Table 2.

Experimental protocol

1. Control (day 1)

1.A. Upright stance–stable support surface

1.A.1. Without vision

1.A.2. Without vision, bilateral triceps surae muscle vibration

1.A.3. Without vision, bilateral lumbar multifidus muscle vibration

1.B. Upright stance–unstable support surface (foam)

1.B.1. Without vision

1.B.2. Without vision, bilateral triceps surae muscle vibration

1.B.3. Without vision, bilateral lumbar multifidus muscle vibration

2. Back muscle fatigue (day 2)

2.A. Upright stance–stable support surface

2.A.1. Without vision

2.A.2. Without vision, bilateral triceps surae muscle vibration

2.A.3. Without vision, bilateral lumbar multifidus muscle vibration

2.B. Upright stance–unstable support surface (foam)

2.B.1. Without vision

2.B.2. Without vision, bilateral triceps surae muscle vibration

2.B.3. Without vision, bilateral lumbar multifidus muscle vibration