Lumbomuscular Proprioceptive Reflexes in body Equilibrium

Abstract

To evaluate the role of reflexes related to the lumbar proprioceptors in maintenance of body equilibrium, changes in equilibrium function of the eyes and body were observed after unilateral procainization of the lumbar erector muscles. Observations were made on normal subjects and vertigo cases with lumbar pain after whiplash injury using various equilibrium tests. The results obtained were as follows:

(1) On unilateral procainization of the lumbar erector muscles of normal subjects, eye nystagmus and disturbances of the righting reflex developed. Simultaneously, changes in drift reactions of the lower limbs were detected by the stepping test. Namely, in many of the subjects examined the direction of stepping deviation became quite different from that before procainization, and stepping after procainization tended to show slight or moderate ataxic features, associated with a sensation of unsteadiness.

(2) When procaine was injected unilaterally into tender spots in the lumbar erector muscles of traumatic vertigo cases, spontaneous eye nystagmus and distrubances of the righting reflex decreased. Simultaneously, significant changes in the drift reactions of the lower limbs were observed in many of the cases examined. Namely, the direction of deviation became the opposite of that before procainization and ataxia in walking almost disappeared with reduction in vertigo.

The following conclusions were drawn from these findings:

(1) The effects of procaine on equilibrium of normal subjects are in sharp contrast to its effects on equilibrium of traumatic vertigo cases. Findings in the former might be due to increased imbalance between the activities of the right and left lumbar proprioceptors, while those in the latter might be due to decreased imbalance between the two.

(2) These findings support the view that from the standpoint of body equilibrium, there are two phases of the prcprioceptive reflex, and that Fukuda's concept of “two phases of the labyrinthine reflex, i.e., a stage of disturbance and a stage of coordination”, can be applied to interpretation of the proprioceptive reflex of lumbar origin.