Magnitude estimation of manually assessed elastic stiffness: Stability of the exponent

Magnitude estimations were obtained for manual assessments of pure elastic stiffness stimuli (metal springs). 20 subjects of varied experience in manu al assessment of spinal stiffness volunteered to participate. The mean expo nent of the power function relating perceived magnitude of elastic stiffnes s to measured physical magnitude was 1.65. Exponents varied across the 20 i ndividuals but were stable across testing sessions held at least 2 weeks ap art, and the size of the exponent was not related to prior experience.