Effects of an Injury Prevention Program on Anterior Cruciate Ligament Injury Risk Factors in Adolescent Females at Different Stages of Maturation.

The ideal timing to implement anterior cruciate ligament injury prevention programs with respect to maturation is unclear. The purpose of this study was to investigate the effects of an injury prevention program on knee mechanics in early-, late-, and post-pubertal females. In the study, 178 adolescent female basketball players were assigned to six groups: early-pubertal training, early-pubertal control, late-pubertal training, and late-pubertal control, post-pubertal training, and post-pubertal control. The training groups performed an injury prevention program for six months. Medial knee displacement, knee flexion range of motion, and the probability of high knee abduction moment were assessed before and after the training period. After the six-month training period, medial knee displacement was significantly increased in the early-pubertal control group whereas it was unchanged in the early-pubertal training group. Knee flexion range of motion was significantly decreased in the early-pubertal control group whereas it did not change in the early-pubertal training group. The probability of high knee abduction moment was increased in the early-pubertal control group whereas it was unchanged in the earl-pubertal training group. The probability of high knee abduction moment was also decreased in the post-pubertal training group whereas it did not change in the post-pubertal control group. The program limited the development of high-risk movement patterns associated with maturation in early puberty while improving the knee mechanics in post-pubertal adolescents. Therefore, an injury prevention program should be initiated in early puberty and continue through the post-puberty years.

Predicting post-operative functional ability from pre-operative measures in ACL-injured individuals.

PURPOSE: This study aimed to quantify the relationship between objective and subjective measures of functional ability and determine if measures in the deficient (ACLd) state were correlated to, and capable of predicting a patient's objective and subjective measures in the reconstructed (ACLr) state. METHODS: Twenty ACL-injured participants completed hop and side cut movements prior to and 10 months post-reconstruction. Their subjective measures (Tegner, Lysholm, IKDC, KOOS, and KNEEs) were related to objective measures of functional ability (peak knee flexion, peak knee extensor moment, stiffness, knee joint center excursion (KJCE), and knee joint center boundary). Correlations were used to determine relationships between variables whereas regressions were used to identify ACLd score's predictive ability of an ACLr score. RESULTS: Relationships between objective and subjective measures were task and ACL status dependent with KJCE and stiffness most commonly being related to subjective scores. The greatest correlation was between knee stiffness and Tegner in the ACLr group during the side cut (r = 0.69). Peak knee flexion angle (adj. R2  = 0.4-0.66) was the best objective predictor between ACLd and ACLr states while KOOS-ADL had the strongest correlations (r = 0.70-0.77) and Tegner had the greatest predictive power (odds ratio: 1.46-1.86) between states in both tasks. CONCLUSION: Objective measures show a wide range of correlation to subjective measures with some being quite strong. Furthermore, objective measures in the ACLd state are more correlated and more often capable of predicting ACLr scores than the subjective measures of functional ability.

Fully Depleted, Trench-Pinned Photo Gate for CMOS Image Sensor Applications.

Tackling issues of implantation-caused defects and contamination, this paper presents a new complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) pixel design concept based on a native epitaxial layer for photon detection, charge storage, and charge transfer to the sensing node. To prove this concept, a backside illumination (BSI), p-type, 2-µm-pitch pixel was designed. It integrates a vertical pinned photo gate (PPG), a buried vertical transfer gate (TG), sidewall capacitive deep trench isolation (CDTI), and backside oxide-nitride-oxide (ONO) stack. The designed pixel was fabricated with variations of key parameters for optimization. Testing results showed the following achievements: 13,000 h+ full-well capacity with no lag for charge transfer, 80% quantum efficiency (QE) at 550-nm wavelength, 5 h+/s dark current at 60 °C, 2 h+ temporal noise floor, and 75 dB dynamic range. In comparison with conventional pixel design, the proposed concept could improve CIS performance.

Anterior cruciate ligament reconstruction improves subjective ability but not neuromuscular biomechanics during dynamic tasks.

PURPOSE: The purpose of this study was to identify high-functioning anterior cruciate ligament-deficient patients and assess the effects of reconstruction on their self-reported functionality, muscle activations and biomechanical properties. METHODS: Twenty young and active patients participated pre- (11.5 ± 14.3 months post-injury) and again 10.5 ± 1.7 months post-reconstruction and were individually matched to 20 healthy controls. Participants completed hop and side cut movements while patient-related outcome measures, lower limb electromyography, kinetic, and whole body kinematic data were collected. One-dimensional statistical parametric mapping was used to test for group differences (healthy vs deficient; deficient vs reconstructed; reconstructed vs healthy). RESULTS: When comparing healthy to anterior cruciate ligament-deficient participants, all questionnaires indicated significant lower subjective function while the only substantial biomechanical difference between these participants was a decreased knee extensor moment in both the hop (peak difference: 0.63 Nm/kg, p < 0.001) and side cut (peak difference: 0.76 Nm/kg, p < 0.001). When comparing patients' pre- and post-reconstruction, no biomechanical differences were observed whereas only half of the questionnaires (Tegner, Lysholm, KNEES-ADL, KNEES-Slackness, KNEES-Looseness, KNEES-Sport Behaviour, IKDC, and KOOS-QoL) indicated higher function in the reconstructed state. When comparing the reconstructed patients to the healthy participants, all questionnaires were still significantly higher in the healthy controls. The reconstructed group also had a smaller flexion angle (peak difference: 14.5°, p = 0.007) and knee extensor moment (peak difference: 0.62 Nm/kg, p < 0.001) during the hop and a smaller knee extensor moment (peak difference: 0.90 Nm/kg, p < 0.001) during the side-cut task. CONCLUSION: At 10-months post-reconstruction, the current results indicate that in high-functioning anterior cruciate ligament-deficient patients, reconstruction had little impact on objective measures of functional ability during dynamic tasks although self-reported function was improved. LEVEL OF EVIDENCE: Therapeutic prospective cohort study, Level II.

Anatomic repair of the distal biceps tendon cannot be consistently performed through a classic single-incision suture anchor technique.

BACKGROUND: Distal biceps tendon ruptures commonly occur in active men, and surgical repair through a single-incision technique using suture anchors has become common. The current study assessed whether an anatomic repair of the biceps to the radial tuberosity can be consistently achieved through a single-incision technique. METHODS: Acute distal biceps tendon repairs using the single-incision technique were retrospectively reviewed. Computed tomography (CT) scans were obtained to investigate tuberosity dimensions and the position of the suture anchors. An isokinetic dynamometer was used to obtain flexion and supination strength. Disabilities of the Arm, Shoulder and Hand (DASH) scores were collected. RESULTS: CT scans were performed in 27 patients, of which, 21 underwent strength testing. The suture anchor placement averaged 50° radial to the apex of the tuberosity. Strength testing showed flexion strength of the repaired side was equal (97%-106%) to the normal side. Supination strength (80%-86%) and work (66%-75%) performed were both weaker on the repaired side (66%-75%; P < .05). The average DASH score was 10.7. CONCLUSIONS: Ideal suture anchor placement, in the ulnar aspect of the tuberosity, could not be reliably achieved through this single-incision technique. This could have clinical importance because supination strength was not fully restored in this group of patients.

Exploring the evolution of mass density and thickness of N-doped Ge-rich GeSbTe during multistep crystallization.

Among phase change materials, Ge-rich GeSbTe alloys (GGST) are key alloys for the next generation of embedded phase change memories because of their good thermal stability, allowing their use for the automotive applications. Several studies have investigated GGST crystallization, which takes place in several stages, including phase separation in the amorphous material, the crystallization of the cubic Ge and GST phases before a complete crystallization for higher thermal budget. So far, however, no information is available on the possible changes in density and thickness of such alloys. This paper investigates such variations in density and thickness for a N-doped GGST layer (GGSTN) during isothermal annealing, following the four main stages of its multistep crystallization process. X-ray reflectivity (XRR) and X-ray diffraction were employed for analysis. The study reveals that density and thickness exhibit distinct changes during crystallization, with density increasing by approximately 9% during transition from amorphous to crystalline states. These changes are attributed to alterations in layer morphology, particularly at the Ge crystallization temperature and at the onset of GST crystal formation. Additionally, at high thermal budgets, discrepancies between XRR analysis methods suggest the formation of a thin, lower density layer near the top interface of the GGSTN layer. These results provide insights into the structural evolution of the GGSTN layer, which is crucial for phase change random access memory applications.

Criteria Used to Determine Unrestricted Return to Activity After ACL Reconstruction in Pediatric and Adolescent Patients: A Systematic Review.

Background: The rates of anterior cruciate ligament (ACL) graft failure or contralateral ACL rupture range from 17% to 30% in pediatric patients after ACL reconstruction (ACLR). A contributing factor to the high reinjury rate in this population may be the limited evidence regarding appropriate criteria for allowing unrestricted return to activity (RTA) postoperatively. Purpose: To review the literature and identify the most commonly used criteria when determining unrestricted RTA after ACLR in pediatric patients. Study Design: Systematic review; Level of evidence, 4. Methods: A search was performed of the Medline/PubMed, Cochrane Central Register of Controlled Trials, Embase, CINAHL, and SPORTDiscus databases using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The authors identified studies that included pediatric patients (<19 years of age) and specified the criteria used to determine RTA after ACLR. Results: A total of 27 articles met all criteria for review, of which 13 studies only used 1 criterion when determining RTA. Objective criteria were the most common type of criteria for RTA (17 studies). Strength tests (15 studies) and hop tests (10 studies) were the most commonly used tasks when deriving RTA criteria. Only 2 studies used validated questionnaires to assess the patient's physiological readiness for RTA, and only 2 studies used an objective assessment of movement quality before RTA. Conclusion: Only 14 of the 27 reviewed studies reported using >1 criterion when determining RTA. Furthermore, few studies used patient-reported outcome measures or lower limb kinematics as RTA criteria, indicating that more research is needed to validate these metrics in the pediatric population.

Females with knee osteoarthritis use a detrimental knee loading strategy when squatting.

BACKGROUND: The purpose of this study was to identify sex differences in lower limb kinematics, kinetics, and muscle activation patterns between individuals with osteoarthritis and healthy controls during a two-legged squat. METHOD: Thirty OA (15 females) and 30 healthy (15 females) participants performed three 2-legged squats. Sagittal and frontal plane hip, knee, and ankle kinematics and kinetics were calculated. Two-way ANOVAs (Sex X OA Status) were used to characterize differences in squatting strategies between sexes and between those with and without knee OA. RESULTS: A greater decrease in sagittal hip, knee, and ankle range of motion and knee joint power was observed in the OA participants compared to the healthy controls. Females with OA had significantly reduced hip and knee adduction angles compared to the healthy females and males with OA. Females also had decreased hip power, hip flexion, and hip adduction moments and knee adduction moments compared to their male counterparts, with the greatest deficits observed in the females with OA. Females with OA also had the highest magnitude of muscle activation for the quadriceps, hamstrings, and gastrocnemius throughout the squat, while males with OA showed increased activation of the vastus lateralis and medial gastrocnemius compared to the healthy males. CONCLUSIONS: OA significantly altered biomechanics and neuromuscular control during the squat, with males employing a hip-dominant strategy, allowing them to achieve a greater lower limb range of motion.

Protocol for the systematic review of return-to-activity criteria in adolescent patients following an anterior cruciate ligament reconstruction.

BACKGROUND: Anterior cruciate ligament (ACL) rupture is a debilitating knee injury associated with sequela such as joint instability and progressive degeneration. Unfortunately, following surgical ACL reconstruction in adolescents, the rates of ACL graft failure range from 17 to 19%. A contributing factor to the high reinjury rate in this population may be the limited evidence regarding appropriate criteria for allowing unrestricted return-to-activities (RTA) postoperatively. Several systematic reviews have already sought to develop a consensus on what criteria should be utilized for releasing patients to unrestricted sports activities; however, these reviews have focused on adult populations, a group at much lower risk for reinjury. Our objective is to systematically examine the literature and identify the criteria used when determining unrestricted RTA following an ACL reconstruction in an adolescent population. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search will be performed of the MEDLINE/PubMed, Cochrane, Embase, CINAHL, and SPORTDiscus electronic databases. Searches will be conducted from January 1, 2000, until submission of the final review. Studies will be identified that include adolescent patients (10-18 years old) undergoing a primary ACL reconstruction and which have specified the criteria used to determine RTA. Each article will be independently screened by two reviewers. To supplement the electronic database search, citations within all included studies will be manually reviewed. Reviewers will record the RTA assessment utilized and the rates of ACL reinjury through a standardized data extraction sheet. Reviewers will resolve full-text screening and data extraction disagreements through discussion. Synthesis of the collected data will focus on compiling and mapping the most commonly used types of RTA criteria. DISCUSSION: This systematic review will determine the most commonly used RTA criteria in adolescent patients post-ACL reconstruction. This will help future interventions build more effective adolescent-specific RTA assessments through the validation of current RTA criteria as well as the implementation of new criteria according to the identified literature gaps.

Altered movement strategy during functional movement after an ACL injury, despite ACL reconstruction.

Knee joint functional deficits are common after anterior cruciate ligament (ACL) injury, but different assessment methods of joint function seem to provide contradicting information complicating recovery monitoring. We previously reported improved perceived knee function and functional performance (forward lunge ground contact time) in patients with an ACL injury from pre to 10 months post ACL reconstruction without improvement in knee-specific biomechanics. To further investigate this discrepancy, we additionally analyzed knee extensor and flexor muscle strength, and movement quality in the forward lunge (subjective and objective evaluations) and performed a full lower limb biomechanical analysis of the forward lunge movement. We included 12 patients with an ACL injury (tested before and after ACL reconstructive surgery) and 15 healthy controls from the previous study to the current investigation. Outcome measures were obtained pre and ~11 months post ACL reconstruction for the patients and at a single time point for the controls. Objective movement quality in the patients with an ACL injury showed an improvement from their pre reconstruction surgery visit to the post reconstruction visit but this was not observable in the subjective evaluation. Knee extensor muscle strength declined after the ACL reconstruction by 29% (p = 0.002) and both knee extensors (p < 0.001) and flexors (p = 0.027) were weaker in the patients post ACL reconstruction compared to healthy controls. ACL injured patients had an altered movement strategy in the forward lunge with reduced knee extensors contribution and increased hip extensor contribution compared to the controls both before and after the reconstruction. The altered movement strategy was associated with knee extensor muscle strength. This explorative study with a limited sample size found that clinicians should be aware that significant functional deficits in the knee extensor muscles, both in isolated muscle strength testing and during a functional movement, may be present although patients perceive an improvement in their knee function and present good functional performance without obvious movement quality issues.

Sex differences in muscle activation patterns associated with anterior cruciate ligament injury during landing and cutting tasks: A systematic review.

Neuromuscular control is critical for maintaining dynamic joint stability and mitigating the risk of anterior cruciate ligament (ACL) injury. Given the increased risk of ACL injury in females, sex-based differential muscle activation strategies are often associated with this risk. For example, the quadriceps-dominant muscle activation strategy sometimes observed in females has been discussed as a cause of their increased risk of ACL injury. However, there has been no synthesised knowledge on sex differences in muscle activation patterns associated with ACL injuries. Therefore, the purpose of this review was to synthesise sex differences in muscle activation patterns in movements associated with ACL injuries in both adult and adolescent populations. A systematic electronic database search was conducted. Thirty studies were included in the review. Females demonstrated higher pre- and post-landing activation of the quadriceps and lower activation of the hamstrings in 15 studies. Females also had higher quadriceps-to-hamstring co-contraction ratios during pre- and post-landing phases compared to their male counterparts in 4 of 9 studies that considered co-contraction. While some studies supported the quadriceps-dominant activation strategies in females, no consensus can be drawn due to methodological inconsistencies and limitations. Also, despite the importance of ACL injury prevention in children and adolescents, the evidence on sex difference in muscle activation patterns in this population is insufficient to draw meaningful conclusions.

Functional muscle synergies to support the knee against moment specific loads while weight bearing.

OBJECTIVE: Externally applied abduction and rotational loads are major contributors to the knee joint injury mechanism; yet, how muscles work together to stabilize the knee against these loads remains unclear. Our study sought to evaluate lower limb functional muscle synergies in healthy young adults such that muscle activation can be directly related to internal knee joint moments. METHODS: Concatenated non-negative matrix factorization extracted muscle and moment synergies of 22 participants from electromyographic signals and joint moments elicited during a weight-bearing force matching protocol. RESULTS: Two synergy sets were extracted: Set 1 included four synergies, each corresponding to a general anterior, posterior, medial, or lateral force direction. Frontal and transverse moments were coupled during medial and lateral force directions. Set 2 included six synergies, each corresponding to a moment type (extension/flexion, ab/adduction, internal/external rotation). Hamstrings and quadriceps dominated synergies associated with respective flexion and extension moments while quadriceps-hamstring co-activation was associated with knee abduction. Rotation moments were associated with notable contributions from hamstrings, quadriceps, gastrocnemius, and hip ab/adductors, corresponding to a general co-activation muscle synergy. CONCLUSION: Our results highlight the importance of muscular co-activation of all muscles crossing the knee to support it during injury-inducing loading conditions such as externally applied knee abduction and rotation. Functional muscle synergies can provide new insight into the relationship between neuromuscular control and knee joint stability by directly associating biomechanical variables to muscle activation.

Sex-specific landing biomechanics and energy absorption during unanticipated single-leg drop-jumps in adolescents: implications for knee injury mechanics.

Females aged between 13 and 17 years old possess the highest non-contact ACL injury incidence of any sex-age strata. Considering that energy absorption strategies have been associated with a reduced risk for sustaining an ACL injury, evaluating landing performance in youth athletes requires investigations beyond the kinematic level. The purpose of this study was to identify sex-specific energy absorption strategies in adolescent males and females, including the relationship between strength and the observed strategies. Thirty-one healthy adolescent athletes completed unanticipated single-leg drop-jump landings on their dominant limb. Sex-specific kinematics and lower-limb contributions to energy absorption were then compared over the landing phase for each jump. Pearson and Spearman correlation coefficients determined the relationship between isometric joint strength and the observed kinematics and energy absorption. Female participants absorbed a larger proportion of the landing energy at the ankle (p = 0.046, d = 0.75) and smaller proportion at the hip (p = 0.028, d = 0.85) compared to males. Females also reached larger peak negative joint power in their knee (p = 0.001, d = 1.1) and ankle (p = 0.04, d = 0.79). Hip extension strength was positively correlated with trunk flexion (r = 0.559, p = 0.001) and negatively correlated with forward pelvic tilt (r = -0.513, p = 0.003). Females adopted an energy absorption strategy which utilized the distal joints to absorb a larger portion of the landing forces and tended to absorb the forces later in the landing phase relative to males. The greater reliance on distal joints is correlated to reduced hip strength and may increase the risk for sustaining an ACL injury.

Divergence analysis of failed and successful unanticipated single-leg landings reveals the importance of the flight phase and upper body biomechanics.

The purpose of this study was to describe neuromuscular and kinematic differences during failed and successful drop-vertical jumps in a pediatric population. Healthy young athletes (n = 32) completed single-leg drop vertical jump landings where the required landing leg was unanticipated. Trials were categorized as failed if the participant shifted their base of support during the landing. Joint kinematics and muscle activation amplitudes were time normalized over the flight and landing phases. Statistical parametric mapping (SPM) was used to compare landings and a moving average convergence divergence oscillator was then calculated to determine where failed and successful waveforms began to diverge prior to reaching statistical significance. SPM determined that participants performed the failed trials with reduced pelvic tilt towards the landing limb during 41-69% of the flight phase, greater trunk flexion angle during 31-100% of the landing phase and greater trunk tilt away from the landing limb during 3-13% and 21-90% of the landing phase. Greater rectus femoris activation during the failed trials was identified during 88-100% of the flight phase, as well as 1-4% and 71-97% of the landing phase. Greater gluteus medius and biceps femoris activation was also identified in the failed trials during 54-72% and 76-89% of the landing phase respectively. These findings indicate that the control of proximal joints has an important role in determining if a participant will fail a landing; and that how athletes prepare for a landing may be more relevant than the kinematics following ground contact.

Relationship of Knee Forces to Subjective Function Pre- and Post-ACL Reconstruction.

PURPOSE: Although basic objective measures (e.g., knee laxity, strength, and hop tests) have been related to subjective measures of function, associations between knee-specific objective and subjective measures have yet to be completed. The objective was to determine if knee joint contact and ligament forces differ between pre- and post-anterior cruciate ligament (ACL) reconstructed states and if these forces relate to their patient's respective subjective functional ability scores. METHODS: Twelve patients performed a hopping task before and after reconstruction. Magnetic resonance images and OpenSim were used to develop patient-specific models in static optimization and joint reaction analyses. Questionnaires concerning each patient's subjective functional ability were also collected and correlated with knee joint contact and ligament forces. RESULTS: No significant differences were observed between deficient and reconstructed groups with respect to knee joint contact or ligament forces. Nevertheless, there were several significant (P < 0.05) moderate to strong correlations between subjective and objective measures including Tegner activity level to contact force in both states (r = 0.67-0.76) and International Knee Documentation Committee to compressive and anterior shear forces (r = 0.64-0.66). CONCLUSION: Knee-specific objective measures of a patient's functional capacity can represent their subjective ability, which explains this relationship to a greater extent than past anatomical and gross objective measures of function. This consolidation is imperative for improving the current rehabilitation schema as it allows for external validation of objective and subjective functional measures. With poor validation of subjective function against objective measures of function, the reinjury rate is unlikely to diminish, continuing the heavy financial burden on health care systems.

Forward lunge before and after anterior cruciate ligament reconstruction: Faster movement but unchanged knee joint biomechanics.

The forward lunge (FL) may be a promising movement to assess functional outcome after ACL reconstruction. Thus, we aimed to investigate the FL movement pattern before and after ACL reconstruction with a comparison to healthy controls to determine if differences were present. Twenty-eight ACL injured participants and 28 matched healthy controls were included. They performed FL movements while sagittal plane biomechanics of the knee and electromyography (EMG) of nine leg muscles was assessed. The ACL injured group was tested before and 10 months after surgery. The perceived knee function and activity level was assessed by questionnaires. The ACL injured group performed the FL significantly slower than the controls before surgery (mean difference: 0.41 s [95%CI: 0.04-0.79 s; p<0.05]) while they performed the FL as fast as the controls after surgery (~28% movement time reduction post-surgery). Perceived knee function and activity level improved significantly post-surgery. The knee joint flexion angle, extensor moment, power, angular velocity in the ACL injured group did not differ from pre to post-surgery. For the ACL injured group, the peak knee extensor moment observed both pre and post-surgery was significantly lower when compared to the controls. The EMG results showed minimal differences. In conclusion, at 10 months post-surgery, the FL was performed significantly faster and the movement time was comparable to that of the controls. While the perceived knee function and activity level improved post-surgery, the knee joint biomechanics were unchanged. This may reflect that knee joint function was not fully restored.

Translation and Validation of the Hospital for Special Surgery Pediatric Functional Activity Brief Scale for French Paediatric Populations.

Purpose: Physical activity level is a prognostic variable for patients with injuries. Self-report questionnaires exist to obtain these measures; however, they are not accessible to all populations because of language barriers. Therefore, the purpose of this study was to translate and validate the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) for francophones. Method: We translated the HSS Pedi-FABS using the forward-reverse translation approach and validated it among bilingual adults and an expert panel before administering it to a paediatric population. A repeated-measures crossover design was used: forty-three middle school students, aged 13.1 (SD 0.75) years, were randomly administered either the English or the French questionnaire. Two days later, all participants completed the other version. The translated questionnaire was assessed for its convergent validity (Spearman's r correlation coefficients [rs ]), internal consistency (Cronbach's α), and reliability (standard error of measurement [SEM]). Results: All assessments had a significance level of p < 0.001 with an excellent Spearman's r correlation coefficient between the participants' total scores on the translated questionnaires (rs  = 0.911). The overall scores for the questionnaire and the individual items of the questionnaire revealed excellent internal consistency (α = 0.868) and reliability (SEM = 0.334). Conclusions: The validated and reliable translated questionnaire can be used by researchers and clinicians to assess physical activity levels in French paediatric populations.

Objectif : le niveau d'activité physique est un pronostic variable pour les patients qui présentent des blessures. Il existe des questionnaires d'autoévaluation pour obtenir ces mesures, mais ils ne sont pas accessibles à toutes les populations à cause de la barrière de la langue. La présente étude visait à traduire et à valider le Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) pour les francophones. Méthodologie : les chercheurs ont traduit le HSS Pedi-FABS au moyen du processus de rétrotraduction et l'ont validé auprès d'adultes bilingues et d'un groupe d'experts avant de l'utiliser auprès d'une population pédiatrique. Ils ont utilisé une méthodologie transversale par mesures répétées : 43 élèves du début du secondaire de 13,1 ans (ÉT 0,75) ont répondu au hasard au questionnaire anglais ou français. Deux jours plus tard, tous les participants ont rempli l'autre version. Les questionnaires traduits ont été évalués pour leur validité convergente (coefficients de corrélation Rho de Spearman [rs ]), leur cohérence interne (coefficient alpha [α] de Cronbach) et leur fiabilité (erreur type de mesure). Résultats : toutes les évaluations présentaient un seuil de signification de p < 0,001 et un excellent coefficient de corrélation Rho de Spearman entre les scores totaux des participants dans les questionnaires traduits (rs  = 0,911). Les scores totaux du questionnaire et de chacun de ses éléments ont révélé une excellente cohérence interne (α = 0,868) et une excellente fiabilité (erreur type de mesure = 0,334). Conclusion : le questionnaire validé et traduit avec fiabilité peut être utilisé par les chercheurs et les cliniciens pour évaluer les niveaux d'activité physique de populations pédiatriques francophones.

Decision Tree Learning Algorithm for Classifying Knee Injury Status Using Return-to-Activity Criteria.

Anterior cruciate ligament (ACL) injury rates in female adolescents are increasing. Irrespective of treatment options, approximately 1/3 will suffer secondary ACL injuries following their return to activity (RTA). Despite this, there are no evidence-informed RTA guidelines to aid clinicians in deciding when this should occur. The first step towards these guidelines is to identify relevant and feasible measures to assess the functional status of these patients. The purpose of this study was therefore to evaluate tests frequently used to assess functional capacity following surgery using a Reduced Error Pruning Tree (REPT). Thirty-six healthy and forty-two ACLinjured adolescent females performed a series of functional tasks. Motion analysis along with spatiotemporal measures were used to extract thirty clinically relevant variables. The REPT reduced these variables down to two limb symmetry measures (maximum anterior hop and maximum lateral hop), capable of classifying injury status between the healthy and ACL injured participants with a 69% sensitivity, 78% specificity and kappa statistic of 0.464. We, therefore, conclude that the REPT model was able to evaluate functional capacity as it relates to injury status in adolescent females. We also recommend considering these variables when developing RTA assessments and guidelines.Clinical Relevance- Our results indicate that spatiotemporal measures may differentiate ACL-injured and healthy female adolescents with moderate confidence using a REPT. The identified tests may reasonably be added to the clinical evaluation process when evaluating functional capacity and readiness to return to activity.

A time-efficient multi-deviant paradigm to determine the effects of gap duration on the mismatch negativity.

The insertion of a silent period (or gap) in a frequently occurring standard stimulus elicits a negative-going event-related potential (ERP), called the Deviant-Related Negativity (DRN). This is often studied using a single-deviant paradigm. To study the effects of gaps with multiple durations, a different sequence would be required for each gap. A more time-efficient multi-deviant paradigm has been developed in which stimuli of various gap widths are included in a single sequence. In the present study, 14 young adults watched a silent video while ignoring an auditory sequence. A single run of a multi-deviant sequence was presented in which 6 different rare deviants alternated with a standard stimulus. The standard was a 200-ms white noise burst. The deviants were constructed by inserting a gap in the standard. The duration of the 6 gaps ranged from 2 to 40 ms. Participants were also presented with multiple runs of single-deviant sequences. Each of the 3 deviants was run in a separate sequence. The amplitude of the DRN elicited by the deviant increased as gap duration became longer, although it did plateau for the longer duration gaps. The amplitudes of the DRNs were larger in the single-deviant paradigm than in the multi-deviant paradigm. However, the difference was only significant when the mastoid reference was used. Behavioural data showed a mean d' of 2.1 for the 5-ms gap. None of the participants were able to detect the 2-ms gap. There was no correlation between d' and the DRN amplitude. Still, the effects of gap duration on the amplitude of the DRN were similar between the single and multi-deviant sequences. This makes the multi-deviant paradigm a possible time-saving alternative to the single-deviant paradigm.

Assessment of objective dynamic knee joint control in anterior cruciate ligament deficient and reconstructed individuals.

BACKGROUND: There is a lack of objective dynamic knee joint control measures that can be related to the status of the anterior cruciate ligament (ACL). The purpose of this study was to introduce two novel measures and apply a third to determine how dynamic knee joint control changes in relation to ACL status during dynamic movements. METHODS: Twenty patients (13 male) were tested pre- (ACLd) and 10-months post- (ACLr) ACL reconstructive surgery and matched to an uninjured participant (CON). Kinetic and kinematic data were synchronously recorded with a force platform and motion capture system. Three objective control measures including dynamic angular stiffness, knee joint center excursion (KJCE), and knee joint center boundary (KJCB) were assessed for each participant when completing the side cut and hop tasks. RESULTS: During the side cut, stiffness was found to be significantly lower in ACLd (0.06 ±â€¯0.01 Nm/kg/°) and ACLr (0.07 ±â€¯0.02 Nm/kg/°) compared to CON (0.08 ±â€¯0.02 Nm/kg/°), while there were no differences in stiffness during the hop. No significant differences were observed in the KJCE during the side cut, while KJCE was significantly greater (p = 0.006) during the hop in CON compared to the ACLd. There were no differences in KJCB. CONCLUSIONS: These high-functioning ACL injured in both ACLd and ACLr phases, aside from reduced stiffness, were able to complete both tasks with similar dynamic control as the CON. Although improvements in self-perceived control between ACLd and ACLr have been observed, this lack of improvement in objective control demonstrates a gap between a patient's self-efficacy and the level of control.