77 Pa. Stat. § 834
Neither the board nor any of its members nor any workers' compensation judge shall be bound by the common law or statutory rules of evidence in conducting any hearing or investigation, but all findings of fact shall be based upon sufficient competent evidence to justify same. All parties to an adjudicatory proceeding are entitled to a reasoned decision containing findings of fact and conclusions of law based upon the evidence as a whole which clearly and concisely states and explains the rationale for the decisions so that all can determine why and how a particular result was reached. The workers' compensation judge shall specify the evidence upon which the workers' compensation judge relies and state the reasons for accepting it in conformity with this section. When faced with conflicting evidence, the workers' compensation judge must adequately explain the reasons for rejecting or discrediting competent evidence. Uncontroverted evidence may not be rejected for no reason or for an irrational reason; the workers' compensation judge must identify that evidence and explain adequately the reasons for its rejection. The adjudication shall provide the basis for meaningful appellate review.
77 P.S. § 834