The employer and insurer appeal from the compensation judge’s finding that the employee’s loss of earning capacity is causally related to his work injury of March 30, 2004, and from the judge’s award of temporary partial disability benefits.  We affirm.

On March 30, 2004, Gregory Norum [the employee] was injured at work when he fell six feet from a platform and fractured his left distal radius in the course of his employment as an aircraft mechanic with Northwest Airlines [NWA], for whom he had worked since 1979.  On the date of his injury, the employee was fifty-two years old and was earning a weekly wage of $1,436.35.  NWA and its insurer, Liberty Mutual Insurance Company [Liberty], accepted liability for the injury and commenced payment of wage loss and medical expense benefits.

Following his injury, the employee was taken by ambulance to St. Joseph’s Hospital in St. Paul, where his left wrist fracture was surgically treated with closed reduction and percutaneous pinning by orthopedist Dr. Daniel Hoeffel.  He was off from work for about ten weeks and then returned to his job as a mechanic with NWA.  By August 9, 2004, the employee continued to report intermittent sharp pain and stiffness in his fingers, but Dr. Hoeffel released him to return to work without limitations.  When seen in follow-up about four months later, on December 6, 2004, the employee reported that he continued to be somewhat limited at work in the positioning of his wrist, and he complained also of ulnar hand, wrist, and elbow pain and decreased grip strength.  His fingers remained stiff, and he needed to wear a brace for sleeping.  Dr. Hoeffel advised the employee that “he [was] probably at maximum medical improvement,” but he did not provide any permanent restrictions.

The employee continued to have increasing pain and stiffness in his left wrist and returned to see Dr. Hoeffel on February 25, 2005.  He reported that he had been experiencing numbness in the wrist, and Dr. Hoeffel diagnosed status post wrist fracture with worsening of range of motion and left upper extremity dysesthesias.  On those findings, the doctor recommended an EMG and a consultation with hand specialist Dr. Mark Holm.

The employee saw Dr. Holm for the first time on May 9, 2005, reporting pain on the ulnar side of his left wrist, with decreased sensation in the left 4th and 5th fingers and limited range of motion.  Dr. Holm noted that the employee had pain with twisting his left wrist and that the pain was located in the region of the triangular fibrocartilage complex [TFCC].  On those findings, he recommended an arthrogram of the left wrist to evaluate the TFCC, anticipating additional surgery depending on the result.

The arthrogram, completed on May 31, 2005, revealed a full-thickness tear of the TFCC, and on July 25, 2005, Dr. Holm performed a submuscular transposition of the ulnar nerve at the left elbow as well as an arthroscopic examination of the triangular fibrocartilage at the left wrist.  When he saw the employee in follow-up on August 8, 2005, Dr. Holm noted that the “seven hole plate and screws” were in good position, and he placed the employee in a long arm cast and restricted him from working through September 30, 2005.

About this same time, NWA and its mechanics union were in the midst of an employment dispute, and on July 20, 2005, the two sides agreed to a thirty-day “cooling off” period, after which either side could take unilateral action--the airline to impose terms and conditions of employment, the union to strike.  On August 17, 2005, Dr. Holm, after being contacted by NWA, agreed to release the employee to return to work with limitations.  The doctor released the employee to work four-hour days with no use of his left arm, and NWA offered the employee one-handed light-duty work to commence on August 22, 2005.  A strike was called by the mechanics union, however, and its members were directed to walk off the job at 12:01 a.m. on August 20, 2005.  Liberty served a Notice of Intention to Discontinue [NOID] the employee’s benefits on August 19, 2005, and, because of the strike, the employee did not return to the one-handed job offered by NWA.  About this same time, NWA evidently imposed new terms and conditions of employment that included a reduced base-pay rate for mechanics.

The employee remained off work and returned to see Dr. Holm on September 19, 2005.  At that time, Dr. Holm removed the employee’s cast and placed him in a strap-on wrist brace. Dr. Holm continued the employee's release to light work with no use of the left arm.

Almost three weeks later, on October 7, 2005, the employee obtained a temporary job as a bus mechanic for South Washington County Public Schools [South Washington] at a wage of $18.60 per hour, a job that evidently entailed medium to heavy work.  South Washington was aware of the employee’s previous wrist injury and provided him with assistance in performing any heavy work.  The employee evidently had some problem performing his job because of pain, numbness, and hypersensitivity in the back of his hand, together with issues of finger dexterity and manipulation of wrenches.

On October 19, 2005, the employee filed an objection to Liberty’s NOID.  He sought reinstatement of temporary total disability benefits through October 6, 2005, and the payment of temporary partial disability benefits while he was employed by South Washington.  The parties later agreed to settle all of the employee’s claims for benefits through November 1, 2005, and an award on stipulation was issued on February 2, 2006.

The employee resigned from his job with NWA in the spring of 2006, and in July of 2006 his temporary job with South Washington ended and he immediately found another job as a bus mechanic with Independent School District #622 [ISD #622].  The job duties at ISD #622 were essentially the same as those at South Washington, and the employee was again provided with help in performing the heavier tasks.  The employee was not under any formal restrictions when he was hired by ISD #622, but he continued to experience the physical symptoms that he had previously reported.  About four months later, the employee and NWA/Liberty entered into another settlement in compromise of an additional claim for benefits by the employee.  On November 29, 2006, an award on stipulation was issued approving settlement of all claims for temporary partial disability benefits through November 1, 2006.

On January 8, 2007, the employee returned to see Dr. Holm for a recheck of his left wrist.  He had been having some aching along the stainless steel plate and screws, and eventually, on March 5, 2007, Dr. Holm removed the hardware.  Seven weeks later, on April 23, 2007, the employee was again released to return to his job as a bus mechanic without limitations.

On May 8, 2007, while working for ISD #622, the employee was assisting a co-worker in changing a tire on a bus when, while simply rotating the tire, he felt a painful snap in his left wrist.  X-rays revealed that his ulnar osteotomy had come apart, and Dr. Holm therefore performed, on May 16, 2007, an "open reduction, internal fixation of left ulnar nonunion with distal radius bone graft."  The employee was totally disabled from work through July 16, 2007, and then released with restrictions by Dr. Holm.

ISD #622 and its insurer, American Compensation Insurance Company [American], denied liability for the employee’s alleged injury but agreed to pay benefits under a temporary order. Benefits paid by RTW, Inc., a third-party administrator, were based on a weekly wage of $828.74.  On August 31, 2007, the employee filed a claim petition for additional workers’ compensation benefits, alleging liability against NWA based on the March 30, 2004, injury and against ISD #622 based on the 2007 incident.  Both employers denied liability for the benefits claimed, and ISD #622 also filed a petition for contribution and/or reimbursement against NWA/Liberty.

On October 2, 2007, the employee was examined at the request of ISD #622 and American by orthopedist Dr. Jeffrey Husband.  Dr. Husband obtained a history, reviewed the employee’s medical records, and performed a physical examination.  The employee’s chief complaints were of left wrist pain, loss of motion, loss of dexterity, and hypersensitivity.  Dr. Husband diagnosed a left distal radius fracture and an associated TFCC tear, sustained when the employee fell on March 30, 2004.  In his opinion, the employee did not sustain an injury to his left forearm on May 8, 2007.  He concluded instead that the employee's earlier osteotomy had gone on to a fibrous union that ultimately failed as a result of normal daily activities.  The doctor concluded that the employee should be restricted from activities that require repetitive forceful gripping with the left hand, forceful left forearm rotation, and lifting of over ten pounds with the left upper extremity.  He attributed the employee’s need for these restrictions solely to the employee’s March 30, 2004, injury.

On October 29, 2007, Dr. Holm reported that the employee had reached maximum medical improvement and that he was released to work permanently restricted from more than occasional lifting/carrying or pushing/pulling of up to fifty pounds.  He recommended also that the employee not engage in repetitive heavy grasping and that he wear his wrist brace as needed.  On November 7, 2007, Dr. Holm reported that the employee qualified for a 7% whole-body impairment rating under Minnesota Rules 5223.0470, subpart 3B(2).  On February 25, 2008, the employee amended his claim petition to include a claim for compensation for the permanent partial disability rated by Dr. Holm.  In a letter dated May 5, 2008, Dr. Holm also opined that the employee did not sustain a new injury to his left wrist on May 8, 2007, while handling the truck tire.  He agreed with Dr. Husband that the employee had a fibrous nonunion at his osteotomy site, which came apart under normal activities.  He too related the employee’s work restrictions and medical treatment to the March 30, 2004, injury.

NWA and Liberty evidently agreed to a settlement with ISD #622 and American, to compensate the employee for the underpayment of temporary total disability benefits paid under the temporary order, and to make payment of the permanent partial disability rated by Dr. Holm.  They continued to dispute, however, the employee’s claim for temporary partial disability benefits commencing July 16, 2007, and they arranged for an employability evaluation by vocational expert Jan Lowe.

Ms. Lowe conducted her assessment of the employee on June 13, 2008, and completed a labor market survey in early July.  She issued a report of the assessment and labor market survey on July 9, 2008, and she testified also at the hearing before the compensation judge on July 17, 2008.  Ms. Lowe testified that the employee’s earnings as a bus mechanic at ISD #622 were a reasonable representation of the employee’s current earning capacity without restrictions.  She did not believe that the restrictions issued by Dr. Holm on October 29, 2007, were a substantial contributing factor in the difference between what the employee was earning with NWA and his current earnings.  She noted that the employee had no restrictions at the time he accepted the job with ISD #622 in 2006.  She attributed the employee’s reduction in wages to his leaving a long-time position in which he had many years of experience.  When he sought employment after leaving that position, she explained, job openings in his labor market simply did not offer him an opportunity to earn at a level he had previously enjoyed with NWA.  Ms. Lowe opined that the employee’s ability to earn in his labor market peaks out at or near what he is currently earning, with or without restrictions.

The employee was seen by Qualified Rehabilitation Consultant [QRC] John Busse at the request of his attorney on July 7, 2008.  QRC Busse did not conduct a formal vocational evaluation, but he did review the employee’s history and Ms. Lowe’s report, and he testified at the hearing. In QRC Busse’s opinion, the employee’s 2004 injury and restrictions preclude his return to employment as an airline mechanic.  QRC Busse acknowledged that there had been a change since 2005 in the wage scale for airline mechanics, but he was still of the opinion that the employee’s surgical history and restrictions represented a substantial contributing factor in his loss of earning capacity.  He testified that airline mechanics currently earn $2.00 to $4.00 more per hour than what the employee is currently earning.  He stated that, if the employee had no restrictions, he would be able to re-enter the airline mechanic field, which could potentially result in increased earnings.

The employee’s claim for temporary partial disability benefits continuing from July 16, 2007, came on for hearing before a compensation judge on July 17, 2008.  In a findings and order issued September 4, 2008, the compensation judge concluded that the employee sustained a work-related injury at NWA that resulted in disability, that he is able to work subject to that disability, and that he has sustained a loss of earning capacity causally related to that disability.  He found that the employee’s post-injury earnings presumptively represented his earning capacity and that NWA and Liberty had failed to rebut the presumption.  The judge therefore awarded temporary partial disability benefits as claimed.  NWA and Liberty appeal.

On appeal, the Workers’ Compensation Court of Appeals must determine whether “the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.”  Minn. Stat. § 176.421, subd. 1 (2008).  Substantial evidence supports the findings if, in the context of the entire record, “they are supported by evidence that a reasonable mind might accept as adequate.”  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.  Id. at 60, 37 W.C.D. at 240.  Similarly, findings of fact should not be disturbed, even though the reviewing court might disagree with them, “unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of evidence or not reasonably supported by the evidence as a whole.”  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).

In order to establish entitlement to temporary partial disability benefits, an employee must show that he has a work-related disability, that he is able to work subject to that disability, and that he has a loss of earning capacity causally related to the disability.  Krotzer v. Browning-Ferris/Woodlake Sanitation Serv., 459 N.W.2d 509, 43 W.C.D. 254 (Minn. 1990); Dorn v. A.J. Chromy Constr. Co., 310 Minn. 42, 245 N.W.2d 451, 29 W.C.D. 86 (1976).  An employee’s post-injury wage is presumptively representative of his reduced earning capacity.  Roberts v. Motor Cargo, Inc., 258 Minn. 425, 104 N.W.2d 546, 21 W.C.D. 314 (1960).  That presumption may be rebutted, however, by evidence establishing that the employee’s earning capacity is different from his actual earnings or that his loss of earnings is not causally related to his disability.  See, e.g., Borchert v. American Spirits Graphics, 582 N.W.2d 214, 215, 58 W.C.D. 316, 318 (Minn. 1998).

In the present case, it is undisputed that the employee has a work-related physical disability and has shown an ability to work subject to that disability.  In his findings on the issue of earning capacity, the judge accepted QRC Busse’s testimony that the employee had physical restrictions that precluded his return to work as an aircraft mechanic.  The judge accepted also the employee’s testimony referencing his physical limitations and his inability to use his left hand in performing certain physical activities.  And the judge concluded that the presumption of earning capacity raised by the employee’s actual earnings had not been rebutted by NWA/Liberty.

NWA/Liberty’s sole argument on appeal is that the employee’s wage loss is exclusively the result of a change in market conditions and that his current earnings reflect his earning capacity regardless of work restrictions.  They contend, therefore, that the employee does not have an actual loss of earning capacity that is causally related to his disability.  In support of their argument, NWA/Liberty point out that, when the employee obtained his job as a mechanic at ISD #622, he had not been provided with any work restrictions by his doctor.  This job, they contend, represented the employee’s value in the labor market without regard to his alleged work-related disability.  Indeed, at trial the employee had agreed that the physical requirements of his bus mechanic job were very similar to the physical requirements of an aircraft mechanic.  In addition, both Mr. Busse and Ms. Lowe testified to a significant industry change in the wage scale for aircraft mechanics following the 2005 strike.  NWA/Liberty argue that, even had he remained at NWA after August 2005, the employee would still have experienced a wage loss due to industry changes.  Because there simply aren’t any aircraft mechanic jobs available in the current economy, and because the employee’s earnings reflect his earning capacity regardless of restrictions, NWA/Liberty contend that the employee’s loss of earning capacity is unrelated to his disability and the judge’s award of temporary partial disability benefits should be reversed.  We are not persuaded.

As previously noted, the compensation judge found persuasive Mr. Busse’s testimony that the employee was physically precluded from returning to work as an aircraft mechanic.  While the employee testified to similarities between his current job with the school district and his job with NWA, he testified also that he could not perform the current job without assistance, that he could not use his left hand for the necessary torquing, and that NWA had not contacted him regarding a return to work since August 2005.  Given the employee’s and Mr. Busse’s testimony, the medical records documenting the employee’s history of symptoms, four surgeries, and subsequent restrictions, and the lack of any job offer from NWA, we believe that the record amply supports the judge’s conclusion that the employee is physically precluded from returning to work as an aircraft mechanic.

With regard to the change in market conditions, Mr. Busse testified that, despite the reduced wage scale for aircraft mechanics, aircraft mechanics still earn two to four dollars more per hour than the employee is currently earning.  He opined that the employee’s physical restrictions and inability to return to his former job were substantial contributing factors in the employee’s wage loss. The judge accepted Mr. Busse’s testimony and was not required to accept the testimony offered by Ms. Lowe, that the employee’s reduction in earnings was due solely to causes other than the work injury.  Whether an employee’s reduction in earnings during a period of post-injury employment is due to the employee’s injury or to some non work-related cause is a question of fact for the compensation judge.  Borchert, 582 N.W.2d at 215, 58 W.C.D. at 318 (citation omitted).

We acknowledge that the problem of wage loss caused partly by economic conditions and partly by disability is complicated.  In the present case, there is clear evidence that aircraft mechanics simply are not earning wages at the level of those they earned before August 2005.  That being said, the judge’s finding that the employee’s loss of earning capacity is also causally related to disability sustained on March 30, 2004, is supported by substantial evidence in the record.  The judge quite correctly determined that the employee’s actual earnings presumptively represent his reduced earning capacity.  Having failed to establish that the reduction in the employee’s earnings is unrelated to his disability, or that the employee’s ability to earn is something affirmatively different from that reflected in his post-injury wage, the judge’s award of temporary partial disability benefits must be affirmed.  See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.