Quantification of reaction time in an Arctic population

Greenland is an Arctic environment with snow and ice on uneven terrain posing lifelong physical challenges to people in Greenland. In addition, Greenlanders are a distinct ethnic group. This led us to (1) quantify reaction time among Greenlanders (2) hypothesising a faster reaction time compared to previous findings among e.g., Scandinavians.

Data were collected using a portable device, the Nintendo Wii Balance Board, with the FysioMeter software validated for estimating reaction time. Participants were healthy Greenlanders living in West Greenland, who filled in a questionnaire on physical activity, disease, prescription medicine, alcohol, and smoking habits. Reaction time was measured for dominant and non-dominant upper and lower extremities.

The 72 women and 42 men participating had a mean age of 50 years, range 20 to 83 years. The age-related increase in reaction time was around 6 milliseconds for each year of advancing age (p < 0.001). Reaction time did not differ between dominant and non-dominant upper (p = 0.7) or lower (p = 0.5) extremities. While the crude comparison showed that age, medication, physical activity and body proportions influenced reaction time, only age (p < 0.001-0.055) and height (p = 0.002-0.044) remained important in the adjusted analysis.

This first study of reaction time in Greenlanders found patterns similar to those observed in e.g., Scandinavians. Interestingly, Greenlanders did not demonstrate faster reaction times despite lifelong exposure to physically demanding and unstable terrain. This finding may be relevant for future research on motor adaptation and environmental influences on balance control.