The Test of Reference Frame Interaction in Balance (TRIB) is designed to measure sensory orientation.
The TRIB built on the same framework as the CTSIB-m, but each item is extended to three variations of foot placement (shoulders with apart, parallel touching and one leg stance), each position with eyes open, eyes closed, on firm and a soft surface. Thus, the TRIB is comprised by 12 items.
The complete test is executed with the patient standing facing the room with the back approximately 0.5 meters from a wall. The rater is standing next to the patient keeping one arm around the patient’s shoulders without touching, but ready to catch the patient if necessary. First, the patient is instructed to stand with feet shoulders apart on the floor. If the patient manages to keep standing in this condition for 10 seconds, the patient is instructed to stand in the same position, but with eyes closed for 10 seconds. In continuation all foot positions are tested on the floor with eyes open and eyes closed and on a soft surface (Airex therapy pillow) with eyes open and eyes closed. The patient is given three trials in each condition and the best of the trials is noted for calculating the score. Only the number of seconds standing in each condition is used for calculating the score, but qualitative aspects can be noted as well. i.e. the amount and direction of sway, degree of dizziness and the patients balance strategy.
Essentially all conditions seldom need to be tested. If the rater already perceives that the patient is capable of standing without support the score of the first item can be noted without testing. Thus, it is assumed, if the patient can stand with feet together in one condition the patient is implicitly capable of passing the same condition with feet shoulders apart.
Three scores are calculated. The summarized score of the TRIB, which expresses the individuals overall sensory orientation capacity, is calculated from the sum of all scores divided with 120 seconds. Thus, the summarized score is a number between 0 to 1 with lower values reflecting lower capacity of overall sensory orientation.
Furthermore, two scores are calculated to measure to which extend the individual relies on a reference frame for balance oriented towards a stable support surface (SO) versus orientation towards vision (VO). SO is calculated from the sum of scores in all conditions standing on soft surface divided with the sum of scores in all conditions standing on the floor. VO is calculated from the sum of scores in all conditions standing with eyes closed divided with the sum of scores in all conditions standing with eyes open. Thus, the SO and VO scores are both a number between 0 and 1 with lower values reflecting higher relative dependence on vision or stable support surface. (In rare circumstances SO or VO can be a value higher than 1. This occurs only if an individual is more stable without vision or on unstable surface and is observed with rare orthopedic deformities or some cases of psychogenic subjective dizziness).
We hypothesize that the relative relationship between SO and VO can be used as a guide to which exercises should be prioritized targeting the individual´s mostly compromised balance strategy.
Even though the TRIB is composed by more items than the CTSIB-m, data on more than 900 balance impaired individuals referred to our clinic shows that the execution time is typically less than two minutes.