Apparatus and method for movement coordination analysis

Abstract

Methods and devices are provided for evaluating among the limbs of a subject the distribution of impairments of the subject's ability to coordinate the muscular contractions to execute effective postural movements. The subject may be placed on two independently movable support surfaces, either of which may be fixed or sway-referenced. The subject's ability to maintain his or her equilibrium position is then monitored. In another embodiment, the subject is perturbed from a position of equilibrium. The perturbation may be caused by a displacement of the support surfaces, or by having the subject grasp a handle, which may be moved, or against which the subject may push or pull. The latency and strength of the responses of the subject's limbs are measured and compared to each other and to a normal population.

Description

[0001]This application is a reissue application of U.S. Pat. No. 5,551,445 which in turn is a divisional of Ser. No. 749,04507 / 749,045, filed Aug. 22, 1991, now issued as U.S. Pat. No. 5,269,318, which is a divisional of Ser. No. 007,29407 / 007,294, filed Jan. 27, 1987, now issued as U.S. Pat. No. 5,052,406, which is a continuation-in-part of Ser. No. 873,12506 / 873,125, filed Jun. 11, 1986, for an invention of Lewis M. Nashner now issued as U.S. Pat. No. 4,738,269, which is in turn a continuation-in-part of Ser. No. 408,18406 / 408,184, filed Aug. 16, 1982, now abandoned, for an invention of Lewis M. Nashner. TheseAll of the above referenced applications are incorporated herein, each in its entirety, by reference.TECHNICAL FIELD[0002]This invention relates generally to medical diagnostic devices and methods, and in particular to diagnostic tools for selectively evaluating the distribution and extent of disorders affecting a patient's ability to execute coordinated postured movement.BAC...

AI Technical Summary

Benefits of technology

[0014]The present invention provides methods and devices for evaluating among the trunk and limbs of the body the distribution two types of disorder affecting posture and equilibrium control: (1) ability to receive and correctly interpret somatosensory orientation and movement information derived from those body and limb parts in contact with supporting surfaces (hereinafter t...

Problems solved by technology

Stroke and traumatic head injury can also impair posture and movement controls.

And, cerebral palsy and certain forms of developmental learning disorders impair these motor functions.

Disorders of this type can result in partial or complete paralysis, or an inability to adequately contract muscles.

Alternatively, impairment of brain centers controlling the activities of muscles can result in dyscoordination, contraction of inappropriate muscles or of appropriate muscles in inappropriate timing sequences (Nashner, et al, 1983).

In the case of equilibrium control, disorders of postural movement control impair a subject's ability to execute coordinated movements back to an equilibrium position following perturbations therefrom.

Disruption of the brain centers and associated afferent neural pathways from peripheral receptors and muscles, in contrast, disrupts ability to receive and correctly interpret incoming somatosensory information used by the brain to sense muscle forces, joint positions, and orientations of body parts in relation to supporting surfaces.

Disorders of this type can result in weak, inappropriate, and inaccurate postural movements and in an inability to maintain an equilibrium position (see for example Kendal and Schwartz, 1981; Chapters 24, 27, and 28).

Presently available clinical methods do not selectively assess both the type and the distribution of sensory and motor disorders impairmenting posture and equilibrium control:(1) deep tendon reflexes: Briskly striking the tendon of a muscle produces a brief stretch input exciting stretch receptor organs and, by way of spinal pathways, motor units of the perturbed muscle.

Deep tendon reflexes, however, do not selectively assess the sensory and motor components of the central brain lesion.

However, it is well known that both sensory and muscle control abnormalities contribute to weakness and paralysis.(3) Conscious sense of limb position: The individual with eyes closed is asked to sense the position of a limb as it is passively moved.

This technique, however, cannot separate and characterize sensory and motor impairment due to spinal cord and central brain disorders.(5) Electromyograms (EMG): The recording of muscle electrical potentials using surface or in-dwelling needle electrodes can be used to identify peripheral neuropathies and number of disorders affecting muscle and muscle contractile mechanisms.

Observations of this type, although valuable, are subjective and therefore cannot selectively assess individual sensory and motor components of posture and equilibrium.

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