ECSS Paris 2023: OP-MH35
INTRODUCTION: Chronic ankle instability (CAI) is not only a peripheral musculoskeletal injury but also involves neurophysiological dysfunction. After an initial ankle sprain, 40% of individuals develop CAI, while others (referred to as "Copers") do not, potentially due to central nervous system alterations. Investigating cortical electrophysiological parameters to understand functional changes in brain activity post-injury holds clinical significance, as it may influence rehabilitation strategies. This study aims to assess sensorimotor cortex activation characteristics during single-leg lateral landing in individuals who developed CAI versus Copers. METHODS: Participants included 46 individuals with CAI (male=23, female=23) and 41 Copers (male=18, female=23). A 64-channel EEG system was used to record cortical activity during a single-leg lateral landing task from a 16 cm-high platform onto a force plate. The α-band power spectral differences in the sensorimotor cortex and time to stabilization (TTS) during landing were analyzed. Statistical analyses included repeated-measures ANOVA (for α-power comparisons within and between groups) and independent t-tests (for TTS). RESULTS: Individuals with CAI exhibited significantly higher α-power at the C3 electrode (sensorimotor cortex) compared to Copers (CAI: 0.53 ± 0.22 vs. Coper: 0.19 ± 0.28, P < 0.001), while showing significantly lower α-power at the C4 electrode compared to Copers (CAI: 0.42 ± 0.23 vs. Coper: 0.57 ± 0.29, P < 0.001). Within-group comparisons revealed hemispheric asymmetry, with CAI showing higher α-power at C3 compared to C4 (P < 0.001), whereas Copers demonstrated the opposite pattern (C4 > C3, P < 0.001). Additionally, the time to stabilization (TTS) was significantly shorter in the CAI group compared to the Coper group (CAI: 1.10 ± 0.43s vs. Coper: 1.98 ± 0.62s, P < 0.001). CONCLUSION: During single-leg lateral landing, individuals with CAI demonstrated asymmetric sensorimotor cortex activation, which may enhance postural control efficiency. These findings provide neurophysiological evidence for altered neural mechanisms underlying postural adjustments in CAI, highlighting the role of central adaptations in functional recovery.
Read CV Bin RuanECSS Paris 2023: OP-MH35
INTRODUCTION: Sensorimotor maladaptation may contribute to diminished static postural control in individuals with recurrent ankle sprains (RAS). Individuals with RAS heavily rely on visual cues for maintaining posture [1]. Visual reliance is linked to poor postural control, potentially associated with increased activation in the visual processing cortices. Transcranial static magnetic stimulation (tSMS) is a non-invasive brain stimulation that reduce neural activity at a specific area, including the visual cortex [2]. tSMS over the visual cortex may decrease visual reliance via tSMS-induced reduction of the visual cortex in individuals with RAS. However, no study has explored effectiveness of tSMS in restoring optimal sensory reweighting in those with visual reliance. Therefore, this study aimed to investigate the acute effects of tSMS on sensory reweighting in individuals with RAS relying on visual cues. METHODS: This randomized, double-blinded placebo-controlled study enrolled 45 participants with RAS from a convenience sample. Participants performed a single-leg assessment of the Clinical Test for Sensory Integration in Balance (CTSIB). Participants relying visual cues were identified by a preference ratio greater than 100 % from the CTSIB. Twenty participants with visual reliance were included (M=11, F=9; Age=21.5±1.5years; Height=167.1±9.2cm; Mass=60.6±8.0kg) and ramdomly assigned to a tSMS (n=10) or sham group (n=10). During intervention, participants sat in an armchair while either a neodymium magnet (tSMS group) or an identical non-magnetic stainless-steel cylinder (sham group) was placed on the scalp over their visual cortex for 30 minutes. Followinng the intervention, participants completed the CTSIB. The CTSIB variables included scores of somatosensory, visual, vestibular, and preference ratios. Independent t-tests were used to compare absolute change scores for each outcome measure between groups. Cohen’s d effect sizes, along with 95% confidence intervals (CI), were calculated for each comparison. Significance was set a priori at P<0.05. RESULTS: The absolute change scores of the preference ratio showed a trend toward a between-group difference with a large effect size (P=0.087, d=-0.81, 95% CIs:-1.71, 0.12). No significant findings were observed in other outcome measures (P>0.05). CONCLUSION: tSMS over the visual cortex demonstrated a trend toward a acute reduction in preference ratio scores. These findings indicate that tSMS might acutely decrease visual reliance during static postural control via tSMS-induced reduction of cortical activity at the visual cortex. Further studies should explore effects of tSMS with somatosensory-targeted interventions for increasing somatosensory use in populations with RAS who exhibit visual dependence. References: [1] Song et al., Med Sci Sports Exerc. 2016. [2] Gonzalez-Rosa et al., J Neurosci. 2015.
Read CV Shunya NonoyamaECSS Paris 2023: OP-MH35
INTRODUCTION: Basketball requires jumping, landing, and rapid changes of direction, all of which place stress on the lower extremities. Ankle sprains have the highest incidence among basketball players, and it has been reported that ankle sprains in adolescence can lead to subsequent chronic ankle instability. Therefore, the prevention of ankle sprains is important, especially with proper coaching on prevention measures. However, coaches’ perceptions and implementation of injury prevention are not clear. This study aims to investigate the perceptions and implementation of ankle sprains prevention measures among basketball coaches. METHODS: A web-based survey was administered to 104 basketball coaches in Japan holding an E-level or higher coaching license, certified by the Japan Basketball Association. “Perception” was assessed through coaches’ views on the importance of ankle sprain prevention; “Implementation” was analyzed according to the presence of ankle sprain prevention measures; and “Knowledge” was evaluated based on their awareness that ankle sprains are the most common injuries among basketball players. RESULTS: After screening, 45 coaches with coaching experience (Age: 38.36±12.14 years, Male: 40 [88.89%], Female: 5 [11.11%]) were analyzed. All respondents (n=45) perceived the importance of ankle sprain prevention. On the other hand, the actual implementation of ankle sprain prevention measures was 57.78%. Most coaches (86.67%) understood that ankle sprains are the most common injury in basketball players. However, 13 of 19 coaches (68.42%) who did not implement preventive measures cited a lack of resources for ankle sprain prevention as one of the main causes for non-implementation. CONCLUSION: Coaches perceived the importance of ankle sprain prevention, but implementation was lacking. A lack of awareness of ankle sprain prevention was one of the reasons for poor implementation.
Read CV Ziqi ZhouECSS Paris 2023: OP-MH35