Hip- and thigh-muscle activation during the star excursion balance test

Area of Science:

• Biomechanics
• Kinesiology
• Sports Medicine

Background:

• The Star Excursion Balance Test (SEBT) is a common tool for assessing dynamic balance and neuromuscular control.
• Limited research exists on hip and thigh muscle activation patterns during SEBT performance.

Purpose of the Study:

• To quantify and compare hip and thigh muscle (gluteus medius, gluteus maximus, vastus medialis) activation during different directions of the SEBT.
• To determine the reliability of electromyography (EMG) measurements during the SEBT.

Main Methods:

• 22 healthy participants (11 men, 11 women) underwent laboratory-based SEBT testing.
• Electromyography (EMG) measured gluteus medius (Gmed), gluteus maximus (Gmax), and vastus medialis (VM) activity during the eccentric phase of anterior, medial, and posteromedial reaches.
• Test-retest reliability was assessed, and muscle activation was compared across reach directions.

Main Results:

• High test-retest reliability (ICC3,1: .91–.99) was observed for EMG data.
• A significant interaction between muscle and reach direction was found.
• Gluteus medius (Gmed) activation was highest in the anterior (A) and medial (M) directions compared to posteromedial (PM).
• Gluteus maximus (Gmax) and vastus medialis (VM) showed no significant differences in activation across the three directions.

Conclusions:

• The anterior and medial SEBT directions most effectively recruit the gluteus medius.
• Vastus medialis activation exceeded strengthening thresholds in all tested directions, while gluteus medius exceeded it in the medial direction.
• Gluteus maximus activation remained below strengthening thresholds across all tested SEBT directions, suggesting limited hypertrophic potential for this muscle with this specific exercise protocol.