems since the October 6, 1994, problem,@ adding, AI do not believe [that the employee=s] cerebral palsy is playing a major role in his ongoing problems following the motor vehicle accident.@
By late July of 1997, some ten months after his work injury, the employee had evidently returned to work for the employer, and on August 5, 1997, he was examined for the employer and insurer by orthopedic surgeon Dr. Bruce Davey. After interview and physical examination of the employee and review of his records from the Noran Neurologic, Mayo, and Jensen Chiropractic clinics, Dr. Davey concluded in his August 13, 1997, report that the case was Aobviously complicated secondary to the [employee=s] cerebral palsy and previous history of multiple back injuries@ and that there was Ano objective evidence or radiologic evidence to suggest any conditions which might cause permanent partial impairment as a result of the [work-related] accident in September 1996.@ It was Dr. Davey=s opinion that the September 1996 work injury had substantially aggravated the employee=s preexisting condition but that that aggravation had been only temporary and had since resolved itself satisfactorily. It was Dr. Davey=s further opinion that the employee had reached maximum medical improvement with regard to that work injury on about November 10, 1996, about six weeks after the injury, without any permanent partial disability and without any current need for restrictions or further medical treatment.
On October 17, 1997, in a report to Dr. Huelskamp, Dr. Noran indicated that the employee=s lumbar disc herniation and radiculopathy were Aconsistent with [the employee=s] prior motor vehicle accident@ but had been Asignificantly aggravated by his work related injury.@ About four months later, after examining the employee on February 19, 1998, Nurse Farmer reported that the employee had indicated that Ahe has really tried to build up on hours, but he just seems to have plateaued at five hours.@ AAfter that,@ she reported,@ it seems like his legs and lower back do not want to support his upper body anymore,@ although Athe leg symptoms have decreased [to] where he is not having leg pain all of the time,@ and A[c]urrently he is not noting leg pain or numbness.@ Two months later, on April 15, 1998, the employee evidently slipped or tripped in a dressing room at work and subsequently experienced a recurrence of his low back pain. No separate workers= compensation claim was apparently ever asserted regarding this event.
On about June 3, 1998, the employee=s employment was terminated by the employer, ostensibly for the employee=s missing work without reporting it. As of that date, the employee had evidently never exceeded a five-hour work day since returning to work in July of 1997. On August 7, 1998, Dr. Huelskamp, with whom the employee apparently continued to treat, rated the employee=s permanent partial disability consequent to his October 1994 motor vehicle accident at 9% of the whole body, and he restricted the employee to light duty, with no lifting over twenty-five pounds. Two weeks later, on August 21, 1998, Nurse Farmer diagnosed A[c]hronic low back injury with lumbar disc injury with no new radiculopathy,@ concluding that it was A[n]ot a surgical problem at this time,@ that the employee had reached maximum medical improvement, and that restrictions remained the same.
On May 18, 1999, Dr. Noran diagnosed lumbar disc herniation with central spinal stenosis at L5-S1, lumbar radiculopathy, and chronic lumbar myoligamentous sprain/strain, with superimposed cerebral palsy disability and a gait abnormality contributing to the persistence of the low back problems. Dr. Noran issued permanent restrictions to very light work with no bending, concluding that the employee, Aif he could work, would only be able to do very limited work. He does have a gun smith=s license and I suppose he could do some light smithing.@ Exactly a year later, however, on May 18, 2000, Nurse Farmer concluded that the employee was totally disabled from all work, and on October 25, 2000, Dr. Jensen recommended to the Department of Economic Security that the employee qualify for Social Security disability benefits, Abecause of his chronic Cerebral Palsy problems on top of the chronic spinal instability and associated back problems.@
The following year, on August 7, 2001, noting that the employee=s lumbar symptoms were worsening, Dr. Noran concluded that the employee=s total disability was permanent. An MRI scan about a month later, on September 5, 2001, was read to reveal no significant change in findings since the CT scan of January 17, 1997, although the radiologist=s report did indicate that that the disc herniation at L5-S1 Adoes extend caudal into the intervertebral disc space,@ lying Acontiguous with the ventral aspect of the thecal sac and S1 nerve sleeves,@ and there were Alikely degenerative changes within the L5-S1 zygapophyseal joints.@ On May 2, 2002, in a letter to the employee=s attorney, Dr. Noran indicated that his Acurrent diagnosis of [the employee=s] condition . . . would be that of a chronic lumbar musculoligamentous injury superimposed on pre-existing lumbar disc injury and a past history of cerebral palsy@ and that Athe work injury of September 25, 1996, has been a substantial contributing factor to [the employee=s] on-going diagnosis.@ Dr. Noran opined on that date that the September 25, 1996, work injury had caused a permanent aggravation of the employee=s back condition and that that condition was Asuch that it prevents [the employee] from working full time in a gainful employment position.@
On October 14, 2002, Dr. Jensen, responding to a letter from Betty Rouse of Peterson Rehabilitation Services, indicated that he believed that the employee was capable of low-stress work, restricted to half-time hours initially and to a fifteen-pound lifting limit, with no working on ladders, around machinery with moving parts, or at repetitive physical activity. Dr. Jensen indicated that these restrictions were Acertainly due in large part to the back injury that [the employee] incurred at [the employer] on September 25, 1996.@ Four days later, on October 18, 2002, Nurse Farmer, also writing to Ms. Rouse, reported that the Noran Clinic had put the employee on permanent total disability status Adue to the findings of moderate sized disc herniation at L5-S1 which came in contact with the S1 nerve root.@ She went on to explain,
Therefore, increased pain and disabilities were directly related to the work related injuries. The disc had progressed out further. [I]t was small in the beginning and was not compressing effacing nerve roots. There was also no degenerative changes in his initial study of February 2, 1995, following a motor vehicle accident, but there are now degenerative changes in the facet joints as well[,] adding mechanical back insult to the disc problem. This is superimposed on his long term disability associated with his cerebral palsy.
Consequently, we do not feel he is able to work any duration of hours during the day due to inability to tolerate standing on his feet in one spot or walking back and forth, or repeated sitting due to the disc problem. We have had him on total permanent disability due to the work related injury since May 18, 1998. We do not feel he can tolerate any change or lifting of restrictions.
The report was subsequently signed by both Nurse Farmer and Dr. Noran.
On November 20, 2002, the employee filed a claim petition, alleging entitlement to permanent total disability benefits continuing from May 26, 1998, consequent to his work injury on September 25, 1996. Apparently in December of 2002, at the request of the employee=s attorney, the employee underwent a vocational evaluation with QRC John E. Peterson, to assess the usefulness of further rehabilitation services. After meeting with the employee on several occasions, administering a battery of vocational aptitude tests, reviewing medical records, and consulting with QRC Betty Rouse, who had also met with the employee and recommended further rehabilitation, QRC Peterson concluded that the employee was not capable of obtaining or sustaining competitive employment.
On January 13, 2003, the employee was examined again for the employer and insurer by Dr. Davey. In his report on that date, Dr. Davey reiterated the following conclusions: that the employee had sustained no permanent partial disability as a result of his September 1996 work injury; that there was no Apermanent acceleration@ [sic] of his preexisting condition consequent to that work injury; that any work-related aggravation injury was temporary and had since resolved; that the employee was capable of performing light to moderate work within a twenty-five-pound lifting restriction and was not permanently disabled; that the employee did not require further medical treatment related to his September 1996 work injury; and that the employee was demonstrating significant functional overlay and exaggeration of his pain complaints.
On August 26, 2003, in a letter to the employee=s attorney, Dr. Noran opined that the employee had sustained an additional permanent injury to his low back as a result of his September 1996 work accident and that, under the current disability schedules, he had a 7% whole body disability consequent to his condition. On February 23, 2004, Placement Specialist Jenny Sabraski, reported on an updated labor market survey that she had conducted regarding the employee=s employability, concluding that the employee Awould be an excellent candidate@ for any of twenty-two retail cashier, bank teller, and hotel front desk positions that she had identified in the employee=s job market. However, in deposition testimony the following day, Dr. Noran reiterated his rating of the employee=s permanent partial disability and his conclusions that the employee=s September 1996 work injury constituted a permanent aggravation of his preexisting low back condition, that that aggravation constituted a substantial contributing factor in his ongoing disability, and that that disability was now permanent and total. Dr. Noran also testified that, so far as he knew, the employee was not precluded from working by any medical practitioners before June 6 of 1998. On March 22, 2004, Dr. Davey also testified by deposition, essentially reiterating the opinions that he had issued in his earlier reports. Dr. Davey testified also that he agreed with testimony of Dr. Noran to the effect that the employee=s prework-injury MRI and CT scans were clinically no different from his post work-injury MRI and other imaging scans.
The matter came on for hearing on March 23, 2004, on which date the employee had not worked or looked for work since his termination from the employer in June of 1998 and had been receiving Social Security disability benefits since 2001. Issues at hearing included the employee=s entitlement to permanent total and permanent partial disability benefits as a consequence of his September 25, 1996, work injury, together with various implied secondary issues. The employee testified at hearing in part that his back and back-related symptoms had never returned to the condition that they were in on the day before his September 1996 work injury. The employee acknowledged in his testimony that he might currently have days when he had no pain, but he suggested that in order for that to happen he would Abasically have to do nothing.@
By findings and order filed May 10, 2004, the compensation judge concluded in part that the employee had been permanently and totally disabled from gainful employment since May 18, 2000. The judge nevertheless denied, however, the employee=s claim for permanent total disability benefits, concluding that the employee=s September 25, 1996, work injury had been only a temporary aggravation of the employee=s Asignificant preexisting disability@ and was not a substantial contributing factor in the employee=s permanent total disability, the work-related temporary aggravation having resolved by November 12, 1996. In support of this conclusion, the judge found (1) that the employee=s chiropractic records indicated that by late October 1996 the employee=s complaints of low back pain had returned to a moderate baseline comparable to his symptom level in the spring of 1996 and (2) that the employee had experienced a number of aggravations of his low back pain from nonoccupational incidents between October 1996 and April 1997. The judge found also that the employee had failed to prove that he had sustained any ratable permanent partial disability as a result of his September 1996, work injury. The employee 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.
The compensation judge found that the employee was permanently and totally disabled from working and was subject to permanent partial disability, but he concluded also that the employee=s September 1996 work injury was not a substantial contributing factor in either that permanent total disability or that permanent partial disability. The employee contends that substantial evidence does not support that conclusion of the judge, asserting that A[a]t issue is why the Employee became permanently and totally disabled and whether the two work-related injuries comprised a significant contributing factor to same@ (underscoring added). Noting that A[t]he Judge made no finding regarding the April 15, 1998 injury,@ the employee argues as follows:
The logical problem presented by the Judge=s findings and explanation of same in his attached Memorandum is that the cause(s) of Employee=s permanent and total disability status is totally unexplained. While it is undisputed that Employee was functioning under significant low back difficulties and limitations prior to September 25, 1996, the fact is that Employee was working full-time until the work-related injury and never returned to full time work thereafter. Something had to occur between September 25, 1996 and May of 2000 to push Employee from an ability to work full-time with significant limitations to a permanent and total disability status. The Compensation Judge=s reference to several >temporary= exacerbations after September 25, 1996 fails to fill the logical void.
(Emphasis in original.) The employee identifies and attempts to rebut several factors that he says the judge identifies, in his memorandum, as support for his denial of benefits - - the similarity between the employee=s pain levels in the months before and the months after his work injury, the lack of explanation for the employee=s restriction from work for ten months after that injury, and evidence that post-injury exacerbations of the employee=s symptoms were causally related to nonwork-related post-injury activities. This is a difficult case, but we are not persuaded that the judge=s denial of benefits is unsupported by substantial evidence.
Initially we would note that no issue regarding an April 15, 1998, work injury was ever identified for litigation either by the employee in a claim petition, by the parties at the hearing, or by the compensation judge in his findings and order. The only work injury at issue was the injury of September 25, 1996.
As the employee has noted first, the compensation judge, in the course of his detailed, five-page memorandum, appears to have based his decision in part on the Jensen clinic=s routine record of the level of the employee=s subjectively reported pain over extended periods of his treatment. The judge noted that the employee=s fluctuating pain levels over the course of the several months of 1996 prior to the work injury were very comparable to his fluctuating pain levels over the course of the several months following the work injury. Those pain levels fluctuated between 5 and 10 early in 1996, rising again to a level 10 in the last prework-injury entry on July 16, and then they actually diminished again for a couple of months after the September work injury, from a level 10 in September to a level 4 in November, before entering another fluctuation mode from 5 to 9 over the course of the months leading up to the employee=s return to work in July 1997. Thus, as noted by the judge in Finding 7, already by late October of 1996, just a month after the employee=s work injury, the employee=s subjective complaints of low back pain had returned to a moderate baseline level comparable to the level of his symptoms in the spring of 1996, half a year before the work injury. The employee contends that such a comparison does not constitute substantial evidence Abecause it is basically meaningless,@ in that Acomplaints of pain are, of course, subjective@ and the prework-injury levels occurred while the employee was under the stress of work, whereas the post-work-injury levels occurred while he was not working. We are not persuaded, however, that this routine record of such broadly fluctuating pain levels over so many months, however subjective each individual report by the employee may have been, was not evidence upon which the judge could reasonably rely in reaching the decision he did.
As the employee has also noted, the judge in his memorandum also appears to question, apparently tangential to the causation issue, the employee=s total disability from working over the course of the ten months following the work injury. The judge notes that the employee did not attempt to return to work over that period, that Athe reason for this is unclear,@ and that chiropractic records contain little objective information supporting total disability during the period. The judge notes also that Nurse Farmer had recommended a gradual return to work on October 10, 1996, that Dr. Noran himself indicated on January 17, 1997, that the employee could return to work, and that Dr. Huelskamp=s only explanation for totally restricting the employee from working during the period was that Ahe has not reached MMI@ - - which, of course, does not explain the restriction. The judge acknowledges that the employee himself testified that his symptoms kept flaring up during this post-injury period, but he emphasizes that the employee Agave no specific testimony regarding his symptoms during the 10 months after the injury@ and A[t]his is critical in light of evidence that his reports of subjective pain levels had returned to the prior baseline in a matter of weeks and because the chiropractic records suggest other possible causes for the employee=s ongoing symptoms.@ The judge cites for example the employee=s increase in pain from 5 to 7 after an incident shutting off a water leak at home on October 7, 1996, an increase in pain from 5 to 8 in late December 1996 after crawling under a truck, a sudden increase in pain in mid January 1997 in the act of leaning back in a beanbag chair, and other increases in pain in early 1997 after slipping at home - - all while clinical tests by Nurse Farmer were producing objective range of motion and spasm findings similar to findings six months prior to the work injury.
The employee contends that Athe logic behind [the judge=s] line of reasoning is highly suspect,@ in that A[t]here was no issue before the Court as to whether Employee was temporarily totally disabled during this period of time,@ and Ait goes without saying that in many circumstances employees are released to return to some type of work but the employer is unable to immediately accommodate the restrictions.@ He argues that no evidence was introduced that the employee could return to work for the employer earlier than he did and that there was no evidence that the post-injury exacerbations cited by the judge Awere anything more than that@ or were other than, as the judge also found, temporary. With regard to the argument that wage replacement for the period prior to July 1997 was not at issue, we conclude that, for our purposes here, the point of the judge=s analysis is not so much that the employee did not conduct a sufficient job search to establish entitlement to benefits during that period as it is that the employee was released to work by his own neurologist and his nurse practitioner during a time when the employee claimed to be incapacitated by a new work injury. This is a causation analysis very applicable to the permanent benefits here at issue, not just to an issue of the employee=s temporary total disability during the period immediately post work injury. The judge=s analysis is further evidence that any eventual permanent and total disability is not causally related to the September 1996 work injury from which it is so separated by a period of very arguable resolution from that injury. As for the employee=s argument that the post-injury exacerbations cited by the judge were only that - - exacerbations - - and were only temporary, we would note that that is arguably akin to the judge=s very point. The employee=s preexisting degenerative spinal condition, particularly including as it does the permanent injury that the employee sustained in his 1994 motor vehicle injury, is repeatedly vulnerable to temporary aggravations and exacerbations of symptoms of the sort reported in the employee=s chiropractic records. The judge appears to be implying that the employee=s September 1996 work injury is only one of several such aggravations, none of them being necessarily a continuing and substantially contributing factor in the employee=s ultimate total disability.
Ultimately, in denying the benefits at issue, the compensation judge appears to have relied upon the expert medical opinion of Dr. Davey, who clearly opined that the employee=s September 1996 work injury was a temporary aggravation of the employee=s preexisting condition that had resolved itself by November 10, 1996, about six weeks after the injury. Moreover, in his memorandum, the judge expressly rejected the opinion of Dr. Noran, noting in particularly that it was not substantially supported by the employee=s pre-injury and post-injury radiological studies. This court has long held that "the 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." Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985). Finding Dr. Davey=s opinion to have been based on no false premises, and finding the judge=s decision not otherwise unreasonable, we affirm the compensation judge=s denial of the permanent total and permanent partial disability benefits at issue on causational grounds. See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.
 According to the compensation judge=s unappealed Finding 18.