The Workers’ Compensation Commission reversed the decision of an Administrative Law Judge and found that the appellant, Leon Crawford, suffered a noncompensable idiopathic injury to his knee on February 13, 2002. On appeal, appellant claims that substantial evidence does not support the Commission’s denial of benefits. We reverse and remand.
In reviewing decisions from the Workers’ Compensation Commission, the appellate court views the evidence and all reasonable inferences deducible therefrom in the light most favorable to the Commission’s findings, and we affirm if the decision is supported by substantial evidence. Carman v. Haworth, Inc., 74 Ark. App. 55, 45 S.W.3d 408 (2001). Substantial evidence exists if reasonable minds could reach the same conclusion. Daniels v. Arkansas Dep’t Human Servs., 77 Ark. App. 99, 72 S.W.3d 128 (2002); Lee v. Dr. Pepper Bottling Co., 74 Ark. App. 43, 47 S.W.3d 263 (2001). We will not reverse the Commission’s decision unless we are convinced that fair-minded persons with the same facts before them could not have reached the conclusions arrived at by the Commission. White v. Georgia-Pacific Corp., 339 Ark. 474, 6 S.W.3d 98 (1999). We readily acknowledge that it is the function of the Commission to determine the credibility of witnesses and the weight to be given their testimony. Wal-Mart Stores, Inc. v. Stotts, 74 Ark. App. 428, 58 S.W.3d 853 (2001).
The appellee, Single Source Transportation, began employing appellant as a cement-truck driver on March 10, 1988. On February 13, 2002, appellant drove a load of cement for appellee to Kickapoo, Louisiana. Upon arriving at the destination, appellant stepped out of his truck, down two steep steps, and onto an oil field. As his foot reached the ground, appellant’s knee “gave” or buckled. As a result, appellant fell to the ground and began to feel pain in his knee. Appellant testified that “I opened the door, and there are two steps and then the ground. I grabbed hold of the steering wheel, and I stepped out on the last step and put my left foot on the ground, and it just gave way with me.” At the time of his injury, appellant was almost sixty years old:
After falling, appellant got up and proceeded to engage the truck’s air lines to release the cement. In order to accomplish this, appellant held onto the truck while maneuvering the air lines and hose. Appellant finished the process and returned to appellee’s plant. Appellant’s knee swelled and continued to hurt on his return trip. Ultimately, appellant drove to his home hoping that his knee would recover. The next day, appellant went to work, but at the end of the day with his knee still hurting, appellant notified appellee of his injury. Appellant went home, and appellee sent a company car to transport him to Southern Clinic for medical attention. After his examination at the clinic, appellant was taken off work for three weeks and referred to Dr. Frank Hamlin, an orthopedic physician in Texarkana.
Appellant presented to Dr. Hamlin one week after the fall, and Dr. Hamlin noted in his medical report:
I first saw [appellant] on 2-20-02 with chief complaint of pain and swelling of his left knee. He had an episode getting out of his truck on 2-13-02, at which time his knee buckled on him. As it did, he did have a twisting, flexion injury to his knee. He said immediately after that he could hardly walk. His knee became swollen almost immediately and it caused him to limp severely.. . He said previous to that, he had been having some soreness over the medial side of his knee when he would repeatedly use his clutch in his track. He evidently drives a large 18 wheeler. He said he has never had any acute episodes like this before. When I saw him he said his knee was not nearly as swollen as it was initially. When I saw him, he said he was placed on some Mobic by his family physician. We x-rayed him the first day I saw him and he did have some degenerative changes with some medial joint space narrowing. Other than that, the x-rays were not remarkable. . . MRI was ordered and did show a tear of the posterior horn of the medial meniscus and possible medical collateral ligament strain.
(Emphasis added.)
On March 14, 2002, Dr. Hamlin admitted appellant to St. Michael Health Care Center for orthroscopic knee surgery and a partial medial meniscectomy. The operative report reflects a preoperative diagnosis of internal derangement of the left knee and possible osteoarthritis of the left knee. The postoperative diagnosis reported a tear of the posterior horn of the medial meniscus of the left knee and osteoarthritis of the femoral intracondylar notch and of the medial femoral condyle. Following the orthroscopic procedure, appellant underwent injections in his left knee. Dr. Hamlin released appellant to work on May 4, 2002.
At the hearing below, appellant sought temporary-total disability benefits in addition to medical benefits for his specific-incident knee injury. We note that appellant did not claim benefits caused by a gradual-onset injury from repeated use of the clutch on appellee’s cement truck. After hearing testimony from appellant and one of appellee’s employees, the ALJ found that appellant suffered an unexplained compensable fall and awarded him temporary-total disability benefits as well as medical benefits. The Commission reversed the ALJ and found that appellant suffered a noncompensable idiopathic fall. We agree with appellant’s argument that his injury was neither idiopathic or unexplained but rather that he sustained a specific-incident injury.
As the claimant, appellant had the burden of proving his compensable injury by a preponderance of the evidence. Ark. Code Ann. § 11-9-102(4)(E)(I) (Repl. 2002). A compensable injury is one arising out of and in the course of employment. Ark. Code Ann. § 11-9-102(4)(A)(I) (Repl. 2002). Arkansas Code Annotated section 11-9-102(4) (D) provides that a compensable injury must be established by medical evidence supported by objective findings. Objective findings are those findings which cannot come under the voluntary control of the patient. Ark. Code Ann. § 11-9-102(16); Carman v. Haworth, Inc., 74 Ark. App. 55, 45 S.W.3d 408 (2001). In order to prove a compensable injury the claimant must prove, among other things, a causal relationship between his employment and the injury. Wal-Mart Stores, Inc. v. Westbrook, 77 Ark. App. 167, 72 S.W.3d 889 (2002).
The Commission found that appellant suffered a noncompensable idiopathic injury. We hold that this finding is not supported by substantial evidence. An idiopathic injury is one whose cause is personal in nature, or peculiar to the individual. See Kuhn v. Majestic Hotel, 324 Ark. 21, 918 S.W.2d 158 (1996); Little Rock Convention & Visitors Bur. v. Pack, 60 Ark. App. 82, 959 S.W.2d 415 (1997); Moore v. Darling Store Fixtures, 22 Ark. App. 21, 732 S.W.2d 496 (1987). Injuries sustained due to an unexplained cause are different from injuries where the cause is idiopathic. ERC Contractor Yard & Sales v. Robertson, 335 Ark. 63, 977 S.W.2d 212 (1998). Where a claimant suffers an unexplained injury at work, it is generally compensable. Little Rock Convention & Visitors Bur., supra. Because an idiopathic injury is not related to employment, it is generally not compensable unless conditions related to the employment contribute to the risk. Id. Employment conditions can contribute to the risk or aggravate the injury by, for example, placing the employee in a position which increases the dangerous effect of a fall, such as on a height, near machinery or sharp corners, or in a moving vehicle. Id.
Here, we believe that appellant’s employment conditions contributed to his injury and thus cannot consider it to be a noncompensable idiopathic injury. In the course of his employment, appellant drove appellee’s cement truck to Louisiana. In order for appellant to enter or exit the driver’s compartment of the truck, he had to negotiate two steep steps. Vicky Dangerfield, who is employed by appellee in its accounting department, testified that the “bottom step is a pretty good distance off the ground. It is very hard for me to get into the truck. I went on one trip, and I required assistance.” At the time of the incident, appellant attempted to exit the truck by descending the steps to an oil field. As appellant made his final stride to the ground below, his knee “gave,” and as a result, he twisted it and suffered an injury.
We cannot say that the injury appellant suffered was simply personal in nature as it was caused while he attempted to exit his employer’s vehicle from an elevated position. As a result, appellant’s employment conditions contributed to his accident. Furthermore, we cannot say that appellant’s injury was unexplainable as his testimony fully informs us as to the circumstances surrounding his fall.
We reverse the decision of the Commission and remand for it to determine the extent of the injury suffered by appellant as a result of his fall, any disability resulting therefrom, and the amount of compensation to which he is entitled.
Reversed and remanded.
Hart, Griffen, and Roaf, JJ., agree. Vaught, J., concurs. Bird, J., dissents.