Bock (1991, as cited by Allard 2001) was interested in determining whether the high incidences of falls in the elderly could be attributed to poor ankle proprioception. How was Bock to find the answer to her question? Bock needed magnitude estimation in order to obtain a quantitative measure of ankle proprioception. Bock presented three magnitude estimation tasks to elderly and young subjects. Each subject provided magnitude estimations for line length, velocity of ankle rotation and force required to produce plantar flexion at the ankle. The results? Bock showed that both the elderly and the young subjects could scale line length systematically (as line length increases so to does estimation of line length). Both groups could scale ankle velocity systematically. The young subjects could scale plantar flexor force systematically but the elderly could not. This lack of systematic judgments suggests that the elderly may not be able to perceive what is going on with force levels at the ankle. Bock concluded that the elderly have weaker ankle proprioception than the young and thus, poor ankle proprioception may lead to the increased incidences of falls in this group.

    A physiotherapist wants to quickly determine how much pain an individual is experiencing, what’s the best way to get a good indication of this sensation? Scaling provides a fast and convenient way to assess an individual’s pain. Experimental research has shown that at high levels of painful stimulus there are distinct gender differences in pain ratings, with female’s ratings being significantly higher. Does this result indicate that for various social reasons woman are more likely to admit pain or does this result indicate that physiological mechanisms underlying pain are truly different? If the former is true, using scaling procedures of pain are rather useless because they are greatly influenced by non-physiological factors and thus, do not provide an accurate portrayal of an individual’s pain. Ellermeier and Westphal (1989) set out to find the answer to this question. Ellermeier and Westphal collected psychophysiological and psychophysical measures of pain in a group of university students. Various levels of pressure were applied to subjects fingers via a lever mechanism to inflict pain. At each level of pressure, the subject’s pupil size was measured and the subject was asked to rate the level of pain experienced on a verbal category scale. Pupil size was measured because pupil size is known to increase with painful stimulus. The results? At higher levels of painful stimulus, women reported higher ratings of pain and showed larger pupil reactions than men. The implications? Pupil dilation is a function of the autonomic nervous system, a function that woman cannot control. The results suggest that gender differences in ratings of pain cannot be attributed simply to various social factors but there appears to be underlying physiological differences.

Paulson, Minoshima, Morrow and Casey (1998) further explored physiological gender differences in the underlying mechanisms of pain that may lead to gender differences in psychometric measures of pain. Previous research has shown that certain areas of the brain are activated by a painful stimulus.  Paulson et al. (1998) wondered if there would be gender differences in this activation. In their study, various levels of heat were applied to subjects forearms to inflict pain. At each level of heat, the subjects cerebral blood flow was assessed via positron emission tomography (PET) and the subject was asked to rate the level of pain experienced on a scale of 0 to 10; 0 being no heat sensation, 10 being just barely tolerable. At higher levels of painful stimulus, women reported higher ratings of pain and showed greater cerebral blood flow in the areas of the brain known to be associated with pain. The implications? There does indeed seem to be gender differences in the underlying physiological mechanisms of pain, this further suggests that using scaling to assess pain picks up on valid differences in sensation.