Femoral and Tibial Bony Risk Factors for Anterior Cruciate Ligament Injuries Are Present in More Than 50% of Healthy Individuals

Background: Anterior cruciate ligament (ACL) injuries are multifactorial events that may be influenced by morphometric parameters. Associations between primary ACL injuries or graft ruptures and both femoral and tibial bony risk factors have been well described in the literature. Purpose: To determine values of femoral and tibial bony morphology that have been associated with ACL injuries in a reference population. Further, to define interindividual variations according to participant demographics and to identify the proportion of participants presenting at least 1 morphological ACL injury risk factor. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Computed tomography scans of 382 healthy participants were examined. The following bony ACL risk factors were analyzed: notch width index (NWI), lateral femoral condylar index (LFCI), medial posterior plateau tibial angle (MPPTA), and lateral posterior plateau tibial angle (LPPTA). The proportion of this healthy population presenting with at least 1 pathological ACL injury risk factor was determined. A multivariable logistic regression model was constructed to determine the influence of demographic characteristics. Results: According to published thresholds for ACL bony risk factors, 12% of the examined knees exhibited an intercondylar notch width <18.9 mm, 25% had NWI <0.292, 62% exhibited LFCI <0.67, 54% had MPPTA <83.6°, and 15% had LPPTA <81.6°. Only 14.4% of participants exhibited no ACL bony risk factors, whereas 84.5% had between 2 and 4 bony risk factors and 1.1% had all bony risk factors. The multivariate analysis demonstrated that only the intercondylar notch width ( P < .0001) was an independent predictor according to both sex and ethnicity; the LFCI ( P = .012) and MMPTA ( P = .02) were independent predictors according to ethnicity. Conclusion: The precise definition of bony anatomic risk factors for ACL injury remains unclear. Based on published thresholds, 15% to 62% of this reference population would have been considered as being at risk. Large cohort analyses are required to confirm the validity of previously described morphological risk factors and to define which participants may be at risk of primary ACL injury and reinjury after surgical reconstruction.

How Do Violinists Adapt to Dynamic Assistive Support? A Study Focusing on Kinematics, Muscle Activity, and Musical Performance

Objective Assessing violinists’ motor and musical performance adaptations to dynamic assistive support (DAS) provided by a passive device, using a force-field adaptation paradigm. Background Up to 93% of instrumentalists are affected by musculoskeletal injuries and particularly violinists. The repetitive nature of their work may lead to muscle fatigue, an injury risk factor. DAS has been used in occupational settings to minimize muscle activations and limit fatigue accumulation. DAS may however affect motor and musical performance. Method Fifteen expert violinists were equipped with reflective markers and surface and intramuscular electromyography (EMG) sensors. Movements, muscle activations, and sound were recorded while participants completed three experimental conditions for which they continuously played a 13-s musical excerpt: Control (no DAS), Adaptation (DAS), and Washout (no DAS). DAS was applied at the left elbow (violin-holding side). Conditions were repeated 1 week later. Participants later listened to their own audio recordings playing with and without DAS and blindly assessed their performances. Linear mixed models were used to compare DAS and no-DAS conditions’ kinematic, EMG, and musical performance data. Results DAS perturbed user kinematics but reduced mean activations of left medial deltoid and superior trapezius. Joint kinematic and muscle activation patterns between DAS and no DAS conditions however remained similar. Musical performance was unchanged with DAS. Conclusion Though DAS modified violinists’ upper-limb configurations, resulting kinematics were not detrimental to musical performance. Reduced muscle activations with DAS could contribute to lessening muscle fatigue. Application Although its effect on muscle fatigue should be further investigated, DAS might be useful in preventing violinists’ injuries.

Changes in the Kinematic and Kinetic Characteristics of Lunge Footwork during the Fatiguing Process

Fatigue is a major injury risk factor. The aim of this study was to investigate the effects of fatigue on lunging during the fatiguing process. The lower extremity joint kinematics and kinetics of fifteen male collegiate badminton players were simultaneously recorded by optical motion-capture and force plate systems during lunging. In addition to statistical analyses of discrete variables, one-dimensional statistical parametric mapping (SPM (1D)) was used to analyze the waveform data. The hypotheses were that the biomechanics of lunging maneuvers would change during the fatiguing process, and the fatigue effects would differ in different periods (I–V) of the stance phase and in different joints. Results showed that the initial contact angles, peak angles, moments, power, and time needed to reach the peak angles at the hip, knee, and ankle in the sagittal plane all decreased post-fatigue. A continuous decreasing tendency was reflected in the moments and power of hip and, in particular, knee joints (mostly p < 0.001). Period IV showed a significant fatigue response. In conclusion, both discrete and waveform data illustrated the effects of fatigue, however, the results of SPM (1D) analysis showed both the key period and body segments affected by the fatigue response.

Sport Injuries in Elite Paralympic Judokas: Findings From the 2018 World Championship

Background: To provide information regarding injury incidence, injury pattern, and associated injury risk factors in elite Paralympic judokas. Methods: Participants in this observational research were elite judokas taking part in the IBSA 2018 World Judo Championship. The entire championship was videotaped, and all injuries were prospectively documented using an all-complaints definition. Results: The tournament featured 267 judokas, (B1 = 58; B2 = 105; B3 = 104). The injury proportion was estimated at 18.9 injuries/100 fighters (B1 = 13.8; B2 = 22.3; B3 = 18.5). A total of 745 athletic exposures were registered. The overall injury rate was 68.5 (95% CI, 52.5–89.2); 62.5 (95% CI, 32–122.3); 79.6 (95% CI, 53.8–17.8); and 61.2 (95% CI, 40–93.5) for the total sample, B1, B2, and B3 judokas, respectively. When only injuries resulting in medical attention were analyzed, the overall injury rate was calculated to be 22.8 (95% CI, 14.3–36.5), and the injury proportion was estimated at 6.3 injuries/100 fighters. No significant differences were found for sex, weight, and visual class regarding injury proportion and injury rates. Conclusion: Paralympic judokas show a high injury rate. However, when only injuries that needed medical attention were taken into account, the proportion of athletes injured was low. The degree of visual impairment was not considered as an injury risk factor.

29 September, International Day of Otolaryngologist

According to the World Health Organisation, deafness is one of the most widely spread sensory disorders in the world affecting about 360 million people worldwide. The causes of deafness can be very diverse, from genetic diseases, the impact of injury-risk factor and infectious agents to the administration of ototoxic drugs. Moreover, otolaryngologists believe that about half of deafness and hearing loss cases could have been prevented. Though otolaryngology was separated as an independent medical science in the mid-18th century, the decision to celebrate the Otolaryngologist Day on September 29 as a professional holiday for medical practitioners in this speciality was made not so long ago. This date at the end of September was chosen on purpose: the influx of patients to medical practitioners in this speciality is observed closer to the mid-autumn, after the first cold snap.

Semi-Automating Low Back Compression Force Estimations with an Inertial Sensor

There are currently no evidence-based practical automated injury risk factor estimation tools to monitor low back compressive force in ambulatory or sporting environments. For this purpose, inertial sensors may potentially replace laboratory-based systems with comparable results. The objective was to investigate inertial sensor validity to monitor low back compression force. Thirty participants completed a series of lifting tasks from the floor. Back compression force was estimated using a hand calculated method, an inertial sensor method and a three-dimensional motion capture method. Results demonstrated that semi-automation with a sensor had a higher agreement with motion capture compared to the hand calculated method, with angle errors of less than six degrees and back compression force errors of less than 200 Newtons. It was concluded that inertial sensors are valid to implement for static low back compression force estimations.