EFFECTS OF ECCENTRIC ENDURANCE TRAINING ON PHYSICAL AND COGNITIVE FALL RISK FACTORS

Abstract

A proactive approach to fall risk prevention may help minimize the likelihood of a fall for older adults not yet classified as being at high risk of falling. These studies focused on assessing how eccentric endurance training (EET) influenced physical and cognitive modifiable fall risk factors. Physical fall risk factor assessments included a 30-second sit-to-stand test (30CST), Berg Balance Scale (BBS), single leg stance with eyes closed (SLS-EC), Functional Gait Assessment (FGA), and Timed Up-and-Go (TUG). Maximal eccentric strength (MES) was also assessed. Cognitive fall risk factor assessments included one measure of dual-tasking, the cognitive Timed Up-and-Go (TUGcog), and two measures of executive function, the Trail Making Test (Parts A and B) and the Stroop Test (Conditions A, B, and C). The sample included 30 older adults (68.2 ± 3.7 years; 16 females, 14 males), with 15 participants completing the EET training (69.0 ± 4.4 years; 8 females, 7 males) and 15 participants in the control group (67.5 ± 2.6 yearsy; 8 females, 7 males). Training group participants completed 1 week of familiarization and 8 weeks of twice weekly EET training. Participants in the control group were asked to maintain their normal activities throughout the 9 week study duration. For both groups, pre-assessments were conducted on the second day of the familiarization week, mid-assessments were conducted on the first day of Week 5, and post-assessments were conducted within 1 week of completing Week 9. There were significant improvements in 30CST, BBS, FGA, and TUG performance. In contrast, no significant changes in SLS-EC or MES were observed. Although a significant change and a large effect size were observed for the BBS, the near maximal scores at pre-assessment made it improbable to elicit meaningful changes. While scores within 1 point of perfect were less frequent on the FGA, there remains to be information regarding minimum detectable changes for this outcome. As such, the 2.2 point increase in performance should be interpreted with caution. The 30CST and TUG also yielded significant improvements and large effect sizes. While minimum detectable changes have not been reported, the 2.6 repetition increase in 30CST and 0.9 second decrease in TUG performance are notable. In contrast, there were no significant differences in the cognitive function outcomes. The TUGcog was the only assessment that did not exhibit a potential learning effect, as there was no significant main effect for time. Although not significant, a 0.66 second improvement was observed for the EET group. In contrast, the Trail Making Test (Part B) and Stroop Tests (A, B, and C) exhibited a main effect for time with no significant interaction. This indicates all participants improved over time, which was likely the result of a learning effect. As such, there is a need for measures of executive function that are less influenced by time. In summation, 8 weeks of EET yielded improvements in physical function without cognitive performance changes. The largest and most meaningful changes were observed in muscular fitness and overall physical function. This mode of training is promising in that a small time commitment is required to see significant improvements in several physical outcome variables associated with one’s risk of falling, specifically for those who do not yet exhibit deficits in performance.