Comparison of balance strategies in mountain climbers during real altitude exposure between 1.500m and 3.200m: Effects of age and expertise.

PURPOSE

The aim of this study was to estimate the effect of altitude (1500m vs. 3200m) on balance strategies, and to determine the influence of age (> or <40 years) and expertise (> or <20days of mountain climbing/year) on postural stability at altitude.

METHOD

Eighty-nine volunteer mountaineers were tested at 1500m, 3200m immediately after exiting the cable car and at 3200m following the climb and return. Double-leg stance with eyes closed and single-leg stance with eyes open were tested. The center of pressure (CoP) was recorded for 12.8s using a stabilometric force platform. Length, surface, ratio (length/surface), and average speed of the CoP, as well as lower limb loading were calculated. Groups and altitudes were compared using ANOVA. Significance was set to p<0.05.

RESULTS

CoP ratio was significantly higher during both balance conditions at 3200m compared to 1500m (p<0.05). Lower limb loading was symmetrical at 1500m but not at 3200m (p<0.05). There was no influence of age or expertise at 1500m (p=NS), however at 3200m, older subjects and subjects with less expertise had greater length and surface of the CoP, showing more instability (p<0.05).

CONCLUSION

Postural stability was immediately reduced on arrival at 3200m, particularly in subjects above the age of 40 years with less expertise.