Unilateral dynamic balance assessment: the test-retest reliability of the OptoJump next drift protocol

Background: The OptoJump Next Drift Protocol is a test designed to assess unilateral dynamic balance. Participants are required to perform a series of unilateral jumps from which left/right and forward/back displacement (Drift) is calculated. Objectives: This investigation set out to establish the test-retest reliability of the OptoJump Next Drift Protocol. Method: Twenty-six participants performed the OptoJump Next Drift Protocol on two separate occasions. Drift Area and Drift Area as a percentage of total available jump area were calculated for each leg. Results: Interclass Correlation Coefficients (ICC) indicated poor reliability for Drift Area and Drift Area as a percentage of total available jump area (right leg r = .44; left leg r = −0.20). However, 95% Limits of Agreement (LoA) suggested a stronger relationship. For Drift Area, between trial Mean Difference for the right leg was 50.87 cm2 (95% LoA = −227.57 – 328.87) and for the left leg it was 54.08 cm2 (95% LoA = −333.62 – 441.79). For Drift Area as a percentage of total available jump area, Mean Difference for the right leg was 0.56% (95% LoA = −2.44 – 3.65) and for left 0.60% (95% LoA = - 3.76–4.89). Conclusions: Based on the 95% LoA data, the authors suggest that the OptoJump Next Drift Protocol does offer an acceptable level of reliability.