COMPUTERIZED DYNAMIC POSTUROGRAPHY / CDP/.

TO BALANCE WITH THE FEET IN-PLACE, THE POSITION OF THE BODY CENTER OF GRAITY /COG/ MUST BE MAINTAINED VER- TICALLY OVER THE BASE OF SUPPORT.

BASE OF SUPPORT FOR STANDING ON A FLAT, FIRM SURFACE IS DEFINED AS THE AREA CONTAINED WITHIN THE PERIMETER OF CONTACT BETWEEN THE SURFACE AND TWO FEET.

LIMITS OF STABILITY THE FURTHEST DISTANCE IN ANY DIRECTION A PERSON CAN LEAN AWAY FROM MIDLINE WITHOUT ALTERING THE BASE OF SUPPORT.

VISUAL, VESTIBULAR AND SOMATOSENSORY SYSTEMS are responsible for balance in upright position.

SOMATOSENSORY INPUT DERIVED FROM THE CONTACT FORCES BETWEEN THE FEET AND SUPPORT SURFACE IS THE DOMINANT SENSORY INPUT TO BALANCE UNDER NORMAL CONDITIONS /SUPPORT SURFACE IS FIXED AND FIRM/.

VISUAL INPUT PLAYS SIGNIFICANT ROLE WHEN THE SUPPORT SURFASE IS UNSTABLE.

VESTIBULAR INPUT IS CRITICAL WHEN SOMATO- SENSORY AND VISUAL INPUTS ARE MISLEADING OR UNAVAILABLE.

COMPUTERIZED DYNAMIC POSTUROGRAPHY /CDP/ IS A QUANTATIVE METHOD FOR ASSESSING UPRIGHT BALANCE FUNCTION. THE TEST PROTOCOLS ARE DESIGNED TO ISOLATE THE PRINCIPLE SENSORY COMPONENTS CONTRI- BUTING TO BALANCE AND TO ANALIZE THE PATIENT`S ABILITY TO USE THESE COMPO- NENTS SINGULARY AND IN CONCERT TO MAINTAIN BALANCE.

indications DISEQUILIBRIUMOF UNKNOWN ORIGIN. HISTORY OF FALLS. PERSISTENT DISEQUILIBRIUM WITH NORMAL ENG AND ROTATIONAL TESTS RESULTS. BALANCE DISFUNCTION SECONDARY TO HEAD TRAUMA.

MINIMUM PHYSICAL REQUIREMENTS FOR CDP TESTING THE PATIENT MUST BE ABLE TO STAND ERECT WITH EYE OPEN AND UNASSISTED FOR PERIODS OF AT LEAST 1 MINUTE. SPECIAL CARE SHOULD BE TAKEN WITH PATIENTS WHO HAVE SEVERE ORTHOPEDIC CONDITIONS.

Ratio Conds. Functional Relevance Somatosensory (SOM) 2/1 Visual (VIS) Pt’s ability to use input from the somatosensory system to maintain balance. Visual (VIS) 4/1 Pt’s ability to use input from the visual system to maintain balance. Vestibular (VEST) 5/1 Pt’s ability to use input to the vestibular system to maintain balance. Preference (PREF) 3+6/2+5 The degree to which pt relies on visual info to maintain balance, even when the info is incorrect.

PHYSIOLOGICALLY INCONSISTENT RESULTS 1. A PATIENT WITH ABNORMAL COMPOSITE SCORE OBTAINS EQUILLIBRIUM SCORES ON THE MORE DIFFICULT CONDITIONS 4, 5 AND 6 WHICH ARE EQUAL OR BETTER THAN THOSE, OBTAINED IN THE EASIER CONDITIONS 1, 2, 3. 2. A VERY POOR SOT RESULT IS SEEN IN A PATIENT WHOSE DAILY LIFE BALANCE AND LOCOMOTION CAPABILITIES ARE NOT OBVIOUSLY IMPAIRED. ABNORMAL CONDITIONS 1 AND 2 SCORES ARE PHYSIOLOGICALLY INCONSISTENT WHEN OBSERVED IN A PATIENT WHO IS NOT ATAXIC AND AMBULATES WITHOUT THE USE OF BALANCE AIDS.

SOMATOSENSORY DISFUNCTION THE PATIENT WITH SOMATOSENSORY DISFUNCTION SHOWS ATAXIA AND INSTABILITY DURING AMBULATION.

VESTIBULAR DYSFUNCTION THE PATIENT WITH VESTIBULAR DYSFUNCTION IS UNSTABLE WHEN BOTH THE SUPPORT SURFACE AND VISUAL INPUT ARE REDUCED BY CONDI- TIONS SUCH AS DARKNESS IN CONJUNCTION WITH IRREGULAR SURFACE OF SUPPORT.

VISION DYSFUNCTION PATIENT WITH VISUAL DISFUNCTION AMBULATE NORMALLY ON A FIXES AND LEVEL SUPPORT SURFACE. THE PATIENT WITH VISUAL DISFUNCTION IS DESTABILIZED BY COMPLIAT, IRREGULAR AND MOVING SUPPORT SURFACES.

CDP IS A LESS SENSITIVE LABORATORY TEST FOR THE DIAGNOSIS OF VESTIBULAR LESSION, BUT IT PROVIDES INFORMATION ABOUT BALANCE FUNCYION AND INTERACTION OF DIFFERENT SENSORY SYSTEMS. IT MAY BE SIGNIFICANT IN IN MONITORING PATIENT`S COMPENSATION PROCESS.