Interpersonal Coordination between Female Soccer Players: Leader-Follower Roles within a Collision-Avoidance Task.

Background/Purpose: Return to sport decision-making may be improved by assessing an athlete's ability to coordinate movement with opponents in sport. The purpose was to investigate whether previous injuries associated with female soccer players' interpersonal coordination during a collision avoidance task. The authors hypothesized that external perturbations would disrupt the strength and stability of coordinated movement, and that individuals with a history of injury would be less likely to recover coordinated movement. Study Design: Cross-Sectional. Methods: Nine female athletes with a history of lower extremity injuries and nine without injuries were paired into dyads. Each dyad completed twenty trials of an externally paced collision-avoidance agility task with an unanticipated perturbation. Participant trajectories were digitized and analyzed using cross-recurrence quantification analysis (CRQA) to determine the strength and stability of interpersonal coordination dynamics. Trials in which participants with injury history assumed leader or follower roles within each dyad were then used to study how dyadic coordination varied across task stages (early, perturbation, and late) using linear mixed effect models. Cohen's d effect sizes were calculated to demonstrate magnitude of differences. In exploratory analysis, psychological readiness (i.e., self-reported knee functioning, fear of injury, and risk-taking propensity) was evaluated for their association with leader-follower status. Results: Perturbation disrupted the strength (R2=0.65, p<0.001, early=49.7±1.7, perturbation=41.1±1.7, d=0.39) and stability (R2=0.71, p < 0.001, early=65.0±1.6, perturbation=58.0±1.7, d=0.38) of interpersonal coordination regardless of leader-follower status. Individuals with injury history failed to restore coordination after the perturbation compared to control participants (injury=44.2.0±2.1, control=50.8±2.6, d=0.39). Neither demographic nor psychological measures were associated with leader-follower roles (B=0.039, p=0.224). Conclusion: Individuals with a history of lower extremity injury may have a diminished ability to adapt interpersonal coordination to perturbations, possibly contributing to a higher risk of re-injury. Level of Evidence: 3.

Single Leg Hop Performance After Anterior Cruciate Ligament Reconstruction: Ready for Landing but Cleared for Take-Off?

CONTEXT: While the landing phases of the single-leg hop for distance (SLHD) are commonly assessed, limited work reflects how the take-off phase influences hop performance in patients with anterior cruciate ligament reconstruction (ACLR). OBJECTIVE: To compare trunk and lower extremity biomechanics between individuals with ACLR and matched uninjured controls during take-off of the SLHD. DESIGN: Cross-sectional study design. SETTING: Laboratory setting. PATIENTS OR OTHER PARTICIPANTS: 16 individuals with ACLR and 18 uninjured controls. MAIN OUTCOME MEASURES: Normalized quadriceps isokinetic torque, hop distance, and respective limb symmetry indices (LSI) were collected for each participant. Sagittal and frontal kinematics and kinetics of the trunk, hip, knee, and ankle, as well as vertical and horizontal ground reaction forces (GRF) were recorded for loading and propulsion of the take-off phase of the SLHD. RESULTS: Those with ACLR had weaker quadriceps peak torque in the involved limb (p=0.001) and greater strength asymmetry (p<0.001) compared to controls. Normalized hop distance was not statistically different between limbs or between groups (p>0.05) and hop distance symmetry was not different between groups (p>0.05). During loading, the involved limb demonstrated lesser knee flexion angles (p=0.030) and knee power (p=0.007) compared to the uninvolved limb, and lesser knee extension moments compared to the uninvolved limb (p=0.001) and controls (p=0.005). During propulsion, the involved limb demonstrated lesser knee extension moment (p=0.027), knee power (p=0.010), knee (p=0.032) and ankle work (p=0.032), anterior- posterior GRF (p=0.047), and greater knee (p=0.016) abduction excursions compared to the uninvolved limb. CONCLUSIONS: Between-limb differences in SLHD take-off suggest a knee underloading strategy in the involved limb. These results provide further evidence that distance covered during SLHD assessment can overestimate function and fail to identify compensatory biomechanical strategies.

Neurocognitive Errors and Noncontact Anterior Cruciate Ligament Injuries in Professional Male Soccer Players.

CONTEXT: Evidence is emerging that core neurocognitive functions such as working memory and inhibitory control (ie, motor-response and attentional inhibition) are linked to the anterior cruciate ligament (ACL) injury risk. Research has been conducted in laboratory settings, but the contribution of neurocognition to actual ACL injuries under real-world conditions is unknown. OBJECTIVE: To describe the possible neurocognitive errors involved in noncontact ACL injury mechanisms. DESIGN: Case series. SETTING: Soccer matches. PATIENTS OR OTHER PARTICIPANTS: A total of 47 professional male soccer players. MAIN OUTCOME MEASURE(S): Three independent reviewers evaluated 47 videos of players sustaining noncontact ACL injuries. Neurocognitive errors in inhibitory control were operationalized as follows: (1) motor-response inhibition was scored when a player demonstrated poor decision-making and approached the opponent with high speed that reduced the ability to stop or change the intended action and (2) an attentional error was scored when a player shifted his selective attention away from the relevant task to irrelevant stimuli. RESULTS: Of 47 noncontact ACL injuries, 26 (55%) were related to a pressing-type injury, 19 (73%) of which involved a deceiving action made by the opponent, suggesting poor inhibitory control of the defender. Of the remaining 21 noncontact ACL injuries (45%), 16 (76%) could be attributed to attentional errors. Agreement among the 3 raters was very good for all items except poor decision-making, which showed fair to good agreement (Fleiss κ = 0.71). Interrater reliability was excellent (intraclass correlation coefficient = 0.99-1.00). CONCLUSIONS: Errors in motor-response inhibitory control and attentional inhibition were common during noncontact ACL injury events in professional male soccer players. The interrater agreement in detecting neurocognitive errors in general was very good.

Relationships Between Task Constraints, Visual Constraints, Joint Coordination and Football-Specific Performance in Talented Youth Athletes: An Ecological Dynamics Approach.

Individual performance in team sports is a multifactorial reflection of how well a player can cope and accomplish tasks in varied playing situations. Thus, performance analysis should not only focus on outcomes, but also on underlying mechanisms of those outcomes. We adopted principles of the ecological dynamics approach (EDA) to investigate the effect of introducing constraints on players' joint coordination responses for a football-specific performance drill outcome. Seventeen talented youth football (soccer) players performed a football-specific drill under different conditions: basic constraints, additional defender dummies, stroboscopic glasses, and a combination of the latter two constraints. We recorded these players' execution time, passing accuracy, and lower extremity joint kinematics. We calculated joint coordination for hip-knee, knee-ankle, and trunk-hip couplings. The added constraints negatively affected execution time and passing accuracy, and caused changes in joint coordination. Furthermore, we identified a relationship between execution time and joint coordination. This study serves as an example how the EDA can be adopted to investigate mechanisms that underlie individual performance in team sports.

Optimising the Early-Stage Rehabilitation Process Post-ACL Reconstruction.

Outcomes following anterior cruciate ligament reconstruction (ACLR) need improving, with poor return-to-sport rates and a high risk of secondary re-injury. There is a need to improve rehabilitation strategies post-ACLR, if we can support enhanced patient outcomes. This paper discusses how to optimise the early-stage rehabilitation process post-ACLR. Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally. We highlight six main dimensions during the early stage: (1) pain and swelling; (2) knee joint range of motion; (3) arthrogenic muscle inhibition and muscle strength; (4) movement quality/neuromuscular control during activities of daily living (5) psycho-social-cultural and environmental factors and (6) physical fitness preservation. The six do not share equal importance and the extent of time commitment devoted to each will depend on the individual patient. The paper provides recommendations on how to implement these into practice, discussing training planning and programming, and suggests specific screening to monitor work and when the athlete can progress to the next stage (e.g. mid-stage rehabilitation entry criteria).

Concurrent validation of the Xsens IMU system of lower-body kinematics in jump-landing and change-of-direction tasks.

Inertial measurement units (IMUs) allow for measurements of kinematic movements outside the laboratory, persevering the athlete-environment relationship. To use IMUs in a sport-specific setting, it is necessary to validate sport-specific movements. The aim of this study was to assess the concurrent validity of the Xsens IMU system by comparing it to the Vicon optoelectronic motion system for lower-limb joint angle measurements during jump-landing and change-of-direction tasks. Ten recreational athletes performed four tasks; single-leg hop and landing, running double-leg vertical jump landing, single-leg deceleration and push off, and sidestep cut, while kinematics were recorded by 17 IMUs (Xsens Technologies B.V.) and eight motion capture cameras (Vicon Motion Systems, Ltd). Validity of lower-body joint kinematics was assessed using measures of agreement (cross-correlation: XCORR) and error (root mean square deviation and amplitude difference). Excellent agreement was found in the sagittal plane for all joints and tasks (XCORR > 0.92). Highly variable agreement was found for knee and ankle in transverse and frontal plane. Relatively high error rates were found in all joints. In conclusion, this study shows that the Xsens IMU system provides highly comparable waveforms of sagittal lower-body joint kinematics in sport-specific movements. Caution is advised interpreting frontal and transverse plane kinematics as between-system agreement highly varied.

Comparing the Effects of Differential and Visuo-Motor Training on Functional Performance, Biomechanical, and Psychological Factors in Athletes after ACL Reconstruction: A Randomized Controlled Trial.

Variation during practice is widely accepted to be advantageous for motor learning and is, therefore, a valuable strategy to effectively reduce high-risk landing mechanics and prevent primary anterior cruciate ligament (ACL) injury. Few attempts have examined the specific effects of variable training in athletes who have undergone ACL reconstruction. Thereby, it is still unclear to what extent the variations in different sensor areas lead to different effects. Accordingly, we compared the effects of versatile movement variations (DL) with variations of movements with emphasis on disrupting visual information (VMT) in athletes who had undergone ACL reconstruction. Forty-five interceptive sports athletes after ACL reconstruction were randomly allocated to a DL group (n = 15), VT group (n = 15), or control group (n = 15). The primary outcome was functional performance (Triple Hop Test). The secondary outcomes included dynamic balance (Star Excursion Balance Test (SEBT)), biomechanics during single-leg drop-landing task hip flexion (HF), knee flexion (KF), ankle dorsiflexion (AD), knee valgus (KV), and vertical ground reaction force (VGRF), and kinesiophobia (Tampa Scale of Kinesiophobia (TSK)) assessed before and after the 8 weeks of interventions. Data were analyzed by means of 3 × 2 repeated measures ANOVA followed by post hoc comparison (Bonferroni) at the significance level of p ≤ 0.05. Significant group × time interaction effects, main effect of time, and main effect of group were found for the triple hop test and all eight directions, SEBT, HF, KF, AD, KV, VGRF, and TSK. There was no significant main effect of group in the HF and triple hop test. Additionally, significant differences in the triple hop test and the seven directions of SEBT, HF, KF, KV, VGRF, and TSK were found between the control group and the DL and VMT groups. Between group differences in AD and the medial direction of SEBT were not significant. Additionally, there were no significant differences between VMT and the control group in the triple hop test and HF variables. Both motor learning (DL and VMT) programs improved outcomes in patients after ACL reconstruction. The findings suggest that DL and VMT training programs lead to comparable improvements in rehabilitation.

Definition of High-Risk Motion Patterns for Female ACL Injury Based on Football-Specific Field Data: A Wearable Sensors Plus Data Mining Approach.

The aim of the present study was to investigate if the presence of anterior cruciate ligament (ACL) injury risk factors depicted in the laboratory would reflect at-risk patterns in football-specific field data. Twenty-four female footballers (14.9 ± 0.9 year) performed unanticipated cutting maneuvers in a laboratory setting and on the football pitch during football-specific exercises (F-EX) and games (F-GAME). Knee joint moments were collected in the laboratory and grouped using hierarchical agglomerative clustering. The clusters were used to investigate the kinematics collected on field through wearable sensors. Three clusters emerged: Cluster 1 presented the lowest knee moments; Cluster 2 presented high knee extension but low knee abduction and rotation moments; Cluster 3 presented the highest knee abduction, extension, and external rotation moments. In F-EX, greater knee abduction angles were found in Cluster 2 and 3 compared to Cluster 1 (p = 0.007). Cluster 2 showed the lowest knee and hip flexion angles (p < 0.013). Cluster 3 showed the greatest hip external rotation angles (p = 0.006). In F-GAME, Cluster 3 presented the greatest knee external rotation and lowest knee flexion angles (p = 0.003). Clinically relevant differences towards ACL injury identified in the laboratory reflected at-risk patterns only in part when cutting on the field: in the field, low-risk players exhibited similar kinematic patterns as the high-risk players. Therefore, in-lab injury risk screening may lack ecological validity.

Reconsideration of Return-to-Sport Decision-Making After Pediatric ACL Injury: A Scoping Review.

CONTEXT: Up to 90% of pediatric athletes return to sport (RTS) after anterior cruciate ligament reconstruction (ACL-R); however, <50% RTS at the same level and second ACL injury rates are up to 32%. OBJECTIVES: (1) Determine which physical and patient-reported outcome measures guide clinical decision-making on RTS in pediatric athletes after ACL-R and (2) present a framework with insights from cognitive and neurophysiological domains to enhance rehabilitation outcomes. DATA SOURCES: PubMed, CINAHL, Embrase, and Cochrane library databases and gray literature. STUDY SELECTION: Data on pediatric (<18 years) ACL-R patients, RTS, tests, and decision-making were reported in 1214 studies. Two authors independently reviewed titles and abstract, excluding 962 studies. Gray literature and cross-reference checking resulted in 7 extra studies for full-text screening of 259 studies. Final data extraction was from 63 eligible studies. STUDY DESIGN: Scoping review. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Details on study population, aims, methodology, intervention, outcome measures, and important results were collected in a data chart. RESULTS: Studies included 4456 patients (mean age, 14 years). Quadriceps and hamstring strength (n = 25), knee ligament arthrometer (n = 24), and hop tests (n = 22) were the most-reported physical outcome measures guiding RTS in <30% of studies with cutoff scores of limb symmetry index (LSI) ≥85% or arthrometer difference <3 mm. There were 19 different patient-reported outcome measures, most often reporting the International Knee Documentation Committee (IKDC) (n = 24), Lysholm (n = 23), and Tegner (n = 15) scales. Only for the IKDC was a cutoff value of 85% reported. CONCLUSION: RTS clearance in pediatric ACL-R patients is not based on clear criteria. If RTS tests were performed, outcomes did not influence time of RTS. Postoperative LSI thresholds likely overestimate knee function since biomechanics are impaired despite achieving RTS criteria. RTS should be considered a continuum, and biomechanical parameters and contextual rehab should be pursued with attention to the individual, task, and environment. There is a need for psychological monitoring of the ACL-R pediatric population.

Comparing lab and field agility kinematics in young talented female football players: Implications for ACL injury prevention.

Modifiable (biomechanical and neuromuscular) anterior cruciate ligament (ACL) injury risk factors have been identified in laboratory settings. These risk factors were subsequently used in ACL injury prevention measures. Due to the lack of ecological validity, the use of on-field data in the ACL injury risk screening is increasingly advocated. Though, the kinematic differences between laboratory and on-field settings have never been investigated. The aim of the present study was to investigate the lower-limb kinematics of female footballers during agility movements performed both in laboratory and football field environments. Twenty-eight healthy young female talented football (soccer) players (14.9 ± 0.9 years) participated. Lower-limb joint kinematics was collected through wearable inertial sensors (Xsens Link) in three conditions: (1) laboratory setting during unanticipated sidestep cutting at 40-50°; on the football pitch (2) football-specific exercises (F-EX) and (3) football games (F-GAME). A hierarchical two-level random effect model in Statistical Parametric Mapping was used to compare joint kinematics among the conditions. Waveform consistency was investigated through Pearson's correlation coefficient and standardized z-score vector. In-lab kinematics differed from the on-field ones, while the latter were similar in overall shape and peaks. Lower sagittal plane range of motion, greater ankle eversion, and pelvic rotation were found for on-field kinematics (p < 0.044). The largest differences were found during landing and weight acceptance. The biomechanical differences between lab and field settings suggest the application of context-related adaptations in female footballers and have implications in ACL injury prevention strategies.HighlightsTalented youth female football players showed kinematical differences between the lab condition and the on-field ones, thus adopting a context-related motor strategy.Lower sagittal plane range of motion, greater ankle eversion, and pelvic rotation were found on the field. Such differences pertain to the ACL injury mechanism and prevention strategies.Preventative training should support the adoption of non-linear motor learning to stimulate greater self-organization and adaptability.It is recommended to test football players in an ecological environment to improve subsequent primary ACL injury prevention programmes.

Concurrent validation of the Noraxon MyoMotion wearable inertial sensors in change-of-direction and jump-landing tasks.

Wearable inertial sensors (WIS) facilitate the preservation of the athlete-environment relationship by allowing measurement outside the laboratory. WIS systems should be validated for team sports movements before they are used in sports performance and injury prevention research. The aim of the present study was to investigate the concurrent validity of a wearable inertial sensor system in quantifying joint kinematics during team sport movements. Ten recreationally active participants performed change-of-direction (single-leg deceleration and sidestep cut) and jump-landing (single-leg hop, single-leg crossover hop, and double-leg vertical jump) tasks while motion was recorded by nine inertial sensors (Noraxon MyoMotion, Noraxon USA Inc.) and eight motion capture cameras (Vicon Motion Systems Ltd). Validity of lower-extremity joint kinematics was assessed using measures of agreement (cross-correlation: XCORR) and error (root mean square deviation; and amplitude difference). Excellent agreement (XCORR >0.88) was found for sagittal plane kinematics in all joints and tasks. Highly variable agreement was found for frontal and transverse plane kinematics at the hip and ankle. Errors were relatively high in all planes. In conclusion, the WIS system provides valid estimates of sagittal plane joint kinematics in team sport movements. However, researchers should correct for offsets when comparing absolute joint angles between systems.

Return to sports after ACL injury 5 years from now: 10 things we must do.

BACKGROUND: The outcome after ACL reconstruction (ACLR) is in general disappointing with unacceptable number of athletes that do not return to pre-injury level of sports, high re-injury rates, early development of osteoarthritis and shorter careers. Athletes after ACLR have high expectation to return to sports which is in contrast with the current outcomes. The aim of this manuscript is to present an overview of factors that are needed to be incorporated and to personalize the rehabilitation process for an athlete who has undergone an ACLR.

Increased Cognitive Demands Affect Agility Performance in Female Athletes - Implications for Testing and Training of Agility in Team Ball Sports.

Agility, a key component of team ball sports, describes an athlete´s ability to move fast in response to changing environments. While agility requires basic cognitive functions like processing speed, it also requires more complex cognitive processes like working memory and inhibition. Yet, most agility tests restrict an assessment of cognitive processes to simple reactive times that lack ecological validity. Our aim in this study was to assess agility performance by means of total time on two agility tests with matched motor demands but with both low and high cognitive demands. We tested 22 female team athletes on SpeedCourt, using a simple agility test (SAT) that measured only processing speed and a complex agility test (CAT) that required working memory and inhibition. We found excellent to good reliability for both our SAT (ICC = .79) and CAT (ICC =.70). Lower agility performance on the CAT was associated with increased agility total time and split times (p < .05). These results demonstrated that agility performance depends on the complexity of cognitive demands. There may be interference-effects between motor and cognitive performances, reducing speed when environmental information becomes more complex. Future studies should consider agility training models that implement complex cognitive stimuli to challenge athletes according to competitive demands. This will also allow scientists and practitioners to tailor tests to talent identification, performance development and injury rehabilitation.

Have We Forgotten Our Patient? An Exploration of Patient Experiences After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Limited information is available on the experiences of patients during rehabilitation after anterior cruciate ligament reconstruction (ACLR). AIM: The current study aimed to identify factors that differentiated positive and negative patient experiences during rehabilitation after ACLR. METHOD AND DESIGN: A survey-based study with an online platform was used to identify factors that differentiated positive and negative patient experiences during rehabilitation after ACLR. Seventy-two patients (age 27.8 [8.8] y) after ACLR participated. Data were analyzed and themes were identified by comparing categories and subcategories on similarity. MAIN FINDINGS: Positive patient experiences were room for own input, supervision, attention, knowledge, honesty, and professionalism of the physiotherapist. Additionally, a varied and structured rehabilitation program, adequate facilities, and contact with other patients were identified as positive patient experiences. Negative experiences were a lack of attention, lack of professionalism of the physiotherapists, a lack of sport-specific field training, a lack of goal setting, a lack of adequate facilities, and health insurance costs. CONCLUSIONS: The current study identified factors that differentiated positive and negative patient experiences during rehabilitation after ACLR. These findings can help physiotherapists in understanding the patient experiences during rehabilitation after ACLR.

Rehabilitation and Return to Sport Testing After Anterior Cruciate Ligament Reconstruction: Where Are We in 2022?

Athletes who sustain an anterior cruciate ligament (ACL) injury often opt for an ACL reconstruction (ACLR) with the goal and expectation to return to sports at the preinjury level. The proportion of athletes who successfully return to preinjury-level sport is low and disappointing, whereas the rate of second ACL injury in athletes under the age of 20 has been reported to be as high as 40% after return to sport (RTS). Although in recent years, new insights pertaining to RTS have been published, the lack of validity of RTS criteria after ACLR remain. The purpose of this clinical commentary is to present a critical overview of the current literature on RTS testing after ACLR.

High Incidence of Anterior Cruciate Ligament Injuries Within the First 2 Months of the Season in Amateur Team Ball Sports.

BACKGROUND: The incidence of anterior cruciate ligament (ACL) injuries is commonly reported as an annual incidence rate. There is relatively little information about the seasonal aspects of these injuries. The aim of the current study was to analyze the distribution of ACL injuries during the season in nonprofessional soccer, handball, and basketball based on a retrospective analysis of a hospital-based registry. HYPOTHESIS: ACL injuries in soccer, handball, and basketball were more common within the first 2 months of the season in comparison with the rest of the year. STUDY DESIGN: Case series. LEVEL OF EVIDENCE: Level 4. METHODS: Injury occurrence during the calendar year was divided into 6 periods of 2 months, with segment 1 (S1) representing the first 2 months of the season. For soccer, S1 corresponded to September and October. The season started 1 month later for handball and basketball, so S1 represented October and November. Chi-square tests were used to analyze the distribution of ACL injuries among segments according to gender, age, sports, and injury mechanism (contact/noncontact). RESULTS: A total of 371 ACL injuries were included (soccer, 258, handball, 56, basketball, 57). Overall, the distribution of ACL injuries was not uniform across the segments (P < 0.01). Almost one-third of the ACL injuries occurred in S1 (n = 104; 28%). Significant differences could be observed according to sports (P < 0.01). There were fewer ACL injuries in S2 for soccer compared with basketball (P < 0.05). In S5, there were significantly more ACL injuries in soccer compared with handball and basketball (P < 0.05). CONCLUSION: A high occurrence of ACL injuries was reported immediately within the first 2 months of the season in nonprofessional soccer, handball, and basketball sports. CLINICAL RELEVANCE: These findings indicate that ACL injury prevention programs should be started in the preseason period to allow for gradual increases of load.

Reintroduction of Running After Anterior Cruciate Ligament Reconstruction With a Hamstrings Graft: Can We Predict Short-Term Success?

CONTEXT: Return to running (RTR) after anterior cruciate ligament reconstruction (ACLR) is a crucial milestone. However, how and when to start a running program are uncertain. OBJECTIVE: To explore the feasibility of a structured program to reintroduce running after ACLR and evaluate the predictive value of potential predictors of short-term success. DESIGN: Longitudinal cohort study. SETTING: Local research center and participants' homes. PATIENTS OR OTHER PARTICIPANTS: Thirty-five participants were recruited after ACLR. INTERVENTION(S): Program with a progression algorithm to reintroduce running (10 running sessions in 14 days). MAIN OUTCOME MEASURE(S): The criterion for short-term success was no exacerbation of symptoms. Potential predictors were (1) the International Knee Documentation Committee (IKDC) subjective knee form score, (2) ACL Return to Sport after Injury questionnaire score, (3) quadriceps and hamstrings strength, (4) step-down endurance test, and (5) modified Star Excursion Balance test. Descriptive statistics were performed to study the feasibility of the RTR program, and Poisson regression analysis was used to evaluate predictors of success. RESULTS: Of the 34 participants, 33 completed the RTR program. Sixteen participants experienced some temporary exacerbation of symptoms, but only 1 had to stop the program. The initial IKDC score was the only significant predictor of a successful RTR, with an area under the receiver operating characteristic curve of 80.4%. An IKDC cut-off of 63.7/100 differentiated responders and nonresponders with the highest sensitivity and specificity (77.8% and 75.0%, respectively). A participant with an IKDC score above this threshold had a 3-fold greater chance of success. CONCLUSIONS: Our results confirm the feasibility of our RTR program and progression algorithm after ACLR. Clinicians should use an IKDC score of >64 as a criterion to reintroduce running after ACLR to increase the likelihood of short-term success.

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. LEVEL OF EVIDENCE: Level 3. 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.

The modifying factors that help improve anterior cruciate ligament reconstruction rehabilitation: A narrative review.

BACKGROUND: The goal of a rehabilitation programme after anterior cruciate ligament (ACL) reconstruction is to manage a patient's goals and expectations (i.e., returning to physical activities and sports) while minimizing the risk of new injury, particularly a new ACL injury. Although general rehabilitation programmes have been proposed, some factors can lead to adapting each programme to each patient. OBJECTIVE: To describe how different variables, including surgical techniques, sports participation, psycho-social and contextual factors can modify the rehabilitation programme. METHODS: We performed a narrative review with input from experts in the field (level of evidence 5). CONCLUSIONS: Modifying factors of the ACL rehabilitation programme are related to the initial lesion or surgery, to sports, or to psychological or social aspects. Regarding the type of graft, the rehabilitation is mainly different in the early postoperative phase; the other phases are not graft-based but rather goal-based rehabilitation. Depending on the meniscal or cartilage repair, the rehabilitation protocol will initially take priority over the anterior cruciate ligament reconstruction protocol. The ACL reconstruction rehabilitation programme should meet the requirements of the anticipated sports, to optimize the athlete's ability to return to the expected level and minimize the risk of reinjury. Psycho-social and contextual factors must also be considered in rehabilitation care to individualize and optimize each patient's programme.