BILL R. CALKINS, Employee/Appellant, v. UNITED PARCEL SERV. and LIBERTY MUT. INS. CO., Employer-Insurer.

WORKERS= COMPENSATION COURT OF APPEALS

NOVEMBER 5, 2003

HEADNOTES

EVIDENCE - CREDIBILITY.  Where the employee had testified that he both experienced and reported to several doctors at least intermittent ongoing pain since the date of his work injury, where medical records in evidence indicated that he had asserted to at least two care providers that his pain had remained unabated and severe since that date, and given the timing of the employee=s complaints to those two providersBimmediately prior to expiration of his wrist-based restrictions from working, after there had been virtually no medical record of any even intermittently ongoing low back problems for fully five months prior to those complaints--the compensation judge=s finding that the employee had testified less than credibly that he had had low back pain since the date of his work injury was not clearly erroneous and unsupported by substantial evidence.

TEMPORARY BENEFITS - FULLY RECOVERED.  Where, prior to his wrist-related work-hardening program, the employee had been released by his treating doctor to return to work upon completion of the work-hardening, where the work-hardening therapist had recorded improvement in the employee=s wrist condition and had consulted the treating doctor=s office upon the employee=s completion of the program, and where the independent medical examiner had subsequently opined that the employee was no longer in need of any treatment or restrictions, the compensation judge=s denial of continuing benefits for the employee=s wrist injury was not clearly erroneous and unsupported by substantial benefits.

EVIDENCE - EXPERT MEDICAL OPINION.  Where it was clear from the judge=s findings and order that the judge had considered the treating doctor=s opinion, and where the independent medical expert=s opinion contained a multipage medical history essentially correspondent to the employee=s medical records, an itemized list of which the doctor had certified having reviewed, neither doctor=s opinion was or should have been dismissed for lack of foundation, and the compensation judge=s decision to rely in part on the independent medical expert=s opinion was warranting of the court=s deference under Nord v. City of Cook.

CAUSATION - SUBSTANTIAL EVIDENCE; TEMPORARY BENEFITS - SUBSTANTIAL EVIDENCE; PRACTICE & PROCEDURE - REMAND.  An injury sustained as a consequence of treatment of a work injury is compensable, even if the later injury is not otherwise related to the earlier injury.  Where the compensation judge clearly found a compensable work-related low back injury in the form of an aggravation of the employee=s preexisting degenerative lumbar disc disease sustained in the course of the employee=s wrist-related work hardening activities, and where there was no reasonably substantial evidence to support the judge=s conclusion that that aggravation was resolved by the date on which the work hardening ended, the compensation judge=s denial of the employee=s claim for benefits subsequent to the date on which work hardening ended was clearly erroneous and unsupported by substantial evidence, absent any assertion by the judge of any other basis for her denial of benefits, and the matter, including the stipulated testimony of the employee=s work-hardening therapist, was remanded to the compensation judge for reconsideration of the employee=s claim.

Affirmed in part, reversed in part, and remanded.

Determined by Pederson, J., Johnson, C.J., and Stofferahn, J.

Compensation Judge:  Carol A. Eckersen

Attorneys:  Gregg B. Nelson, Nelson Law Office, Woodbury, MN, for the Appellant.  David J. Odlaug and Carrie L. Hund, Hansen, Dordell, Bradt, Odlaug & Bradt, St. Paul, MN, for the Respondents.

OPINION

WILLIAM R. PEDERSON, Judge

The employee appeals from the compensation judge's denial of benefits for an ongoing low back injury and for a permanent or ongoing left wrist injury, based on issues of the employee=s credibility and the support of expert medical opinion.[1]  We affirm the judge=s denial of benefits for an ongoing wrist injury, the judge=s conclusion that certain testimony by the employee regarding his low back injury was not credible, and the judge=s reliance on expert medical opinion, but we reverse the judge=s finding that the employee=s low back aggravation had resolved by June 29, 2001, and we remand the matter for reconsideration of the employee=s claims for benefits related to that injury.

BACKGROUND

On December 18, 2000, Bill Calkins sustained various work-related injuries when he slipped off an icy ramp at the back of his truck while unloading a four- to seven-hundred-pound barrel of dialysis solution at a clinic in West Plains, Missouri, in the course of his employment as a delivery driver for United Parcel Service.  Immediately subsequent to his injury, Mr. Calkins [the employee] went into the clinic where his delivery was being made and received assistance in cleaning up his surface wounds, thereafter continuing with his deliveries for the day.  Later in the day, after conferring with a supervisor at United Parcel Service [the employer], the employee sought treatment in the Emergency Department at Lucy Lee Hospital in Poplar Bluff, Missouri, where he complained to Dr. Ken Studyvin of pain in his left wrist, right shoulder, right knee, chest, right hip, and low back.  X-rays were essentially normal, and Dr. Studyvin diagnosed multiple contusions and abrasions and lumbar strain and prescribed a wrist splint and medications.  On the date of his injury, the employee was thirty-nine years old and was earning a weekly wage of $742.40.  The employer admitted liability for a work injury and commenced payment of benefits.

The employee=s symptoms continued, and on December 26, 2000, he was seen at the NowCare Medical Center in Minneapolis, for problems related to his right knee, hip, ribs, shoulder, left wrist, and low back.  X-rays were taken of the left wrist, which revealed a small congenital spur arising from the ulnar styloid but no fractures or other abnormalities, and the employee was released to return to work with restrictions against gripping or grasping with his left hand through January 4, 2001.  On January 4, 2001, the employee returned to NowCare complaining of continuing pain in his left wrist and forearm, and the attending physician, making no mention of any continuing low back or other non-wrist complaints, diagnosed tendonitis of the left wrist and prescribed physical therapy, medication, and work restrictions.

On January 8, 2001, the employee saw orthopedic surgeon Dr. Jon Engelking regarding the condition of his left wrist.  X-rays were normal except for a small spur on the ulnar styloid from an old injury, and Dr. Engelking diagnosed a wrist sprain and recommended a wrist splint, physical therapy, and moderate work restrictions, anticipating that the employee would return to work without any restrictions effective the first part of February 2001.  Dr. Engelking made no reference in his office notes to any problems aside from wrist pain.  On January 11, 2001, the employee underwent a routine general physical examination conducted by Dr. Craig Howard, who noted Aa recent left wrist fracture . . . now healed very well@ but no low back or other recent injury.

On January 23, 2001, the employee followed up with an associate of Dr. Engelking, Dr. Andrea Saterbak.  Examination findings were minimal, repeat x-ray findings were normal, and Dr. Saterbak diagnosed a left wrist sprain, issued a wrist splint, and continued moderate work restrictions.  Dr. Saterbak=s records make no reference to any low back problems, nor did the employee indicate on his in-processing diagrams or questionnaires on that date that he was experiencing any low back pain or other disability.  On January 29, 2001, the employee saw his family physician, Dr. Chuck Stevens, complaining that he had awakened that morning with back pain so severe that he could not get out of bed.  Dr. Stevens noted that the problem Aseems to date back to 12/18/00 when he fell out of the back of a semi truck when he was unloading it,@ noting also that A[h]is back had actually been OK for about the last two w[ee]ks@ and that Ahe has really just been out of work now because of his left wrist.@  Dr. Stevens diagnosed acute low back pain, adding,

It=s a little unclear what has happened here in that he did have an injury although he seemed to have recovered from that pretty well and now he gets an acute exacerbation.  I=m not certain this is related to his injury although it would seem most likely without any prior history of similar pains.

Dr. Stevens prescribed medication and physical therapy, recommending that the employee integrate the back therapy with the wrist therapy that he was already getting and that he follow up with Dr. Saterbak on his back as well as his wrist, Aas she has been managing his Work Comp illness and I think she can [follow up] with him regarding the back as well.@  On January 31, 2001, Dr. Stevens wrote to Dr. Saterbak reiterating that recommendation.  Neither Dr. Stevens= office note nor his letter to Dr. Saterbak contains any recommendation as to work restrictions.  Notwithstanding Dr. Stevens= recommendation to the employee and to Dr. Saterbak that the latter assume follow-up care for the employee=s low back complaints, Dr. Saterbak made no mention of any non-wrist problem in her notes on her next appointment with the employee, on February 20, 2001.  She noted only improvement in the employee=s wrist symptoms and, to assist in diagnosing some possible tendon damage, ordered an MRI scan, which, conducted on that same date, was read to be essentially unremarkable.

Apparently about that same time, in February of 2001, the employee moved from Minnesota to the Village of Thebes, Illinois, where on April 1, 2001, he took over management of Thebes Landing Campground for the Village of Thebes, a function he evidently continued to perform until late November 2001, receiving in exchange for his work no pay but utilities-paid use of a lot at the campground.  On April 10, 2001, noting that the employee=s left wrist MRI had been read as normal and that the employee had recently moved to Illinois, Dr. Saterbak discontinued her treatment, recommending that the employee find a hand specialist in Illinois and refrain from working through May 1, 2001.  On April 20, 2001, the employee saw Missouri orthopedic surgeon Dr. William Kapp, who reported complaints by the employee of left wrist problems but not of any low back or other problems.  Upon examination and x-rays that were read to be unremarkable, Dr. Kapp administered a steroid injection and renewed the employee=s restrictions and splint prescription.

When the injections administered by Dr. Kapp appeared to have been counterproductive, Dr. Kapp referred the employee to Missouri bone and joint specialist Dr. David Brown, who examined the employee on May 16, 2001.  In his report on that date, Dr. Brown recounted the employee=s history of a work injury to his right wrist on December 18, 2000, but physical examination and x-rays revealed no significant bone or joint abnormality, and, concluding that A[t]he cause of [the employee=s] radial sided left wrist pain is not clear,@ Dr. Brown ordered an arthrogram. There was no mention in Dr. Brown=s report of any low back injury or low back pain.   Results of the arthrogram were apparently inconclusive, and on June 1, 2001, Dr. Brown restricted the employee to one-handed work and referred him for two weeks of physical therapy, finding no fracture and no evidence of ligamentous injury to explain the employee=s symptoms.  Dr. Brown=s report on that date does not mention any complaints of low back problems.  On June 15, 2001, Dr. Brown recommended two weeks of work hardening and released the employee to return to full duty without restrictions on July 2, 2001, again without mention of any condition or symptoms aside from the employee=s wrist problem.

The employee underwent physical therapy on his left arm and wrist from June 6 to June 18, 2001, and then, on June 19, 2001, he commenced about ten days of work hardening.  In a report on June 20, 2001, Craig Brown, the therapist supervising the work hardening, reported that the employee had informed him of his December 2000 work injury, stating, AI fell onto my right side, but I jammed my left wrist and my left lower back has been hurting since.@  Mr. Brown reported also that the employee had reported Agood results@ with his conservative therapy and had stated, AI don=t know why we didn=t keep going with the stuff we were doing, I was getting better.@  Mr. Brown noted also that the employee Aappeared to tolerate the initial work hardening evaluation well, reporting slight soreness after the first day and general fatigue after the second day.@  In a report on June 22, 2001, Mr. Brown noted that the employee had reported Asoreness@ in all of his extremities after his first sessions of work hardening, as well as in his low back, reporting also that Athis [low back] discomfort has been present since the DOI and has not improved.@  In his final report on the employee=s work hardening program, on June 29, 2001, Mr. Brown indicated that, while the employee=s wrist condition had improved over the course of the work hardening program, the employee Adoes report an increase in right side L[ower ]B[ack ]P[ain] with static sitting and standing, but reports that walking relieves his symptoms to some degree.@  He went on to state that lumbar range of motion had decreased since the initial work hardening assessment, but no treatment had been initiated for these symptoms, and Mr. Brown indicated that the plan was to Afollow physician recommendations, which are to resume full-duty work on 07/02/2001,@ with A[n]o further treatment planned at this time.@

On that same date, June 29, 2001, the employee saw nurse practitioner Richard Kinsey at a family medical center, whose notes indicate that the employee had complained to him of lower back and A[b]ad hip pain for 6 mos.@  The employee indicated also to Nurse Kinsey that his work hardening program had aggravated his back Aextremely@ and that his pain was Aworse standing and sitting.@  Nurse Kinsey prescribed medication, ordered a CT scan, and restricted the employee from working pending results of the scan.  On July 5, 2001, the employee underwent the recommended scan, which was read to be normal except for a Avery mild@ disc protrusion at L5-S1 with Avery mild@ impingement on the S1 nerve root, together with some Aborderline@ spinal stenosis at L4-5 and an Aold small@ Schmorl=s node at L4.  Nurse Kinsey diagnosed a Alow back injury with spinal stenosis@ and restricted the employee from working until he had been examined by a neurosurgeon and evaluated for nerve impairment.  On July 6, 2001, the employee faxed a message to his Operations Manager at the employer, Randy French, enclosing the two work release slips from Nurse Kinsey, further explaining as follows:

During physical therapy, I experienced increasing back pain.  Radiologist now reports lower back injury.  I have an appointment with neuro-surgeon on 7/30/01.  Wrist is much stronger but still experiencing some pain and loss of movement.

On July 11, 2001, Operations Manager French, having evidently been informed that the employee had been released by Dr. Brown to return to work without restrictions, and noting that the employee had nevertheless elected to remain in Illinois, wrote to the employee, informing him that his Aservices are no longer needed@ with the employer and that, A[e]ffective July 9, 2001, your employment has been terminated and all benefits severed.@

On July 30, 2001, the employee complained of back and right leg pain to neurosurgeon Dr. Kee Park, to whom he reported a work injury to his low back in the December 18, 2000, incident.  Noting that a CT scan had revealed a disc bulge at L5-S1, Dr. Kee diagnosed Aright leg pain suggesting lumbar radiculopathy and discogenic pain,@ ordered an MRI scan, and restricted the employee from working pending a follow-up visit.  On August 15, 2001, the employee underwent the MRI scan, which was read to reveal a possible annular tear at L4-5 and a disc bulge at L5-S1 but no evidence of nerve root involvement.  The following day, in a brief office note, Dr. Park indicated that he believed that the employee=s low back condition Aoccurred as a result of his injury sustained on December 19, 200[0] given the fact that he denies any previous history of hip trouble prior to this.@  Dr. Park ordered a discogram with CT scan, which was conducted on September 6, 2001.  The tests were read to reveal in part concordant pain at L5-S1 and an annular tear at that level, and on September 17, 2001, Dr. Park recommended a discectomy and fusion at L5-S1. 

On October 12, 2001, the employee commenced full-time work as City Manager for the Village of Thebes, and on December 3, 2001, he filed a claim petition, alleging entitlement to wage replacement benefits continuing from July 1, 2001, to undetermined permanent partial disability benefits, to various medical benefits, and to rehabilitation assistance, all consequent to his work injuries on December 18, 2000.

On December 17, 2001, the employee was examined for the employer and insurer by orthopedic surgeon Dr. Paul Wicklund, who diagnosed bulging discs at L4-5 and L5-S1, with a high intensity zone tear on the right at the latter level, and subjective left wrist pain without objective findings.  With regard to the employee=s low back condition, Dr. Wicklund reported that the employee

told me that he did not have any low back problems until he was involved in a work hardening physical therapy program in the summer of 2001 when he was lifting 100 pound boxes and doing 280 pound leg thrusts.  It was at that point that he noticed pain in his low back and his right hip felt like it was on fire.  He said this got worse during the second week of physical therapy.

Later in his report, Dr. Wicklund indicated that the employee was subject to multilevel degenerative disc disease and that the employee had told him that, prior to his work hardening therapy,

he had fully recovered from his low back strain or contusion that happened when he fell off the truck, therefore it would be my opinion to a reasonable degree of medical certainty that the diagnostic studies, the MRI=s and diskograms and all the treatment from Dr. Park are due to the superseding, intervening event in his work hardening program and not due to his work injury at UPS.

With regard to the employee=s left wrist condition, Dr. Wicklund noted no objective findings to substantiate the employee=s complaints of pain, and he concluded that the employee had reached maximum medical improvement with no disability or limitations and without need for any further treatment or studies or tests or restrictions.

In a letter to the employee=s attorney dated February 4, 2002, Dr. Park confirmed his opinion, within a reasonable degree of medical certainty, that the employee=s low back pain and need for surgery was causally related to the employee=s December 18, 2000, work injury.  Dr. Park indicated further that Adiscogenic back pain from internal disc disruption is not typically a constant pain,@ that A[i]t is exacerbated by certain activities such a sitting, lifting and bending,@ and that A[i]t is not a surprising fact to me that [the employee] has [at] times experienc[ed] periods of relief but overall his general course has been one of progressively worsening symptoms.@

The matter came on for hearing before a compensation judge on April 25, 2002.  Issues at hearing included the nature and extent of the employee=s low back and left wrist injuries on December 18, 2000, the employee=s entitlement to wage replacement benefits continuing from July 1, 2001, and the employee=s entitlement to rehabilitation benefits.  At the hearing, the employee testified in part that whatever low back pain he may have had on January 4, 2001, was of insufficient concern to mention to the doctor whom he saw at NowCare on that date.  Although there is also no mention of any report of a low back injury in the records of Drs. Engelking or Saterbak, the employee testified further that, when he saw Dr. Engelking and Dr. Saterbak  on January 8 and January 23, 2001, respectively, he mentioned to them not only that he had hurt his low back in addition to his wrist on December 18, 2000, but that he was continuing to experience symptoms.  In answer to the question A[o]n January 8 of 2001, did you tell Dr. Engelking that you were having symptoms in your low back?@, he answered AYes.  Because he asked for a general synopsis of my problems.@  The employee fluctuated in his testimony as to whether or not he was actually experiencing any low back pain when he saw Dr. Saterbak, first testifying that he wasn=t really noticing any problems with his low back at that point in time but later answering unequivocally AYes@ to the question ASo you B you did have some pain in your back when you saw her.@  He testified that this pain was an aching sensation A[i]n my low back, right side.  In my hip, maybe.  Or maybe every once in a while there was shooting pain.@  The employee testified that he also told both Dr. Kapp and Dr. Brown, in April and May of 2001, respectively, that he was continuing to experience low back problems, although there is, again, no mention of such problems in the reports of those doctors.  The employee eventually explained that his low back pain subsequent to his December 2000 work injury was intermittently Aongoing@ but not Acontinuous@ in the sense that he would never be without it for a single day.  Late in his testimony, the employee was asked,  AAfter you had completed . . . that two-week work-hardening and a period of time had gone by, did you notice improvement in your back symptoms?@, to which question the employee answered, AYes.@  He was then asked, ADid they go back to the way they were?  Where you have . . . this pain that you have in the buttock and the back that you note particularly with long standing and sitting,@ and the employee again answered, AYes.@

Also testifying at hearing, by telephone, was physical therapist Craig Brown.  According to a reconstruction of that testimony stipulated to by the parties,[2] Mr. Brown testified in part

that the employee told him that sitting and standing were the only activities that bothered him during the work hardening program.  Brown further testified that the lifting circuit and the leg presses had nothing to do with the employee=s increased pain in his low back and that the employee complained to him only of increased pain with sitting and standing.

Mr. Brown testified further that Athe employee did not complain of any increased pain while performing leg presses or lifts@ and that Mr. Brown Awould not have the employee engage in any activity that would have caused injury to the employee=s back.@  Mr. Brown testified also that the employee=s tolerance for lifting had actually increased by the end of the work hardening session.  He testified further that, at the completion of the work hardening program, he had contacted Dr. Brown=s office for confirmation of Dr. Brown=s return-to-work order in light of some Acontinuing subjective wrist complaints@ and was informed by a staff member of Dr. Brown, who had evidently consulted the doctor, that the employee was indeed still released to work without restrictions.  Mr. Brown testified finally that the employee did tell him Aat the conclusion of the therapy, that his back condition required physician care@ and that he thereupon told the employee Athat he should seek the advi[c]e of a physician.@

The employer and insurer contended at hearing in part that, whatever low back contusion and strain the employee may have sustained as a part of his work injury on December 18, 2000, the employee=s low back injury had resolved by some point in January 2001.  They argued that the first documented low back pain complaints after the employee=s complaints to Dr. Stevens in late January of 2001 were to therapist Brown at the beginning of his prescribed work hardening program in late June 2001, just after being released to return to work as of July 2, 2001.  They contended that the employee began to complain about his back at that time primarily in an effort to avoid returning to work.  They argued that whatever low back problems the employee may have been experiencing at that time were due not to his December 2000 work injury but to his underlying degenerative disc disease.

By findings and order filed July 5, 2002, the compensation judge denied the employee=s claims for both wage replacement and rehabilitation services, based in part on findings that A[t]he employee=s testimony that he had low back pain since the date of the injury is not credible@ and that ADr. Park=s opinion lacks adequate foundation,@ in that ADr. Park did not indicate that he reviewed the records of the employee=s medical care from December 18, 2000 through July 30, 2001 when he began treating [the employee].@  In support of her denial of benefits for an ongoing low back injury, the judge found also that any aggravation of the employee=s low back condition sustained during his work hardening program in June of 2001 lasted only about a week and was not a substantial contributing cause of the employee=s low back condition after completion of the program, having been only, according to the judge=s memorandum, Aa temporary aggravation of his degenerative disk disease that resolved by June 29, 2001.@  The judge found further that the employee did not have any restrictions after July 1, 2001, related to any work injury or aggravation, that the employee=s loss of earning capacity from July 2, 2001, through October 12, 2001, was therefore not causally related to any work injury, and that the employee was no longer precluded from engaging in his date-of-injury employment due to any work injury and so was not entitled to any rehabilitation benefits.   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.

DECISION

The employee contests the compensation judge=s decision on grounds that the judge=s finding as to the employee=s credibility and her denial of benefits in apparent reliance on the medical opinion of Dr. Wicklund over that of Dr. Park are unsupported by substantial evidence.

1.  The Employee=s Credibility

At Finding 7 of her decision, the compensation judge found in part that A[t]he employee=s testimony that he had low back pain since the date of the injury is not credible.@  The employee asserts that A[t]he compensation judge specifically found that the employee testified that he noted back pain on a continuous basis from and after the date of the injury@ and that @[t]he employee did not testify to that.@  He argues that, A[b]y incorrectly recording and then rejecting the employee=s testimony, the compensation judge then was forced to incorrectly attribute an employee history to the independent medical examiner[=]s report that did not exist in the record, and find proper foundation for it as well.@  We are not persuaded.

To begin with, the compensation judge did not Aspecifically f[i]nd@ that the employee testified to having experienced back pain Aon a continuous basis@ since his injury.  We conclude that the compensation judge=s phrase Asince the date of injury@ easily embraces the concept of intermittently Aongoing@ pain that the employee has alleged.  It was clearly the employee=s testimony that he was continuing to have--and to report to virtually all of his doctors--at least intermittent ongoing pain subsequent to his work injury.  Moreover, medical records in evidence indicate that the employee did assert to therapist Brown and to nurse practitioner Kinsey that he had been having low back pain since the injury arguably more chronic than simply intermittent: to Therapist Brown he reported on June 21 or 22, 2001, that he had been experiencing low back discomfort that had been Apresent since the DOI and has not improved,@ and to Nurse Kinsey he complained on June 29, 2001, of lower back pain and A[b]ad hip pain for 6 mos.@  Given the employee=s testimony that he both experienced and reported to several doctors at least intermittent ongoing pain since the date of his work injury, and given his assertions to Mr. Brown and Nurse Kinsey that his pain had remained unabated and severe since that date, it was not unreasonable for the compensation judge to characterize the employee=s testimony as being Athat he had low back pain since the date of the injury.@  Moreover, particularly given the timing of the employee=s complaints to Mr. Brown and Nurse KinseyBimmediately prior to expiration of his wrist-based restrictionsBafter there had been virtually no medical record of any even intermittently ongoing low back problems for fully five months prior to those complaints, it was also not unreasonable for the compensation judge to find less than credible the employee=s claim of even intermittent ongoing low back pain since the date of his injury.  Because it was neither clearly erroneous nor unreasonable, we affirm the compensation judge=s finding to that effect.  See Brennan v. Joseph G. Brennan, M.D., 425 N.W.2d 837, 839-40, 41 W.C.D. 79, 82 (Minn. 1988) (assessment of a witness's credibility is the unique function of the trier of fact), citing Spillman v. Morey Fish Co., 270 N.W.2d 781, 31 W.C.D. 187 (Minn. 1978); Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.

At the end of the section of his brief in which he argues his appeal from the compensation judge=s finding as to the credibility of his claim to ongoing low back pain, the employee spends a brief paragraph contending also that substantial evidence does not support the judge=s conclusion in Finding 8 that the employee had no wrist-related restrictions after July 2, 2001, arguing that there is no Acontemporaneous@ record to support this finding.  We conclude that Dr. Brown=s June 15, 2001, release of the employee to work without restrictions as of July 2, 2001, is substantial evidence in support of the judge=s decision on this issue, supported as it is by Therapist Brown=s record of improvement in the employee=s wrist condition by the end of the work hardening, by his testimony as to his post-work-hardening communication with Dr. Brown=s office, and by the opinion of Dr. Wicklund on the issue.  Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.

2.  Medical and Other Substantial Evidence

At Finding 12 the compensation judge concluded in part that ADr. Park=s opinion lacks adequate foundation and is not adopted by the court.@  At Finding 13 she concluded in part that Dr. Wicklund Ahad a complete factual history and all relevant medical records for a complete foundation for his opinions.@  The judge did not expressly adopt Dr. Wicklund=s opinions en masse, but in that same Finding 13 she did note that Dr. Wicklund had Adiagnosed multilevel degenerative disk disease@ and that he had found the employee=s testing and treatment unrelated to the work injury.  Moreover, in her memorandum the judge did find persuasive Dr. Wicklund=s conclusion Athat the work injury was not a substantial contributing cause of the employee=s low back condition.@  The employee contends that Dr. Wicklund=s Aopinions . . . are not based upon facts present in this case@ and therefore Alack foundation,@ contending that those opinions cannot be reconciled even with the factual findings of the compensation judge.  The employee argues that Dr. Wicklund found a Aconsequential injury@ and that the employee is Aentitled to a finding of a consequential aggravation based upon the evidence.@  We are not persuaded that either doctor=s opinion was or should be dismissed for lack of foundation, but we reverse and remand the judge=s denial of benefits in light of the medical and other evidence.

A.  Foundation.  It is apparent, both from the judge=s admission of Dr. Park=s opinion into evidence and from the length and substance of her discussion of that opinion in Finding 12, that, notwithstanding her reference to inadequate Afoundation,@ the compensation judge did not actually exclude Dr. Park=s opinion from evidence.  Instead, the judge evidently weighed the opinion as evidence and then chose not to rely on it.  The judge=s refusal to credit Dr. Park=s opinion was evidently on grounds that Dr. Park Adid not indicate that he reviewed the records of the employee=s medical care from December 18, 2000 through July 30, 2001 when he began treating [the employee]@[3] and Adoes not explain why the employee did not consistently report low back symptoms during the six months following the injury.@[4]  We conclude that the judge=s refusal to credit Dr. Park=s opinion for those reasons was not unreasonable.  Nor do we agree that Dr. Wicklund=s opinion is without sufficient Afoundation@ to have been weighed by the compensation judge, containing as it does a several-page medical history essentially correspondent to the employee=s medical records, an itemized list of which Dr. Wicklund certified having reviewed.  We concede that all aspects of Dr. Wicklund=s opinion do not entirely mesh with the compensation judge=s decision, but there is no indication that the judge adopted Dr. Wicklund=s opinions in their entirety, nor was the judge obligated to do so in order to rely on those opinions in part.  See Johnson v. L. S. Black Constr. Co., slip op. (W.C.C.A. Aug. 18, 1994) (a compensation judge is free to accept a portion of an expert's opinion, yet reject other portions of that expert's opinions), citing City of Minnetonka v. Carlson, 298 N.W.2d 763, 767 (Minn. 1980) (a factfinder generally "may accept all or only part of any witness' testimony").  To the extent to which she based her decision on the opinion of Dr. Wicklund that the employee sustained, as a result of his work-hardening activities, an aggravation of a preexisting degenerative disc disease, and to the extent that that opinion was not based on any false premises, the compensation judge was entitled to rely on Dr. Wicklund=s opinion and to have this court=s deference in doing so.  See Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985) ("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").

B.  Substantial evidence.  With regard to the compensation judge=s use of Dr. Wicklund=s opinions, we conclude that the totality of the evidence, including those opinions themselves, requires a reversal of the judge=s denial of benefits for a low back injury, and we remand the matter for the judge=s reconsideration of the employee=s claim.  Dr. Wicklund expressly concluded that the employee=s low back problems here at issue were ones related to a preexisting degenerative disc disease and not ones related to the employee=s December 2000 work injury.  Nevertheless, even while doing so, Dr. Wicklund appears to have accepted the employee=s contention that those problems appeared as a direct result of work-hardening activities that were themselves consequent to that work injury, and he acknowledges that apparently reasonable ongoing treatment ensued.  The compensation judge clearly accepted, in both Finding 10 and Finding 14, Dr. Wicklund=s diagnosis of the employee=s low back problems as a work-hardening aggravation of a degenerative disc disease, and she accepted also his opinion that that aggravation was not compensable under the employee=s claim for benefits after July 2, 200l.  However, in justifying her denial of benefits, the judge based her decision in important part not on Dr. Wicklund=s rationaleBthat the aggravation was due to a Asuperseding, intervening event@ in the work hardening programBbut on a conclusion, stated in Finding 14, that the aggravation lasted only through June 29, 2001, a date preceding the period of the employee=s claim.  In support of that finding, the judge asserted at the end of her memorandum that A[t]he employee and Mr. Brown testified that the employee recovered by the end of the work hardening,@ reiterating that A[t]he employee sustained a temporary aggravation of his degenerative disk disease that resolved by June 29, 2001.@  The employee contends that there is no substantial evidence that his back problems resolved by that date or that either he or Mr. Brown testified to that effect.  We agree.

By stipulation of the parties, Mr. Brown did testify that, in his view, the employee=s tolerance for lifting had actually increased by the end of the work hardening session, but he also testified that the employee=s complaints of low back pain had increased over the course of the program, and his office reports indicate that the employee=s lumbar range of motion had decreased over that same period.  Moreover, by stipulation of the parties, Mr. Brown testified that the employee was claiming that he needed a doctor for his low back upon conclusion of the program and that Mr. Brown had encouraged him to consult one.  Medical records in evidence indicate that the employee went out that same day to a family clinic and talked with Nurse Practitioner Kinsey about his low back problems.  Nurse Kinsey in turn referred him to Dr. Park, who concluded upon examination and radiological evidence that the employee=s low back problems were severe enough to warrant surgery.

With regard to the employee=s own testimony regarding resolution of his back problems, we note in support of the judge=s decision only the employee=s brief testimony that his low back symptoms eventually, A[a]fter [he] had completed . . . that two-week work-hardening and a period of time had gone by@ (emphasis added), returned to the level at which they had been prior to the work hardeningBwhich he agreed entailed Apain . . . in the buttock and the back that [he] note[d] particularly with long standing and sitting.@  In contrast to this evidence, the employee repeatedly and rather emphatically testified, both at hearing and in his prehearing deposition, as to his frustration at being released to work at the end of June 2001 while his low back pain was far from resolved, and he clearly brought the same complaint to Nurse Kinsey on the day of his release from work hardening, to whom he specifically related his problem to the work-hardening program that he had just completed.

The compensation judge clearly found a compensable work-related injury in the form of an aggravation of the employee=s preexisting degenerative disc disease sustained in the course of the employee=s work hardening activities.  An injury sustained as a consequence of treatment of a work injury is compensable, even if the later injury is otherwise unrelated to the earlier injury.  See Smith v. Fenske=s Suburban Sanitation, 266 N.W.2d 892, 30 W.C.D. 411 (Minn. 1978) (a cervical injury sustained by the employee as a consequence of chiropractic treatment for a low back work injury was compensable).  Finding no reasonably substantial evidence to support the judge=s conclusion that that aggravation resolved by June 29, 2001, or that either Mr. Brown or the employee testified to such a resolution, and absent any expressed basis for the judge=s denial of benefits alternative to that basis, we reverse the compensation judge=s denial of benefits and remand the matter to the judge for reconsideration of the employee=s claim.  See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.  We acknowledge that the testimony of Mr. Brown that is now of record--the reconstruction stipulated to by the parties--may not comport in every detail with the compensation judge=s memory of the original testimony.  On remand, the compensation judge should presume that the stipulated testimony now of record is the evidence rendered.