You want to test for waxy flexibility at the bedside in a patient with reduced spontaneous movement. Which single approach is most appropriate?
Gently and passively moving a limb into a mildly unusual position, then observing both the resistance quality during the movement and whether the position is sustained afterward, is the correct bedside test for waxy flexibility. Asking about subjective stiffness, testing reflexes, or asking for active resistance test different things entirely and would not elicit this specific motor sign.
Key discriminating feature: Waxy flexibility is specifically tested by passive, gentle movement of a limb, assessing both the smooth quality of resistance during the movement and whether the new position is then sustained — an active resistance test or reflex test would not elicit or assess this specific sign.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 8, 'Motor Disorders'.