Experementation critique

September 16th, 2013

The Balance Evaluation Systems Test to Differentiate Balance Deficits Experimentation Critique. The article viewed presents the framework, preliminary concurrent validity and interrater credibility for the specific tool. The Balance Evaluation Systems Test, also known as BESTest. The overall goal of this particular study was the development of a clinical balance tool for assessment which focus’ on six separate systems of balance control, so that isolated rehabilitation mapping can be put into place for different balance deficiencies. Sampling subjects and healthy subjects with different balance deficits make up the independent variable. The balance assessment tools use currently do not assist therapist in identifying underlying postural control systems that are responsible for low functional balance. They do however help identify if there is a risk of falling or what and where the balance deficits are such as visual function, reaction time delays or impaired proprioception. Although the risk is identified, what is not identified is what is causing them. Another problem with current methods is that treatment seems to be standard balance training for a standard balance problem.

By identifying the cause of the balance deficits of each individual patient the therapist will then be able to direct specific individualized types of intervention for different types of problems. BESTest is made up of thirty six items that are grouped into six systems: • Biomechanical constraints for standing balance that include ankle and hip strength, postural alignment, the quality of base for the foot support, and the ability to get up off the floor to a standing position. • Stability limits/verticality includes how far the body can travel over its support base before changing the support of losing balance, the ability to realign the head and the trunk back to normal vertical, lateral limits such as leaning as far as possible in a sitting position with eyes closed, and in standing to reach as far as possible to the front and out to the side, • Anticipatory postural adjustments includes anticipating the need to adjust the bodies postural position, • Postural responses includes being able to adjust the body by stepping in response to someone pushing from front, back, or either side, • Sensory orientation identifies an increase in the sway of the body associated with changing visual or surface information, • Stability in gait includes evaluating balance during gait and balance when it is challenged during gait by speed, rotation of the head, pivot turns, or stepping over objects, it also includes a test called “Get up and GO” which is timed and assesses the speed a patient can do a task in sequence by rising from a chair, walking 3 meters, turning around, and sitting back down again without assistance. This also has a secondary cognitive task to challenge a patients attention.

The development of the BESTest has been in the works since 1990. Horak and Shumway-Cook came up with the framework of this test to initially detect underlying balance function in their continuing medical education courses. During these courses they were provided with feedback about the different aspects of the test such as clarity, sensitivity, and practically of some of the items in the test. Some of the tasks of balance in the test have been taken from from current balance test already being used but are now placed in a theoretical framework. This test also has modified patient and therapist instructions along with rating scales to improve reliability and consistency. There had been two interrater trials performed, 22 subjects either having or not having balance disorders. The subjects ranged in age from 50 to 88 years old. These subjects were rated on the BESTest by 19 balance researchers, students and therapists.. The first triail was conducted on 12 ambulatory adults that showed a broad range of balance function. They were chosen for convenience (!) from a group who had previously participated in other research studies that were based on balance and postural control. One stipulation was that they had never completed the BESTest prior to this particular study. There were three subjects had Parkinson’s Disease, five subjects with vestibular dysfunction, one subject had peripheral neuropathy and previously recieved a full hip arthroplasty.

There was also three subjects who were completely healthy. Every one of of the participants met the criteria of having the ability to follow 3-step commands, provide informed consent, ambulate 20 feet without assistance, and perform the balance task without extensive fatigue. They were given breaks when breaks were needed. There were five female and seven male ranging in age of 50 to 80 and none of them using assistive devises. The nine raters consisted of six physical therapist from various practice settings and three Doctors of Physical Therapy students from Pacific University. The criteria for the physical therapist was to have a valid Oregon physical therapy license and the students had to have completed course work relating to evaluation and treatment of balance disorders. Eighteen months after the first trial was done, the original BESTest was revised. They found that the Biomechanical Constraints and Stability of Gait sections were inadequate due to the low intraclass correlation coefficient. For this second trial they were concentrating on improving the reliability of the Stability of Gait section by having the raters viewed the subjects from the front and the back during times when they were walking. This second trial consisted of eleven raters which included three from the first session; two of the raters had PhD’s and conducted extensive research of human balance disorders.

In this trial there were eleven subjects that included four that had been utilized in the previous trial. The rest were recruited by individuals who had participated in previous trials or studies but had not taken BESTest. The subjects consisted of six subjects that were healthy, one subject with a unilateral vestibular loss, and another single subject with bilateral vestibular loss, two more subjects that had Parkinson’s disease and the final subject having both peripheral neuropathy and bilateral hip arthroplasty. There subject were 5 females and 6 males ranging from 67 to 88 years old. To administer the test the raters were given the BESTest one week before the session. They attended a forty-five minute session that allowed them training with a developer of the BESTest on the day of the study. During the experimental sessions someone who was not a rater administered the test and the raters could position themselves to get the best view. The test was done times, the first time for the raters to score and the second to score consistency.

Because patients with different diagnosis and based on the differential results, the treatment with the patients with Parkinson’s Disease would consist of practicing stepping in response to external forces pushing on the body and a patient with peripheral neuropathy the treatment would consist of practicing moving from one stable posture to another. The BESTest may have patients with the same pathologies but different profiles and they may have different compensation strategies, which would mean the treatment would change to address the specific individual. The interrater reliability statistics for the BESTest total scores were excellent with an intraclass correlation coefficient of .91. This means that the BESTest is just as good if not better than the shorter mostly widely used balance test such as the Berg Balance Scale or the Tinetti Mobility Assessment.

The score from students and therapist were broken down into more detail, but all scored high. Even though the inexperienced raters without physical therapy experience were able to learn, with prior instruction on how to score the test due to their limited knowledge and unfamiliarity have greater risk of making errors when recording. The second session scored higher in the Stability in Gait scored higher than the first session due to the change in instructions for raters to view from front or back. The median scores of all the subjects ranged from 65% to 95% with the control group clustered at the high end and the subjects which have Parkinson’s Disease clustered at the low end. The problem with the BESTest is that it takes approximately thirty minutes to administer even by an experienced therapist. An abbreviated test would be helpful. In this test due to it is still so new there may be unnecessary, insensitive, or redundant items so further studies may need to be conducted to make those eliminations. The BESTest is strong due to the fact that it allows the therapist to work an specific section if they are low on time or want to direct a balance test at a specific postural system. It also measures aspects of balance functionally relevant to patients. The test scale is quantitative and scoring is reproducible for the test as a whole and for each subsection which is important. As with any test, its success is dependant on the information that is gathered to better assist therapist to individualize the therapy session to the patient to improve their lives.

Reference:

Horak, F., Wrisley, D., & Frank, J.. (2009). The Balance Evaluation Systems Test (BESTest) to Differentiate Balance Deficits. Physical
Therapy, 89(5), 484-98. Retrieved Sept 16th, 2013, from Career and Technical Education.