Appellant, Robert Ford, appeals the decision of the Workers’ Compensation Commission, which reversed the administrative law judge’s award of benefits for an allegedly compensable work-related injury. The Commission found that the claimant failed to prove by a preponderance of the evidence that the incident of which he complained caused internal or external physical harm to the body and failed to establish a compensable injury by medical evidence supported by objective findings. On appeal, appellant contends that there is no substantial evidence to support the Commission’s findings (1) that he lacked credibility; (2) that he had a preexisting neck problem from his degenerative condition at the time he was injured at work; and (3) that he did not have an acute injury supported by objective findings. We affirm.
Appellant worked as a tile/bricklayer for appellee and traveled around the country working on large industrial projects. On April 29, 1994, while working at the Georgia-Pacific plant in Crossett, Arkansas, appellant contended that he bumped his head on some scaffolding as he exited the chest he was tiling, knocking his hard hat off his head. Appellant did not file an accident report for the incident, but he testified that he told his supervisor that he had “knocked” his hard hat off and “popped” his neck. Appellant completed that job and then completed jobs in Georgia, South Carolina, and North Carolina. After the North Carolina job, which ended approximately the second week of June, appellant returned home complaining of pain in his neck and headaches when he wore his hard hat. He notified the division manager of the pain he was experiencing and asked to be off work for awhile, believing the pain would subside with rest. At that time, appellant applied for and began receiving unemployment benefits.
Appellant did not seek medical attention until June 29, 1994, when he was seen by Dr. David Mattice, an associate of his family practitioner, Dr. Glenn Campbell. At that time, he related to Dr. Mattice a “mild toothache quality pain in the back of his neck.” The x-rays taken that day appeared normal. In his record of appellant’s August 26, 1994, office visit, Dr. Campbell noted that appellant “had to wear a hard hat recently” and had noticed that his neck was sore when he wore a hard hat during the day. During that visit, Dr. Campbell also noted mild spasm in appellant’s neck area and referred him to a neurosurgeon for further evaluation.
During examinations in September and November of 1994, Dr. Kerry Bernardo, a neurosurgeon, found that appellant had cervical spondylosis and an osteophyte at C6-7, both degenerative changes, which he opined predated the April 1994 incident. He also indicated that examination of appellant’s neck revealed palpable cervical and trapezius muscle spasms. Dr. Bernardo prescribed medication and a cervical collar and pillow for appellant’s neck spasms, and he ordered appellant to undergo physical therapy for a period of three weeks. After completion of physical therapy, Dr. Bernardo diagnosed ulnar neuropathy in appellant’s left hand. An MRI revealed that the osteophyte was impinging upon the thecal sac, and a bone scan verified the degenerative changes in appellant’s neck. Dr. Bernardo performed an anterior cervical dis-kectomy on appellant on November 29, 1994.
The standard of review in workers’ compensation cases is well settled. On appeal, this court must determine whether there is substantial evidence to support the Commission’s decision. Weaver v. Whitaker Furniture Co., 55 Ark. App. 400, 935 S.W.2d 584 (1996). Substantial evidence is that relevant evidence which a reasonable mind might accept as adequate to support a conclusion. Id. The evidence is viewed in the light most favorable to the findings of the Commission and is given its strongest probative value in favor of the Commission’s decision. Barrett v. Arkansas Rehabilitation Servs., 10 Ark. App. 102, 661 S.W.2d 439 (1983). The issue is not whether we might have reached a different result or whether the evidence would have supported a' contrary finding; if reasonable minds could reach the Commission’s conclusion, we must affirm its decision. Smith v. Riceland Foods, Inc., 61 Ark. App. 132, 965 S.W.2d 794 (1998).
A claimant has the burden of proving the compensability of his claim by a preponderance of the evidence. Georgia-Pacific Corp. v. Carter, 62 Ark. App. 162, 969 S.W.2d 677 (1998). An accidental injury is caused by a specific incident, identifiable by time and place of occurrence. Ark. Code Ann. § 11-9-102(5)(A)(i) (Supp. 1997). For an accidental injury to be com-pensable, the claimant must show that he sustained an accidental injury; that it caused internal or external physical injury to the body; that the injury arose out of and in the course of employment; and that the injury required medical services or resulted in disability or death. Id. Additionally, the claimant must establish a compensable injury by medical evidence, supported by objective findings. Ark. Code Ann. § ll-9-102(5)(D). “Objective findings” are those findings which cannot come under the voluntary control of the patient. Ark. Code Ann. § 11-9-102(16). The requirement that a compensable injury be established by medical evidence supported by objective findings applies only to the existence and extent of the injury. Stephens Truck Lines v. Millican, 58 Ark. App. 275, 950 S.W.2d 472 (1997).
Appellant first contends that there was not substantial evidence to find that he was not credible. At the hearing, appellant testified that he tried wearing a hard hat around the house to see if he would be able to return to work. In its opinion, the Commission stated, “We simply find no validity in claimant’s testimony that he simply wore a hard hat around the house to see if he could.” The Commission noted that Dr. Campbell’s August 24, 1994, office note reflected that appellant had had to wear a hard hat recently, but there was no further explanation as to why he was required to wear a hard hat during this time. The Commission observed that appellant was drawing unemployment at the time Dr. Campbell noted that he had to wear his hard hat.
It is within the Commission’s sole discretion to determine the credibility of each witness and the weight to be given to their testimony, Johnson v. Hux, 28 Ark. App. 187, 772 S.W.2d 362 (1989), and it is not required to believe or disbelieve the testimony of any witness. Green v. Jacuzzi Brothers, 269 Ark. 733, 600 S.W.2d 448 (Ark. App. 1980). The Commission may accept and translate into findings of fact only those portions of the testimony it deems worthy of belief. Univ. of Ark. Med. Sciences v. Hart, 60 Ark. App. 13, 958 S.W.2d 546 (1997). Once the Commission has made its decision on issues of credibility, the appellate court is bound by that decision. Linthicum v. Mar-Bax Shirt Co., 23 Ark. App. 26, 741 S.W.2d 275 (1987). Although we might have reached a different conclusion concerning appellant’s credibility if we were reviewing the case de novo, the determination of witness credibility is exclusively within the Commission’s province, and we are bound by its decision.
For his second and third points, appellant argues that there is not substantial evidence to support the Commission’s findings that he had a preexisting neck problem related to his degenerative condition prior to his injury at work and that there were no objective findings of an acute injury. Appellant contends that the Commission denied benefits because it found that the April 29, 1994, incident was not the major cause of his injury. Although we agree that there is no major-cause requirement for injuries caused by a specific incident, see Farmland Ins. Co. v. Dubois, 54 Ark. App. 141, 923 S.W.2d 883 (1996), that was not the basis for the denial of appellant’s claim. The Commission denied the claim on the determination that there was no medical evidence supported by objective findings to support appellant’s contention that he suffered an accidental injury that resulted in internal or external physical harm to the body.
During his deposition, Dr. Bernardo stated his belief that the April 1994 incident triggered the symptoms that appellant was experiencing. However, he admitted that during the November 29, 1994, cervical diskectomy, he found severe spondylosis and osteophyte formation, both being preexisting degenerative conditions, but found no frank herniation of a disk and nothing that indicated an acute injury. Because there is no medical evidence supported by objective findings to establish the existence of an injury, appellant has failed to establish a compensable injury.
There was objective evidence, namely the presence of the spondylosis and osteophyte, that appellant suffered from degenerative changes. The only other objective evidence in the record concerning appellant’s neck complaints was the existence of muscle spasms, first noted in Dr. Campbell’s office notes on August 26, 1994. Although the Commission and this court have accepted muscle spasms as objective medical findings, High Capacity Prods. v. Moore, 61 Ark. App. 1, 962 S.W.2d 831 (1998), there was no evidence that connected the muscle spasms to the April 29 incident. The Commission correctly pointed out that the spasms were first observed almost four months after the April occurrence and after appellant’s “mandatory” hard-hat-wearing incident. The Commission has the authority to accept or reject medical opinions, and its resolution of the medical evidence has the force and effect of a jury verdict. Johnson v. Democrat Printing & Lithograph, 57 Ark. App. 274, 944 S.W.2d 138 (1997). We may reverse the Commission’s findings only when we are convinced that fair-minded people with the same facts before them could not have arrived at the conclusion reached by the Commission. McClain v. Texaco, Inc., 29 Ark. App. 218, 780 S.W.2d 34 (1989).
The dissent, citing McMillan v. U.S. Motors, 59 Ark. App. 85, 953 S.W.2d 907 (1997), states that when a preexisting injury is aggravated by a later compensable injury, compensation is in order. While this is true, the dissent totally ignores the requirement that the aggravation be a “compensable injury.” An aggravation, being a new injury with an independent cause, must meet the requirements for a compensable injury. Farmland Ins. Co. v. DuBois, supra. Because appellant did not meet the requirements for a compensable injury, any aggravation of his preexisting condition is not compensable.
We find that the Commission did not err in finding that appellant failed to prove his case by a preponderance of the evidence with respect to the April 29, 1994, incident, and that there is substantial evidence to support the Commission’s denial of benefits.
Affirmed.
Arey, Jennings, and Crabtree, JJ., agree. Bird and Neal, JJ., dissent.