Injury Biomechanics Research Articles

The diagnostic precision of computed tomography for traumatic cervical spine injury: An in vitro biomechanical investigation

BackgroundCT is considered the best method for vertebral fracture detection clinically, but its efficacy in laboratory studies is unknown. Therefore, our objective was to determine the sensitivity, precision, and specificity of high-resolution CT imaging compared to detailed anatomic dissection in an axial compression and lateral bending cervical spine biomechanical injury model. Methods35 three-vertebra human cadaver cervical spine specimens were impacted in dynamic axial compression (0.5 m/s) at one of three lateral eccentricities (low 5% of the spine transverse diameter, middle 50%, high 150%) and two end conditions (19 constrained lateral translation and 16 unconstrained). All specimens were imaged using high resolution CT imaging (246 μm). Two clinicians (spine surgeon and neuroradiologist) diagnosed the vertebral fractures based on 34 discrete anatomical structures using both the CT images and anatomical dissection. FindingsThe sensitivity of CT was highest for fractures of the facet joint (59%) and vertebral endplate (57%), and was lowest for pedicle (13%) and lateral mass fractures (23%). The precision of CT was highest for spinous process fractures (83%) and lowest for pedicle (21%), uncinate process and lateral mass (both 23%) fractures. The specificity of CT exceeded 90% for all fractures. The Kappa value between the two reviewers was 0.52, indicating moderate agreement. InterpretationIn this in vitro cervical spine injury model, high resolution CT scanning missed many fractures, notably those of the lateral mass and pedicle. This finding is potentially important clinically, as the integrity of these structures is important to clinical stability and surgical fixation planning.

Biomecânica e Traumatologia do Boxe

Amateur boxing practiced at the Olympic Games has been evolving in conditions of safety for its athletes. The most common injuries are head wounds and lacerations, brain concussions and fractures. However, professional boxing has not kept up with this trend of revising rules and promoting greater safety, turning their athletes prone to severe injuries, especially head and neck injuries. The knowledge of epidemiology and biomechanics of boxing injuries may allow athletes and coaches to anticipate injuries and adopt effective prevention strategies.

Systematic Video Analysis of Anterior Cruciate Ligament Injuries in Professional Male Rugby Players: Pattern, Injury Mechanism, and Biomechanics in 57 Consecutive Cases.

Background:Anterior cruciate ligament (ACL) injuries represent a significant burden to rugby players. Improving our understanding of the patterns and biomechanics that result in ACL injury may aid in the design of effective prevention programs.Purpose:To describe, using video analysis, the mechanisms, situational patterns, and biomechanics of ACL injuries in professional rugby matches. Further aims were to document injuries according to pitch location and timing within the match.Study Design:Case series; Level of evidence, 4.Methods:A total of 62 ACL injuries were identified in players of the 4 most important rugby leagues across 4 consecutive seasons. We analyzed 57 (92%) injury videos for injury mechanism and situational patterns; biomechanical analysis was performed on indirect and noncontact ACL injuries only (38 cases available). Three reviewers independently evaluated each video.Results:More injuries occurred while attacking than defending (41 [72%] vs 16 [28%]; P < .01). Regarding mechanism, 18 (32%) injuries were direct contact; 15 (26%), indirect contact; and 24 (42%), noncontact. Most direct contact injuries involved being tackled directly to the knee (n = 10). Three situational patterns were identified for players who had a noncontact or indirect contact injury: offensive change of direction (COD) (n = 18), being tackled (n = 10), and pressing/tackling (n = 8). Injuries generally involved a knee-loading strategy in the sagittal plane, which was accompanied by knee valgus loading in most cases (94%). Overall, 73% of injuries occurred during the first 40 minutes of effective playing time.Conclusion:Most ACL injuries in professional male rugby players happened through a noncontact or indirect contact mechanism (68%). Three situational patterns were described, including offensive change of direction, being tackled, and pressing/tackling. Biomechanical analysis confirmed a multiplanar mechanism, with a knee-loading pattern in the sagittal plane accompanied by dynamic valgus. As most injuries occurred in the first 40 minutes, accumulated fatigue appears not to be a major risk factor for ACL injury.

Biomechanics of Lumbar Spine Injury in Road Barrier Collision–Finite Element Study

Literature and field data from CIREN database have shown that lumbar spine injuries occur during car crashes. There are multiple hypotheses regarding how they occur; however, there is no biomechanical explanation for these injuries during collisions with road safety barriers (RSBs). Therefore, the objective of this study was to investigate the mechanics of vertebral fractures during car collisions with concrete RSBs. The finite element method was used for the numerical simulations. The global model of the car collision with the concrete RSB was created. The lumbar spine kinematics were extracted from the global simulation and then applied as boundary conditions to the detailed lumbar spine model. The results showed that during the collision, the occupant was elevated, and then dropped during the vehicle landing. This resulted in axial compression forces 2.6 kN with flexion bending moments 34.7 and 37.8 Nm in the L2 and L3 vertebrae. It was shown that the bending moment is the result of the longitudinal force on the eccentricity. The lumbar spine index for the L1–L5 section was 2.80, thus indicating a lumbar spine fracture. The minimum principal strain criterion of 7.4% and damage variable indicated L2 and L3 vertebrae and the inferior part of L1, as those potentially prone to fracture. This study found that lumbar spine fractures could occur as a consequence of vehicle landing during a collision with a concrete RSB mostly affecting the L1–L3 lumbar spine section. The fracture was caused by a combination of axial forces and flexion bending moments.

Does the direction of impact influence how the athlete presents following a sport-related concussion?

Background: Previous research has investigated the biomechanics of head injury including impact location as it relates to sport-related concussion (SRC). However, there is limited data investigating the potential association between the direction of impact and its influence on SRC outcomes. The purpose of this study was to investigate if impact direction influences athlete symptomology and video signs of SRC.

Suture Tape–Augmented Posterior Cruciate Ligament Repair Should Be Tensioned and Fixed at Approximately 100° Knee Flexion to Prevent Loss of Full Flexion

PurposeTo evaluate the biomechanics of simulated posterior cruciate ligament injuries (SimPCL) with and without internal brace suture tape augmentation (IBSTA) in cadaver knees.MethodsA total of 20 cadaveric knees were used, all male, with an average age of 65 ± 18 years. Femoral tunnel isometry was evaluated at the 1/11 o’clock and 2/10 o’clock femoral positions. SimPCL were created in 6 knees. IBSTA was performed, and load data were collected through knee range of motion. An additional 6 specimens were evaluated at the 1/11 femoral tunnel position, and load cell recordings were obtained at 10 different knee flexion angles. Cyclic displacement in 8 cadaver knees was assessed using an Instron machine. Load and displacement data were recorded. Testing was performed under 3 conditions for each specimen: intact PCL, SimPCL, and SimPCL/IBSTA using the 1/11 femoral tunnel position.ResultsThere was no difference in isometry when comparing the 1/11 o’clock (7.1 ± 4.0 ft∗lb) femoral position and the 2/10 o’clock (7.6 ± 4.2 ft∗lb) position (P = .467). SimPCL/IBSTA suture tape tension gradually increased with progressive flexion to a peak at approximately 120° of knee flexion. For cycle 100 tibial displacement, there was no difference between intact (4.41 mm) and SimPCL/IBSTA (5.59 mm, P = .391). There was a difference between intact (4.41 mm) and SimPCL (7.19 mm, P = .006) , but there was no significant difference between SimPCL/IBSTA (5.59 mm) and SimPCL (7.19 mm, P = .140). There was a difference in cycle 1 stiffness between intact (62.3 N/mm) and Sim2PCL (37 N/mm, P = .005). There was no difference between other groups.ConclusionsIn this cadaver study, there was a 1.18-mm average difference in posterior tibial displacement when comparing intact and SimPCL/IBSTA. The internal brace construct should be tensioned and fixed at approximately 100° of knee flexion to prevent loss of full flexion.Clinical RelevanceThe presented biomechanical data for internal bracing of PCL injuries may lead to improved surgical techniques.

Subject-Specific Head Model Generation by Mesh Morphing: A Personalization Framework and Its Applications.

Finite element (FE) head models have become powerful tools in many fields within neuroscience, especially for studying the biomechanics of traumatic brain injury (TBI). Subject-specific head models accounting for geometric variations among subjects are needed for more reliable predictions. However, the generation of such models suitable for studying TBIs remains a significant challenge and has been a bottleneck hindering personalized simulations. This study presents a personalization framework for generating subject-specific models across the lifespan and for pathological brains with significant anatomical changes by morphing a baseline model. The framework consists of hierarchical multiple feature and multimodality imaging registrations, mesh morphing, and mesh grouping, which is shown to be efficient with a heterogeneous dataset including a newborn, 1-year-old (1Y), 2Y, adult, 92Y, and a hydrocephalus brain. The generated models of the six subjects show competitive personalization accuracy, demonstrating the capacity of the framework for generating subject-specific models with significant anatomical differences. The family of the generated head models allows studying age-dependent and groupwise brain injury mechanisms. The framework for efficient generation of subject-specific FE head models helps to facilitate personalized simulations in many fields of neuroscience.

Novel biomechanical injury risk score demonstrates correlation with lower limb posterior chain injury in 50 elite-level rugby union athletes

ObjectivesLower limb posterior chain injury (PCI) is common among athletic populations, with multifactorial risk factors including age, previous injury, strength measurements, range of motion and training load. Biomechanics are commonly...

Analysis of Foot-Ankle-Leg Injuries in Various Under-Foot Impact Loading Environments With a Human Active Lower Limb Model.

Lower limb injuries caused by under-foot impacts often appear in sport landing, automobile collision, and antivehicular landmine blasts. The purpose of this study was to evaluate a foot-ankle-leg model of the human active lower limb (HALL) model, and used it to investigate lower leg injury responses in different under-foot loading environments to provide a theoretical basis for the design of physical dummies adapted to multiple loading conditions. The model was first validated in allowable rotation loading conditions, like dorsiflexion, inversion/eversion, and external rotation. Then, its sensitivity to loading rates and initial postures was further verified through experimental data concerning both biomechanical stiffness and injury locations. Finally, the model was used to investigate the biomechanical responses of the foot-ankle-leg region in different under-foot loading conditions covering the loading rate from sport landing to blast impact. The results showed that from -rovide a theoreticaln to 30 deg dorsiflexion, the neutral posture always showed the largest tolerance, and more than 1.5 times tolerance gap was achieved between neutral posture and dorsiflexion 30 deg. Under-foot impacts from 2 m/s to 14 m/s, the peak tibia force increased at least 1.9 times in all postures. Thus, we consider that it is necessary to include initial posture and loading rate factors in the definition of the foot-ankle-leg injury tolerance for under-foot impact loading.

Monteggia Fracture-Dislocation with Associated TFCC Injury and DRUJ Subluxation – A Very Rare Case Report

Introduction:Monteggia fracture-dislocation is defined as a proximal third ulna fracture with radiocapitellar joint dislocation. The term “Monteggia equivalent or variant” describes various injuries with similar radiographic patterns and injury biomechanics. Several isolated cases of unusual injuries associated with Monteggia fractures have been reported. However, an associated TFCC injury has not been described in the literature before. We present a rare report of a 24-year-old female with a Monteggia fracture and associated TFCC injury – a crisscross type of injury. Case Report:A 24-year-old female was involved in a road traffic accident and presented to our level I trauma center with pain and deformity in the left forearm. On evaluation, she was found to have type I Monteggia fracture-dislocation. Intraoperatively, once the proximal ulna was fixed, she had clicking in the wrist during rotations. Fluoroscopic images showed DRUJ subluxation, but it was stable in supination. Hence was splinted in a reduced position. The patient continued to have persistent symptoms in the wrist despite adequate conservative measures. Hence, she underwent arthroscopic TFCC repair and DRUJ pinning. At her last follow-up (3 months), the patient was clinically better with a good range of motion and no pain. Conclusion:In treating Monteggia fracture-dislocations, high index of suspicion is needed to diagnose radioulnar joint instability. If they are missed, they can result in long-term disability, so appropriate evaluation to diagnose TFCC and DRUJ injuries is required. DRUJ stabilization and TFCC repair can produce consistent results when treated adequately. Keywords:TFCC, monteggia, wrist, arthroscopy, proximal ulna.

생체역학적 운동 효율 분석 및 부상 방지를 위한 지능형 개인 운동 모니터링 시스템

본 논문은 개인이 운동을 수행할 때 정확한 자세와 더불어 목표 근육의 사용 여부를 동시에 모니터링할 수 있는 지능형 운동 모니터링 시스템을 제안한다. 제안하는 시스템은 먼저 키넥트 카메라를 이용하여 사용자의 관절 각도를 측정하고, Unity 환경에서 가상환경 아바타를 통해 전신 자세를 실시간으로 모니터에 가시화해준다. 이와 동시에 밴드형 근전도 센서를 이용하여 사용자의 타깃 근육들의 근전도를 측정하고, 사용자의 근육 활성화에 따른 누적피로도를 가시화해준다. 다음으로, 측정된 관절 각과 근전도를 학습된 신경망의 입력으로 하여 현재 사용자에 의해 행해지는 운동의 이름을 출력하며, 운동이 올바로 수행되었는지에 대한 정보를 제공한다. 파일럿 테스트를 통해, 제안된 시스템의 운동 분류 성능과 올바른 운동 유도 및 부상 방지에 대한 기대효과를 검증한다.

The effect of angle on change of direction biomechanics: Comparison and inter-task relationships

ABSTRACT The aim of this was study to examine the inter-task relationships and compare change of direction (COD) biomechanics between different angles (45°, 90°, and 180°). Twenty-seven men performed three COD tasks, whereby lower-limb and trunk kinematics and kinetics were assessed via 3D motion and ground reaction force (GRF) analysis. Key mechanical differences (p ≤ 0.025, η 2 = 0.024–0.940) in velocity profiles, GRF, sagittal joint angles and moments, multiplanar knee joint moments, and technical parameters existed between CODs. The primary findings were that as COD angle increased, velocity profiles decreased (p < 0.001, d = 1.56–8.96), ground contact times increased (p < 0.001, d = 3.00–5.04), vertical GRF decreased (p < 0.001, d = 0.87–3.48), and sagittal peak knee joint moments decreased (p ≤ 0.040, d = 0.62–2.73). Notably, the greatest peak knee internal rotation (KIRMs) and abduction moments (KAMs) and angles were observed during the 90° COD (p < 0.001, d = 0.88–1.81), indicating that this may be the riskiest COD angle. Small to very large (r = 0.260–0.702) associations in KAMs and KIRMs were observed between tasks, indicating that evaluations at different angles are needed to develop an athlete’s biomechanical injury risk profile. The results support the concept that COD biomechanics and potential surrogates of non-contact anterior cruciate ligament injury risk are “angle-dependent”; which have important implications for COD coaching, screening, and physical preparation.

Configurations of underreported cyclist-motorised vehicle and single cyclist collisions: Analysis of a self-reported survey

Lower severity cycling collisions, and single cyclist collisions (or single bicycle crashes) are significantly underreported in police statistics, introducing biases into the types of collisions that are available for analysis. Furthermore, many lower severity collisions do not appear in other collision data sources (e.g. hospital and insurance data). This in turn affects priorities for cyclist safety and puts an underemphasis on certain collision types. Due to an absence of data, little is known of the configurations of unreported collisions. In this paper, data from a recent self-reporting survey of cycling collisions in Ireland is used to provide details of cyclist collisions with motorised vehicles and single cyclist collisions, with the inclusion of unreported collision types. Pre-crash scenarios and impact configurations for cyclist collisions with bonnet-type vehicles, and collision factors and fall types for single cyclist collisions are coded. Injury patterns and police underreporting levels are compared, and representative collision scenarios are identified.This study highlights the relative importance of collisions resulting from the cyclist and vehicle travelling in the same direction, specifically, nearside-hook, vehicle lane changing, and overtaking manoeuvres are emphasised. Furthermore, cases involving the cyclist struck from the side by vehicle fronts comprise a smaller share than previous studies. Specifically, side to side impacts, impacts between the front of the cyclist/bicycle and the side of the vehicle, and impacts with open(ing) doors emerge as important impact configurations with the inclusion of self-reported cases. For single cyclist collisions, the importance of loss of traction of the tyres due to slippery road conditions and interactions with tram tracks and kerbs are emphasised. Fall types differ between single cyclist collision scenarios and are related to differences in injury severity.These findings add to existing knowledge for fatal and higher severity collisions, demonstrating that cyclist safety priorities change with inclusion of underreported, and lower severity collisions. The findings are particularly relevant to road infrastructural planners, as well as in the fields of injury biomechanics, and automated vehicle safety (ADAS). Representative scenarios for collisions with bonnet-type vehicles and single cyclist collisions have been identified, allowing for their future inclusion in development of collision and injury prevention strategies. The dataset generated in this study is available from the authors on reasonable request.

Study on the Effect of Sample Temperature on the Uniaxial Compressive Mechanical Properties of the Brain Tissue.

Craniocerebral injury has been a research focus in the field of injury biomechanics. Although experimental endeavors have made certain progress in characterizing the material behavior of the brain, the temperature dependency of brain mechanics appears to be inconclusive thus far. To partially address this knowledge gap, the current study measured the brain material behavior via unconstrained uniaxial compression tests under low strain rate (0.0083 s−1) and high strain rate (0.83 s−1) at four different sample temperatures (13°C, 20°C, 27°C, and 37°C). Each group has 9~12 samples. One-way analysis of variance method was used to study the influence of sample temperature on engineering stress. The results show that the effect of sample temperature on the mechanical properties of brain tissue is significant under the high strain rate, especially at low temperature (13°C), in which the hardening of the brain tissue is very obvious. At the low strain rate, no temperature dependency of brain mechanics is noted. Therefore, the current results highlight that the temperature of the brain sample should be ensured to be in accordance with the living subject when studying the biomechanical response of living tissue.

Impact Device for Biomechanics of Human Head-Neck Injuries

This paper describes experimental tests in LARM2 in Rome to analyze impacts on a human head. The tests consist of performing three different types of impact by hitting a commercial head mannequin with a rigid object. Inertial Measurement Unit (IMU) sensors and force sensors measure each impact’s effect and evaluate the results. The sensors are located on suitable head points to monitor force, acceleration, and angular displacement on small and large lateral impact and top impact events. Results of tests are discussed to investigate and characterize the biomechanics in human head impacts. Considerations from results are used to formulate a new criterion for head-neck injury by impacts.

Association between biological maturation and anterior cruciate ligament injury risk factors during cutting.

Adolescent females are particularly susceptible to suffering anterior cruciate ligament (ACL) injuries, likely influenced by well-established maturational changes. This study investigated ACL biomechanical injury risk factors and their association with biological maturation in females. Thirty-five adolescent females (15±1 year) completed a series of maximum-effort 90° unanticipated cutting maneuvers. Established biomechanical ACL injury risk factors (including external knee abduction moments, knee abduction, hip abduction, knee flexion, ground reaction force) were derived from an optoelectronic motion analysis system and force platforms, with inter-limb asymmetries in these risk factors also computed. Biological maturation (percentage of predicted adult stature) was assessed using validated regression equations, incorporating anthropometric measures of participants and their biological parents. Significant bilateral asymmetries were observed with higher peak external knee abduction moments, higher ground reaction forces and less knee flexion (from 0-18% and 30-39% of contact) during the non-dominant vs. dominant cuts (effect sizes =0.36, 0.63 and 0.50, respectively). Maturation did not appear to influence these asymmetries; however, less hip abduction was observed (e.g., 21-51% of contact for dominant cuts) in more biologically-mature females. These results highlight a potential maturation-related change in cutting technique that may explain the apparent heightened ACL injury risk in this population. As females mature, training targeted at neuromuscular control of hip abductor (e.g. gluteal) muscle groups could potentially mitigate ACL injury risk.

DOES BRAIN ACTIVATION DURING FUNCTIONAL MOVEMENT TASKS DIFFERENTIATE BETWEEN GOOD AND BAD MOVERS? AN INTEGRATED NEUROIMAGING ASSESSMENT OF MOTOR CONTROL IN YOUNG ATHLETES

Background:Aberrant frontal and sagittal plane knee motor control biomechanics contribute to increased anterior cruciate ligament (ACL) injury risk. Emergent data further indicates alterations in brain function may underlie ACL injury high risk biomechanics and primary injury. However, technical limitations have limited our ability to assess direct linkages between maladaptive biomechanics and brain function.Hypothesis/Purpose:(1) Increased frontal plane knee range of motion would associate with altered brain activity in regions important for sensorimotor control and (2) increased sagittal plane knee motor control timing error would associate with altered activity in sensorimotor control brain regions.Methods:Eighteen female high-school basketball and volleyball players (14.7 ± 1.4 years, 169.5 ± 7 cm, 65.8 ± 20.5 kg) underwent brain functional magnetic resonance imaging (fMRI) while performing a bilateral, combined hip, knee, and ankle flexion/extension movements against resistance (i.e., leg press) Figure 1(a). The participants completed this task to a reference beat of 1.2 Hz during four movement blocks of 30 seconds each interleaved in between 5 rest blocks of 30 seconds each. Concurrent frontal and sagittal plane range of motion (ROM) kinematics were measured using an MRI-compatible single camera motion capture system.Results:Increased frontal plane ROM was associated with increased brain activity in one cluster extending over the occipital fusiform gyrus and lingual gyrus (p = .003, z > 3.1). Increased sagittal plane motor control timing error was associated with increased brain activity in multiple clusters extending over the occipital cortex (lingual gyrus), frontal cortex, and anterior cingulate cortex (p < .001, z > 3.1); see Figure 1 (b).Conclusion:The associations of increased knee frontal plane ROM and sagittal plane timing error with increased activity in regions that integrate visuospatial information may be indicative of an increased propensity for knee injury biomechanics that are, in part, driven by reduced spatial awareness and an inability to adequately control knee abduction motion. Increased activation in these regions during movement tasks may underlie an impaired ability to control movements (i.e., less neural efficiency), leading to compromised knee positions during more complex sports scenarios. Increased activity in regions important for cognition/attention associating with motor control timing error further indicates a neurologically inefficient motor control strategy.Figure 1:(a) Participant positioned in the leg press apparatus during fMRI and instrumented with MRI-compatible motion analysis markers (b) Brain activity associated with poor knee frontal plane (green) and sagittal plane (red) kinematics.

Individual response to multi-density midsoles to minimise biomechanical injury risk factors of Achilles tendinopathy in distance running

Modifications of midsole geometry and material properties are essential footwear design features to prevent overuse injuries (OIs) in distance running. With an injury frequency of 10.9%, Achilles t...

IMU-based knee flexion, abduction and internal rotation estimation during drop landing and cutting tasks

Anterior cruciate ligament (ACL) injury is a common and severe knee injury in sports. Knee flexion, abduction and internal rotation angles are considered crucial biomechanical indicators of the ACL injury risk but currently are computed in a laboratory with an optical motion capture. This paper introduces an inertial measurement unit (IMU) based algorithm for knee flexion, abduction and internal rotation estimation during ACL injury risk assessment tests, including drop landing and cutting tasks. This algorithm includes a special two-step complementary-based orientation filter and a special single-pose sensor-to-segment calibration procedure. Fourteen healthy subjects performed double-leg, single-leg drop landing and cutting tasks. Each subject wore four IMUs and reflective marker clusters on their thighs and shanks. For the presented knee angles algorithm with an empirical initial segment orientation, the root mean square errors (RMSEs) of the estimated continuous knee flexion, abduction and internal rotation cross all the movement tasks were 1.07°, 2.87° and 2.64°, and RMSEs of the peak knee flexion and peak knee abduction errors were 1.22° and 3.82°. The knee angles algorithm was capable of estimating knee abduction and internal rotation angles during drop landing and cutting tasks, and knee flexion estimation was substantially more accurate than previously reported approaches. Additionally, we found that for the presented algorithm, the accuracy of initial segment orientation was a critical factor for knee abduction and internal rotation estimations. The presented IMU-based knee angles algorithm could serve as a foundation to enable in-field biomechanical ACL injury risk assessment.

Editorial: Youth and Winter Sports

3. This congress was multidisciplinary with key notes and parallel sections on both life sciences and social sciences. We received communications about physical preparation, physiology, biomechanics, sport medicine, rehabilitation as well as history, sociology, management, psychology, teaching.The following world-class experts gave six key notes presentations:• Milena Parent (Canada) -Governance and legacy of the YOG.• Hans-Christer Holmberg (Sweden) -Biomechanics and physiology in nordic skiing.• Andrew Denning (USA) -History of the human-environment relationships in the Alps through the sport of skiing.• Erich E. Muller (Austria) -Biomechanics and prevention of injuries in alpine Skiing.• Oyvind Sandbakk (Norway) -Norwegian success in winter sports. Despite that the research topic was multidisciplinary in line with the content of the congress, only articles in exercise physiology, biomechanics and nutrition are published. years old -physiological characteristic (i.e., high total haemoglobin mass expressed in g/kg) is a relevant predictor of success at senior level in endurance sports as cross-country ski or triathlon.Finally, this research topic includes three reviews (compression garments, injuries and nutritional considerations) relevant to all winter sports: