RJ Sport & Cycle and its insurer,^[1] administered by Berkley Risk Administrators Company, appeal the compensation judge’s findings on permanent partial disability as well as apportionment of liability between the July 1, 1996, and February 22, 2006, work-related injuries.  We affirm.

Glenn Armstrong, the employee, began working for RJ Sport & Cycle, the employer, in 1987.  He started as a janitor and worked his way up to senior mechanic.  In September 1988, the employee was diagnosed with low back strain, which resolved without further treatment.  The employee was treated for low back pain again in February 1990.  He underwent physical therapy and returned to work without restrictions.  On July 1, 1996, the employee sustained an admitted work-related low back injury while installing a motor.  At that time, the employer’s insurer for workers’ compensation liability was administered by Berkley Risk Administrators Company.

The employee treated with Dr. Carl Sjoding at Duluth Clinic West Family Practice.  Dr. Sjoding diagnosed acute lumbar strain and took the employee off work.  The employee was referred for physical therapy and released for light duty work a few weeks later.  The employee returned to Dr. Sjoding on July 31, 1996, and was released for work with a 50-pound lifting restriction in place for one month.  On October 9, 1998, the employee returned to the clinic and treated with Dr. H. Chris Chapman, reporting recurrent left lumbosacral and left leg pain that had worsened over the last two weeks.  Dr. Chapman diagnosed low back pain with paresthesias and probable L5-S1 radiculopathy.  He also recommended physical therapy, ordered an MRI scan, and released the employee for light duty work.  An October 19, 1998, lumbosacral spine MRI scan indicated a small central prolapsed disc at L4-5 and a slightly larger prolapsed herniated disc at L5-S1 with probable left S1 nerve compression.

In December 1998, Dr. Chapman assigned the employee a 20-pound lifting restriction and referred him to Dr. Jed Downs, an occupational medicine specialist.  Dr. Downs assessed a two-level annular tear with discogenic and mechanical back pain and secondary myofacial restrictions.  He opined that the employee’s injury was work related and recommended spinal mobilization exercises, an epidural spinal injection, and a home traction unit.  In January 1999, the employee reported some improvement and Dr. Downs recommended stabilization exercises with chiropractic treatment and also assigned the employee a 30-pound lifting restriction.  In March 1999, Dr. Downs recommended continued exercises and a 75-pound lifting restriction.  Dr. Downs further found the employee had reached maximum medical improvement as of March 2, 1999, and assigned the employee a 3.5 percent permanent partial disability for his low back condition under Minn. R. 5223.0390, subp. 3.B.  The appellants paid the permanent partial disability under the schedule.  In June 1999, the employee experienced a significant flare-up of his symptoms and returned to Dr. Downs, who recommended chiropractic care and stabilization exercises, and reduced the employee’s lifting restriction to 50 pounds.  The employee later reported improvement.

On February 22, 2006, the employee sustained another low back incident while building a trailer at work for the employer.  At that time, the employer was insured for workers’ compensation liability by West Bend Mutual Insurance Company (West Bend).  He sought treatment with Dr. Chapman, who took the employee off work and referred him for chiropractic treatment.  After a few weeks of treatment, the employee returned to work with restrictions.  In April 2006, Dr. Chapman referred the employee to Dr. Timothy Morton, a physical medicine and rehabilitation specialist at Duluth Clinic.  An April 3, 2006, MRI scan, when compared to an earlier MRI scan, indicated unchanged L5-S1 degenerative changes with left S1 nerve root involvement and slightly worse findings at L4-5 with some central inferior extrusion and slight left L5 nerve root involvement.  Dr. Morton assessed lumbar strain/sprain, left L4-5 facet injury, and questionable radiculopathy.  He continued the employee’s restrictions, prescribed a back brace, and ordered L4-5 facet joint injections.  The employee reported that the injections provided temporary relief.  A few months later, the employee underwent a radiofrequency ablation procedure which helped his low back pain, but he continued to have left S1 joint pain.  The employee was prescribed a left S1 joint belt and referred to physical therapy.  In August 2006, Dr. Morton prescribed a Medrol Dose-Pak for the left leg radicular symptoms and referred the employee for a left S1 joint injection.  In September 2006, the employee reported to Dr. Morton that his left leg pain had resolved.  Dr. Morton released the employee to work without restrictions, primarily because restricted duty was not available for the employee with the employer.

In October 2006, the employee returned to Dr. Morton, reporting a sharp increase in pain with tingling down the back of his leg.  Dr. Morton prescribed a Medrol Dose-Pak.  A November 24, 2006, MRI scan indicated no interval changes at L4-5 and L5-S1.  In December 2006, Dr. Morton referred the employee for a neurosurgical evaluation and a left leg EMG, and restricted the employee to sedentary work duties.

On December 14, 2006, the employee was evaluated by Dr. Richard Strand at the employer and West Bend’s request.  Dr. Strand assessed degenerative disc disease and degenerative spondylosis of the lumbar spine at multiple levels with bulging discs.  He opined that the February 2006 incident was a temporary aggravation of the employee’s pre-existing degenerative condition and that the employee had reached maximum medical improvement for this condition.  He recommended conservative care and a work restriction of no lifting over 50 pounds.  A January 2007 EMG performed by Dr. Steven Erlemier was read as normal with no significant peripheral neuropathy or lumbar radiculopathy.  On January 15, 2007, the employee was evaluated by Dr. Nancy Ensley, a neurosurgeon.  Dr. Ensley diagnosed degenerative disc disease of the lumbosacral spine with disc protrusion at L4-5 and L5-S1.  She recommended physical therapy and an epidural steroid injection at left L5-S1.  The employee continued with conservative care and physical therapy.  In September 2007, Dr. Ensley opined that the employee was near maximum medical improvement for conservative care and that the employee could not return to his previous job.  She referred the employee to a neurosurgeon for a possible discectomy.

An October 15, 2007, MRI scan showed little radiographic change.  In November 2007, the employee was evaluated by Dr. Mark Glazier, who opined that the employee had tried all conservative measures and proposed surgical treatment consisting of a left L4-5 discectomy.  The employee was evaluated again by Dr. Strand in January 2008.  Dr. Strand opined that the employee had an extruded fragment disc at L4-5 with compression on the dural sac and the left nerve root.  He concluded that the employee was a candidate for the proposed surgery.  On March 8, 2008, the employee underwent the L4-5 microdiscectomy, performed by Dr. Glazier.  After the surgery, the employee’s radicular pain resolved, but he continued to have back pain.  Dr. Glazier referred the employee for physical therapy and a work hardening program.  After completing the program, the employee’s functional capacities were not adequate for him to return to his previous employment.  Dr. Glazier recommended that the employee consider retraining.

On September 2, 2008, the employee was evaluated by Dr. Tilok Ghose at the appellants’ request.  Dr. Ghose opined that employee’s need for medical treatment and work restrictions were not related to the employee’s July 1996 injury.  In October 2008, Dr. Chapman recommended a functional capacities evaluation and a chronic pain management program.  The functional capacities evaluation indicated that the employee had sustained work limitations.  The employee underwent another evaluation with Dr. Strand in January 2009.  Dr. Strand opined the employee could work with a 25-pound lifting restriction and no repetitive bending or lifting.  He concluded that the employee would not benefit from a chronic pain management program and assigned the employee an 11 percent permanent partial disability rating.  Dr. Chapman referred the employee again to Dr. Morton, in February 2009.  Dr. Morton treated the employee with trigger point injections and referred the employee for a chronic pain program.  In May 2009, Dr. Morton opined that the employee had reached maximum medical improvement but that the employee had chronic pain and could not tolerate any work.  Dr. Morton and Dr. Chapman continued to recommend a chronic pain program.

In July 2009, the employee was evaluated by Dr. Robert Hoffman, a psychologist, at the request of the Social Security Administration.  Dr. Hoffman assessed an adjustment disorder and chronic pain disorder, and recommended counseling.  In December 2009, the employee was assessed by Douglas Heck, Ph.D., a licensed psychologist at the Duluth Psychological Clinic.  The employee saw Dr. Heck again in January 2010 and May 2011.

The employee continued to treat with Dr. Morton throughout 2010.  Dr. Morton recommended physical therapy, which was not approved, and prescribed medication.  He strongly recommended a chronic pain program.  Dr. Strand had opined that the employee would not benefit from a pain management program and also opined that physical therapy was not reasonable and necessary.  After a hearing in 2010, a compensation judge ordered the employer and West Bend to pay for a pain management program.  The employer and West Bend appealed, and this court vacated the award for payment of the pain program and ordered payment of an admission evaluation for a pain program.^[2]  On May 17, 2011, the employee underwent a pain management consultation at Essentia Health’s Pain Management Center, and was found to be eligible for the program.  He began the 16-week program in September 2011.  The employee’s treating psychologist during this program opined that the employee’s 2006 work injury was a substantial contributing factor to the employee’s depression, which she related to his chronic pain.

In March 2012, the employee was evaluated by Dr. Thomas Gratzer, a psychiatrist, at the request of the employer and West Bend.  Dr. Gratzer opined that the employee’s adjustment disorder was not related to his work injuries.  The employee returned to Dr. Chapman for treatment in April 2012.  Dr. Chapman referred the employee for physical therapy for a TENS unit.  In June 2012, Dr. Strand reviewed the employee’s medical records and reports, and concluded that the employee was not permanently and totally disabled.  In July 2012, Dr. Morton recommended another MRI scan and trigger point injections.  The employee underwent a lumbar MRI scan on July 20, 2012, which indicated left-sided L4-L5 foraminal narrowing and right-sided L5-S1 foraminal narrowing, which had progressed significantly.  Dr. Morton indicated that the MRI scan revealed progressive spondylosis with no clear nerve root involvement.

This matter has a complicated procedural history.  Numerous hearings were reset throughout the proceedings.  The employer and West Bend filed a petition for contribution and/or reimbursement in July 2007.  The employee filed a claim petition on January 15, 2008, which was amended on January 24, 2008, claiming permanent partial disability and temporary partial disability benefits.  On March 28, 2008, the employer and West Bend filed a petition for a temporary order.  A temporary order was served and filed on April 7, 2008, requiring the employer and West Bend to pay medical expenses and rehabilitation benefits as well as wage loss benefits beginning March 10, 2008.  The employee amended the claim petition on February 20, 2009, to include claims for prescription medication and a chronic pain program.  An objection to discontinuance was filed on May 21, 2009, and was consolidated with the pending claim petition on May 29, 2009.  On October 1, 2009, the employee filed an amended claim petition for 11 percent permanent partial disability, medical expenses, retraining benefits, and permanent total disability benefits.  The employee filed a request for rehabilitation assistance on April 16, 2010, and a request for medical assistance on May 20, 2010, which were consolidated.  A hearing was held on the medical and rehabilitation request.  As mentioned above, the compensation judge’s decision on these issues was appealed, and this court affirmed in part, modified in part, and vacated in part.

On March 23, 2011, the employee’s claim petitions and the objection to discontinuance were dismissed without prejudice.  On July 20, 2011, the employer and West Bend filed an amended petition for contribution and/or reimbursement against the appellants.  The appellants denied the claim for contribution and/or reimbursement.  On December 19, 2011, the employee filed another claim petition for permanent total disability and retraining.  The employer and West Bend denied the claim.  The appellants also denied the claim, and specifically alleged that any benefits paid for the 1996 injury were paid under a mistake of fact.  They argue that any benefits payable to the employee are related to the 2006 work injury.  On January 18, 2012, the petition for contribution and the claim petition were consolidated for hearing.

A hearing was held before a compensation judge on August 29, 2012.  The issues presented to the judge included 1) whether the employee met the 17 percent threshold for permanent total disability benefits; 2) whether the employee has been permanently totally disabled from February 22, 2006; 3) whether the employer and West Bend are entitled to contribution from the appellants; and 4) the percentage of apportionment for any award of contribution.  At the close of the hearing, the appellants submitted Exhibit H, a trial memorandum and argument regarding the apportionment issue, to the court “for illustrative purposes.”^[3]  The compensation judge found that the employee’s work injuries were not substantial contributing factors to his psychiatric condition and that the employee had not met the necessary threshold to qualify for permanent total disability.  The judge also found that both work injuries were substantial contributing factors to the employee’s disability and need for treatment, and that the payments listed in the evidence represent payment for reasonable and necessary medical treatment and accompanying wage loss benefits.  The judge apportioned liability as 30 percent to the 1996 injury and 70 percent to the 2006 work injury, except for the 11 percent permanent partial disability which was assigned to the 2006 injury.  Based on this apportionment, the judge awarded contribution payments to the employer and West Bend.  This appeal followed.

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.^[4]  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.^[5]  Fact findings are clearly erroneous if the reviewing court, looking at the entire evidence, is left with a definite and firm conviction that a mistake has been committed.^[6]  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 the evidence or not reasonably supported by the evidence as a whole.”^[7]  A decision which rests upon the application of a statute or rule to essentially undisputed facts generally involves a question of law which the Workers’ Compensation Court of Appeals may consider de novo.^[8]

At the hearing below, the appellants argued that the employee’s 1996 injury was not a substantial contributing factor to the employee’s low back condition after 2006.  They also argued that any apportionment of liability should only apply to expenses incurred after the temporary order was issued on April 13, 2008.^[9]  In their notice of appeal, the appellants appealed from the compensation judge’s findings that 1) the employee’s injuries of July 1, 1996, and February 22, 2006, both represent substantial contributing factors in the employee’s need for medical treatment and his disability; 2) the employee’s medical treatment expenses and disability payments represent reasonable and necessary medical treatment and accompanying wage loss benefits are causally related to employee’s July 1, 1996, and February 22, 2006, work injuries; 3) that liability for the employee’s disability was equitably apportioned between the two dates of injury for the low back condition; and 4) that the employee was paid 3.5 percent permanent partial disability pursuant to Minn. R. 5223.0390, subp. 3.B., by the appellants for the employee’s July 1, 1996, work injury.^[10]  They also appealed Order 3 regarding apportionment of liability for payment of benefits related to the employee’s low back condition.

In their brief on appeal, the appellants raise another issue by arguing that any award of equitable apportionment was outside the statutory authority of Minn. Stat. § 176.191.  We note that this particular argument was not raised by the parties and litigated before the compensation judge at the hearing below.  Generally, an issue raised for the first time on appeal is not properly before this court and will not be addressed.^[11]

This argument, however, includes an issue the appellants did raise at the hearing, namely, that apportionment should only be available after the date of the temporary order.  The appellants argue that the compensation judge’s award of apportionment before and after the date of the temporary order violates the limitations on equitable apportionment under Minn. Stat. § 176.191, subd. 1.  They argue that the statute does not allow contribution or reimbursement claims from other employers or insurers except in certain circumstances, such as payments under a temporary order.  Here, the appellants argue that since the original contribution claim that was based on the temporary order was dismissed, and the amended petition for contribution/reimbursement was not based on the temporary order, the contribution claim does not fall under any of the exceptions in the statute and therefore the claim should have been dismissed.  We disagree with this argument.

The Minnesota Supreme Court has ruled that Minn. Stat. § 176.191, subd. 1a, while limiting the circumstances in which equitable apportionment of liability is allowed, applies “only in those situations in which the sole dispute is how responsibility for benefits should be allocated among successive employers and their respective insurers when all are undisputedly liable for some portion of the employee’s disability for the period in question.”^[12]  However, in this case, the appellants denied liability for any portion of the employee’s disability for the time period at issue.  Therefore, Minn. Stat. § 176.191 does not apply in these circumstances, and the compensation judge did not err by addressing the contribution claim.

Equitable apportionment is not solely a medical determination, but is a finding of fact based on all the circumstances of a case.  Factors considered in determining apportionment include the nature and severity of the initial injury, the employee’s physical symptoms following the initial injury and before the second injury, the nature and severity of the second injury, and the period of time between the injuries.^[13]  In considering the evidence in the present case, the information relied on by the compensation judge regarding the employee’s two back injuries was developed by testimony from the employee and the employee’s medical records.  The judge was presented with two competing medical opinions from independent medical examiners as to whether the two injuries contributed to the employee’s disability.  Dr. Ghose opined that employee’s need for medical treatment and work restrictions were not related to the employee’s July 1996 injury.  Dr. Strand opined that the February 2006 incident was a temporary aggravation of the employee’s pre-existing degenerative condition and that the employee had reached maximum medical improvement for this condition.  Where there is adequate foundation for the opinion adopted by the judge, this court generally upholds the compensation judge’s choice among experts.^[14]  A compensation judge may rely on part of a medical expert’s opinion and is not obligated to accept either all or none of the expert’s opinions in order to rely on that doctor’s expertise.^[15]

The compensation judge weighed the evidence submitted including oral testimony and the medical records, and concluded that both injuries were substantial contributing factors to the employee’s low back condition.  The judge’s determination of equitable apportionment is supported by substantial evidence in view of the entire record as submitted and we affirm.

The appellants contend the compensation judge erroneously relied on the payment benefit summary^[16] submitted by the employer and West Bend to order reimbursement when the payment summary did not identify the date of service, the provider, or nature of services rendered.  To that end, the appellants maintain the court should remand this issue to the judge for further findings on what payments are associated with non-compensable, psychological or psychiatric treatment and which payments would be associated with a physical injury and are subject to apportionment.^[17]  We are not persuaded by the appellants’ argument.

The compensation judge apportioned benefits paid by West Bend between the two insurers.  There is no evidence in the record to suggest West Bend paid for non-compensable, psychiatric treatment and the judge’s findings only reflect an award to reimburse payments made.  The payment benefit summary contains information identifying the type of benefit paid, the payee, the start and end date of treatment, the billed draft amount number, and the amount paid.  The record contains medical reports which are identified by medical provider, date of service, and nature of services rendered.  The record also contains the description of services billed and services paid.  Medical treatment and disability benefits can be matched with the payment benefit summary identified as respondents employer and West Bend’s Exhibit 3 and the compensation judge noted in his memorandum that he “carefully considered the medical evidence and factual background”^[18] in arriving at his conclusion.

The appellants did not identify which expenses are associated with non-compensable injuries nor did they identify which expenses they claim are unrelated, unreasonable, or unnecessary to the employee’s work-related injuries.  We find substantial evidence supports the compensation judge’s equitable apportionment award of all charges listed in Exhibit 3 and we affirm the judge on this issue.

The appellants also appeal the compensation judge’s finding that the employee was paid 3.5 percent permanent partial disability pursuant to Minn. R. 5223.0390, subp. 3.B., by the appellants for the employee’s July 1, 1996, work injury.  While the appellants had claimed in their answer to the employee’s claim petition that any payments for benefits for the 1996 work injury were paid under a mistake of fact, they did not litigate this issue at the hearing.  Again, we note that generally, an issue raised for the first time on appeal is not properly before this court and will not be addressed.  There is no indication in the record that the 3.5 percent permanent partial disability was litigated at the hearing below.  Therefore, we need not address this issue further.