dissenting.
The majority’s opinion erroneously holds plaintiff presented competent evidence to establish a causal relationship between her work-related accident and alleged annular disc tear and affirms the Commission’s Opinion and Award granting plaintiff temporary total disability benefits. Dr. Maxy’s expert medical opinion concerning the cause of plaintiff’s injury was based upon mere speculation and conjecture and is insufficient to meet plaintiff’s burden of proof to establish the essential element of causation. I respectfully dissent.
I. Standard of Review
[W]hen reviewing Industrial Commission decisions, appellate courts must examine whether any competent evidence supports the Commission’s findings of fact and whether those findings . . . support the Commission’s conclusions of law. The Commission’s findings of fact are conclusive on appeal when supported by such competent evidence, even though there is evidence that would support findings to the contrary.
McRae v. Toastmaster, Inc., 358 N.C. 488, 496, 597 S.E.2d 695, 700 (2004) (internal citations and quotations omitted).
The Commission’s mixed findings of fact and conclusions of law and its conclusions of law applying the facts are fully reviewable de novo by this Court. Hilliard v. Apex Cabinet Co., 305 N.C. 593, 595, 290 S.E.2d 682, 684 (1982); Cauble v. Soft-Play, Inc., 124 N.C. App. 526, 528, 477 S.E.2d 678, 679 (1996), disc. rev. denied, 345 N.C. 751, 485 S.E.2d 49 (1997).
II. Causal Relationship
Defendants assign error to the Commission’s Opinion and Award and argue plaintiff failed to establish the essential element of a causal relationship between her work-related accident and alleged annular disc tear. I agree and vote to reverse the Commission’s Opinion and Award.
A. Speculation and Conjecture
The burden of proof rests upon the plaintiff to produce relevant, probative, and competent evidence to establish a causal relationship exists between the work-related accident and the alleged injury. See Holley v. ACTS, Inc., 357 N.C. 228, 231, 581 S.E.2d 750, 752 (2003) (“In a worker’s compensation claim, the employee has the burden of *37proving that his claim is compensable.” (Citation and quotation omitted)). “The quantum and quality of the evidence required to establish prima facie the causal relationship will of course vary with the complexity of the injury itself.” Hodgin v. Hodgin, 159 N.C. App. 635, 639, 583 S.E.2d 362, 365 (citation omitted), disc. rev. denied, 357 N.C. 578, 589 S.E.2d 126 (2003). “In cases involving complicated medical questions far removed from the ordinary experience and knowledge of laymen, only an expert can give competent opinion evidence as to the cause of the injury.” Holley, 357 N.C. at 232, 581 S.E.2d at 753 (citation and quotation omitted).
When medical opinion testimony is necessary, “medical certainty is not required, but an expert’s speculation is insufficient to establish causation.” Adams v. Metals USA, 168 N.C. App. 469, 475-76, 608 S.E.2d 357, 362 (citation and quotation omitted), aff’d per curiam, 360 N.C. 54, 619 S.E.2d 495 (2005). This Court recently reiterated:
[Our] Supreme Court has allowed “could” or “might” expert testimony as probative and competent evidence to prove causation. However, “could” or “might” expert testimony is insufficient to support a causal connection when there is additional evidence or testimony showing the expert’s opinion to be a guess or mere speculation. An expert witness’ testimony is insufficient to establish causation where the expert witness is unable to express an opinion to any degree of medical certainty as to the cause of an illness. Likewise, where an expert witness expressly bases his opinion as to causation of a complex medical condition solely on the maxim post hoc ergo propter hoc (after it, therefore because of it), the witness provides insufficient evidence of causation.
Raper v. Mansfield Sys., Inc., 189 N.C. App. 277, 281-82, 657 S.E.2d 899, 904 (2008) (quoting Adams, 168 N.C. App. at 476, 608 S.E.2d at 362.) (emphasis supplied)); see also Holley, 357 N.C. at 233, 581 S.E.2d at 753 (“Although expert testimony as to the possible cause of a medical condition is admissible if helpful to the jury, it is insufficient to prove causation, particularly when there is additional evidence or testimony showing the expert’s opinion to be a guess or mere speculation.” (Internal citation and quotation omitted)).
Here, defendants challenge the following findings of fact contained in the Commission’s Opinion and Award regarding the issue of causation:
3. On the morning of October 20, 2005, plaintiff was working with her back to the conveyor line when one of the heavier boxes was *38being pushed off the conveyor line by another employee. Plaintiff was unaware of the box and was struck in her mid to low back area and was pushéd forward, which twisted her spine in the process. As plaintiff was falling to the floor she landed on some racks.
8. On November 23, 2005, plaintiff had a spinal MRI, which revealed an L4-5 annular disc tear. Dr. Maxy testified that more likely than not, plaintiffs injury at work caused the traumatic L4-5 annular disc tear, which is the reason for plaintiffs ongoing pain and plaintiffs absence of symptoms prior to her injury at work.
9. The Full Commission gives greater weight to the testimony of Dr. Ralph Maxy, who specializes in spinal disorders, than to Dr. Daley, who does not specialize in spinal disorders.
The Commission concluded as a matter of law, “[o]n October 20, 2005, plaintiff sustained an injury by accident, arising out of and in the course of her employment with defendant resulting in an annular disc tear injury.” Findings of fact numbered 3 and 8 are not supported by competent evidence in the record before us and do not support the Commission’s conclusion of law.
Finding of fact numbered 3 states, “[p]laintiff was unaware of the box and was struck in her mid to low back area and was pushed forward, which twisted her spine in the process.” (Emphasis supplied). During the hearing, plaintiff offered no testimony or any other evidence tending to support the notion that she had “twisted” her spine as she fell to the ground after being hit with a box. “We are not bound by the findings of the Commission when they are not supported by competent evidence in the record.” English v. J.P. Stevens & Co., 98 N.C. App. 466, 471, 391 S.E.2d 499, 502 (1990).
The dispositive issue before this Court becomes whether Dr. Maxy’s expert testimony was sufficient to establish a causal relationship between plaintiff’s work-place accident and her injury. Dr. Maxy’s testimony and other record evidence shows his expert opinion was based upon mere conjecture or speculation. Holley, 357 N.C. at 233, 581 S.E.2d at 753.
On direct examination, and after being asked a hypothetical question that paralleled the facts at bar, Dr. Maxy testified that “[i]t *39is quite possible that [the 20 October 2005 incident] caused the injury noted on the MRI, the annular tear.” (Emphasis supplied). Dr. Maxy based his opinion upon “the objective finding on the MRI plus her history, the fact she did not have these symptoms prior to the box hitting her on her back.” Dr. Maxy testified he had not reviewed plaintiffs MRI itself, but only the Radiology Report. Dr. Maxy testified that the objective finding he was referring to indicated: “that there are findings that represent — may represent an atypical annular tear.” (Emphasis supplied). Upon review of the actual Radiology Report, the “objective finding” Dr. Maxy was referencing states, “2. Fluid signal within the left posterolateral aspect of the interverebral L4-5 disc. This may represent a somewhat atypical annular tear or simply fluid within the substance of the disc material.” (Emphasis supplied).
Dr. Maxy further testified that the annular tear “could” cause the symptoms plaintiff was experiencing, but that “[i]t doesn’t commonly” and acknowledged that other patients can present with an annular tear based upon a “degenerative change.” Dr. Maxy’s concerns and plaintiff’s non-cooperation were also noted in Dr. Maxy’s physical exam:
Also there were some findings on exam [sic] that seemed to be somewhat perplexing. I couldn’t examine her motor function very well because it seemed, as if she was giving me less than full effort. And so I couldn’t tell whether or not she had any true weakness. She also seemed to walk with a left-sided antalgic gait, in other words, a left-sided limp when in fact she told us that the pain was worse down the right side than it was on the left. So there were some inconsistencies.
(Emphasis supplied). Dr. Maxy testified that if there had not been “an objective finding” on the MRI, he would not have placed plaintiff on any work restrictions.
The following colloquy on cross-examination is quite significant and indicative of the wholly speculative nature of Dr. Maxy’s testimony:
[Defense counsel]: I believe if I understand your testimony correctly and you testified that it certainly was possible for the force of a box striking someone’s back, I assume that the box striking the back caused enough force to jar the area between the two vertebrae?
*40[Dr. Maxy]: Right, exactly. It’s not the box itself that hits the disk and causes a rupture. That’s not what happens, but the box hitting her in the back could cause a violent, violent motion between two vertebrae. For example, if she arched her back violently, that would cause violent motion between two vertebrae which could in fact lead to an annular tear. That’s the sense in which it can cause an annular tear, any violent motion from the box hitting the back.
[Defense counsel]: Again so I’m assuming if a box comes with some significant force and hits you in the back or then throws you forward or in a manner that doesn’t cause you to do the violent motion, then it would not cause an annular tear?
[Dr. Maxy]: That’s correct. It’s not the blunt force of the box itself that causes the tear as much as the violent motion between the two vertebrae that could cause the tear.
[Defense counsel]: So without knowing exactly how [plaintiff] reacted when the box struck her, can you really tell for sure if that incident is what caused the annular tear?
[Dr. Maxy]: Well, you can’t tell for sure in any of this, to tell you the truth. You really can’t. I base my opinion on her history and the findings. If she told me she had had a long history of back pain, it would be less likely the cause.
(Emphasis supplied). Dr. Maxy clearly based his expert opinion on the presumption that plaintiff had “arched her back violently” or that some other “violent motion” occurred after she was hit with the box. However, as the majority’s opinion correctly states, “no competent evidence supports a finding that plaintiff in fact arched or twisted her back when she was hit by the box[.]” Further, Dr. Maxy frankly acknowledged that without knowing how plaintiff reacted when the box struck her, he could not opine whether the incident at ILG caused the annular tear.
After a review of Dr. Maxy’s deposition testimony, I agree with Commissioner Sellers’s dissenting opinion and would hold that Dr. Maxy’s medical opinion regarding the cause of plaintiff’s injury is only “a guess or mere speculation.” Holley, 357 N.C. at 233, 581 S.E.2d at 753. Dr. Maxy did not review plaintiff’s MRI and based his diagnosis in part on a finding in the Radiology Report that “may represent an atypical annular tear.” (Emphasis supplied). Based solely on his *41own physical exam, Dr. Maxy would not have placed plaintiff on any work restrictions.
B. After it., therefore because of it
Dr. Maxy heavily emphasized plaintiffs medical history, “the fact she did not have these symptoms prior to the box hitting her on her back[,]” and implicitly stated that if plaintiff had presented a history of back pain, his diagnosis would have been different. Dr. Maxy’s opinion is also pure post hoc ergo propter hoc testimony and does not prove causation. See Raper, 189 N.C. App. at 281-82, 657 S.E.2d at 904 (“[Wjhere an expert witness expressly bases his opinion as to causation of a complex medical condition solely on the maxim post hoc ergo propter hoc (after it, therefore because of it), the witness provides insufficient evidence of causation.”).
On cross-examination, Dr. Maxy testified that without knowing how plaintiff reacted when the box struck her, he “[could not] tell for sure” if the incident at ILG is what caused the annular tear. Nonetheless, Dr. Maxy opined that based upon the “objective finding” in the Radiology Report, in combination with plaintiff’s history, plaintiff’s work-related accident “more likely than not” caused an annular tear.
Because a majority of the Commission assigned greater credibility to Dr. Maxy’s opinion and we are bound by this determination, a review of the quantum of Dr. Maxy’s testimony shows it is insufficient to establish to a reasonable medical certainty that plaintiff’s accident was causally related to her annular disc tear. See Holley, 357 N.C. at 233, 581 S.E.2d at 753 (“Although expert testimony as to the possible cause of a medical condition is admissible if helpful to the jury, it is insufficient to prove causation, particularly when there is additional evidence or testimony showing the expert’s opinion to be a guess or mere speculation.” (Internal citation and quotation omitted)).
Dr. Maxy’s expert testimony is insufficient to support the Commission’s conclusion of law that “[o]n October 20, 2005, plaintiff sustained an injury by accident, arising out of and in the course of her employment with defendant resulting with an annular disc tear injury.” Because the Commission’s Opinion and Award is affected with error on this basis, it is unnecessary to address defendant’s remaining assignment of error.
*42II. Conclusion
Dr. Maxy’s testimony is insufficient to establish to a reasonable degree of medical certainty that plaintiffs work-related accident was causally related to her annular disc tear. Holley, 357 N.C. at 233, 581 S.E.2d at 753; Adams, 168 N.C. App. at 476, 608 S.E.2d at 362. Under de novo review, the Commission’s conclusion of law that plaintiff sustained an injury by accident, arising out of and in the course of her employment, resulting in an annular disc tear is unsupported by its findings of fact and is erroneous as a matter of law. The Commission’s Opinion and Award granting plaintiff temporary total disability benefits is erroneous and should be reversed. I respectfully dissent.