The employer and insurer argue that the compensation judge erred by not applying collateral estoppel to bar the employee’s claim for rehabilitation benefits.  We affirm.

On June 9, 1992, and September 8, 2003, Tony C. Vick, the employee, sustained work-related injuries while working for Northern Engraving Corporation, the employer, which was insured for workers’ compensation liability by Sentry Insurance Company.  The parties have engaged in extensive litigation on various issues involving these injuries.  In 2006, the parties stipulated that the employee had sustained work-related low back injuries on the dates listed above.^[1]  In 2008, the employee filed a claim for medical expenses related to the admitted work injuries or to newly claimed work injuries.  At the February 8, 2008, hearing on this claim, the parties stipulated that the employee had permanent restrictions including a 50 pound lifting limit and avoiding repetitive bending, lifting, and twisting.  One of the issues litigated was whether the employee’s permanent restrictions were related to any work injuries.  In a Findings and Order served and filed April 7, 2008, the compensation judge found that the employee had not sustained any new work injuries and that the employee’s permanent restrictions were related to a degenerative condition unrelated to the work injuries.  Neither party appealed this decision.

The employee was evaluated in July 2009 by Dr. R. Wynn Kearney, Jr., who opined that the employee’s treatment was reasonable, necessary, and causally related to his work injuries.  He recommended restrictions including a 35 pound lifting limit, avoiding or severely limiting bending, twisting, and lifting, allowing frequent changes of position, and limiting climbing.  In December 2010, the parties litigated the employee’s claim for additional medical expenses not previously addressed by the compensation judge.  The judge specifically rejected Dr. John Dowdle’s opinion that the employee had recovered from his work injuries and found that the employee had ongoing symptoms related to the work injuries, partly relying on Dr. Kearney’s opinion.^[2]  The judge concluded that the medical expenses at issue at that time were reasonable, necessary, and causally related to the employee’s work injuries.

In January 2011, the employee’s treating physician, Dr. Daniel Wientzen, opined that the employee was medically disabled and could not engage in any work activity.  The employee underwent a rehabilitation consultation with QRC Julie Turtle on March 30, 2011.  The QRC determined that the employee had significant restrictions and that the employee was eligible for rehabilitation benefits.  On May 18, 2011, Dr. Wientzen released the employee for work with ongoing restrictions including a 15 pound lifting limit, occasional sitting, standing, and walking, limited bending and twisting, and no crawling, squatting, or climbing.  The employer and insurer denied payment for any rehabilitation services, claiming that the employee’s restrictions were the result of a pre-existing condition.  The QRC continued to provide services including medical management, vocational counseling, and job search assistance.

The employee filed a rehabilitation request for rehabilitation services on August 8, 2011, and a medical request for medical expenses and medical mileage on December 16, 2011.  By that time, Dr. Wientzen indicated that the employee was again unable to work due to severe disabling pain and the QRC recommended terminating job search assistance.  As of January 2012, the QRC remained on the file for medical management.

The employee was evaluated by Dr. Kristen Zeller-Hack at the employer and insurer’s request on February 23, 2012.  Dr. Zeller-Hack opined that none of the employee’s conditions or his need for treatment were related to his work injuries.  In a March 27, 2012, report, Dr. Wientzen opined that the employee’s chronic pain condition and his medical treatment were causally related to his injuries.  A hearing was held on March 29, 2012, on the employee’s rehabilitation and medical requests.  The compensation judge found that the claimed medical treatment and mileage were reasonable and necessary to cure or relieve the effects of the employee’s work injuries and that the employee was entitled to vocational rehabilitation services.  The employer and insurer appeal the compensation judge’s award of rehabilitation services.

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.^[3]  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.^[4]  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.^[5]  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.”^[6]  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.^[7]

The employer and insurer appeal the compensation judge’s award of rehabilitation benefits, arguing the judge committed an error of law in failing to apply collateral estoppel to bar the employee’s claim for rehabilitation benefits.  We are not persuaded.

Minn. Stat. § 176.102, subd. 1(b), states the actual intention and purpose of rehabilitation benefits.  “Rehabilitation is intended to restore the injured employee so the employee may return to a job related to the employee’s former employment or to a job in another work area which produces an economic status as close as possible to that the employee would have enjoyed without disability.”^[8]  Minn. R. 5220.0130 assists in furthering the statutory objective by defining who is eligible for rehabilitation benefits.  An employee must be a “qualified employee” before a rehabilitation plan is implemented.^[9]  An employee is deemed “qualified,” or eligible for rehabilitation services, where the compensation judge determines that the employee is likely to be permanently precluded from the employee’s customary occupation or pre-injury job as a result of the work injury.  The precise issue implicit in this determination is whether or not the employee has restrictions.  Without restrictions, an employee is not a “qualified employee” under the rule.^[10]

After the February 8, 2008, hearing, the compensation judge held that the employee’s permanent restrictions were related to a degenerative condition unrelated to the work injuries.  Based on the 2008 findings, the employer and insurer argue that the employee’s claim of new restrictions necessitates re-litigation of the same issue, and therefore contend the compensation judge erred by failing to apply the principle of collateral estoppel to bar the employee’s claim for rehabilitation benefits.  The employer and insurer maintain that the employee is not entitled to rehabilitation services when the receipt of services requires the recipient to be a “qualified employee” under the meaning of the rule and the employee is not qualified without re-litigating an issue that had previously been fully litigated and decided in a judge’s findings and order in 2008.

The employer and insurer contend the threshold issue of whether the employee has work-related restrictions and therefore qualifies for rehabilitation services has been fully and completely litigated and decided by a compensation judge in the April 7, 2008, Findings and Order.  In that decision, the judge determined the employee’s permanent restrictions as outlined in 2008 were unrelated to his work injuries.  The employer and insurer maintain the employee is not free to re-litigate the issue even when the issue is a threshold question to determine entitlement in a new period of time and for a different disability benefit.  To that end, they argue that the compensation judge erred as a matter of law in failing to apply the principle of collateral estoppel to bar the employee’s claim for rehabilitation benefits.  We are not persuaded.

We agree that collateral estoppel bars the re-litigation of issues that have previously been fully litigated in claims presented to a compensation judge and decided in a findings and order.  Principles of res judicata are applicable in workers’ compensation proceedings.^[11]  Collateral estoppel is a limited form of res judicata where “a former judgment is conclusive in a later suit between the same parties . . . as to determinative issues finally decided in the former suit.”^[12]  The doctrine of res judicata, however, applies in workers’ compensation cases only with respect to issues and claims that were in fact decided in an earlier decision.^[13]  Where the claim at the later hearing involves eligibility for benefits based on factual circumstances after the prior decision, the prior decision is res judicata only with respect to the period considered in the former hearing,^[14] including determinations relative to medical restrictions.^[15]

In this case, a prior finding in an earlier decision has a claim preclusion effect only if the claim asserted in the subsequent hearing was litigated and decided at the time of the February 8, 2008, hearing.  In 2008, the employee litigated the issue of the causal relationship between the employee’s physical condition and his work abilities up to and after the time he was laid off from work in October 2005.  In denying the employee’s wage loss claims, the compensation judge made several findings.  The judge found that the employee was laid off in 2005 for economic reasons unrelated to his work-related injuries, and at that time he was performing the full duties of his job without any restrictions.^[16]  The judge also found that the “permanent restrictions, as outlined by Dr. Dowdle in his IME report of July 5, 2006, . . . represent restrictions which are reasonable to allow the employee to avoid undue risk for further injury and are reasonable based on the employee’s underlying degenerative condition and not related to his work-related injury or injuries.”^[17]  The compensation judge made these findings regarding the employee’s work restrictions in determining the employee’s eligibility for wage loss benefits through the date of the 2008 hearing.^[18]  The judge also noted in her memorandum that:

The employee’s claims at the present hearing and before us on appeal are new claims for medical and rehabilitation benefits based on new medical evidence for a new period in time, including evidence of ongoing clear and specific restrictions from the employee’s physician.  At the time of the 2008 hearing, the employee had been released to work with a 50 pound lifting limit, and by 2011, the restrictions had changed to working with a 15 pound lifting limit or being off work entirely.  In an unappealed finding, the compensation judge found that employee had a long history of back/leg pain and related treatment.^[20]  The judge observed that the physical effects of work injuries on employees can ebb and flow over time.  He commented that in many cases, work restrictions are subject to change due to alterations in the employee’s medical treatment or physical condition, and concluded that the employee’s physical conditions in this case presented symptoms that deemed additional work restrictions necessary.

The compensation judge also accepted Dr. Wientzen’s opinions, that the employee’s physical conditions were related to the work injuries and that his restrictions had changed, as credible expert opinions.  The compensation judge could reasonably conclude that the employee’s physical restrictions are now related to the low back work injuries and not entirely related to the non-work related medical conditions.  The findings regarding work restrictions from the prior hearing do not preclude a finding that the employee has work-related restrictions four years later.  The compensation judge’s determinations regarding the employee’s work restrictions are not barred under the principle of collateral estoppel, and we affirm.

In the alternative, the employer and insurer argue the evidence is insufficient to find an appreciable medical change in the employee’s condition to warrant a need for restrictions.  They maintain the only appreciable change in the employee’s overall medical condition is that the employee “has been diagnosed with significant other comorbidities, including chronic pain syndrome, hip and knee arthritis, peripheral neuropathy, depression, gout, antisocial personality disorder, and poly-substance abuse.”^[21]  We note, however, that the employee need not prove a substantial change in condition or circumstances, but “what is required is proof of the actual existence of a disability during the period of time for which benefits are claimed . . . [which] may entail new evidence covering the subsequent period of time” and not necessarily evidence of a material change in condition.^[22]

In reviewing the evidence, we note that the compensation judge did consider the records and report of the independent medical examiner, Dr. Zeller-Hack, and included in his findings and order a detailed record review of the employee’s treatment with, and reports of, Dr. Wientzen and Dr. Kearney.  The judge accepted the testimony of the employee as credible and accepted the medical opinions of Drs. Wientzen and Kearney over the opinion of Dr. Zeller-Hack.  Having carefully reviewed the record, we conclude the evidence is adequate to support the decision of the compensation judge.

Overall, the compensation judge took into account the new medical evidence, the employee’s testimony, and the opinions of QRC Turtle in determining the employee was qualified and entitled to rehabilitation services.  The connection between the employee’s physical condition today and the employee’s ability to presently engage in work activities is measured by work restrictions related to the work injuries.  The judge did not err by concluding that the employee’s claim for vocational rehabilitation benefits is not barred by collateral estoppel.  The compensation judge determined that the employee was entitled to rehabilitation services, and we affirm.