Effective Attentional Focus Strategies after Anterior Cruciate Ligament Reconstruction:A Commentary

Individuals after anterior cruciate ligament reconstruction (ACLR) have a high rate of reinjury upon return to competitive sports. Deficits in motor control may influence reinjury risk and can be addressed during rehabilitation with motor learning strategies. When instructing patients in performing motor tasks after ACLR, an external focus of attention directed to the intended movement effect has been shown to be more effective in reducing reinjury risk than an internal focus of attention on body movements. While this concept is mostly agreed upon, recent literature has made it clear that the interpretation and implementation of an external focus of attention within ACLR rehabilitation needs to be better described. The purpose of this commentary is to provide a clinical framework for the application of attentional focus strategies and guide clinicians towards effectively utilizing an external focus of attention in rehabilitation after ACLR

A VALIDITY STUDY COMPARING XSENS WITH VICON

Conducting on-field measurements is warranted to investigate and reduce real-world anterior cruciate ligament (ACL) injury risk. However, validation is first warranted to ensure how Xsens relates to Vicon. The purpose of this study was therefore to compare lower extremity kinematics from Xsens with Vicon. Ten recreational ball team sport athletes (5 females, 5 males) were included, who performed isolated and dynamic movements. Strong correlations were found for movement patterns (\u3e0.7) for the isolated as well as the dynamics movements. However, absolute joint angles differ between both systems (ranging from 0.7º - 14.5º). This should be considered when using Xsens in an applied sport setting as drawing conclusions for being or not being at risk for ACL injury may depend on the system used. A major strength of this study is the inclusion of movements that are restricted to one plane and one joint as well as dynamic high-intensity movements resembling movements which occur in sports (e.g. change of direction). This analysis of methods of data collection leads to further advancement of knowledge the science of biomechanics in applied sports setting

Neurocognitive and Neurophysiological Functions Related to ACL Injury:A Framework for Neurocognitive Approaches in Rehabilitation and Return-to-Sports Tests

Context: Only 55% of the athletes return to competitive sports after an anterior cruciate ligament (ACL) injury. Athletes younger than 25 years who return to sports have a second injury rate of 23%. There may be a mismatch between rehabilitation contents and the demands an athlete faces after returning to sports. Current return-to-sports (RTS) tests utilize closed and predictable motor skills; however, demands on the field are different. Neurocognitive functions are essential to manage dynamic sport situations and may fluctuate after peripheral injuries. Most RTS and rehabilitation paradigms appear to lack this aspect, which might be linked to increased risk of second injury. Objective: This systematic and scoping review aims to map existing evidence about neurocognitive and neurophysiological functions in athletes, which could be linked to ACL injury in an integrated fashion and bring an extensive perspective to assessment and rehabilitation approaches. Data Sources: PubMed and Cochrane databases were searched to identify relevant studies published between 2005 and 2020 using the keywords ACL, brain, cortical, neuroplasticity, cognitive, cognition, neurocognition, and athletes. Study Selection: Studies investigating either neurocognitive or neurophysiological functions in athletes and linking these to ACL injury regardless of their design and technique were included. Study Design: Systematic review. Data Extraction: The demographic, temporal, neurological, and behavioral data revealing possible injury-related aspects were extracted and summarized. Results: A total of 16 studies were included in this review. Deficits in different neurocognitive domains and changes in neurophysiological functions could be a predisposing risk factor for, or a consequence caused by, ACL injuries. Conclusion: Clinicians should view ACL injuries not only as a musculoskeletal but also as a neural lesion with neurocognitive and neurophysiological aspects. Rehabilitation and RTS paradigms should consider these changes for assessment and interventions after injury

Development of a test battery to enhance safe return to sports after anterior cruciate ligament reconstruction

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Brain Activation During Maximum Concentric and Eccentric Knee Extension Muscle Contractions

Purpose: In spite of mounting evidence indicating that concentric and eccentric knee extensor muscle contractions might have special nervous system control strategies, the differentiation of brain frequencies between concentric and eccentric movements and how the motor cortex programs this contraction has been less studied. In this study, the brain and muscle activation differences during maximum concentric and eccentric contractions were compared. Methods: Nine healthy volunteers performed 20 maximum eccentric and 20 maximum concentric knee extensor contractions. Electroencephalography (EEG) signals from sensorimotor-related cortical areas were recorded simultaneous with the electromyography (EMG) of the knee extensor muscles. In the spectral analysis the performance related power values were calculated for Theta (4-7 Hz) and Alpha (7-12 Hz). Results: The time-domain results revealed, longer time and greater cortical activity is required for the preparation of an eccentric contraction. For the eccentric task, the cortical activity was greater, but the EMG was lower in comparison to the concentric task values. Statistical analysis showed significant higher and lower Theta and Alpha power in both types of contractions compared to the resting state, respectively. Conclusion: These findings suggest that increased Theta power is associated with task complexity and focused attention and decreased Alpha power values with increased information processing in the somatosensory cortex