Effects of passive Bi-axial ankle stretching while walking on uneven terrains in older adults with chronic stroke

Many people with stroke experience foot drop while walking. Further, walking on uneven surfaces is a common fall risk for these people that hinder with their daily life activities. In addition, a few years after a stroke, lower-limb exercises become less focused, especially the ankle joint movement. The objective of this study is to determine the gait performance of older adults with chronic stroke on an uneven surface in relation to ankle mobility after a four-week bi-axial ankle range of motion (ROM) exercise session. Fifteen older adults with chronic post-stroke hemiparesis (N = 15; mean age = 65 years) participated in a total of 12 bi-axial ankle ROM exercises that consisted of three 30-min training sessions per week for four weeks. Basic clinical tests and gait performance in even and uneven surfaces were evaluated before and after training. Participants with chronic post-stroke hemiparesis showed significantly improved ankle functions, decreased ankle stiffness (from 0.140 ± 0.059 to 0.128 ± 0.067 N·m/°; p = 0.025), and increased paretic ankle passive ROMs (dorsiflexion(DF)/plantarflexion(PF): from 27.3 ± 14.7° to 50.6 ± 10.3°, p < 0.001; inversion(INV)/eversion(EV): 21.7 ± 9.7° to 28.6 ± 9.9°; p = 0.033) after training. They exhibited significant improvements in the walking performance over an uneven surface, step kinematics (walking speed 0.257 ± 0.17 to 0.320 ± 0.178 m/s; p = 0.017; step length: 0.214 ± 0.109 to 0.243 ± 0.108 m; p = 0.009), and clinical balance and mobility (Berg balance scale: 47.2 ± 4.7 to 50.1 ± 3.9, p = 0.0001; timed-up and go test: 23.9 ± 10.3 to 20.2 ± 7.0 s, p = 0.0156). This study is the first research to investigate the walking performance on uneven surfaces in the elderly with chronic stroke in relation to the ankle biomechanical property changes.