Defendant-appellant appeals a judgment in a workmen’s compensation case awarding benefits to plaintiff-appellee. We affirm.
*11Appellee was employed by appellant in 1969 to work in appellant’s acid plant. On June 1, 1971, appellee accidently injured his back while working in the course and scope of his employment. However, he continued to work until 1975. At the beginning of that year, appellee transferred to appellant’s rubber shop. In June of 1975, appellee again injured his back. Shortly thereafter, appellee underwent surgery for this back condition. After returning to work in March, 1976, appellee continued to have pain in his lower back. Upon examination by his surgeon, conservative treatment was recommended. On April 11, 1977, while opening and closing a vulcanizer door, appellee again injured his back but continued to work for two more days. On April 14, 1977, appellee failed to appear for work and did not return to appellant’s plant until May 2, 1977. Upon his return, appellant assigned him to less strenuous tasks. Appellee continued to work on these tasks until June 15, 1977. Because of his back pain and the onset of more strenuous work, appellee again ceased working and this action followed.
Appellant relies upon the following five points for reversal: (1) the finding of total permanent disability is not supported by substantial evidence; (2) the finding that appellee suffered an accidental injury on April 11, 1977, is not supported by substantial evidence; (3) the finding that appellant had actual knowledge of the April 11, 1977 accident is not supported by substantial evidence; (4) the trial court erred in retaining jurisdiction and reserving its decision on the first cause of action; and (5) the award of attorney fees was excessive. We will discuss each point seriatim.
Total Permanent Disability
Under this point, appellant challenges the trial court’s findings of fact no. 5 which reads as follows:
“As a result of the compensable accidental injury sustained by plaintiff, plaintiff is wholly unable to perform the usual tasks in the work he was performing at the time of his injury, and is wholly unable to perform any work for which he is fitted by age, education, training, general physical and mental capacity, and previous work experience.
It is well settled in New Mexico that the findings of a trial court in a workmen’s compensation case will not be disturbed on appeal if they aré supported by substantial evidence. Gammon v. Ebasco Corporation, 74 N.M. 789, 399 P.2d 279 (1965); Moorhead v. Gray Ranch Co., 90 N.M. 220, 561 P.2d 493 (Ct.App.), cert. denied, 90 N.M. 254, 561 P.2d 1347 (1977). Substantial evidence is relevant evidence which a reasonable mind accepts as adequate to support the conclusion. Shirley v. Venaglia, 86 N.M. 721, 527 P.2d 316 (1974); Cave v. Cave, 81 N.M. 797, 474 P.2d 480 (1970); Tapia v. Panhandle Steel Erectors Company, 78 N.M. 86, 428 P.2d 625 (1967). In deciding whether a finding has substantial support, we must view the evidence, together with all inferences reasonably deducible from such evidence, in the light most favorable to support the finding. Gallegos v. Duke City Lumber Co., Inc., 87 N.M. 404, 534 P.2d 1116 (Ct.App.1975). We will reverse only if convinced that the evidence thus viewed cannot sustain the finding. Furthermore, only favorable evidence will be considered; any unfavorable evidence will not be considered. United Veterans Organization v. New Mexico Property Appraisal Department, 84 N.M. 114, 500 P.2d 199 (Ct.App.1972). We will not weigh the evidence or determine the credibility of witnesses. Platero v. Jones, 83 N.M. 261, 490 P.2d 1234 (Ct.App.1971). The trier of facts is the, sole judge of the credibility of witnesses and the weight to be given their testimony. State ex rel. Reynolds v. Lewis, 84 N.M. 768, 508 P.2d 577 (1973).
After reading the record and applying the foregoing principles, we rule that there is substantial evidence to support the trial court’s finding that appellee is totally and permanently disabled as per § 59-10-12.18, N.M.S.A. 1953 (2d Repl.Vol. 9, pt. 1, 1974). See Maes v. John C. Cornell, Inc., 86 N.M. 393, 524 P.2d 1009 (Ct.App.1974). In Quintana v. Trotz Construction Company, 79 N.M. 109, 440 P.2d 301 (1968), the Su*12preme Court stated that the following tests must be met in order for a claimant to be totally disabled: “(1) complete inability ‘to perform the usual tasks in the work he was performing at the time of his injury’; and (2) absolute inability ‘to perform any work for which he is fitted by age, education, training, general physical and mental capacity, and previous work experience.’ ” Id. at 111, 440 P.2d at 303. We note, in passing, that the court’s finding essentially contains these two tests.
With respect to the first of these tests, the testimony of appellee’s doctor, Dr. Allan Wilson, and supervisor establish that appellee is unable to perform the usual tasks required of an employee in appellant’s rubber shop. Thus the first test was met. With respect to the second test, the testimony of various witnesses on direct, cross, redirect and recross examination can be interpreted as containing certain inconsistencies. On direct examination, appellee’s doctor testified that appellee could probably do work which allowed alternative periods of setting and standing. Appellee’s doctor then testified on cross-examination that appellee could do sedentary work and light work with accompanying pain. However, on redirect examination, the doctor modified his previous testimony by stating that, with respect to the above types of work, appellee would have to attempt to do this work before he would be able to give an opinion concerning appellee’s capacity to do the work. Likewise, appellee testified on cross-examination that he did not know whether he could do any other jobs. On redirect examination, he testified that, based on his past work experience and training and because of his injury, he could no longer do that work which he was capable of doing before he was injured. However, on recross examination, appellee stated that there might be portions of work in appellant’s rubber shop and acid plant which he might be able to do.
Before analyzing the import of the above testimonies, we note that opinion testimony of a medical expert may be considered as substantial evidence upon which a finding of disability may be made. Roybal v. County of Santa Fe, 79 N.M. 99, 440 P.2d 291 (1968); Ortega v. New Mexico State Highway Department, 77 N.M. 185, 420 P.2d 771 (1966); Casaus v. Levi Strauss & Co., 90 N.M. 558, 566 P.2d 107 (Ct.App.1977). In addition, once causation is established by appropriate medical evidence, the extent of disability may be established by the plaintiff. Garcia v. Genuine Parts Company, 90 N.M. 124, 560 P.2d 545 (Ct.App.), cert. denied, 90 N.M. 254, 561 P.2d 1347 (1977). Whether the second test can be established by the testimony of appellee’s doctor or appellee, therefore, depends upon the effect the above inconsistencies have upon this establishment. With respect to this issue, Tapia v. Panhandle Steel Erectors Company, supra, and Montano v. Saavedra, 70 N.M. 332, 373 P.2d 824 (1962) govern.
In the former case, the Supreme Court was faced with certain inconsistencies in plaintiff’s testimony and stated:
We are not required to determine whether there are in fact contradictions in Tapia’s testimony. If there are, they only affect the credibility of the witness. It has been firmly established in this jurisdiction that only the trier of the facts may weigh the testimony, determine the credibility of witnesses, reconcile inconsistent or contradictory statements of a witness, and say where the truth lies.
Id. at 89, 428 P.2d at 628; accord, Ortiz v. Mason, 89 N.M. 472, 553 P.2d 1279 (1976); Curtiss v. Aetna Life Insurance Company, 90 N.M. 105, 560 P.2d 169 (Ct.App.), cert. denied, 90 N.M. 7, 558 P.2d 619 (1976). In Montano, a workmen’s compensation case, the medical witness testified on direct examination that the accident was the probable cause of the disability. On cross-examination, he admitted it would be difficult to say with any degree of probability that the accident was the cause of the condition; on redirect, he again stated that the accident was the most probable cause of the disability but was subject to argument. The Supreme Court ruled there was evidence from which the trial court could have found that *13the accident was the probable cause of the condition. However, it upheld the refusal to so find and held it was the function of the trial court to evaluate all the evidence and determine where the truth lay. See also, Martinez v. Flour Utah, Inc., 90 N.M. 782, 568 P.2d 618 (Ct.App.1977); Moorhead v. Gray Ranch Company, supra.
Applying the reasoning of these two cases to the case at bar, we rule that the trial court was justified in disregarding that testimony which was inconsistent with a finding that appellee is wholly unable to perform any work for which he is fitted by age, education, training, general physical and mental capacity, and previous work experience. In addition, we hold that appellee’s testimony is substantial evidence to support this finding. Thus the second test for the establishment of total disability was met. In so holding, we point to the language of the Supreme Court in Ideal Basic Industries, Inc. v. Evans, 91 N.M. 460, 575 P.2d 1345 (1978):
The determination of the degree of disability in workmen’s cases is generally a matter for the trial court, and absent misapplication of the law or a lack of substantial evidence, an appellate court should not substitute its judgment for that of the trial court.
Id. at 1346. We also note that appellant’s witness, Abraham Mackler, testified that appellee could perform various jobs despite his disability. However, as stated before, the trier of facts is the sole judge of the credibility of witnesses and the weight to be given their testimony. State ex rel. Reynolds v. Lewis, supra. Therefore, the trial court was justified in disregarding this testimony.
Accidental Injury on April 11, 1977
Under this point, appellant contends that the trial court’s findings of fact no. 2 is not supported by the required evidence. This finding reads as follows:
On or about the 11th day of April, 1977, plaintiff sustained a compensable accidental injury arising out of and in the course of his employment by the defendant, Kerr-McGee Nuclear Corporation.
Appellant’s argument that the trial court erred in finding the occurrence of an accidental injury on this date is based primarily upon two grounds: first, appellant contends that the testimony reveals that appellee’s pain related back to the 1971 accident and continued until the last day of his employment and, second, the testimony shows that the occurrence was only a continuation of painful incidents appellee had previously experienced while working on the vulcanizer can. Therefore, appellant asserts that April 11, 1977, has no major significance. In response, appellee argues that the court’s finding has substantial support in the evidence, as the word “accident” has been interpreted by New Mexico case law. We agree.
After all it is a question of accident or no accident, and the precise second, minute, hour or day that it occurred is but evidence to be considered with the other facts and circumstances of the case in deciding whether the injury was in fact accidental. True, there must be a time when it can be said with certainty that a compensable accidental injury has been inflicted; but the cause, and the coming into existence of the evidence characterizing it as a compensable one, need not be simultaneous events. An injury may be gradual and progressive, and not immediately discoverable; yet certainly and definitely progress to discovery and then to a compensable injury.
Id. at 285-86, 141 P.2d at 337. See also Salazar v. County of Bernalillo, 69 N.M. 464, 368 P.2d 141 (1962). Accidental injury was also defined in Stevenson v. Lee Moor Contracting Co., 45 N.M. 354, 115 P.2d 342 (1941). In that case, the Supreme Court said:
It is not necessary that the injury should result momentarily, to be accidental. It may be the result of hours, even a day or longer * * * depending upon the facts of the case.
*14 Id. at 367, 115 P.2d at 350. Therefore, it is apparent that the meaning of “accident” is not limited to sudden injuries, nor is its meaning limited by any time test. Salazar v. County of Bernalillo, supra.
In addition, appellee’s doctor, Dr. Allan Wilson, testified that after April 11, 1977, appellee began to experience some pain in his right buttock and leg. Dr. Wilson stated that this pain was new to appellee’s pain syndrome. Furthermore, this witness testified that after the April incident, he found tenderness to palpation in appellee’s left and right sciatic notches and pain going into appellee’s right leg. This was also a new finding. Finally, Dr. Wilson testified that appellee was more symptomatic both by history and on physical examination in June, 1977, than he was in June 1976, and that the April incident could be said to be the cause in this increase in symptoms. Dr. Wilson’s testimony, therefore, establishes that appellee’s weakened back condition was accelerated by the April incident. Such an acceleration is enough to establish an accidental injury. As this court stated in Lyon v. Catron County Commissioners, 81 N.M. 120, 464 P.2d 410 (Ct.App.1969), cert. denied, 81 N.M. 140, 464 P.2d 559 (1970):
Based upon the reasoning of these cases we take it that a malfunction of the body itself, such as a fracture of the disc or tearing a ligament or blood vessel, caused or accelerated by doing work required or expected in employment is an accidental injury within the meaning and intent of the compensation act. (Emphasis added.)
Id. at 125, 464 P.2d at 415. See also Ortiz v. Ortiz & Torres Dri-Wall Company, 83 N.M. 452, 493 P.2d 418 (Ct.App.1972); 1B A. Larson, Workmen’s Compensation Law, § 38.00 at 7-9 (1978). Therefore, we hold that the trial court’s findings of fact no. 2 is supported by substantial evidence.
Actual Knowledge of the April 11, 1977 Accident
Again appellant attacks one of the trial court’s findings of fact. In this instance, appellant challenges findings of fact no. 6 and contends that it is not supported by substantial evidence. This finding reads:
The plaintiff’s superintendents and foreman at Kerr-McGee Nuclear Corporation had actual knowledge of the accidental injury.
In order to be entitled to benefits, a claimant' must give written notice to his employer of the accident and injury within the statutory time period. § 59-10-13.4, N.M.S.A. 1953 (2d Repl.Vol. 9, pt. 1, 1974). However, § 59-10-13.4B provides that written notice is not required in the following situation:
No written notice is required to be given where the employer or any superintendent or foreman or other agent in charge of the work in connection with which the accident occurred had actual knowledge of its occurrence.
It is well settled in New Mexico that verbal reporting of an accidental injury to an employer or its agent may possibly satisfy the requirement of this section. Baca v. Swift & Company, 74 N.M. 211, 392 P.2d 407 (1964); Lozano v. Archer, 71 N.M. 175, 376 P.2d 963 (1962). However, the fact that a verbal report has been made is not, in itself, determinative of whether the requirement has been satisfied. All of the circumstances of the case must be considered. Gutierrez v. Wellborn Paint Manufacturing Company, 79 N.M. 676, 448 P.2d 477 (Ct.App.1968). The record indicates that when appellee returned to appellant’s plant on May 2, 1977, he spoke to his superintendents and mentioned specifically that opening and closing the vulcanizer door, along with the required bending and climbing, was bothering him too much. Appellee also testified that he thinks he told these superintendents at this meeting that this was the reason he had to take off from work. In response to this information, appellee’s superintendents attempted to shelter him from strenuous activity and provide him with lighter work for the time being.
Under the particular facts of this case, it is difficult to distinguish and separate the injury fi ,m the accident that *15caused it, i. e. the injury, the compression of the nerves going into the leg from the lower back by the L4-5 vertebrae, was the accident. In this situation, appellee gave the best notice he could. He described to his superintendents the activities which caused the acceleration of his weakened back condition and which gave him additional pain. By giving him lighter work, his supervisors understood the meaning of this notice. Under these circumstances, we rule that appellee’s verbal report gave appellee’s superintendents and foreman actual knowledge of the April 11, 1977 accidental injury and that, therefore, the court’s findings of fact no. 6 is supported by substantial evidence.
In so ruling, we note that appellant’s superintendents testified that appellee made no mention to them on May 2, 1977, of the April 11 activities or of his reason for leaving work. In addition, we note appellee’s immediate supervisor testified that he had no record of appellee working with the vulcanizer on April 11. We repeat, the trier of facts is the sole judge of the credibility of witnesses and the weight to be given their testimony. State ex rel. Reynolds v. Lewis, supra. Therefore, the judge was free to take the evidence that seemed reasonable and truthful and make a finding based on that evidence. As long as the finding is based on substantial evidence, it will not be disturbed on appeal. Gammon v. Ebasco Corporation, supra; Moorhead v. Gray Ranch Co., supra.
Retention of Jurisdiction on the First Cause of Action
Appellant argues that the trial court erred in retaining jurisdiction and reserving its decision on the first cause of action. We affirm the court’s retention of jurisdiction with the following comments. Appellee’s complaint contains two causes of action. One relates to an injury in 1971; the second, upon which final judgment was entered, relates to an injury sustained on or about April 11,1977. Appellant’s argument that the trial court committed error is based upon several contentions. We will respond specifically to only one. Appellant contends that the 1971 claim is barred by § 59-10-13.6, N.M.S.A.1953 (2d Repl.Vol. 9, pt. 1, 1974). Inherent in this contention is the argument that the trial court should have dismissed this claim pursuant to § 59-10-13.6. The trial court did not choose to so act; instead the court, in its Judgment, chose to act pursuant to Rule 54(b)(1) of the New Mexico Rules of Civil Procedure. Section 21-l-l(54)(b)(1), N.M.S.A.1953 (Repl.Vol. 4, Supp.1975). Rule 54(b)(1) states:
Judgment upon multiple claims. Except as provided in Rule 54(bX2), when more than one  claim for relief is presented in an action, whether as a claim, counterclaim, cross-claim, or third-party claim, the court may enter a final judgment as to one  or more but fewer than all of the claims only upon an express determination that there is no just reason for delay.
The trial court’s Judgment contains the required determination. Therefore, it has retained jurisdiction over the 1971 injury. Thus, the effect of the court’s use of Rule 54(b)(1) is that its judgment is a final order only with respect to the 1977 claim. Under these circumstances, our review is limited to the 1977 claim. See Quintana v. Quintana, 82 N.M. 698, 487 P.2d 126 (1971); Pacheco v. Pacheco, 82 N.M. 486, 484 P.2d 328 (1971). Only when a final order with respect to the 1971 claim is appealed can the question of the propriety of the court’s present retention of jurisdiction be appropriately considered. Appellant’s other contentions on this point are at this time without merit. They are based on no legal authority and establish no reasonable basis for a ruling that the trial court’s present, legitimate exercise of Rule 54(b)(1) is error.
Appellant argues that the trial court’s award of attorney fees in the sum of $11,958.52 plus tax is excessive. Section 59-10-23D, N.M.S.A.1953 (2d Repl.Vol. 9, 1974) governs the award of such fees and reads in part as follows:
*16[T]he trial court in determining and fixing a reasonable fee must take into consideration:
(1) The sum, if any offered by the employer
(a) before the workman’s attorney was employed; and
(b) after the attorney’s employment but before court proceedings were commenced; and
(c) in writing thirty  days or more prior to the trial by the court of the cause; and
(2) The present value of the award made in the workman’s favor.
To support its argument, appellant contends (1) that consideration must be given to the amount of work performed by the claimant’s attorney, (2) that attorney fees should not be based on a percentage of the award made in the claimant’s favor, and (3) that the possibility of a reduction in compensation benefits based upon a reduced degree of disability after the original trial should be considered. In making these contentions, appellant does concede, however, that the result obtained for the claimant by his attorney should be considered.
With respect to appellant’s first contention, we note that § 59-10-23D does not include, among those considerations for determining a reasonable fee, the amount of work expended by a claimant’s attorney. In addition, we have indicated in prior decisions that this factor is not determinative. Gallegos v. Duke City Lumber Co., Inc., supra; Maes v. John C. Cornell, Inc., supra. However, even if the amount of effort expended were determinative, the facts of the present case indicate that the amount and caliber of work done by appellee’s attorney is such .that the present award is not excessive. That appellee’s attorney expended much effort on his client’s case is apparent by the complaint filed in this suit alleging two causes of action, the motion for a protective order against allowing a mental examination of appellee, the interrogatories filed, and the one pre-deposition conference and the seven depositions attended by appellee’s attorney. In addition, at trial there were many complex issues involved covering questions such as the definition of “accident,” the degree of disability, notice of accident and substantial evidence questions.
As to appellant’s second contention, we note that the right to attorney fees rests in the sound discretion of the trial court and will not be disturbed on appeal absent an abuse of that discretion. Gallegos v. Duke City Lumber Co., Inc., supra; Adams v. Loffland Brothers Drilling Company, 82 N.M. 72, 475 P.2d 466 (Ct.App.1970). Therefore, we cannot say as a matter of law that the trial court abused its discretion merely because its award was based on a percentage figure. See Gallegos v. Duke City Lumber Co., Inc., supra, where an award based on 15% of the total recovery was held not to be an abuse of discretion despite the fact that the trial was brief and involved only simple issues.
With respect to appellant’s last contention, we rule that the possibility of a future reduction in benefits cannot be a feasible consideration in the award of attorney fees since such a possibility cannot always be anticipated. In promulgating § 59 — 10-23D, the Legislature did not include such a possibility. Until the Legislature establishes guidelines to provide for this possibility, we choose not to utilize appellant’s last contention as a basis for ruling that the trial court’s award was excessive. Therefore, we hold that the award of attorney fees in the present case was not an abuse of discretion nor a violation of § 59-10-23D.
Based upon the foregoing, the judgment of the trial court is affirmed and the appellee is awarded $2,000.00 attorney fees on this appeal.
IT IS SO ORDERED.
SUTIN, J., specially concurs.
HERNANDEZ, J., dissents.