The detection of sensitivity of proprioception by a new clinical test: the dual joint position test

To date, very few studies have paid attention to the joint sense (proprioception) of toes other than the big toe. We evaluated the sensitivity of joint position sense at the joint of the great toe in comparison to other digits, and with that determined by the dual digit stimulation test, in a sample of healthy normal controls and patients with clinical diagnosis of the lemniscal system dysfunction.

Seventy-two patients with lemniscal system dysfunction (55 clinically definitive multiple sclerosis, 17 vasculitis) and 110 healthy volunteers participated in the study. All subjects underwent the joint position sense test of all digits of upper and lower extremities. The position sense resulting from the combined operation of the joints of the second and the fourth digits (simultaneous two digits position sense) was also measured and subsequently compared with the results of the great toe position sense.

Upper extremities: no difference was found in recognition of the position sense in the single digits of the upper extremities between patients and healthy volunteers. There was a significant difference in the dual joint position test of the right upper extremity between patients and the case group (p<0.05) but not in the left upper extremity. Lower extremities: there was no significant difference in proprioception of the great toe neither in the right and nor in the left side between patients and normal subjects. However, the joint position sense of other single digits was deteriorated in the patients, a difference that was significant compared to normal controls (p<0.05). Additionally, patients and normal controls displayed a difference in dual digit position sense of the right and left lower extremities (p<0.05).

We show in this paper that the proprioception of simultaneous dual digits is diminished in patients when compared to a single digit position sense. Moreover, the great toe proprioception is less sensitive than other digits. Taken together, these observations lend evidence for a new clinical method which we named as dual joint position test. We suggest this novel method offers clinical utility to demonstrate lemniscal system dysfunction.