Using Gait Analysis and Medical History for DWI Defense
By: Evan Levow and Paul Greenberg
Often the arresting officer will document the gait pattern of the client when she got out of the car to perform the field exercises. Was this gait pattern the usual and customary pattern for this person? Did obesity, arthritis, high blood pressure, high heeled or uneven shoes affect the situation? Does the subject have poor peripheral circulation, numbness in the toes or feet, diabetes, gout, carotid stenosis, mitral valve prolapse, chronic obstructive pulmonary disease, P.T.S.D., or myriad other medical problems that can alter the way she walks and reacts? There are over 100 documented diseases that can affect a person’s gait, particularly on initial ambulation, such as getting out of the car, and upon attempting the one leg stand or walk-and-turn tests.
When the arresting officer observed the client walking the line or standing on one leg, he documented a subjective evaluation, since all the medical factors , still not known at the time of initial police evaluation, were acting to create a gait pattern that may be incorrectly attributed to alcohol consumption.
The objective of a thorough gait evaluation by a medical professional, specially trained in gait pattern evaluation and testing, is critical to a defense attorney offering the client the most aggressive and complete defense possible. Through use of a thorough medical history, as well a vascular, neurologic, orthopedic, visual and computer gait evaluation, the defense attorney is replacing the subjectivity of the assessment with a medical or scientific basis to explain the client’s behavior.
Normal gait patterns consist of:
A. Stance phase (60% of the gait cycle and made up of heel strike, foot, flat, mid stance, and toe off); and
B. Swing phase (40% of the gait cycle and made up of acceleration mid swing, and deceleration.)
Normal gait patterns may demonstrate a high arch, flat foot, internal limb rotation or external limb rotation. A lack of gait pathology is significant, as correlation of normal gait findings with the presence of medical problems may also be of importance. Was there a glaucoma or diabetic incident at the time of the stop? Does the client have “white coat syndrome” with elevated blood pressure? Does the client have orthostatic hypotenseion, i.e., dizziness from a car, which is associated with low blood pressure?
Was the walking pattern consistent or inconsistent? Was there any medical cause of the inconsistent pattern? A high arched foot and a flat foot all have distinct gait patterns and stability issues that may affect balance. Problems maintaining balance can be exacerbated by poor lighting, general balance issues for persons over 40 years of age, vision changes, diabetes, and many more illnesses. All the history, subjective observations, and objective data must be correlated.
By looking at medical issues noted during a focuses thorough history, and coupling these issues with a gait analysis in addition to a clinical repetition of the SFST walk-and-turn and one leg stand, defense counsel may now develop reproducible data. The data can be used to scientifically challenge the arresting officer’s subjective claim, based on the officer’s observations of gait and balance, that the client was under the influence of alcohol or drugs. This client’s abnormal gait may, in fact, be the pattern normal for him and may not be due to alcohol consumption. Factors that can contribute to a police officer’s incorrect assessment of sobriety include medical conditions, fatigue, poor night vision, obesity, worn shoes and incorrectly sized shoes due to swelling of feet. All of these factors might result in an incorrect police assessment fo sobriety.
There are common medical condition that have an impact on gait that are capable of being documented. Photographs often will assist to clarify pathology. Among the most common condition that may alter gait are obesity ( more than 50 pounds: overweight); arthritis; corns; calluses; fungal infections; injuries including hear, shoulder, arm, and lower extremities; gout; acoustic neuromas; asthma; neurologic disorders; or diabetes. The medical history taken prior to the gait analysis by the doctor, who is trained to establish a good history, is an important adjunct to the gait analysis and becomes part of his expert witness opinion, either in a written report or during actual testimony.
Gait analysis is the modern era can be broken down into two phases- visual gait analysis, as discussed above, and computer gait analysis. Computer gait analysis consists of obtaining electronic data as the client walks over a mat that records and measures center of force, pressure versus time, and peak pressure versus time in a graphic analysis format. Gait analysis is thus defined as the systematic study of human walking through visual and video analysis. Objective assessment is now obtainable by visual methods. Through the use of computer gait analysis, a significant amount of data can now be collected and compared with large data based evaluation.
Alternative methods of motion analysis data collection include high speed video with the use of optical markers attached to the subject. Data conversion to quantitative data requires manual digitization and be error prone. In recent years, the interest in human kinesiology (i.e. Movement) has increased greatly. The good news for DWI defense lawyers is that many gait analysis laboratories now exist. Rehabilitation Medicine: Principle and Practice is considered a leading text in gait analysis.
The goal is to reframe the paradigm, and in doing so, the level the playing field. Take away the challenge of whether the client is properly within the 65 percent of 68 percent of those categorized by the NHTSA SFSTs as being under the influence. Consider having the client medically and physiologically evaluated by a podiatrist or orthopedic specialist who can offer an in-depth look into the client’s pattern of walking. The physical exam, coupled with the computerized gai evaluation, takes the hocus occurs and mystery out of what may be referred to as the road-side “stupid human tricks.” providing a written report from a qualified medical professional may give the prosecution good reason to give the defense attorney what she is seeking on behalf of her client. If that is not enough, the defense is now ready to present the witness during trial, and demonstrate to the finder of fact that the field testing does not establish beyond a reasonable doubt that the client was under the influence of alcohol or drugs.
The Morales Law Firm would like to thank The National Association of Criminal Defense Lawyers Champion for sharing this information with us.