THE PITTING TEST: AN INVESTIGATION OF AN UNSTANDARDIZED ASSESSMENT OF LYMPHEDEMA

Abstract

Soft tissue pitting is the occurrence of atemporary indentation on the body surfaceafter the release of sustained thumb or fingerpressure. In the management of lymphedema,presence or absence of pitting can contributeto clinical reasoning and guide healthcaremanagement. However, the pitting test and itsapplication has not been described consistentlynor is it a standardized part of assessment.Therefore investigations are needed to assessthe outcome measures of pitting identificationand characterization of lymphedematoustissue. To determine valid testing parametersfor a future study, we evaluated six therapistsof varying lymphedema experience whoassessed a range of locations on six patientswith lymphedema representing the breadth ofpitting assessment techniques used clinically.The consequence of an unstandardized assessmentis demonstrated by the large variation intechniques observed for test duration (1.1 to76.0 seconds), pressure (1.3 to 14.4 N/cm2)and contact area (0.2 to 6.8 cm2). Experiencedtherapists performed the pitting test with asignificantly different technique from theirinexperienced counterparts, involving a longerduration (p<0.001), higher pressure (p<0.001)and a larger contact area (p<0.001). Theresults of this pilot study support the need forevaluation of the underlying tissue responseto sustained pressure and release, in order to inform the development of a standardizedprocedure.