Kinematic Analysis of Selected Reach Directions of the Star Excursion Balance Test Compared With the Y-Balance Test

Abstract

The Star Excursion Balance Test (SEBT) and the Y-Balance Test (YBT) have 3 common reach directions: anterior (ANT), posteromedial (PM), and posterolateral (PL). Previous research has indicated that reach-distance performance on the ANT reach direction of the SEBT differs from that on the YBT. Kinematic patterns associated with the ANT reach direction of the SEBT and YBT need to be investigated to fully understand this difference, along with the PM and PL reach directions, to deduce any kinematic discrepancies between the 2 balance tests. To compare and contrast the kinematic patterns associated with test performance on the reach directions common to the SEBT and YBT. Controlled laboratory study. University laboratory. 15 healthy male (age 23.33 ± 2.02 y, height 1.77 ± 0.04 m, body mass 80.00 ± 9.03 kg) and 14 healthy female (age 21.14 ± 1.66 y, height 1.63 ± 0.06 m, body mass 59.58 ± 7.61 kg) volunteers. Each participant performed 3 trials of the ANT, PM, and PL reach directions of the SEBT and YBT on their dominant leg. Sagittal-plane lower-limb kinematic profiles were recorded using a 3-D motion-analysis system. Reach distances were also recorded for each reach direction. A significant main effect (P < .05) was observed for test condition with participants reaching farther on the ANT reach direction of the SEBT compared with the YBT. While reaching in the ANT direction participants were characterized by a more flexed position of the hip joint at the point of maximum reach on the YBT (27.94° ± 13.84°) compared with the SEBT (20.37° ± 18.64°). Based on these observed results, the authors conclude that test performance on the SEBT and YBT differ in terms of dynamic neuro-muscular demands, as evidenced by differences in reach distances achieved in the ANT reach direction and associated test kinematic profile.