Author(s): FREITAG, C., BEHRENS, M., BIELITZKI, R., BEHRENDT, T., AL-NOSAIRY, K., STOLLE, F., PRABHAKARAN, G., BEYER, R., THIEME, H., HOFFMANN, M., SCHEGA, L., Institution: OTTO VON GUERICKE UNIVERSITÄT MAGDEBURG, Country: GERMANY, Abstract-ID: 864

INTRODUCTION:
In the early stages of open angle glaucoma (OAG), the symptoms are almost unnoticeable. However, OAG-induced visual field defects are associated with impaired gait performance during single- (STW) and dual-task walking (DTW), which increases the risk of falling. Resistance and motor-cognitive exercises/training have been shown to improve postural control and to reduce the fear of falling. Thus, a combination of both training modalities might be more effective in improving spatio-temporal gait parameters during STW and DTW. Therefore, the present study aimed to investigate the effect of 12 weeks of resistance training (unimodal, UM) versus resistance combined with motor-cognitive training (multimodal, MM) on STW and DTW gait performance in OAG.
METHODS:
Nineteen OAG patients were included in a 12-week intervention containing either UM (N=10) or MM training (N=9). Before and after the intervention period, participants performed STW and DTW. During DTW, patients walked at comfortable velocity and had to perform different concurrent cognitive tasks in a random order: (i) Verbal Fluency Task, (ii) N-Back Task, and (iii) Reaction Time Task, with two difficulty levels, respectively. To calculate dual task costs (DTC), each cognitive task was also performed while sitting. During STW and DTW, spatio-temporal gait parameters were assessed using inertial measurement units (sampling frequency 100Hz). DTC in gait performance were assessed by the differences between STW and DTW. For statistical analysis, three-way (time × condition × group) repeated measures analyses of covariance were conducted. The practical relevance of the results was judged on the basis of the effect size, with a medium effect (η_p^2≥0.06) being considered meaningful.
RESULTS:
Due to drop out/processing issues, only 12 participants (6 UM, 70.5±2.3years), 6 MM (69.2±6.5years) were included in the final analysis. For the MM group, changes in minimal toe clearance (MTC), stride length, and the coefficient of variation (CoV) of the respective parameters were indicated by time × group interactions for MTC (p=.151,η_p^2=0.22) and stride length (p=.444,η_p^2=0.07) and for CoV of stride length (p=.309,η_p^2=0.12) and of gait velocity (GV) (p=.301, η_p^2=0.12). Furthermore for DTC, time × group interactions were found in the UM group for cognitive performance (p=.450,η_p^2=0.07), MTC (p=.016,η_p^2=0.54), MTC CoV (p=.005,η_p^2=0.65), stride length (p=.046,η_p^2=.411), GV (p=.525,η_p^2=0.06) and GV CoV (p=.364,η_p^2=0.10) revealing a reduction in these DTC in the UM group.
CONCLUSION:
The UM and MM intervention affected gait performance differently. While the MM intervention improved several parameters of gait performance, the UM intervention reduced cognitive and gait performance DTC. Consequently, both the UM and MM intervention may be beneficial to counteract the deterioration of gait performance during STW and DTW walking in OAG patients, even though with different effects on gait parameters.