The employer and insurer appeal from the compensation judge’s award of temporary partial disability benefits.  We affirm.

Gary W. Kosnopfal, the employee, sustained a personal injury to his low back on December 6, 2002, while working for Connexus Energy, the employer.  The employer and its insurer accepted liability for the employee’s injury.

Following treatment with his family physician, the employee saw Dr. John Stark, an orthopedic surgeon, in February 2002.  The doctor diagnosed a lumbar radiculopathy secondary to disc collapse at L5-S1, permanently aggravated by a lifting incident at work, and took the employee off work.  On April 14, 2003, Dr. Stark performed a bilateral decompression at L4-5 and L5-S1 based upon a diagnosis of bilateral spinal stenosis with lateral recess stenosis at those levels.

In May 2003, Dr. Stark released the employee to very light work.  The doctor prepared an R-33 form on August 14, 2003, that limited all of the employee’s activities except lifting and carrying up to 10 pounds.  Dr. Stark stated, “Restrictions considered permanent.” (Ee Ex. C.)  The employee returned to work with the employer on June 4, 2003, in a job within these restrictions. On September 23, 2003, the doctor diagnosed mechanical back pain status post lumbar decompression and stating, “The working plan then is for the patient to stabilize his work situation either with a better relationship with his employer or a new job.  Restrictions were not given today, fearing they might limit him.”  (Ee Ex. C.)  In a Report of Work Ability dated November 24, 2003, Dr. Stark referred to the permanent restrictions contained in the R-33 form.  In November 2003, Dr. Stark rated a 15 percent whole body disability and concluded the employee had reached maximum medical improvement on October 10, 2003.

On March 9, 2004, David Mickelson, a qualified rehabilitation consultant, met with the employee for a rehabilitation consultation.  Mr. Mickelson stated the employee was then working full-time for the employer in a temporary position, concluded the employee was qualified for rehabilitation services and prepared a rehabilitation plan.  The employee was terminated by the employer on June 28, 2004, and he commenced a job search.  On August 18, 2004, the employee started a job working for his brother at K & R Masonry in Chatsfield, Minnesota.  The employee worked three days per week at $6.00 an hour driving a truck and doing some painting and repairing of equipment.  The employee testified he continued to look for other work.

On September 2, 2004, Dr. Stark prepared a Work Ability Report stating the employee was able to work without restrictions.  That same day, the doctor prepared a statement for the Minnesota Department of Unemployment & Economic Development stating the employee was totally disabled from December 2002 through September 2, 2004, but was “now able to return, without restrictions.”  (Resp. Ex. 1.)

Dr. Stark reexamined the employee on September 7, 2004, and noted the employee was seen for “follow-up of his ongoing disability and controversies.”  The doctor’s physical examination suggested pain around the right PSIS with pain on forward flexion in the thighs.  Dr. Stark stated he believed the employee “would be employable at the Casino and I attempted to put out some documentation towards that.  Unfortunately it came out as inconsistent with some of his other work forms for the State of Minnesota and the department of economic development.”  The doctor’s report noted that Mrs. Kosnopfal accompanied the employee and had “some very good questions today about exactly what his limitations would be, how he would return to work, whether or not the inconsistencies would prompt some type of disqualification of benefits already paid and so on.  I related to her and to him that I am doing the best I can to provide him with documentation for allowing him to return to work.  He obviously has a lingering disability, which is interfering with his ability to work.”  (Ee Ex. C.)  Dr. Stark ordered a functional capacity evaluation which he stated the employee and his QRC would return to discuss.  There are no later records from Dr. Stark in evidence.

The employee began a job at Grand Casino as a security guard on October 7, 2004, earning $8.25 per hour.  When he applied for the job, the employee represented that he was capable of working without restrictions.  During the time he worked at Grand Casino, the employee testified he continued to have low back and right leg pain which he stated caused him problems at work and limited his non-work physical activity.  While working at the Casino, the employee testified he continued to look for better paying jobs.  He stated, however, he felt unable to perform certain jobs such as masonry and truck driving because of his injury.  The employee worked at Grand Casino until May 16, 2005.  On May 23, 2005, the employee obtained a job as a forklift driver/material, handler at Woodcraft, Inc., which he procured through Doherty Temporary Services.  In July 2005, the employee was taken off the forklift job and placed in an assembly position because he was having low back pain.  He testified the assembly position required extensive standing which caused low back and right leg pain.

The employee filed a claim petition seeking temporary partial disability benefits.  Following a hearing in August 2005, the compensation judge found the December 6, 2002, personal injury resulted in restrictions and permanent partial disability and awarded temporary partial disability benefits.  The employer and insurer appeal.

To establish entitlement to temporary partial disability benefits, an employee must demonstrate a work-related physical disability and an actual loss of earning capacity that is causally related to the disability.  Krotzer v. Browning-Ferris, 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).  The employee must be subject to physical limitations caused by a work injury to be entitled to wage replacement benefits.  Kautz v. Setterlin Co., 410 N.W.2d 843, 40 W.C.D. 206 (Minn. 1987).  The appellants contend the compensation judge erred by ignoring the opinion of Dr. Stark stating the employee can work without restrictions.  A determination of an employee’s physical functional capabilities, the appellants argue, is a medical issue and the compensation judge is not free to disregard unopposed medical testimony.  Accordingly, the appellants seek a reversal of the award of temporary partial disability benefits.

As a general rule, a fact finder is not free to disregard unopposed medical opinion.  Olson v. Midwest Printing Co., 347 N.W.2d 43, 46, 36 W.C.D. 623, 627 (Minn. 1984).  "The reason for giving binding effect to medical testimony is that such testimony concerns issues not within the realm of knowledge of the [factfinder]."  Id.  There is a difference, however, between disregarding unopposed medical opinion and rejecting it on the basis of other evidence.  Clark v. Archer Daniels Midland, slip op. (W.C.C.A. Feb. 14, 1994).  In resolving factual disputes, a compensation judge is not necessarily bound by medical opinion.  Tuomela v. Reserve Mining Co., 299 Minn. 203, 204, 216 N.W.2d 638, 639, 27 W.C.D. 312, 313 (1974) (per curiam).

In finding number 10, the compensation judge found,

Clearly, the compensation judge did consider the report of Dr. Stark stating the employee had no work restrictions.  The judge, however, rejected that opinion based, in part, on the testimony of the employee.  The employee is the person most familiar with the severity of his symptoms and the limitations they place on his physical activities.  See Brening v. Roto-Press, Inc., 306 Minn. 562, 337 N.W.2d 383, 28 W.C.D. 225 (1975).  Where the testimony of an employee is substantial and credible, that testimony alone is a sufficient basis for a finding of disability.  Grgurich v. Sears, Roebuck & Co., 301 Minn. 291, 223 N.W.2d 120, 27 W.C.D. 563 (1974).  The compensation judge could properly reject the opinion of Dr. Stark based upon the testimony of the employee.

Furthermore, Dr. Stark’s opinions regarding work restrictions are not as unequivocal and unambiguous as the appellant contends.  On several occasions, Dr. Stark stated the employee’s restrictions were permanent.  On September 2, 2004, Dr. Stark prepared a Work Ability Report and a Department of Unemployment and Economic Development form indicating that the employee was able to work without restrictions.  On September 7, however, the doctor noted those reports were inconsistent with his prior opinions and stated the employee “obviously has a lingering disability which is interfering with his ability to work.”  (Ee Ex. C.)

Based upon the records of Dr. Stark and the testimony of the employee, the compensation judge could reasonably conclude the employee has restrictions on his physical activities.  Accordingly, the compensation judge’s award of temporary partial disability benefits is affirmed.

The appellant contends the employee has made representations to the employer and others that are contrary to his direct testimony before the compensation judge.  These representations include submitting to the Department of Employment and Economic Development Dr. Stark’s opinion that he was able to work without restrictions, a union grievance, and his representations to Grand Casino and Doherty Services that he had no physical restrictions.  The appellant argues the employee’s inconsistent representations estop him from claiming wage loss benefits.  We disagree.

In Le v. State, Univ. of Minn., 330 N.W.2d 453, 35 W.C.D. 665 (Minn. 1983), the Supreme Court held an injured employee may not receive wage loss benefits during a period of retraining, absent certification for retraining or demonstrated inability to find other employment.  While undertaking retraining, Mr. Trac Le also received unemployment compensation for nine months.  In a footnote, the court stated,

The statement is clearly dicta, and the precise intent of the footnote in the Le case is not clear to us.  Under Minn. Stat. § 268.085, subd. 3a, an applicant is not eligible for unemployment benefits for any week in which the applicant is receiving or has received workers’ compensation benefits in an amount equal to or in excess of the applicant’s unemployment benefit.  If the applicant receives unemployment compensation and later receives workers’ compensation benefits, the unemployment benefits paid are subject to recoupment to the extent the workers’ compensation constitutes overpaid unemployment benefits.  Minn. Stat. § 268.085, subd. 3a(b).  The statute clearly contemplates the possibility of receipt of both workers’ compensation and unemployment benefits.  Minn. Stat. § 268.085, subd. 3a(c).

There is a difference between the public purposes of unemployment compensation and workers’ compensation benefits.  Unemployment compensation is available for wage loss caused by economic conditions.  Minn. Stat. § 268.03, subd. 1.  Accordingly, to be eligible for unemployment benefits, an applicant must be able to work, be available for work and be actively seeking work.  Minn. Stat. § 268.05, subd. 1(4).  Workers’ compensation benefits, on the other hand, are available for wage loss attributable to physical disability.  It is not inherently inconsistent that an applicant for unemployment benefits could represent that he or she was able to work and available for work and also represent to a compensation judge that he or she was totally disabled because no employer offered a job within the employee’s physical restrictions.  See 4 Larson’s Workers’ Compensation Law § 84.05 at 84-23 et seq. (2005).  Nor is there an inherent inconsistency between an unemployment applicant’s representation that he is able to work and available for work and a later claim for temporary partial disability benefits where the employee sought and obtained work at a wage loss.

The appellants appear to rely on the doctrine of judicial estoppel or estoppel by judical record.  The elements of judicial estoppel, and its application, have not been clearly defined in Minnesota.  Vukelich v. Potlatch Corp., No. WC04-315 (W.C.C.A. Mar. 21, 2005).  As a general rule, however, under the doctrine of judicial estoppel, a party who has successfully asserted a position in a prior proceeding may be estopped from asserting an inconsistent position in a subsequent proceeding.  The underlying purpose of judicial estoppel is the avoidance of inconsistent results.  See, e.g., Paschke v. Retool Indus., 445 Mich. 502, 519 N.W.2d 441 (1994).  In this case, the employee testified he was not successful and did not receive unemployment benefits.  Moreover, there is no evidence regarding the nature of the proceeding involved.  We do not know why the form with Dr. Stark’s opinion was submitted, the assertions made by the parties, or anything else about the unemployment proceeding.  Under these circumstances, we decline to apply the doctrine of judicial estoppel.

While the doctrine of equitable estoppel has been applied in workers compensation cases,^[1] the seeker of the equitable remedy must demonstrate that it suffered some loss through a reasonable reliance on the conduct of the party to be estopped.  See, e.g., Magariner v. General Cleaning, No. WC05-152 (W.C.C.A. Sept. 6, 2005).  In this case, there is no evidence that the employee’s position regarding his ability to work induced the employer to act or fail to act in any way.  Rather, the employer appropriately submitted the opinion of Dr. Stark into evidence as a defense to the employee’s claim.  Nor does the employer have standing to assert representations made to other employers as a basis for equitable estoppel.  While the employee’s previous assertions may go to the credibility of the employee, that is a question for the compensation judge to weigh and resolve.  Considering the facts in this case, we find no compelling reason to apply either the doctrine of judicial or equitable estoppel.  We, therefore, affirm.