Prevention of slip-related backward balance loss: the effect of session intensity and frequency on long-term retention.

Abstract

To examine the effects of session intensity (number of slip exposures) and frequency on the retention of acquired adaptation for prevention of backward balance loss after repeated-slip training. A 4-group, randomized, and controlled study. Biomechanics research laboratory. Healthy young subjects (N=46; 21 men). Twenty-four subjects experienced a high-intensity session of 24 repeated right-side slips; 12 received additional single-slip sessions at a frequency of 1 week, 2 weeks, and 1 month, whereas the rest got no ancillary training. Another 24 subjects received a low-intensity initial session of a single slip; 12 received the same high-frequency ancillary training, whereas the rest got none. All groups were retested with a single slip 4 months after the first session. The incidence of backward balance loss, gait stability, and limb support. The high-intensity groups, irrespective of ancillary training, displayed similar improvements in all 3 outcome measures. Remarkably, the low-intensity group receiving ancillary training also significantly improved in all measures, with retention comparable to that observed in the other 2 groups. A single-slip exposure without ancillary sessions was insufficient to yield a longer-term effect. Frequent ancillary sessions may be unnecessary for slip-related fall prevention up to 4 months if the initial session intensity is sufficient. Furthermore, the minimum of a single slip may be as effective if the subject is exposed to frequent ancillary sessions.