A firmness tester is disclosed which conducts its test through one or more rolling indenters impinging upon the surface of a subject. Most firmness sensors require the sample to be held stationary relative to the tester's reference plane. This invention allows the tester to differentiate between the firmness of the sample and movement of the sample relative to the sensing device. This is desirable in the application of an automatic massage chair where the roller/sensor presses upon the user's back and may cause the point of contact on the user's body to move away by means of the user flexing at the hips or arching through the back. The rolling feature is desirable in the field of automated chair massage where the massage indenters slide across the user's back with significant pressure through a membrane. This membrane would wear quickly if the indenters were not equipped with such a rolling mechanism.