Brain Neuroplasticity Related to Lateral Ankle Ligamentous Injuries: A Systematic Review.

BACKGROUND: Lateral ankle sprains are the most common ankle injuries in sports and have the highest recurrence rates. Almost half of the patients experiencing lateral ankle sprains develop chronic ankle instability. Patients with chronic ankle instability experience persistent ankle dysfunctions and detrimental long-term sequelae. Changes at the brain level are put forward to explain these undesirable consequences and high recurrence rates partially. However, an overview of possible brain adaptations related to lateral ankle sprains and chronic ankle instability is currently lacking. OBJECTIVE: The primary purpose of this systematic review is to provide a comprehensive overview of the literature on structural and functional brain adaptations related to lateral ankle sprains and in patients with chronic ankle instability. METHODS: PubMed, Web of Science, Scopus, Embase, EBSCO-SPORTDiscus and Cochrane Central Register of Controlled Trials were systematically searched until 14 December, 2022. Meta-analyses, systematic reviews and narrative reviews were excluded. Included studies investigated functional or structural brain adaptations in patients who experienced a lateral ankle sprain or with chronic ankle instability and who were at least 18 years of age. Lateral ankle sprains and chronic ankle instability were defined following the recommendation of the International Ankle Consortium. Three authors independently extracted the data. They extracted the authors' name, publication year, study design, inclusion criteria, participant characteristics, the sample size of the intervention and control groups, methods of neuroplasticity testing, as well as all means and standard deviations of primary and secondary neuroplasticity outcomes from each study. Data reported on copers were considered as part of the control group. The quality assessment tool for observational and cross-sectional studies was used for the risk of bias assessment. This study is registered on PROSPERO, number CRD42021281956. RESULTS: Twenty articles were included, of which only one investigated individuals who experienced a lateral ankle sprain. In all studies combined, 356 patients with chronic ankle instability, 10 who experienced a lateral ankle sprain and 46 copers were included. White matter microstructure changes in the cerebellum have been related to lateral ankle sprains. Fifteen studies reported functional brain adaptations in patients with chronic ankle instability, and five articles found structural brain outcomes. Alterations in the sensorimotor network (precentral gyrus and supplementary motor area, postcentral gyrus and middle frontal gyrus) and dorsal anterior cingulate cortex were mainly found in patients with chronic ankle instability. DISCUSSION: The included studies demonstrated structural and functional brain adaptations related to lateral ankle sprains and chronic ankle instability compared to healthy individuals or copers. These adaptations correlate with clinical outcomes (e.g. patients' self-reported function and different clinical assessments) and might contribute to the persisting dysfunctions, increased re-injury risk and long-term sequelae seen in these patients. Thus, rehabilitation programmes should integrate sensorimotor and motor control strategies to cope with neuroplasticity related to ligamentous ankle injuries.

Can Creatine Combat the Mental Fatigue-associated Decrease in Visuomotor Skills?

PURPOSE: The importance of the brain in sports was recently confirmed by the negative effect of mental fatigue (MF) on sport-specific psychomotor skills. Creatine supplementation improves strength but can also improve cognitive functioning. To explore the role of creatine in combating MF, we evaluated whether creatine supplementation counteracts the MF-associated impairment in sport-specific psychomotor skills. METHODS: In 23°C, 14 healthy participants (4 females, 10 males; mean ± SD, age = 24 ± 3 yr, mass = 74 ± 13 kg, height = 179 ± 9 cm) performed a 90-min mentally fatiguing task (counterbalanced, crossover, and double-blinded; i.e., Stroop task) in two different conditions: after a 7-d creatine supplementation (CR; 20 g·d) and after a 7-d calcium lactate supplementation (placebo [PLAC]), separated by a 5-wk washout. In both conditions, a 7-min sport-specific visuomotor task, a dynamic handgrip strength endurance task, and a 3-min Flanker task was performed before and after the mentally fatiguing task. Physiological and perceptual responses were measured throughout the protocol. RESULTS: Handgrip strength endurance was higher in CR compared with PLAC (P = 0.022). MF impaired visuomotor response time (+4.4%; P = 0.022) and Flanker accuracy (-5.0%; P = 0.009) in both conditions. Accuracy on the Stroop task was higher in CR compared with PLAC (+4.9%; P = 0.026). Within the perceptual and physiological parameters, only motivation and vigor (P ≤ 0.027) were lower in CR compared with PLAC. CONCLUSION: Creatine supplementation improved physical (strength endurance) and prolonged cognitive (Stroop accuracy) performance, yet it did not combat MF-induced impairments in short sport-specific psychomotor or cognitive (Flanker) performance. These results warrant further investigation in the potential role of creatine in combating the MF-associated decrements in prolonged (e.g., 90-min soccer game) sport performance and suggest a role of brain phosphocreatine in MF.

Bringing context to balance: development of a reactive balance test within the injury prevention and return to sport domain.

BACKGROUND: Balance tests are commonly used in clinical practice with applicability in injury prevention and return to sport decisions. While most sports injuries occur in a changing environment where reacting to a non-planned stimulus is of great importance, these balance tests only evaluate pre-planned movements without taking these dynamics environmental aspects into account. Therefore, the goal of this paper was to develop a clinician-friendly test that respects these contextual interactions and to describe the test protocol of an adapted Y-balance test that includes environmental perception and decision-making. METHODS: Within the theoretical construct of balance and adaptability, balance errors were selected as outcome measures for balance ability and, visuomotor reaction time and accuracy are selected as outcome measures for adaptability. A reactive balance task was developed and described using the Y-balance test for the balance component, while the FitLight training systemTM was chosen for the environmental perception and decision-making component of the test. RESULTS: This paper describes the test protocol of a reactive balance test as an adapted Y-balance test. The LED-lights of the FitLight training systemTM are placed at 80% of the maximal reach distance for each axis along the Y-Balance test kitTM. To induce cognitive load within the visuomotor task, colours were fixed to a corresponding axis, and both the order of the visual stimuli as the interstimulus time were randomised to integrate environmental perception and decision-making. CONCLUSION: The reactive balance test is a functional test that allows clinicians to score balance ability and athlete adaptability easily.