Immediate effects of verbal instructions with internal focus of attention and external focus of attention on forward reach movement while standing

[Purpose] This study aimed to examine the immediate effects of verbal instructions with an internal and external focus of attention on forward reach movement while standing. [Participants and Methods] Thirty-seven healthy young males performed reach movement in three conditions: control, internal focus of attention, and external focus of attention. The measurements recorded were the movement distance of the third metacarpal bone (reach distance), the distance of the center of pressure, and the movement angles between the acromion and malleolus lateralis and between the acromion and trochanter major. [Results] Compared to the control condition, the internal focus of attention condition had a lower reach distance, angles between the acromion and malleolus lateralis and between the acromion and trochanter major, and center of pressure distance. In contrast, compared to the control condition, the external focus of attention condition showed higher reach distance and angles between the acromion and malleolus lateralis and between the acromion and trochanter major. The change rate of reach distance in the internal and external focus of attention conditions correlated significantly with the change rates of the angles between the acromion and malleolus lateralis and between the acromion and trochanter major. [Conclusion] Verbal instructions with attentional focus resulted in the simultaneous adjustment of the positional relationship between trunk and hip and immediately affected the reach distance. Our findings suggest that verbal instruction with attentional focus is an important factor affecting reach movement.