Affordance-Based Assessment is Neither Subjective nor Objective Outcome Measure
There is increasing awareness of the need to include patient-reported outcome (PRO) instruments in evaluatingthe measurement of clinical outcomes, withan increasing focus placed on the patients’perspective.Scientists have tried to link PROs with objective outcomes, providing unique information formanaging patient care. Traditionally, objective and patient-reportedoutcomes (such as the Knee Injury and Osteoarthritis OutcomeScore (KOOS)) are considered two distinct constructs, which cannotserve as a direct proxy for each other. Gibson´s affordances are properties taken with reference to the patient. They are neither objective nor subjective.The present article develops a theoretical framework called entrainment of touch and posturethat advocates the vis viva (living force) as the proper gauge for the dynamical action of a force, and that could explain “possibilities for action or affordance” during outcome measurement.
