About a year ago, the Pennsylvania Workers’ Compensation community was turned on its head when the Commonwealth Court issued its initial opinion in Diehl v. WCAB (IA Construction Liberty Mutual Insurance). That opinion shocked compensation practitioners in the course of eviscerating the impairment rating provisions of Act 57, superimposing the requirement that employers seeking to modify injured employees’ compensation status from temporary total to temporary partial, in reliance upon an impairment rating, must present evidence of “earning power” as originally held by the workers’ compensation judge, with the Appeal Board’s reasoned analysis of that issue being overturned in the Commonwealth Court opinion that was issued on April 28, 2008.