Four Square Step Test (FSST). FSST is a clinical measure of rapid stepping and obstacle avoidance . The equipment required for the FSST includes a stopwatch and 4 canes. The square is formed by using 4 canes resting flat on the floor. Canes are 90cm long, and the direction and type of handle used is not important. The subject stands in square number 1 facing square number 2. The aim is to step as fast as possible into each square in the following sequence. Square number 2, 3, 4, 1, 4, 3, 2, and 1. This sequence requires the subject to step forward, backward, and sideway to the right and left. The score is recorded as the time taken to complete the sequence. The stopwatch starts when the first foot contacts the floor in square 2 and finishes when the last foot comes back to touch the floor in square 1. The following instructions are given to the subject, "Try to complete the sequence as fast as possible without touching the sticks. Both feet must make contact with the floor in each square. If possible, face forward during the entire sequence." The sequence is then shown to the subject.