By appropriate assignment of error defendants contend that the Commission’s finding of fact number 2 is not supported by the evidence. There is ample competent evidence in the record to support this finding of fact, and in addition thereto, defendants state in their brief:
“The question in this case is not whether Blalock sustained an injury to the calf of his leg while moving a heavy object on the job. This is admitted. The question in the case is whether certain operations and the ultimate amputation of Blalock’s leg above the knee were causally connected with a minor injury to the calf of his leg which Blalock sustained *503in moving the heavy object some 21/2 months prior to the first operation and 5% months prior to the amputation.”
 By assignments of error 1, 2 and 3, defendants contend that the hypothetical questions asked of plaintiff’s expert witnesses', Dr. Alexander and Dr. Johnson, were improperly phrased and contained assumptions of fact not warranted under the evidence adduced. In hearings before the Industrial Commission, a hypothetical question asked of an expert witness is competent when it assumes facts which the evidence directly, fairly, and reasonably tends to establish. Blassingame v. Asbestos Co., 217 N.C. 223, 7 S.E. 2d 478 (1940) ; MacRae v. Unemployment Compensation Com., 217 N.C. 769, 9 S.E. 2d 595 (1940). We have examined all of the hypothetical questions asked of the expert witnesses and conclude that they assume only facts which were established by the evidence either directly or by fair and necessary implication. The probative force of the witnesses’ responses is for the Commission.
The defendants’ additional assignments of error present the question of whether there is any competent evidence in the record to support the Commission’s determinative finding that plaintiff’s injury by accident to his left leg on 23 November 1968 caused the clot which occluded the artery in his left leg which resulted in the amputation of the leg on 5 June 1969.
Expert witness Dr. Lawrence Alexander, a general practitioner, testified that he first examined and treated the plaintiff’s injury, allegedly sustained on 23 November 1968, on 27 November 1968. The plaintiff remained under his care and treatment from 27 November 1968 until he was referred to Dr. Johnson at N. C. Memorial Hospital. With respect to the injury by accident on 23 November 1968 and its causal connection with the subsequent amputation of the left leg, Dr. Alexander testified :
“My own personal opinion would be like this: this was obviously the onset of symptoms for this particular illness that led to the period of disability, to the surgery to try to improve the circulation and finally to the amputation. This was the beginning of this particular illness.
* * *
Apparently, from the very beginning, although we could not measure it exactly, and could not pinpoint it exactly; some *504vascular injury must have occurred at the time of the onset of the pain.”
With respect to the vascular injury, Dr. Alexander testified:
“I have an opinion that that vascular injury made the circulation even worse than it was.”
Expert witness Dr. George Johnson, Jr., a specialist in general and vascular surgery, first saw and examined plaintiff with respect to the particular illness on 9 February 1969. He performed the femoral artery bypass graft on 13 February 1969 and was present and participated in the amputation of plaintiff’s leg on 5 June 1969.
In response to a competent hypothetical question, Dr. Johnson testified: “I think that it is possible that the amputation could have been the result of the accident.”
In explaining his answer to the hypothetical question, Dr. Johnson stated:
“ [T] rauma to a vessel, a direct blow on a vessel, as allegedly happened, in some instances apparently has resulted in injury to the vessel sufficient to cause the vessel to clot. If this is what happened to Mr. Blalock, I think it is possible that this could have caused a thrombosis in that segment of the vessel. ...”
[3, 4] The findings of fact of the Industrial Commission are conclusive and binding on appeal if supported by competent evidence in the record even though the record contains evidence which would support a contrary finding. Hollman v. City of Raleigh, 273 N.C. 240, 159 S.E. 2d 874 (1968). The Commission is the sole judge of the credibility of the witnesses and the weight to be given their testimony; it may accept or reject all of the testimony of a witness; it may accept a part and reject a part. Robbins v. Nicholson, 10 N.C. App. 421, 179 S.E. 2d 183 (1971); Morgan v. Furniture Industries, Inc., 2 N.C. App. 126, 162 S.E. 2d 619 (1968) ; Anderson v. Motor Co., 233 N.C. 372, 64 S.E. 2d 265 (1951). The Commission has the duty and authority to resolve conflicts in the testimony of a witness or witnesses. If the findings made by the Commission are supported by competent evidence, they must be accepted as final truth. Rooks v. Cement Co., 9 N.C. App. 57, 175 S.E. 2d 324 *505(1970); Petty v. Associated Transport, 4 N.C. App. 361, 167 S.E. 2d 38 (1969). Webster’s Third New International ’Dictionary (1967) defines trauma as “an injury or wound to a living body caused by the application of external force or violence [injuries . . . such as sprains, bruises, fractures, dislocation, concussion — indeed traumata of all kinds — Lancet]
 After considering all of the testimony in the record in the light of the foregoing well established principles of law, it is our opinion that there is sufficient competent evidence in the record to support the Commission’s' finding that the trauma sustained by plaintiff on 23 November 1968 caused a clot to form in plaintiff’s leg which caused blockage of one of the arteries which eventually resulted in amputation of the leg.
The findings of fact support the conclusion that as a result of the injury by accident on 23 November 1968 the plaintiff sustained the loss of his left leg for which he is entitled to compensation.
The opinion and award of the North Carolina Industrial Commission dated 25 March 1971 is affirmed.
Chief Judge Mallard and Judge Campbell concur.