History Of Anterior Cruciate Ligament Reconstruction Research Articles

From Control to Chaos: Visual-Cognitive Progression During Recovery from ACL Reconstruction.

BACKGROUND: Anterior cruciate ligament tear is a serious knee injury with implications for central nervous system (CNS) plasticity. To perform simple knee movements, people with a history of ACL reconstruction (ACL-R) engage cross-modal brain regions and when challenged with cognitive-motor dual-tasks, physical performance deteriorates. Therefore, people with ACL-R may increase visual-cognitive neural processes for motor control. CLINICAL QUESTION: What components of CNS plasticity should the rehabilitation practitioner target with interventions, and how can practitioners augment rehabilitation exercises to target injury associated plasticity? KEY RESULTS: This clinical commentary (1) describes the neurophysiological foundation for visual-cognitive compensation after ACL-R, (2) provides a theoretical rationale for implementing visual-cognitive challenges throughout the return to sport (RTS) continuum, and (3) presents a framework for implementing visual-cognitive challenges from the acute phases of rehabilitation. The 'Visual-Cognitive Control Chaos Continuum (VC-CCC) framework consists of five training difficulties that progress visual-cognitive challenges from high control to high chaos, to better represent the demands of sport. CLINICAL APPLICATION: The VC-CCC framework augments traditional rehabilitation so that each exercise can progress to increase difficulty and promote sensorimotor and visual-cognitive adaptation after ACL-R.

Effects of clamshell exercises in terminal extension lag after ACL reconstruction

BackgroundTerminal extension lag (TEL) is common following anterior cruciate ligament reconstruction (ACLR). Clamshell exercises have been suggested as a potential intervention to address TEL, but limited research has been conducted in this area. ObjectiveThis study aimed to determine the effects of Clamshell exercises in terminal extension lag after anterior cruciate ligament reconstruction. MethodsThis randomized controlled trial included 40 participants with a history of ACLR between 1 and 3 years prior. Participants were randomly assigned to either the experimental group (Group A) or the control group (Group B). Group A received conventional exercises along with isolated hip strengthening rehabilitation, while Group B received conventional exercises without specific hip strengthening. The primary outcomes were pain levels (Numeric Pain Rating Scale), knee function (International Knee Documentation Committee scores, (IKDC)), range of motions (goniometer) and strength (sphygmomanometer). ResultsIn between the group comparison shows that all outcome measures (NPRS, IKDC, Goniometer, Sphygmomanometer) show significant results (p < 0.05). Within-group comparisons (paired sample t-test) show that there was a significant difference (p < 0.05) in all outcome measures of both groups. ConclusionThe addition of Clamshell exercises to the rehabilitation program resulted in a significantly greater reduction in TEL compared to the control group. These findings suggest that Clamshell exercises were found to be an effective intervention for addressing TEL after ACLR.

Psychological Factors Are Related to Neuromuscular Asymmetries After Anterior Cruciate Ligament Reconstruction.

After an anterior cruciate ligament reconstruction (ACLR), only 47% of military members return to full duty, possibly due to persistent neuromuscular asymmetries. Psychological factors may also contribute to reduced return to duty in military members. Psychological factors and time since surgery would be associated negatively with neuromuscular asymmetries, asymmetries would be greater in cadets postsurgery when compared with healthy controls, and asymmetries would be greater at earlier timepoints after ACLR. Case control. Level 4. This study examined the relationship between psychological factors and time since surgery with neuromuscular asymmetry, compared neuromuscular asymmetries between cadets with and without a history of ACLR, and explored differences in neuromuscular asymmetries at different timepoints in cadets with a history of ACLR. A total of 37 cadets post-ACLR (18.3 ± 9 months) and 28 controls participated. Psychological factors were assessed using the Tampa Scale of Kinesiophobia and Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI). Participants performed a drop-jump landing, joint positioning sense (JPS), and isometric quadriceps strength testing. Peak vertical ground-reaction forces (vGRF), absolute angle of replication, peak quadriceps torque, rate of torque development (RTD), and RTD time torque interval 200 ms (TTI200) were analyzed. The ACL-RSI score was significantly related to limb symmetry index (LSI) peak quadriceps torque (r = 0.617, P < 0.01), LSI RTD (r = 0.367, P = 0.05), and LSI TTI200 (r = 0.0489, P < 0.01), but not time since surgery, JPS, or LSI peak vGRF. Cadets with a history of ACLR had significantly lesser ACL-RSI scores and greater asymmetries compared with controls. Reduced psychological readiness was associated with increased neuromuscular asymmetries after ACLR. Clinicians should assess psychological readiness during rehabilitation after ACLR.

Mechanical energy flow analysis in athletes with and without anterior cruciate ligament reconstruction during single-leg drop landing

Techniques that reduce mechanical energy have been linked to lower chances of experiencing an Anterior Cruciate Ligament (ACL) injury. Although there is evidence that movement patterns are altered in athletes who have undergone Anterior Cruciate Ligament Reconstruction (ACLR), energy transfer mechanisms have not been examined. This study aimed to compare energy flow mechanisms during single-leg drop landing between athletes with and without history of ACLR. A total of 20 female athletes were included in this study. Ten participants underwent ACLR 12 months ago (mean age, 21.57 ± 0.41 years) and 10 were healthy controls (mean age, 20.89 ± 0.21 years). Participants executed the single-leg drop landing (SLL) maneuver by descending from a 30 cm wooden box and landing on the tested leg on an embedded force plate. Information collected during the SLL trials was refined using rigid-body analysis and inverse dynamics within Nexus software, ultimately allowing construction of skeletal models of the athletes. Ankle and knee mechanical energy expenditure (MEE) was higher in the control participants during landing. However, the result for the hip MEE demonstrated that MEE of the control group was significantly lower compared with the ACLR group, but MEE of the control subjects was higher as compared to ACLR group (p ˂ 0.05). Results suggest the avoidant use of the quadriceps muscle post ACLR leads to knee-avoidant mechanics and loss of knee joint power generation during a SLL task.

Postural Control During Single-Leg Landing in Female Athletes After Anterior Cruciate Ligament Reconstruction.

Secondary anterior cruciate ligament (ACL) injury is a complication of ACL reconstruction (ACLR), which may result from altered neuromuscular control affecting anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) required for maintaining balance during movement. However, it remains unclear how APAs and CPAs differ in single-leg landings post-ACLR compared to healthy subjects. The purpose of this study was to clarify the differences in muscle activities of APAs and CPAs, lower limb kinematics, and kinetics between athletes with a history of ACLR and healthy athletes during single-leg landing. Cross-sectional study. Eighteen female athletes were recruited and divided into ACLR (n = 9) and control groups (n = 9). The experimental task involved a single-leg landing from a 30 cm box. Joint angles and moments were determined using a 3-dimensional motion analysis system, while muscle activity was assessed using surface electromyography. Analysis intervals were divided into two phases: the APA phase (-150 ms to 50 ms) and the CPA phase (50 ms to 250 ms), with initial contact (0 ms) as the reference point. Muscle activity onset time was defined as the time when the baseline exceeded by the sum of mean values and 2 standard deviations. No significant differences were observed in muscle activity or onset time between the ACLR and control groups. However, an increased hip external rotation moment was observed during the CPA phase in the ACLR group. These findings suggest that APAs and CPAs of athletes who returned to sports more than 1 year post-ACLR may be similar. The increased hip external rotation moment in the ACLR group during the CPA phase could represent a specific compensatory strategy to decrease the hip internal rotation angle post-ACLR. III.

The influence of body mass index on physical activity engagement following anterior cruciate ligament reconstruction: A systematic literature review

BackgroundThe objective of this study was to summarize available literature that explored the impact of body mass index (BMI) on physical activity participation among individuals who were subjected to the anterior cruciate ligament reconstruction (ACLR). MethodsA total of three electronic databases, including Web of Science, Scopus, and PubMed, were comprehensively searched to identify relevant investigations. The following inclusion criteria were applied: (1) study design was observational; (2) participants underwent the ACLR; (3) BMI was estimated as a predictor variable; and (4) outcomes evaluated referred to physical activity. The risk of bias was assessed with the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. ResultsAfter a database search, 787 studies were found, and only 10 of them met each of the eligibility criteria and were included in the qualitative analysis. Regarding respondents' characteristics, 7171 individuals underwent ACLR, 4080 males and 3091 females, with a mean age of 25.5 years. Most importantly, the average BMI of the examined population was 24.9 kg/m2. In all studies, physical activity was evaluated subjectively using the Tegner activity scale and the Marx activity scale. The main findings unambiguously demonstrated that a negative relationship between BMI and physical activity engagement was observed. More specifically, there is convincing evidence that BMI over 25 kg/m2 harmfully affected subjectively assessed physical activity in individuals with a history of ACLR. ConclusionThe results obtained in the presented research indicated that increased values of BMI were a factor that correlated with reduced physical activity levels in the ACLR population. Hence, taking into account the clinical and health implications of reduced physical activity participation, stimulation of a healthy lifestyle, such as a combination of adequately designed physical exercise and nutrition, seems necessary for the analyzed population.

Return to Sport After Anterior Cruciate Ligament Reconstruction Among Physically Active Adults

An anterior cruciate ligament (ACL) is one of athletes' most severe and frequent knee ligament injuries. The primary function of the ACL is preventing excessive anterior tibial translation, and it limits varus/valgus stress when the knee is in full extension and rotatory movements. Returning to sport after an ACL injury is a crucial aim of ACL reconstruction (ACLR). Multiple factors, modifiable and nonmodifiable, can influence the time to return to sport. This study aimed to discuss factors that affect optimal return-to-play (RTP) timing, symptom recurrence, and long-term consequences of an ACL injury. This is a cross-sectional study involving patients who are following in orthopedic surgery outpatient clinics with a history of ACLR at least six months before surgery and not beyond six years after surgery. Participants received a survey about their sociodemographic data, details of the type and site of injury, and ACL return to sport before and after reconstruction scale. Full data description and testing of dependent variables against participant variables using two-sided tests were performed with a significance level of P ≤ 0.05. The study involved 129 participants, of which the majority were male Bisha residents aged 20 to 29 years. The study found that the right leg was the most commonly injured, with the dominant leg being the most frequently reconstructed due to problems with knee function. Before the injury, most participants ran, cut (quick changes of direction during running), decelerated, and pivoted activities four or more times per month. However, physical activities notably reduced after ACLR. Age and body mass index (BMI) showed statistical significance related to the likelihood of returning to physical activities. The study found a significant reduction in the frequency of activities such as cutting, deceleration, and running after ACLR. Age was identified as a predictor affecting the likelihood of returning to the sport, with older patients being less likely to return than younger ones.

Hamstrings fatigue does not improve quadriceps function in individuals with anterior cruciate ligament reconstruction

ObjectivesOur purpose was to investigate the immediate and prolonged effects of hamstrings fatigue on quadriceps neuromuscular function in individuals with anterior cruciate ligament reconstruction (ACLR) and matched uninjured controls. DesignCross-Sectional. SettingLaboratory. Participants16 participants with a history of ACLR and 16 uninjured controls. Main outcome measuresQuadriceps peak torque (PT), central activation ratio (CAR), early (RTD100) and late (RTD200) rate of torque development, vastus medialis and lateralis electromyographic (EMG) activity, and hamstrings-to-quadriceps co-activation assessed at baseline. Outcomes were evaluated pre-fatigue (PRE), immediately post-fatigue (POST), and 30min post-fatigue (POST30). The involved limbs of individuals with ACLR were assessed and control limbs were matched based on limb dominance. ResultsIndividuals with ACLR demonstrated lesser quadriceps PT (p = 0.004), CAR (p < 0.001), RTD100 (p = 0.042), RTD200 (p = 0.028), and vastus medialis EMG (p = 0.040) than controls, regardless of time. Quadriceps CAR (p < 0.001) and RTD200 (p < 0.001) decreased at POST and POST30, whereas RTD100 (p < 0.001) decreased at POST, regardless of group. ConclusionsThe observed reductions in quadriceps neuromuscular function may suggest involvement of central fatigue mechanisms, which should be explored prior to recommending hamstrings fatigue as a therapeutic intervention.

Exploratory Examination of Knee Self-Efficacy in Individuals With a History of ACL Reconstruction and Sport-Related Concussion.

Knee self-efficacy and injury-related fear are associated with poor self-reported knee function and decreased physical activity (PA) after ACL reconstruction (ACLR). Limited research has explored contextual factors that may influence psychological responses in this population, such as history of sport-related concussion (SRC). After SRC, individuals may experience increased negative emotions, such as sadness and nervousness. However, it is unknown how SRC history may influence knee-self efficacy and injury-related fear in individuals with ACLR. The purpose of this study was to compare knee self-efficacy and injury-related fear in individuals after ACLR who present with and without history of SRC. Cross-sectional study. Forty participants ≥1year postunilateral ACLR were separated by history of SRC (no SRC = 29, SRC = 11). The Knee Self-Efficacy Scale (KSES) and subscales measured certainty regarding performance of daily activities (KSES-ADL), sports/leisure activities (KSES-Sport), physical activities (KSES-PA), and future knee function (KSES-Future). The Tampa Scale of Kinesiophobia-11 measured injury-related fear. Mann-Whitney U tests were used to examine between-group differences. Hedges g effect sizes and 95% confidence interval were used to examine clinically meaningful group differences. Individuals with a history of ACLR and SRC demonstrated worse KSES-PA (7.5 [5.3]) compared with those without a history of SRC (8.1 [6.1], P = .03). No other statistically significant differences were observed. A medium effect size was present for the KSES-PA (0.62), KSES-ADL (0.42), KSES-Present (ADL + PA + Sport) (0.48), KSES-Total (0.53), and Tampa Scale of Kinesiophobia-11 (0.61) but must be interpreted with caution as 95% confidence interval crossed 0. This exploratory study indicated that individuals with a history of ACLR and SRC had worse knee self-efficacy for PA compared with those without history of SRC. Rehabilitation specialists should monitor knee self-efficacy deficits in the post-ACLR population and recognize the potential influence of cumulative injury history on rehabilitative outcomes.

Reliability of Continuous Shear Wave Elastography in the Pathological Patellar Tendon.

Patellar tendon injuries occur via various mechanisms such as overuse, or due to surgical graft harvest for anterior cruciate ligament reconstruction (ACLR). Quantified patellar tendon stiffness after injury may help guide clinical care. Continuous shear wave elastography (cSWE) allows for the assessment of viscosity and shear modulus in tendons. The reliability of the measure, however, has not been established in the patellar tendon. The purpose of this study was to investigate the interrater reliability, intrarater reliability, and between-day stability of cSWE in both healthy and pathological patellar tendons. Participants with patellar tendinopathy (n=13), history of ACLR using bone-patellar tendon-bone autograft (n=9), and with no history of patellar tendon injury (n=13) were recruited. cSWE was performed 4 times by multiple raters over 2 days. Intraclass correlations (ICC) and minimum detectable change (MDC95% ) were calculated. Good to excellent between-day stability were found for viscosity (ICC=0.905, MDC95% =8.3Pa seconds) and shear modulus (ICC=0.805, MDC95% =27.4kPa). The interrater reliability measures, however, were not as reliable (ICC=0.591 and 0.532). cSWE is a reliable assessment tool for quantifying patellar tendon viscoelastic properties over time. It is recommended, however, that a single rater performs the measure as the interrater reliability was less than ideal.

Association Between the Functional Movement Screen and Landing Kinematics in Individuals With and Without Anterior Cruciate Ligament Reconstruction

The purpose of this study was to compare functional movement screen (FMS) scores and drop vertical jump (DVJ) kinematics between those with and without anterior cruciate ligament reconstruction (ACLR), and to evaluate the association between FMS composite score and DVJ kinematics. Cross-sectional. Sixty individuals with and without a history of ACLR. Composite FMS score and the dorsiflexion, knee-flexion, hip-flexion, knee abduction, hip adduction, and trunk-flexion angles during a DVJ. The FMS scores did not differ between groups (P > .05). There were smaller peak and initial contact hip-flexion angles in the ACLR and contralateral limbs compared with controls, and smaller peak dorsiflexion angles in the ACLR compared with contralateral limbs (P < .05). Lower FMS score was associated with a smaller peak dorsiflexion angle, smaller peak knee-flexion angle, and larger peak knee abduction angle in the ACLR limb (ΔR2 = .14-.23); a smaller peak dorsiflexion angle and smaller peak knee-flexion angle in the contralateral limb (ΔR2 = .17-.19); and a smaller peak dorsiflexion angle, smaller peak knee-flexion angle, and larger peak knee abduction angle in the control limb (ΔR2 = .16-.22). The FMS scores did not differ between groups, but were associated with DVJ kinematics and should be a complementary rather than substitute assessment.

The relationship between kinesiophobia and biomechanics in anterior cruciate ligament reconstructed females

ObjectiveKinesiophobia has been associated with deleterious biomechanical alterations during dual-limb landing tasks in anterior cruciate ligament (ACL) reconstructed females, however, no research has yet investigated single-limb tasks related to ACL injury. The aim of this investigation was to examine the relationship between kinesiophobia and biomechanics during a series of dual and single-limb functional tasks associated with ACL injury risk. DesignCross-sectional study. ParticipantsFifteen females (age = 22.67 ± 2.58yrs, height = 1.65 ±0 .05m, mass = 65.28 ± 10.36 kg) with a history of ACL reconstruction (time post surgery = 3.40 ±0 .74yrs) were recruited for this investigation. Main outcome measuresKinesiophobia, measured via the Tampa Scale of Kinesiophobia (TSK-11). Kinematics and muscle activation were measured during three functional tasks: the drop jump (DJ), single-limb hop (SLH), and single-limb landing (SLL). ResultsFor the DJ task, there was a strong negative correlation between kinesiophobia and knee flexion (r = −.592, p = .20) and between kinesiophobia and trunk flexion (r = −0.724, p = .002). For the SLH task, there was a strong positive correlation between kinesiophobia and hip flexion (r = 0.560, p = .03). ConclusionsThese findings indicate that kinesiophobia is associated with movement alterations years after completion of ACL reconstruction and rehabilitation.

Plyometrics Did Not Improve Jump-Landing Biomechanics in Individuals With a History of Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

Second anterior cruciate ligament (ACL) injury has similar biomechanical risk factors as primary injury. Standard of care rehabilitation does not adequately mitigate these biomechanical risks. This study examined the effectiveness of a 4-week plyometric intervention on biomechanical risk factors of second ACL injury versus no intervention in patients with a history of ACL reconstruction. Thirty adults post-ACL reconstruction received 12 sessions of plyometric (age: 19.9 ± 1.62 years; body mass index: 23.9 ± 2.6 kg/m2; months postoperative: 35.7 ± 24.2) or no (age: 21.3 ± 3.5 years; body mass index: 27.7 ± 4.8 kg/m2; months postoperative: 45.3 ± 25.4) exercise intervention. Hip and knee biomechanics were quantified during a jump-landing task before and after the intervention. Individual response to the intervention was evaluated via minimal detectable change. Hip flexion angle had the greatest response to plyometric training. Overall, focused plyometric intervention did not adequately mitigate biomechanical risk factors of second ACL injury; thus, development of interventions capable of modifying biomechanics known to contribute to ACL injury risk remains necessary.

The Utilization of the Theory of Planned Behavior and Self-Determination Theory to Improve Physical Activity Following Anterior Cruciate Ligament Reconstruction

Patients with a history of anterior cruciate ligament reconstruction (ACLR) report decreased levels of physical activity participation, which can result in a significant public health burden. Psychosocial factors, such as fear of reinjury and decreased self-efficacy, negatively impact physical activity levels in this population. However, factors such as attitudes and beliefs toward exercise, motivation, self-efficacy, and social support are known to positively influence physical activity participation. The Theory of Planned Behavior (TPB) and Self-Determination Theory (SDT) incorporate such constructs and have been utilized to predict and improve physical activity behaviors in a variety of populations. Emerging evidence has applied the TPB and SDT to rehabilitation adherence in populations with musculoskeletal injury and post-ACLR. However, we believe a combination of the TPB and SDT will provide a framework for increasing physical activity engagement for people with a history of ACLR. The purpose of this review is to present an integrated theoretical model that combines the TPB and SDT with the aim of increasing physical activity after ACLR. Recommendations for future research and clinical practice based on the proposed model are also discussed.

Suppressed quadriceps fascicle behavior is present in the surgical limbs of those with a history of ACL reconstruction

The balance of published data have largely focused on adaptations in muscle and fiber size after anterior cruciate ligament reconstruction (ACLR), failing to account for the dynamic changes in the behavior of the muscles’ contractile elements that strongly contribute to force production. To better understand the sources of quadriceps dysfunction, the purpose of our research was to determine if alterations in fascicle behavior are present after ACLR. Unilateral ACLR individuals (9 m/9f; 21 ± 3 yrs; 1.74 ± 0.12 m;71.58 ± 13.31 kg; months from surgery:38 ± 36) and healthy controls (3 m/6f; 23 ± 2 yrs; 1.67 ± 0.10 m; 63.51 ± 10.11 kg) participated. In-vivo vastus lateralis fascicle behavior was recorded using ultrasonography during three maximal isokinetic knee extensions (60°·s−1). Fascicle length, angle, and shortening velocity were calculated and analyzed from rest to peak torque. Peak knee extension torque was averaged between isokinetic trials (Nm·kg−1). Group by limb interactions were assessed using separate two-way analyses of variance and were further evaluated by comparing 95% confidence intervals where appropriate. Significant interactions were present for fascicle angle at peak torque (P = 0.01), fascicle length excursion (P = 0.05), fascicle angle excursion (P < 0.01), fascicle shortening velocity (P = 0.05) and strength (P = 0.03). Upon post-hoc evaluation, the surgical limb displayed altered in-vivo fascicle behavior compared to all limbs (P < 0.05) and reduced strength compared to the contralateral and right control limbs (P < 0.05). No other significant interactions were present (P > 0.05). Our data show that those with a history of ACLR have fascicles that are slower, lengthen less and operate with lower angles relative to the axis of force production. Altered fascicle behavior after ACLR may be an important underlying factor to explaining the protracted quadriceps dysfunction.

Implementation of In vivo exposure therapy to decrease injury-related fear in females with a history of ACL-Reconstruction: A pilot study

ObjectiveThe objective of this pilot study was to examine the preliminary feasibility and efficacy of in vivo exposure therapy (IVET) to decrease injury-related fear in females with history of ACLR. DesignPilot Study. SettingSports Medicine Research Laboratory. Participants12 female participants with history of ACLR (≥ 1 year post-operative) were randomized into a 5-week IVET group (n = 6) or 5-week sham physical activity (PA) monitoring group (n = 6). Main outcome measuresThe independent variables were Group and Time. The dependent variables were the Photographic Series of Sports Activities for ACLR (PHOSA-ACLR) and the Tampa Scale of Kinesiophobia-11 (TSK-11) scores. A Group x Time repeated measures two-way analysis of variance was completed for the PHOSA-ACLR and the TSK-11. Partial η2 effect sizes were used to examine clinically meaningful differences. ResultsHigh retention and adherence rates were observed in the intervention group. The PHOSA-ACLR exhibited a significant main effect for Time (F1,10 = 9.92, p = 0.01, partial η2 = 0.50), but not for Group. No statistically significant or clinically meaningful differences were observed for the TSK-11. ConclusionBoth groups exhibited decreased injury-related fear for specific functional tasks. Future research should further examine the efficacy of IVET and PA monitoring to decrease injury-related fear in patients after ACLR.

Perspectives on the Gamification of an Interactive Health Technology for Postoperative Rehabilitation of Pediatric Anterior Cruciate Ligament Reconstruction: User-Centered Design Approach.

BackgroundPediatric and adolescent athletes are a large demographic undergoing anterior cruciate ligament reconstruction (ACL-R). Postoperative rehabilitation is critical, requiring patients to complete home exercise programs (HEPs). To address obstacles to HEP adherence, we developed an interactive health technology, interACTION (iA), to monitor knee-specific rehabilitation. iA is a web-based platform that incorporates wearable motion sensors and a mobile app that provides feedback and allows remote monitoring. The Wheel of Sukr is a gamification mechanism that includes numerous behavioral elements. ObjectiveThis study aims to use a user-centered design process to incorporate behavioral change strategies derived from self-management theory into iA using the Wheel of Sukr, with the aim of influencing patient behavior.MethodsIn total, 10 athletes aged 10-18 years with a history of ACL-R were included in this study. Patients were between 4 weeks and 1 year post–ACL-R. Participants underwent a 60-minute triphasic interview. Phase 1 focused on elements of gaming that led to high participation and information regarding surgery and recovery. In phase 2, participants were asked to think aloud and rank cards representing the components of the Wheel of Sukr in order of interest. In phase 3, the patients reviewed the current version of iA. Interviews were recorded, transcribed, and checked for accuracy. Qualitative content analysis segmented the data and tagged meaningful codes until descriptive redundancy was achieved; next, 2 coders independently coded the data set. These elements were categorized according to the Wheel of Sukr framework. The mean age of participants was 12.8 (SD 1.32) years, and 70% (7/10) were female. Most participants (7/10, 70%) reported attending sessions twice weekly. All patients were prescribed home exercises. Self-reported HEP compliance was 75%-100% in 40% (4/10), 50%-75% in 40% (4/10), and 25%-50% of prescribed exercises in 20% (2/10) of the participants.ResultsThe participants responded positively to an app that could track home exercises. Desirable features included exercise demonstrations, motivational components, and convenience. The participants listed sports specificity, competition, notifications, reminders, rewards, and social aspects of gameplay as features to incorporate. In the Wheel of Sukr card sort exercise, motivation was ranked first; self-management, second; and growth, esteem, and fun tied for the third position. The recommended gameplay components closely followed the themes from the Wheel of Sukr card sort activity.ConclusionsThe participants believe iA is a helpful addition to recovery and want the app to include exercise movement tracking and encouragement. Despite the small number of participants, thematic saturation was reached, suggesting the sample was sufficient to obtain a representative range of perspectives. Future work will implement motivation; self-management; and growth, confidence, and fun in the iA user experience. Young athlete ACL-R patients will complete typical clinical scenarios using increasingly developed prototypes of the gamified iA in a controlled setting.

Association of Prior Anterior Cruciate Ligament Tear With Decreased Career Longevity in Women's National Basketball Association.

Background:The incidence of anterior cruciate ligament (ACL) injuries in women’s basketball exceeds that of men. There is a paucity of data regarding career performance in Women’s National Basketball Association (WNBA) athletes with a history of ACL reconstruction.Purpose:To determine whether WNBA athletes with a history of ACL injury prior to professional play have reduced career game utilization, defined as games played and started and minutes per game (MPG), as well as statistical performance, defined by player efficiency rating (PER).Study Design:Cohort study; Level of evidence, 3.Methods:Included were 42 WNBA players from 1997 to 2018 who had a history of ACL reconstruction before entering professional leagues. Body mass index (BMI), age, and position were collected for each player. Career data and performance statistics were likewise collected for each player’s entire WNBA career. A control group of WNBA players with no history of ACL injury were matched by position, BMI, and age at the time of WNBA debut. Statistics compared game utilization and performance to assess the impact of ACL reconstruction.Results:Athletes who sustained an ACL tear before entering the league played in fewer games per season in their first 3 professional seasons compared with healthy controls (24.2 ± 8.4 vs 28.2 ± 6.1; P = .02). Among athletes with a history of ACL reconstruction, 11 (26.2%) played only a single WNBA season, while no control athletes played in just 1 season. Additionally, athletes who had a previous ACL tear started significantly fewer games per season (9.0 ± 9.4 vs 14.0 ± 9.0; P < .01) and played fewer MPG (15.5 ± 7.2 vs 20.7 ± 5.5; P < .01) during their WNBA career. Athletes with a history of ACL tear had significantly shorter WNBA careers (4.8 ± 4.1 vs 8.1 ± 3.3 seasons; P < .001). Total professional play duration (WNBA + overseas) was significantly reduced in players with an ACL tear compared with controls (P < .05). PER was not significantly different between cohorts at any time point.Conclusion:WNBA athletes with a history of an ACL tear before professional play had decreased career game utilization and workload throughout their career despite having similar PER compared with healthy controls.

A - 32 The Influence of Sport-Related Concussion History on Self-Reported and Objective Physical Functioning Following ACL Reconstruction

Abstract Objective The purpose of this study was to examine differences in self-reported physical functioning via the Modified Disablement in the Physically Active Scale (mDPA) and single-leg hop limb symmetry index (LSI) between individuals with a history of anterior cruciate ligament reconstruction (ACLR) and SRC compared to an ACLR group without history of SRC. Methods Forty participants [24 female; mean age = 24.3 +/− 4.1 years; height (cm) = 169.9 (SD = 9.1); weight (kg) = 73.2 (SD = 15.1)] with a history of ACLR (≥1-year post-operative) were separated into a SRC history group (SRC; n = 11) and no SRC history group (NO SRC; n = 29). Participants completed the mDPA physical summary component (mDPA-PSC) and hop testing (single-leg hop, crossover-hop, and triple-hop all for distance). SRC history was self-reported as yes/no and LSI was calculated using the equation: (mean distance involved limb/mean distance uninvolved limb) x 100. Mann–Whitney U tests (p &amp;lt; 0.05) were used to examine between-group differences. Hedge’s g effect sizes (ES) and 95% confidence intervals (95%CI) were used to detect clinically meaningful differences. Results The SRC history group reported worse physical functioning on the mDPA-PSC compared to the no SRC history group [SRC = 10 (IQR = 13), NO SRC = 5 (IQR = 10), p = 0.02, ES = -0.79, 95%CI = -1.49 to −0.08]. No statistical differences were observed for the single-leg hop or triple-hop, but the SRC history group performed worse on the crossover-hop [SRC = 0.96 (IQR = 0.07), NO SRC = 1.02 (IQR = 0.10), p = 0.006, ES = 0.74, 95%CI = 0.03–1.43]. Conclusions These results suggest that SRC history may negatively influence subjective evaluation of physical functioning and objective lower-extremity functional performance in patients after ACLR.

Commonly used clinical criteria following ACL reconstruction including time from surgery and isokinetic limb symmetry thresholds are not associated with between-limb loading deficits during running

ObjectivesWe included objective measures of gait and functional assessments to examine their associations in athletes who had recently commenced running after ACL reconstruction. DesignCross-sectional. SettingSports medicine. Participants65 male athletes with a history of ACL reconstruction. Main outcome measuresTime from surgery, isokinetic knee extension/flexion strength (60°/s), and peak vertical ground reaction force (pVGRF) measured during running using an instrumented treadmill. We also investigated if a range of recommended isokinetic thresholds (e.g. > 70% quadriceps limb symmetry index) affected the magnitude of pVGRF asymmetry during running. ResultsThere were significant relationships between quadriceps (r = 0.50) and hamstrings (r = 0.46) peak torque and pVGRF. Quadriceps peak torque explained a quarter of the variance in pVGRF (R2 = 0.24; p < 0.001). There was no association was between running pVGRF and time from surgery. Between-group differences in running pVGRF LSI% were trivial (d < 0.20) for all quadriceps and hamstring peak torque LSI thresholds. ConclusionsCurrent clinical criteria including time from surgery and isokinetic strength limb symmetry thresholds were not associated with lower pVGRF asymmetry measured during running. Quadriceps strength is important, but ‘minimum symmetry thresholds’ should be used with caution.