Background: Chronic ankle instability (CAI), which is characterized by deficient postural control, could be improved through kinesiology taping (KT). However, the effect of KT on postural control in CAI individuals is controversial. Therefore, this study aimed to investigate the acute effect of KT on postural control through computerized dynamic posturography (CDP) and self-perceived sensation in CAI individuals.Methods: Participants with CAI received four different ankle treatments randomly, including KT, athletic taping (AT), sham taping (ST), and no taping (NT). A series of postural stability measurements was performed using CDP subsequently. The measurements included sensory organization test (SOT), unilateral stance (US), limit of stability (LOS), motor control test (MCT), and adaption test (ADT). In addition, selfperceived sensation was measured through visual analog scaling. Repeated measures analysis of variance was conducted to determine whether the difference among KT, AT, ST, and NT was significant; Bonferroni test was used for post hoc analysis.Results: No significant difference was observed for parameters in SOT, US, and LOS in four different taping treatments. In MCT, the amplitude scaling scores of KT were 35.87% significantly lower than that of NT [p < 0.001, 95% confidence interval (CI) = 0.548-1.795] in forward-small slip and 21.58% significantly lower than that of ST (p = 0.035, 95% CI = 0.089-3.683) in backward-large slip. In ADT, sway energy scores were 7.59% significantly greater in ST than in AT (p = 0.028, 95% CI = −8.343 to −0.320). For perceived stability, KT was significantly greater than ST (p < 0.001, 95% CI = 0.552-1.899) and NT (p < 0.001, 95% CI = 0.797-2.534), and AT was significantly greater than ST (p = 0.001, 95% CI = 0.423-2.246) and NT (p < 0.001, 95% CI = 0.696-2.852). For perceived comfort, KT was significantly greater than AT (p = 0.001, 95% CI = 0.666-3.196) and NT (p = 0.031, 95% CI = 0.074-2.332), and ST was significantly greater than AT (p = 0.007, 95% CI = 0.349-2.931). Conclusion:KT and AT have limited effect to facilitate postural control for CAI individuals during SOT, US, and LOS. However, KT and AT could provide effective support to cope with sudden perturbation in MCT and ADT. Moreover, KT provided excellent perceived stability and comfort, whereas AT provided excellent perceived stability but least comfort.

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Large number of studies showed that landing with great impact forces may be a risk factor for knee injuries. The purpose of this study was to illustrate the different landing loads to lower extremity of both genders and examine the relationships among selected lower extremity kinematics and kinetics during the landing of a stop-jump task. A total of 35 male and 35 female healthy subjects were recruited in this study. Each subject executed five experiment actions. Lower extremity kinematics and kinetics were synchronously acquired. The comparison of lower extremity kinematics for different genders showed significant difference. The knee and hip maximum flexion angle, peak ground reaction force and peak knee extension moment have significantly decreased during the landing of the stop-jump task among the female subjects. The hip flexion angle at the initial foot contact phase showed significant correlation with peak ground reaction force during landing of the stop-jump task (r=-0.927, p<0.001). The knee flexion angle at the initial foot contact phase had significant correlation with peak ground reaction force and vertical ground reaction forces during landing of the stop-jump task (r=-0.908, p<0.001; r=0.812, P=0.002). A large hip and knee flexion angles at the initial foot contact with the ground did not necessarily reduce the impact force during landing, but active hip and knee flexion motions did. The hip and knee flexion motion of landing was an important technical factor that affects anterior cruciate ligament (ACL) loading during the landing of the stop-jump task.

Foot strike patterns influence the running efficiency and may be an injury risk. However, differences in the leg stiffness between runners with habitual forefoot (hFFS) and habitual rearfoot (hRFS) strike patterns remain unclear. This study aimed at determining the differences in the stiffness, associated loading rate, and kinematic performance between runners with hFFS and hRFS during running. Kinematic and kinetic data were collected amongst 39 runners with hFFS and 39 runners with hRFS running at speed of 3.3 m/s, leg stiffness (Kleg), and vertical stiffness (Kvert), and impact loads were calculated. Results found that runners with hFFS had greater Kleg ( P = 0.010 , Cohe n ’ s   d = 0.60 ), greater peak vertical ground reaction force (vGRF) ( P = 0.040 , Cohe n ’ s   d = 0.47 ), shorter contact time( t c ) ( P < 0.001 , Cohe n ’ s   d = 0.85 ), and smaller maximum leg compression ( Δ L ) ( P = 0.002 , Cohe n ’ s   d = 0.72 ) compared with their hRFS counterparts. Runners with hFFS had lower impact peak (IP) ( P < 0.001 , Cohe n ’ s   d = 1.65 ), vertical average loading rate (VALR) ( P < 0.001 , Cohe n ’ s   d = 1.20 ), and vertical instantaneous loading rate (VILR) ( P < 0.001 , Cohe n ’ s   d = 1.14 ) compared with runners with hRFS. Runners with hFFS landed with a plantar flexed ankle, whereas runners with hRFS landed with a dorsiflexed ankle ( P < 0.001 , Cohe n ’ s   d = 3.35 ). Runners with hFFS also exhibited more flexed hip ( P = 0.020 , Cohe n ’ s   d = 0.61 ) and knee ( P < 0.001 , Cohe n ’ s   d = 1.15 ) than runners with hRFS at initial contact. These results might indicate that runners with hFFS were associated with better running economy through the transmission of elastic energy.