A novel approach to enhance ACL injury prevention programs

The Effect of Neurocognitive Training on Biomechanical Risk Factors Related to Anterior Cruciate Ligament Injury in Athletes: A Narrative Review

CONTEXT

The best current evidence supports the effectiveness of neuromuscular training in reducing the risk of injury; however, the rate of anterior cruciate ligament (ACL) injuries is still high. Neurocognitive training (NT) has successfully improved biomechanical risk factors, but they have been considered in only a few studies.

OBJECTIVE

To review the literature to determine the effect of NT on biomechanical risk factors related to ACL injury in athletes.

EVIDENCE ACQUISITION

We searched PubMed, Google Scholar, Scopus, Science Direct, and the Physiotherapy Evidence Database from inception to August 2011. We included randomized controlled trials that used motor learning approaches and injury prevention programs to investigate kinematic and kinetic risk factors related to ACL injury. The quality of each clinical trial study was evaluated by the Physiotherapy Evidence Database scale. The eligibility criteria were checked based on the PICOS (population, intervention, comparison, outcome, and study type) framework.

EVIDENCE SYNTHESIS

A total of 9 studies were included in the final analysis. Motor learning approaches include internal and external focus of attention, dual tasks, visual motor training, self-control feedback, differential learning, and linear and nonlinear pedagogy, combined with exercise programs. In most of the studies that used NT, a significant decrease in knee valgus; tibial abduction and external rotation; ground reaction force; and an increase in knee-, trunk-, hip-, and knee-flexion moment was observed.

CONCLUSION

In classical NT, deviation from the ideal movement pattern especially emphasizing variability and self-discovery processes is functional in injury prevention and may mitigate biomechanical risk factors of ACL injuries in athletes. Practitioners are advised to use sport-specific cognitive tasks in combination with neuromuscular training to simulate loads of the competitive environment. This may improve ACL injury risk reduction and rehabilitation programs.

Lived experiences of physical therapists treating traumatic knee injury using integrated psychological training (MOTIFS): a qualitative interview study

BACKGROUND

The novel Motor Imagery to Facilitate Sensorimotor Re-Learning (MOTIFS) training model, which began development in 2018, integrates psychological training into physical rehabilitation in knee-injured people.

OBJECTIVE

This qualitative interview study aims to understand, interpret, and describe how physical therapists perceive using the MOTIFS Model.

METHODS

One-on-one semi-structured interviews were conducted with six physical therapists familiar with the MOTIFS model and eight with experience with care-as-usual training only, analyzed using Interpretive Phenomenological Analysis.

RESULTS

Two major themes were generated in the MOTIFS group: 1) "MOTIFS increases psychological focus during rehabilitation training"; and 2) "Care-as-Usual training is mainly physical, and lacks the necessary psychological focus." Physical therapists perceived structured methods of addressing psychological factors, such as using imagery to influence patients' motivation, fear, and preparation for return to activity. Three major themes were generated in the Care-as-Usual group: 1) "Rehabilitation is mainly to restore physical function"; 2) "Rehabilitation training includes a biopsychosocial interaction"; and 3) "Psychological factors are important to address, but strategies are lacking."

CONCLUSION

Physical therapists perceive MOTIFS as a method of consciously shifting perspective toward an increased focus on psychological factors in knee-injury rehabilitation. Results indicate that a training model with integrated psychological strategies to create more holistic rehabilitation may be beneficial.

How to optimise the fidelity of exercises in an unsupervised golf injury prevention programme? A pilot study

Background

Golf is an individual sport that is usually done without the supervision of a trainer or coach. Therefore, an injury prevention programme in golf will primarily be performed without supervision and feedback. However, the effectiveness of any preventive exercise programme is determined by exercise fidelity.

Objective

To investigate the different instruction options of an injury prevention programme on exercise fidelity in individual golfers.

Methods

We randomly assigned golfers to one of three groups receiving different exercise instructions. One group received only instructional cards (A), one received only instructional videos (B) and a third group (C) received both instructional cards and videos. The golfers were allowed to familiarise themselves with the exercises based on the provided instruction option, after which we recorded their exercise execution on video. Two authors independently scored each exercise's fidelity from these recordings.

Results

In total, 18 golfers (12 women and 6 men, average age of 61.94 years) were equally divided across the 3 study groups completed 108 exercises. In group A 73.7% of exercises were executed as intended, in group B 88.6% and in group C 86.3%. Significantly more exercises were conducted correctly in groups B and C compared with group A (p<0.05).

Conclusion

Golfers who received instructions that included a video explanation had a higher exercise fidelity when compared to only written instructions.

Using a target as external focus of attention results in a better jump-landing technique in patients after anterior cruciate ligament reconstruction - A cross-over study

BACKGROUND

Improving jump-landing technique during rehabilitation is important and may be achieved through different feedback techniques, i.e., internal focus of attention (IF) or external focus of attention using a target (EF). However, there is a lack of evidence on the most effective feedback technique after anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to investigate the potential difference in jump-landing techniques between IF and EF instructions in patients after ACLR.

METHODS

Thirty patients (12 females, mean age 23.26 ± 4.91 years) participated after ACLR. Patients were randomly assigned into two groups that each followed a different testing sequence. Patients performed a drop vertical jump-landing test after receiving instructions with varying types of focus of attention. The Landing Error Scoring System (LESS) assessed the jump-landing technique.

RESULTS

EF was associated with a significantly better LESS score (P < 0.001) compared with IF. Only EF instructions led to improvements in jump-landing technique.

CONCLUSION

Using a target as EF resulted in a significantly better jump-landing technique than IF in patients after ACLR. This indicates that increased use of EF could or might result in a better treatment outcome during ACLR rehabilitation.

Videogestütztes Feedbacktraining als präventives Techniktraining – Eine exploratorische Studie

Hintergrund Im Sport wird angenommen, dass ein dynamischer Knievalgus bei einbeinigen Landungen einen relevanten Verletzungsmechanismus des vorderen Kreuzbands darstellt. Während bestehende effektive Präventionsprogramme zur Reduktion des Knievalgus primär auf die Verbesserung allgemeiner konditioneller und/oder koordinativer Einflussgrößen ausgerichtet sind, fokussiert ein Video-Feedback-Training die Korrektur individueller Defizite in der sportlichen Technik, um u. a. ein potenzielles Verletzungsrisiko zu reduzieren.

Ziel Evaluation der kurz- und insbesondere mittel- und langfristigen Wirksamkeit eines Video-Feedback-Trainings zur Veränderung des frontalen Kniewinkels bei einbeinigen Landungen.

Methode Im Rahmen einer exploratorischen Studie wurden 10 sportlich aktive Personen (Alter: 25 ± 5 Jahre, Größe: 170,8 ± 4,5 cm) getestet. Diese führten in Anlehnung an das Landing Error Scoring System (LESS-Test) einbeinige Drop-Jumps in einem Pretest, in einer Aneignungsphase mit Video-Feedback und 2 Retentionstests 2 und 6 Wochen nach der Aneignungsphase ohne Video-Feedback aus. Das Video-Feedback wurde in der Aneignungsphase bei jedem zweiten Sprung und zusätzlich selbstbestimmt auf Nachfrage über ein Expertenmodell mit neutraler Kniestellung im Overlay-Modus aus der Frontalperspektive gegeben.

Ergebnisse Die Ergebnisse wurden nach Sprung- und Nichtsprungbein der Proband*innen differenziert. Sie zeigen eine bedeutsame Verringerung des frontalen Kniewinkels für das Sprungbein (F1, 9 = 10,43, p = 0,01, η2 p = 0,54, 95 % CI [0,04; 0,74]) bei einbeinigen Landungen in der Aneignungsphase, jedoch keine statistisch bedeutsame Verringerung für das Nichtsprungbein (F1, 9 = 4,07, p = 0,08, η2 p = 0,31, 1-β = 0,44). Im Retentionstest nach 6 Wochen nähert sich der frontale Kniewinkel beidseitig dem Ausgangsniveau aus dem Pretest wieder an.

Schlussfolgerung Ein Video-Feedback-Training bietet sich als einfach durchzuführendes, alternatives Verletzungspräventionsprogramm an. Eine fehlende mittel- und langfristige Veränderung und hohe Variabilität des frontalen Kniewinkels lassen eine mehrfache und/oder regelmäßige Durchführung eines Video-Feedback-Trainings sinnvoll erscheinen. In weiteren Studien mit Kontrollgruppendesign und unterschiedlichen Feedback-Prozeduren wird systematisch zu prüfen sein, ob eine längerfristige Reduktion eines potenziellen Verletzungsrisikos des vorderen Kreuzbands erreicht werden kann.

Effect of combining eight weeks of neuromuscular training with dual cognitive tasks on landing mechanics in futsal players with knee ligament dominance defect: a randomized controlled trial

Background

The performing of jump and landing in futsal simultaneous with divided attention is one of the most common mechanisms of non-contact anterior cruciate ligament (ACL) injury. Neuromuscular training has effectively reduced the risk of ACL injury, but the effect of neurocognitive training has received less attention. This study investigated the effect of combining 8 weeks of neuromuscular training with dual cognitive tasks on the landing mechanics of futsal players with knee ligament dominance defects.

Methods

Thirty male futsal players (mean ± SD: age: 21.86 ± 3.27 years) with knee ligament dominance defects were purposefully identified by the tuck jump test and were randomly divided into the intervention and the control group. The intervention group performed dual task (DT) training for three weekly sessions for 8 weeks and 60 min each, while the control group only did activities of daily living. During the drop vertical jump test, 2D landing kinematics in two moments of initial contact (IC) and full flexion (FF) were assessed. Data were analyzed by means of 2 × 2 repeated measures ANOVA followed by post hoc comparison (Bonferroni) at the significance level of (α ≤ 0.05).

Results

A significant improvement was observed in the intervention group compared to the control group for the dynamic knee valgus at IC (F1,28 = 6.33; P = 0.02, ES = 0.31) and FF (F1,28 = 13.47; P = 0.003, ES = 0.49), knee flexion at IC (F1,28 = 20.08; P = 0.001, ES = 0.41) and FF (F1,28 = 13.67; P = 0.001, ES = 0.32), ankle dorsiflexion at IC (F1,28 = 37.17; P = 0.001, ES = 0.72) and FF (F1,28 = 14.52; P = 0.002, ES = 0.50), and trunk flexion at FF (F1,28 = 20.48; P = 0.001, ES = 0.59) angles. Changes in the trunk flexion at IC (F1,28 = 0.54; P = 0.47, ES = 0.03) and trunk lateral flexion at IC (F1,28 = 0.006; P = 0.93, ES = 0.00) and FF (F1,28 = 2.44; P = 0.141, ES = 0.148) angles were not statistically significant.

Conclusions

DT training compared to the control group improved landing mechanics in futsal players with knee ligament dominance defects.

Trial registration: Current Controlled Trials using the IRCT website with ID number IRCT20210602051477N1 prospectively registered on 20/06/2021.

Do ACL Injury Risk Reduction Exercises Reflect Common Injury Mechanisms? A Scoping Review of Injury Prevention Programs

CONTEXT

Anterior cruciate ligament (ACL) injury risk reduction programs have become increasingly popular. As ACL injuries continue to reflect high incidence rates, the continued optimization of current risk reduction programs, and the exercises contained within them, is warranted. The exercises must evolve to align with new etiology data, but there is concern that the exercises do not fully reflect the complexity of ACL injury mechanisms. It was outside the scope of this review to address each possible inciting event, rather the effort was directed at the elements more closely associated with the end point of movement during the injury mechanism.

OBJECTIVE

To examine if exercises designed to reduce the risk of ACL injury reflect key injury mechanisms: multiplanar movement, single limb stance, trunk and hip dissociative control, and a flight phase.

DATA SOURCES

A systematic search was performed using PubMed, Medline, EBSCO (CINAHL), SPORTSDiscus, and PEDro databases.

STUDY SELECTION

Eligibility criteria were as follows: (1) randomized controlled trials or prospective cohort studies, (2) male and/or female participants of any age, (3) exercises were targeted interventions to prevent ACL/knee injuries, and (4) individual exercises were listed and adequately detailed and excluded if program was unable to be replicated clinically.

STUDY DESIGN

Scoping review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

A total of 35 studies were included, and 1019 exercises were extracted for analysis.

RESULTS

The average Consensus on Exercise Reporting Template score was 11 (range, 0-14). The majority of exercises involved bilateral weightbearing (n = 418 of 1019; 41.0%), followed by single limb (n = 345 of 1019; 33.9%) and nonweightbearing (n = 256 of 1019; 25.1%). Only 20% of exercises incorporated more than 1 plane of movement, and the majority of exercises had sagittal plane dominance. Although 50% of exercises incorporated a flight phase, only half of these also involved single-leg weightbearing. Just 16% of exercises incorporated trunk and hip dissociation, and these were rarely combined with other key exercise elements. Only 13% of exercises challenged more than 2 key elements, and only 1% incorporated all 4 elements (multiplanar movements, single limb stance, trunk and hip dissociation, flight phase) simultaneously.

CONCLUSION

Many risk reduction exercises do not reflect the task-specific elements identified within ACL injury mechanisms. Addressing the underrepresentation of key elements (eg, trunk and hip dissociation, multiplanar movements) may optimize risk reduction in future trials.

Altered trunk and lower extremity movement coordination after neuromuscular training with and without external focus instruction: a randomized controlled trial

Background

This study sought to determine the effects of a 6-week neuromuscular training (NMT) and NMT plus external focus (NMT plus EF) programs on trunk and lower extremity inter-segmental movement coordination in active individuals at risk of injury.

Methods

Forty-six active male athletes (controls = 15, NMT = 16, NMT plus EF = 15) participated (age = 23.26 ± 2.31 years) in this controlled, laboratory study. Three-dimensional kinematics were collected during a drop vertical jump (DVJ). A continuous relative phase (CRP) analysis quantified inter-segmental coordination of the: (1) thigh (flexion/extension)—shank (flexion/extension), (2) thigh (abduction/adduction)—shank (flexion/extension), (3) thigh (abduction/adduction)—trunk (flexion/extension), and (4) trunk (flexion/extension)—pelvis (posterior tilt/anterior tilt). Analysis of covariance compared biomechanical data between groups.

Results

After 6 weeks, inter-segmental coordination patterns were significantly different between the NMT and NMT plus EF groups (p < 0.05). No significant differences were observed in CRP for trunk-pelvis coupling comparing between NMT and NMT plus EF groups (p = 0.134), while significant differences were observed CRP angle of the thigh-shank, thigh-trunk couplings (p < 0.05).

Conclusions

Trunk and lower extremity movement coordination were more in-phase during DVJ in the NMT plus EF compared to NMT in active individuals at risk of anterior cruciate ligament injury.

Trial registration: The protocol was prospectively registered at UMIN_RCT website with ID number: UMIN000035050, Date of provisional registration 2018/11/27.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-021-00326-9.

Integrating neurocognitive challenges into injury prevention training: A clinical commentary

Despite the efforts of many traditional lower extremity injury prevention programs (IPP), the incidence of anterior cruciate ligament injuries in young athletes continues to rise. Current best practices for IPPs include training lower extremity neuromuscular control and movement quality during cutting, jumping, and pivoting. Emerging evidence indicates neurocognition may contribute to injury incidence and injury risk biomechanics. Therefore, IPP outcomes may improve if clinicians also consider neurocognitive contributions to neuromuscular control and athletic performance. A substantial barrier to neurocognitive challenge integration during injury prevention training in the group setting is the lack of structured neuromuscular and neurocognitive progressions. Therefore, our aim is to provide clinicians with a defined framework and recommendations from clinical experience for how to implement neurocognitive challenges within group IPPs that requires minimal extra time and resources. This clinical commentary proposes a three-phase model adopted from motor learning literature to simultaneously progress neuromuscular and neurocognitive challenges through a structured IPP.

Visual Perturbation to Enhance Return to Sport Rehabilitation after Anterior Cruciate Ligament Injury: A Clinical Commentary

Anterior cruciate ligament (ACL) tears are common traumatic knee injuries causing joint instability, quadriceps muscle weakness and impaired motor coordination. The neuromuscular consequences of injury are not limited to the joint and surrounding musculature, but may modulate central nervous system reorganization. Neuroimaging data suggest patients with ACL injuries may require greater levels of visual-motor and neurocognitive processing activity to sustain lower limb control relative to healthy matched counterparts. Therapy currently fails to adequately address these nuanced consequences of ACL injury, which likely contributes to impaired neuromuscular control when visually or cognitively challenged and high rates of re-injury. This gap in rehabilitation may be filled by visual perturbation training, which may reweight sensory neural processing toward proprioception and reduce the dependency on vision to perform lower extremity motor tasks and/or increase visuomotor processing efficiency. This clinical commentary details a novel approach to supplement the current standard of care for ACL injury by incorporating stroboscopic glasses with key motor learning principles customized to target visual and cognitive dependence for motor control after ACL injury.

LEVEL OF EVIDENCE

5.

Effect of Foot-Planting Strategy on Anterior Cruciate Ligament Loading in Women During a Direction Diversion Maneuver: A Musculoskeletal Modeling Approach

Background

Although there is a higher prevalence of noncontact anterior cruciate ligament (ACL) injuries during a direction diversion maneuver (DDM), no previous studies have reported how foot-planting strategies affect ACL loading.

Purpose

To investigate the effect of foot-planting strategies on ACL loading in women during a DDM task using a musculoskeletal modeling approach.

Study Design

Descriptive laboratory study.

Methods

A total of 13 female participants performed a DDM task, which involved running at 4.5 ± 0.2 m/s and turning left at 35° to 55° under a foot-planting strategy in 3 directions: neutral, toe-in, and toe-out. Kinematic and kinetic data were measured with the use of a 3-dimensional motion capture system and force platform to calculate variables such as joint angle, shear force, and moment. Anterior ACL and posterior ACL forces were extracted using musculoskeletal modeling.

Results

The peak anterior ACL force was significantly larger for the toe-out condition (31.29 ± 4.02 N/body weight [BW]) compared with the toe-in condition (25.43 ± 5.68 N/BW) (P = .047), with no significant difference in the neutral condition. The toe-out condition had a higher knee valgus angle (2.98° ± 4.20°; P = .041), knee shear force (10.20 ± 1.69 N/BW; P = .009), and knee internal rotation moment (-0.18 ± 0.16 N·m/BW×height; P = .012) than the toe-in and neutral conditions.

Conclusion

Through musculoskeletal modeling, we were able to conclude that the toe-out condition during the DDM might result in a higher risk of ACL injuries. Athletes and sports practitioners should avoid the toe-out foot-planting strategy when participating in a sporting activity.

Clinical Relevance

Based on these findings, medical professionals and athletic coaches can gain knowledge on how foot-planting strategy affects ACL loading. Understanding the actual cause of an ACL injury can be useful for designing preventive training programs or strategies to decrease the risk of such injuries.

External Focus in Long Jump Performance: A Systematic Review

External focus is a way to guide human movement based on outcome rather than execution, therefore all instructions are provided based on factors present in the environment. The aim of this review is to search information about the effects of external focus in the long jump task and to compare its outcomes with other learning methods. For the research, online database search engines such as PubMed, ScienceDirect, Embase, Cinahl, and Scopus were used from January 2010 to June 2020. About 41 articles were identified by searching the online databases, 12 were discarded because they were duplicates, 11 were excluded due to the content of the abstract, and finally, 5 were excluded after evaluating the content of the full text, leaving 13 articles to be included in this review. This review sought to summarize the findings in the literature on the use of external focus in the practice of long jump. The authors concluded that the external focus is a relevant approach and can be used as a tool for the learning process.

Biomechanical asymmetries persist after ACL reconstruction: results of a 2-year study

PURPOSE

This study was aimed to examine longitudinal (6, 12, 18, 24 months) asymmetries in double-leg landing kinetics and kinematics of subjects with and without unilateral ACLR.

METHODS

Three-dimensional kinematic and kinetic parameters of 40 participants (n = 20 post-ACLR, n = 20 healthy) were collected with a motion analysis system and force plate during a drop-landing task, and asymmetry indices were compared between groups.

RESULTS

The asymmetry index (AI) in the ACLR group compared to the healthy group decreased from six to 24 months for vertical ground reaction force (vGRF) from 100% to 6.5% and for anterior posterior ground reaction force (a-pGRF) from 155.5% to 7%. Also, the AI decreased for peak hip flexion moment from 74.5% to 17.1%, peak knee flexion moment from 79.0% to 5.8% and peak ankle dorsiflexion moment from 59.3% to 5.9%. As a further matter, the AI decreased for peak hip abduction moment from 67.8% to 5.1%, peak knee adduction moment from 55.7% to 14.8% and peak knee valgus angle from 48.7% to 23.5%.

CONCLUSIONS

Results obtained from this longitudinal study showed that ACLR patients still suffer from limb asymmetries during landing tasks, which appear to normalize by 24-monthspost-surgery. This finding can help us to better understand biomechanics of the limbs after ACLR, and design more efficient post-surgery rehabilitation programs.

LEVEL OF EVIDENCE

Level III.

The Effects of Instruction Exercises on Performance and Kinetic Factors Associated With Lower-Extremity Injury in Landing After Volleyball Blocks

CONTEXT

Female volleyball players are more predisposed to anterior cruciate ligament injury in comparison with their male counterparts. Recent research on anterior cruciate ligament injury prevention strategies has shown the positive results of adopting the external focus (EF) of attention in sports.

OBJECTIVE

To determine the effect of 6-week EF instruction exercises on performance and kinetic factors associated with lower-extremity injury in landing after the volleyball blocks of female athletes.

DESIGN

Pretest and posttest control study.

SETTING

University research laboratory.

PARTICIPANTS

Thirty-two female volleyball players (18-24 y old) from the same team randomly divided into experimental (n = 16) and control (n = 16) groups.

INTERVENTION

The experimental group performed a 6-week exercise program with EF instructions. The control group continued its regular volleyball team schedule.

MAIN OUTCOME MEASURES

To assess function, single-leg triple hop test for distance was used. A force plate was used to evaluate kinetic variables including vertical ground reaction forces, the rate of loading, and dynamic postural stability index. All data were assessed at baseline and after the intervention.

RESULTS

There was a significant increase in single-leg triple hop test (P < .05) and in the first and second peak ground reaction force, rate of loadings, dynamic postural stability index (P < .05).

CONCLUSION

According to the results of this study, anterior cruciate ligament injury prevention programs should incorporate EF instruction exercises to enhance the kinetics and to increase athletes' functional performance.