PER CURIAM.

Levert Hedgemon, Sr. ("the employee"), sued his employer, United Parcel Service, Inc. ("the employer"), on September 5, 1997, seeking to recover workers' compensation benefits for a back injury he had suffered during the course of his employment. The employer voluntarily paid permanent-partial-disability benefits based upon a six-percent impairment rating assigned by the employee's treating physician. Subsequently, however, the employer later filed a counterclaim seeking reimbursement of the benefits it had paid, averring that, not long before the counterclaim was filed, the employee had been determined to have suffered no permanent disability. Following an ore tenus proceeding, the trial court entered the following judgment:

"This cause came on to be heard upon testimony taken and other evidence presented at an oral hearing, without jury. This case is basically a workmen's compensation case, but it has the additional issue of the employer's claim for reimbursement for money paid in good faith for permanent partial disability benefits if the Court finds that there is no permanent partial disability arising out of a compensable injury under the Workers' Compensation Act (`Act').

"The facts in this case are generally stipulated and not in dispute. The parties are subject to the Act and an employer/employee relationship existed on October 31, 1995, when the employee had an accident while driving for the employer in the line and scope of his employment. The employee's average weekly wage, including the value of benefits, was ONE THOUSAND ELEVEN AND 27/100 DOLLARS ($1,011.27). The employer paid temporary total disability benefits of EIGHT THOUSAND FOUR HUNDRED EIGHTY AND NO/ 100 DOLLARS ($8,480.00) (19 weeks and 6 days) and permanent partial disability benefits (`PPD') of SEVEN THOUSAND TWO HUNDRED SEVENTY NINE AND 35/100 DOLLARS ($7,279.35).

"It was thought that the employee had reached Maximum Medical Improvement (`MMI') no later than May 17, 1996, when he had been returned to work `full duty' by Dr. Keith Weaver and Dr. Weaver gave the employee a 6% permanent partial impairment to the body as a whole.

"In 1999, the employee had new medical problems which resulted in surgery being performed by Dr. [Rick] McKenzie in October 1999. Based upon the evidence submitted to it, the Court finds that the 1999 problems were not related to the 1995 accident and further that the problems are a natural condition of the employee and are not job related. Thus, the Court finds that the treatments by Dr. Rick McKenzie and Dr. Wesley Spruill are not related to the October 31, 1995, work related accident.

"Based on the May, 1996 opinion of Dr. Weaver, the employer has been making PPD payments to the employee. Subsequent doctors have now found that the employee has no PPD as a result of the accident. The employer is now seeking reimbursement of the PPD payments. It is the opinion of the Court that all parties were in error when they determined that the employee had a 6% PPD. Since the employee returned to full time work at a wage equal to and then greater than the amount he was making at the time of the accident, this is not to be considered vocational disability.

"In support of the employee's position, the Court notes that the rights under the Act are strictly statutory and that thus generally the remedies must be determined within the four corners of the Act. In support of the employer's position are the general principles that when money is mistakenly paid, the party paying the money is entitled to its return, and also the policy of the Act, which encourages an employer to make voluntary payments to the employee pending a final determination of the employee's rights. The Act provides that overpayment may be recouped from future payments due under the Act, but it is silent as to any right of reimbursement if no future payments are made.

"It is the opinion of the Court that since the Act allows recoupment of overpayments from future benefits, it should also be interpreted to allow recoupment of overpayments when there are no future benefit payments. To hold otherwise would conflict with the policy in the Act which encourages voluntary payments. The Court finds that the employee did reach MMI no later than May, 1996 and that he did not have permanent partial disability. The Court thus finds that the employer is entitled to a reimbursement of SEVEN THOUSAND TWO HUNDRED SEVENTY-NINE AND 35/100 DOLLARS ($7,279.35) from the employee."

The employee appeals.

This case is governed by the Workers' Compensation Act, as amended, § 25-5-1 et seq., Ala. Code 1975 (hereinafter "the Act"). The Act provides that an appellate court's review of the trial court's conclusions as to the appropriate standard of proof and other legal issues shall be without a presumption of correctness. Ala. Code 1975, § 25-5-81(e)(1). It further provides that when an appellate court reviews a trial court's judgment based on its findings of fact, that judgment will not be reversed if the findings of facts are supported by substantial evidence. Ala. Code 1975, § 25-5-81(e)(2). Our Supreme Court "has defined the term `substantial evidence,' . . . to mean `evidence of such weight and quality that fair-minded persons in the exercise of impartial judgment can reasonably infer the existence of the fact sought to be proved.'" Ex parte Trinity Indus., Inc., 680 So.2d 262, 268 (Ala. 1996) (quoting West v. Founders Life Assurance Co. of Florida, 547 So.2d 870, 871 (Ala. 1989)). This court has also concluded: "The new Act did not alter the rule that this court does not weigh the evidence before the trial court." Edwards v. Jesse Stutts, Inc., 655 So.2d 1012, 1014 (Ala.Civ.App. 1995).

The employee contends that the trial court erred in determining that he had suffered no permanent disability. He relies upon medical evidence in the record that, he says, would support a determination that he suffered a six-percent permanent impairment.

This court has stated:

"A trial court is not bound to accept a physician's assigned impairment rating and is free to make its own determination as to an employee's impairment. The impairment rating assigned by a physician is but one factor a court may consider in satisfying its duty to determine the extent of one's disability. The trial court has the duty to determine the extent of disability and is not bound by expert testimony in making that determination; yet, in making its determination, it must consider all the evidence, including its own observations, and it must interpret the evidence in accordance with its own best judgment."

Fuller v. BAMSI, Inc., 689 So.2d 128, 131 (Ala.Civ.App. 1996) (citations omitted). We note that the resolution of conflicting evidence is within the exclusive province of the trial court, and that we must affirm the judgment of the trial court if it is supported by substantial evidence.Ex parte Trinity Indus., supra. It is the trial court that is in the best position to observe the demeanor and credibility of the employee and other witnesses in a workers' compensation case. Ex parte Alabama Ins. Guar. Ass'n, 667 So.2d 97 (Ala. 1995).

A detailed recitation of the facts and evidence in this case is not necessary. Suffice it to say that the trial court's determination that the employee suffered no permanent partial disability as the result of the work-related accident is supported by substantial evidence. Accordingly, the judgment of the trial court is affirmed as to that issue.

The employee also argues that the trial court erred in entering a judgment in favor of the employer on its counterclaim and in requiring him to reimburse the employer $7,279.35 in permanent-partial-disability benefits.

The trial court correctly points out in its judgment that remedies under Alabama's Workers' Compensation Act "generally . . . must be determined within the four corners of the Act." The Act provides that workers who are permanently partially disabled are given the right to certain enumerated benefits; however, in this case, the trial court has determined that the employee is not permanently partially disabled.

Our common law embodies various equitable and other remedies by which one party may recover from another monetary payments that the latter may not be entitled to retain. There is nothing in the Act that expressly deprives an employer of any common-law remedies that may otherwise be available for the recovery of monetary payments that, in equity and good conscience, do not belong to an employee. In this regard, Alabama's Act contrasts with Minnesota's workers' compensation laws, upon which the Minnesota decisions cited by the employee in his brief to this court are based. Although our Act was patterned after Minnesota's original workers' compensation act (see, e.g., Ex parte Kimberly-Clark Corp., 779 So.2d 178, 180 (Ala. 2000)), our Legislature has seen fit not to adopt a provision comparable to Minn. Stat. § 176.179 (2000), which generally disallows reimbursement.

Conversely, the Alabama Legislature has seen fit to adopt a provisionnot found in Minnesota's act, i.e., Ala. Code 1975, § 25-5-56, that expressly reflects a policy of encouraging voluntary payments by employers. Section 25-5-56 provides, in pertinent part:

"All moneys voluntarily paid by the employer or insurance carrier to an injured employee in advance of agreement or award shall be treated as advance payments on account of the compensation. In order to encourage advance payments, it is expressly provided that the payments shall not be construed as an admission of liability but shall be without prejudice."

(Emphasis added.)

In Gold Kist, Inc. v. Mullinax, 650 So.2d 937 (Ala.Civ.App. 1994), this court construed § 25-5-56 as being consistent with allowing credit for advance payment of permanent-partial-disability benefits. We explained that

"[t]his interpretation of § 25-5-56 favors the employee by encouraging employers to make payments to the injured employee while waiting, if necessary, for a court determination regarding liability and benefits due. The disallowance of credit for advance payments for permanent partial disability would, in all likelihood, discourage advance payments."

Id. at 939 (emphasis added). Under the same reasoning, it can be said that allowing employers to obtain reimbursement for overpayment of benefits, even if there are no future benefits against which the reimbursement can be credited, would also tend to promote advance payments to employees generally, consistent with legislative intent and with the beneficent purposes of the Act.

We must construe Alabama's Workers' Compensation Act as written. The Act, and Alabama precedents, express a policy to encourage voluntary payments. The Act gives no right to permanent-partial-disability benefits to employees who are not permanently partially disabled. Unlike Minnesota's act, Alabama's Act does nothing to abrogate an employer's common-law rights as they bear on this issue.

While there is no uniform legislative or judicial approach to this subject, several courts have recognized that "the voluntary payment of compensation benefits during the pendency of [compensation] proceedings . . . is a matter of great importance to an injured worker and should not be discouraged." Western Cas. Sur. Co. v. Adkins, 619 S.W.2d 502, 503-04 (Ky.Ct.App. 1981). "Any statutory interpretation which would penalize an employer who voluntarily makes weekly payments to an injured employee in excess of his ultimate liability would certainly discourage voluntary payment by employers and would therefore constitute a disservice to injured workers generally." Id. at 504. See also Apex Lines, Inc. v. Lopez, 112 N.M. 309, 312, 815 P.2d 162, 165 (Ct.App. 1991) (allowing the award of overpaid benefits to an employer under a common-law restitutionary theory); Frazier v. AFG Indus., Inc., (No. 03S01-9308-CV-00058, June 14, 1994) (Tenn. 1994) (unpublished) (to same effect).

The trial court's judgment in this case ordered the employee to pay reimbursement of $7,279.35 to the employer. Obviously, such a result is not inconsistent with the authorities discussed herein. Nonetheless, we note that the trial court's judgment in this regard is based on its legal conclusion that, "since the Act allows recoupment of overpayments from future benefits, it should also be interpreted to allow recoupment of overpayments when there are no future benefit payments." There is no language in the Act, however, that expressly provides for such recoupment.

It is true that the Act does not bar such recoupment. In fact, the Act expresses a policy preference "to encourage advance payments" and provides that the fact of advance payments "shall be without prejudice" to the employer. See Ala. Code 1975, § 25-5-56. Accordingly, theMullinax court rightly recognized that, in order to make an award of future benefit payments to an employee that would result in the employee's receiving the correct total amount of benefits to which he or she was entitled under the terms of the Act, it obviously had to allow a credit for all similar payments made in advance of the trial court's judgment. Mullinax, 650 So.2d at 939. Nothing in Mullinax, however, is in any way inconsistent with the general principle that remedies under the Workers' Compensation Act "generally must be determined within the four corners of the Act." Indeed, the essence of our holding today is that there is no provision within the "four corners" of the Act stating that an employee has any right to permanent-partial-disability benefits unless the employee in fact meets the requirements for such benefits under the Act and, concomitantly, that the Act does not contain any language that would deprive an employer of any otherwise available common-law remedy to recover payments that, it is ultimately determined, need not have been made. By the same token, however, there is nothing within the four corners of the Act that expressly creates some additional remedy or cause of action under the Act itself, by which an employer can make such recovery. Thus, employers are left to their common-law remedies, if any.

For all that appears from the trial court's judgment, that portion of the judgment ordering reimbursement of overpaid benefits is based not upon any common-law theory of recovery, but only upon an interpretation of the terms of the Workers' Compensation Act. Nonetheless, we will affirm a trial court's judgment if, as a matter of law, it is right for any reason, even one not recited by the trial court. See Ex parte Wiginton, 743 So.2d 1071, 1076-77 (Ala. 1999). However, whether or not a common-law theory of recovery was presented at trial, see Rule 15(b), Ala.R.Civ.P., and adequately proven as a factual matter are questions that should be addressed in the first instance by the trial court in this case. We therefore vacate that portion of the trial court's judgment ordering such reimbursement and remand this case for additional findings and an entry of judgment consistent with this opinion.

AFFIRMED IN PART; VACATED IN PART; AND REMANDED WITH INSTRUCTIONS.

Pittman and Murdock, JJ., concur.

Thompson, J., concurs in the result.

Yates, P.J., and Crawley, J., concur in part and dissent in part.