scholarly journals Goal-Oriented Optimization of Dynamic Simulations to Find a Balance between Performance Enhancement and Injury Prevention during Volleyball Spiking

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 598
Author(s):  
Dhruv Gupta ◽  
Cyril J. Donnelly ◽  
Jody L. Jensen ◽  
Jeffrey A. Reinbolt
Keyword(s):  
Injury Prevention ◽  
Shoulder Joint ◽  
Injury Risk ◽  
Performance Enhancement ◽  
Optimization Methods ◽  
Knee Extension ◽  
Peak Height ◽  
Whole Body ◽  
Dynamic Simulations ◽  
Joint Torques

Performance enhancement and injury prevention are often perceived as opposite sides of a coin, where focusing on improvements of one leads to detriment of the other. In this study, we used physics-based simulations with novel optimization methods to find participant-specific, whole-body mechanics of volleyball spiking that enhances performance (the peak height of the hitting hand and its forward velocity) while minimizing injury risk. For the volleyball spiking motion, the shoulder is the most common injury site because of the high mechanical loads that are most pronounced during the follow-through phase of the movement. We analyzed 104 and 209 spiking trials across 13 participants for the power and follow-through phases, respectively. During the power phase, simulations increased (p < 0.025) the peak height of the hitting wrist by 1% and increased (p < 0.025) the forward wrist velocity by 25%, without increasing peak shoulder joint torques, by increasing the lower-limb forward swing (i.e., hip flexion, knee extension). During the follow-through phase, simulations decreased (p < 0.025) peak shoulder joint torques by 75% elicited by synergistic rotation of the trunk along the pathway of the hitting arm. Our results show that performance enhancement and injury prevention are not mutually exclusive and may both be improved simultaneously, potentially leading to better-performing and injury-free athletes.

The acute effects of vibratory stimuli during exercise on the sensorimotor control of the shoulder complex: A pilot study

2021 ◽  
pp. 1-9
Author(s):  
Somu Kotoshiba ◽  
Noriaki Maeda ◽  
Masanori Morikawa ◽  
Mitsuhiro Yoshimi ◽  
Shogo Sakai ◽  
...  
Keyword(s):  
Upper Limb ◽  
Shoulder Joint ◽  
Injury Risk ◽  
Weight Bearing ◽  
Sensorimotor Control ◽  
Whole Body ◽  
Partial Weight Bearing ◽  
Serratus Anterior ◽  
The Impact ◽  
Partial Weight

BACKGROUND: Functional stability of the shoulder requires a balance of active forces, passive forces, and control subsystems of the joint complex. Although whole-body vibration enhances shoulder muscle function and proprioception, the impact of vibration on the sensorimotor control of the shoulder joint remains unclear. OBJECTIVE: To investigate the acute effect of vibratory stimuli on the sensorimotor control of the shoulder joint. METHODS: Fifteen male participants (age, 22.7 ± 2.3 years) were included and performed the exercise in a modified push-up position with partial weight-bearing on a vibration platform with and without vibratory stimuli. The vibration protocol included six sets lasting for 30 s each with a 30-s rest between sets. The main outcome measures included the upper limb static stability test, Upper Quarter Y Balance Test (UQYBT), and electromyography data of the upper limb. RESULTS: Vibratory stimuli resulted in an increased UQYBT score (all directions; P< 0.01) and infraspinatus, serratus anterior, and lower trapezius muscle activity (P< 0.05) between pre- and post-exercise versus the control condition. Stabilometric parameters showed no significant interaction between condition and time. CONCLUSIONS: Vibratory stimuli could maximize training benefits while limiting injury risk for athletes. Our findings could guide the development of rehabilitation programs for patients with shoulder instability.

scholarly journals Age-Related Differences in Functional Hamstring/Quadriceps Ratio Following Soccer Exercise in Female Youth Players: An Injury Risk Factor

2018 ◽  
Vol 30 (3) ◽  
pp. 376-382 ◽  
Author(s):  
Mark De Ste Croix ◽  
Abigail Priestley ◽  
Rhodri Lloyd ◽  
Jon Oliver
Keyword(s):  
Knee Flexion ◽  
Injury Risk ◽  
Knee Extension ◽  
Peak Height ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
Specific Exercise ◽  
Movement Velocity ◽  
Full Extension ◽  
Age Related

Purpose: Fatigue negatively alters dynamic knee control, and the functional hamstring/quadriceps ratio (H/QFUNC) plays an important role in stabilizing the joint. The aim of this study was to investigate the influence of soccer-specific exercise on H/QFUNC in under (U) 13-, U15-, and U17-year-old female soccer players. Methods: A total of 36 female players performed concentric and eccentric actions of the hamstrings at 60°, 120°, and 180°/s before and after an age group–specific field-based soccer protocol. H/QFUNC was determined in the first 30° of knee flexion. Results: Significant angle × velocity (P = .001) and time × angle (P = .033) interaction effects were found indicating a lower H/QFUNC with increased movement velocity at 0°–10° as opposed to greater knee flexion angles. Fatigue-related effects were only evident near full knee extension. Probabilistic inferences indicated that changes in H/QFUNC were generally unclear in U13s, likely detrimental in U15s, and very likely beneficial in U17s. Conclusions: Altered muscular control following soccer-specific exercise is age dependent with players’ 1-year post-peak height velocity at greatest risk of injury. Injury prevention and screening need to be age and maturation appropriate, should consider the effects of fatigue, and include movements near full extension.

Optimal Estimation of Dynamically Consistent Kinematics and Kinetics for Forward Dynamic Simulations

2007 ◽  
Author(s):  
Christian D. Remy ◽  
Darryl G. Thelen
Keyword(s):  
Large Scale ◽  
Dynamic Models ◽  
Optimization Problems ◽  
Optimal Estimation ◽  
Whole Body ◽  
Dynamic Simulations ◽  
Joint Torques ◽  
Dynamic Constraints ◽  
Traditional Approaches

Forward dynamic simulation provides a powerful framework for characterizing in vivo loads, for investigating the muscular coordination of movement, and for predicting changes in movement due to injury, impairment or surgical intervention. However, the computational challenge of generating simulations has greatly limited the use and application of dynamic models. Traditional approaches use optimization to determine a set of input trajectories (e.g. muscle forces or joint torques) that drive a model to track experimental motion and force measurements [1,2]. Optimization is needed, in part, to resolve dynamic inconsistencies between measured kinematics and ground reactions. Large scale dynamic optimization problems of this type are inherently difficult to solve, often necessitating model simplifications. It has previously been shown that dynamic inconsistencies can be efficiently resolved on a per-frame basis by enforcing whole-body dynamic constraints [3,4]. However, forward simulations cannot be generated from such data since integration of the accelerations will not re-produce measured velocities and positions.

Injury prevention knowledge, beliefs and strategies in elite female footballers at the FIFA Women’s World Cup France 2019

2021 ◽  
pp. bjsports-2020-103131
Author(s):  
Celeste Geertsema ◽  
Liesel Geertsema ◽  
Abdulaziz Farooq ◽  
Joar Harøy ◽  
Chelsea Oester ◽  
...  
Keyword(s):  
Risk Factors ◽  
Injury Prevention ◽  
Injury Risk ◽  
Risk Level ◽  
Attitudes And Beliefs ◽  
Implementation Barriers ◽  
World Cup ◽  
Positive Attitudes ◽  
High Level ◽  
Women's Football

ObjectivesThis study assessed knowledge, beliefs and practices of elite female footballers regarding injury prevention.MethodsA survey was sent to players participating in the FIFA Women’s World Cup France 2019. Questions covered three injury prevention domains: (1) knowledge; (2) attitudes and beliefs; (3) prevention practices in domestic clubs. Additionally, ACL injury history was assessed.ResultsOut of 552 players, 196 women responded (35.5%). More than 80% of these considered injury risk to be moderate or high. Players listed knee, ankle, thigh, head and groin as the most important injuries in women’s football. The most important risk factors identified were low muscle strength, followed by poor pitch quality, playing on artificial turf, too much training, reduced recovery and hard tackles. In these elite players, 15% did not have any permanent medical staff in their domestic clubs, yet more than 75% had received injury prevention advice and more than 80% performed injury prevention exercises in their clubs. Players identified the two most important implementation barriers as player motivation and coach attitude. Two-thirds of players used the FIFA 11+ programme in their clubs.ConclusionsThis diverse group of elite players demonstrated good knowledge of risk level and injury types in women’s football. Of the risk factors emphasised by players, there was only one intrinsic risk factor (strength), but several factors out of their control (pitch quality and type, training volume and hard tackles). Still players had positive attitudes and beliefs regarding injury prevention exercises and indicated a high level of implementation, despite a lack of medical support.

scholarly journals Implementation of the Activate injury prevention exercise programme in English schoolboy rugby union

2021 ◽  
Vol 7 (2) ◽  
pp. e001018
Author(s):  
Craig Barden ◽  
Keith A Stokes ◽  
Carly D McKay
Keyword(s):  
Injury Prevention ◽  
Injury Risk ◽  
Behavioural Change ◽  
Exercise Programme ◽  
Rugby Union ◽  
Support Staff ◽  
Barriers To Implementation ◽  
Common Barriers ◽  
Perceptions Of School ◽  
Intervention Uptake

ObjectivesThe implementation of the Activate injury prevention exercise programme has not been assessed in an applied context. This study aimed to (1) describe the knowledge and perceptions of school rugby coaches and players towards injury risk, prevention and Activate and (2) evaluate Activate implementation in schoolboy rugby using the reach, effectiveness, adoption, implementation and maintenance framework.MethodsBespoke electronic surveys were administered to coaches (including support staff) and players at participating English schools (2018–2020). Most questions and statements were answered using a 7-point Likert scale. At baseline, participants detailed their Activate awareness and perceptions of injury risk and prevention in schoolboy rugby. At postseason, participants reported Activate use throughout the study and their perceptions towards the programme.ResultsAt baseline, significant differences existed between coaches (n=106) and players (n=571) in Activate awareness (75% and 13% respectively; χ2=173.5, p<0.001). Coaches perceived rugby had a significantly greater injury risk than players, while holding more positive perceptions towards injury prevention. At postseason, coaches reported greater Activate adoption compared with players (76% and 18% respectively; χ2=41.8, p<0.001); 45% of players were unaware if they used the programme. Median session adherence was twice weekly, with a median duration of 10–15 min. This suggests Activate was not implemented as intended, with recommendations of three 20 min sessions per week. Both groups identified common barriers to implementation, such as lack of time and inclusion of a ball.ConclusionCoaches are instrumental in the decision to implement Activate. Targeting behavioural change in these individuals is likely to have the greatest impact on intervention uptake.

scholarly journals Somatic maturation and the relationship between bone mineral variables and types of sports among adolescents: cross-sectional study

2017 ◽  
Vol 135 (3) ◽  
pp. 253-259 ◽  
Author(s):  
Ricardo Ribeiro Agostinete ◽  
Igor Hideki Ito ◽  
Han Kemper ◽  
Carlos Marcelo Pastre ◽  
Mário Antônio Rodrigues-Júnior ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Peak Height ◽  
Cross Sectional Study ◽  
Height Velocity ◽  
Whole Body ◽  
Sectional Study ◽  
Peak Height Velocity ◽  
Mineral Density ◽  
Cross Sectional

ABSTRACT CONTEXT AND OBJECTIVE: Peak height velocity (PHV) is an important maturational event during adolescence that affects skeleton size. The objective here was to compare bone variables in adolescents who practiced different types of sports, and to identify whether differences in bone variables attributed to sports practice were dependent on somatic maturation status. DESIGN AND SETTING: Cross-sectional study, São Paulo State University (UNESP). METHODS: The study was composed of 93 adolescents (12 to 16.5 years old), divided into three groups: no-sport group (n = 42), soccer/basketball group (n = 26) and swimming group (n = 25). Bone mineral density and content were measured using dual-energy x-ray absorptiometry and somatic maturation was estimated through using peak height velocity. Data on training load were provided by the coaches. RESULTS: Adolescents whose PHV occurred at an older age presented higher bone mineral density in their upper limbs (P = 0.018). After adjustments for confounders, such as somatic maturation, the swimmers presented lower values for bone mineral density in their lower limbs, spine and whole body. Only the bone mineral density in the upper limbs was similar between the groups. There was a negative relationship between whole-body bone mineral content and the weekly training hours (β: -1563.967; 95% confidence interval, CI: -2916.484 to -211.450). CONCLUSION: The differences in bone variables attributed to sport practice occurred independently of maturation, while high training load in situations of hypogravity seemed to be related to lower bone mass in swimmers.

Biomechanics Differ for Individuals With Similar Self-Reported Characteristics of Patellofemoral Pain During a High-Demand Multiplanar Movement Task

2020 ◽  
pp. 1-10
Author(s):  
Matthew K. Seeley ◽  
Seong Jun Son ◽  
Hyunsoo Kim ◽  
J. Ty Hopkins
Keyword(s):  
Ground Reaction Force ◽  
Injury Risk ◽  
Reaction Force ◽  
Patellofemoral Pain ◽  
Joint Torque ◽  
Whole Body ◽  
Ground Contact ◽  
High Demand ◽  
Contact Phase ◽  
Hip Extension

Context: Patellofemoral pain (PFP) is often categorized by researchers and clinicians using subjective self-reported PFP characteristics; however, this practice might mask important differences in movement biomechanics between PFP patients. Objective: To determine whether biomechanical differences exist during a high-demand multiplanar movement task for PFP patients with similar self-reported PFP characteristics but different quadriceps activation levels. Design: Cross-sectional design. Setting: Biomechanics laboratory. Participants: A total of 15 quadriceps deficient and 15 quadriceps functional (QF) PFP patients with similar self-reported PFP characteristics. Intervention: In total, 5 trials of a high-demand multiplanar land, cut, and jump movement task were performed. Main Outcome Measures: Biomechanics were compared at each percentile of the ground contact phase of the movement task (α = .05) between the quadriceps deficient and QF groups. Biomechanical variables included (1) whole-body center of mass, trunk, hip, knee, and ankle kinematics; (2) hip, knee, and ankle kinetics; and (3) ground reaction forces. Results: The QF patients exhibited increased ground reaction force, joint torque, and movement, relative to the quadriceps deficient patients. The QF patients exhibited: (1) up to 90, 60, and 35 N more vertical, posterior, and medial ground reaction force at various times of the ground contact phase; (2) up to 4° more knee flexion during ground contact and up to 4° more plantarflexion and hip extension during the latter parts of ground contact; and (3) up to 26, 21, and 48 N·m more plantarflexion, knee extension, and hip extension torque, respectively, at various times of ground contact. Conclusions: PFP patients with similar self-reported PFP characteristics exhibit different movement biomechanics, and these differences depend upon quadriceps activation levels. These differences are important because movement biomechanics affect injury risk and athletic performance. In addition, these biomechanical differences indicate that different therapeutic interventions may be needed for PFP patients with similar self-reported PFP characteristics.

scholarly journals Shoe cushioning, body mass and running biomechanics as risk factors for running injury: a study protocol for a randomised controlled trial

BMJ Open ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. e017379 ◽  
Author(s):  
Laurent Malisoux ◽  
Nicolas Delattre ◽  
Axel Urhausen ◽  
Daniel Theisen
Keyword(s):  
Risk Factors ◽  
Randomised Controlled Trial ◽  
Injury Prevention ◽  
Body Mass ◽  
Injury Risk ◽  
Cox Regression ◽  
Controlled Trial ◽  
Study Groups ◽  
Self Report ◽  
Randomised Controlled

IntroductionRepetitive loading of the musculoskeletal system is suggested to be involved in the underlying mechanism of the majority of running-related injuries (RRIs). Accordingly, heavier runners are assumed to be at a higher risk of RRI. The cushioning system of modern running shoes is expected to protect runners again high impact forces, and therefore, RRI. However, the role of shoe cushioning in injury prevention remains unclear. The main aim of this study is to investigate the influence of shoe cushioning and body mass on RRI risk, while exploring simultaneously the association between running technique and RRI risk.Methods and analysisThis double-blinded randomised controlled trial will involve about 800 healthy leisure-time runners. They will randomly receive one of two running shoe models that will differ in their cushioning properties (ie, stiffness) by ~35%. The participants will perform a running test on an instrumented treadmill at their preferred running speed at baseline. Then they will be followed up prospectively over a 6-month period, during which they will self-report all their sports activities as well as any injury in an internet-based database TIPPS (Training and Injury Prevention Platform for Sports). Cox regression analyses will be used to compare injury risk between the study groups and to investigate the association among training, biomechanical and anatomical risk factors, and injury risk.Ethics and disseminationThe study was approved by the National Ethics Committee for Research (Ref: 201701/02 v1.1). Outcomes will be disseminated through publications in peer-reviewed journals, presentations at international conferences, as well as articles in popular magazines and on specialised websites.Trial registration numberNCT03115437, Pre-results.

scholarly journals Injury Risk and Injury Burden Are Related to Age Group and Peak Height Velocity Among Talented Male Youth Soccer Players

2018 ◽  
Vol 6 (12) ◽  
pp. 232596711881104 ◽  
Author(s):  
Hans Jan Bult ◽  
Maarten Barendrecht ◽  
Igor Joeri Ramon Tak
Keyword(s):  
Injury Risk ◽  
Age Groups ◽  
Peak Height ◽  
Soccer Players ◽  
Height Velocity ◽  
Incidence Density ◽  
Chronological Age ◽  
Peak Height Velocity ◽  
The Mean ◽  
Injury Burden

Background: The relationship between injury risk (IR) in age groups and periods around peak height velocity (PHV) remains unclear. PHV is defined as the moment of the largest increase in body height. Purpose: To investigate injury risk and injury burden as functions of growth velocity (periods around PHV) and chronological age groupings (under 12 years [U12] to U19) in talented youth male soccer players. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 170 players from the youth academy of a Dutch soccer club (highest professional league: Eredivisie) were observed for 1 to 3 seasons. Injuries, exposure, PHV age, and chronological age were registered. The injury incidence density (IID) and injury burden per 1000 hours of soccer participation, with 95% CIs, were calculated for 5 PHV periods and 7 age groups. These were compared with the overall cohort results using incidence ratios (IRs) and burden ratios (BRs) with 95% CIs. Results: The mean age at PHV was 14.4 ± 0.65 years (range, 12.8-16.5 years). The mean IID for the total cohort was 8.34 injuries per 1000 hours (95% CI, 7.71-9.02). Compared with the overall mean, a significantly higher IID was found for PHV period 4+5 (IR, 1.31 [95% CI, 1.00-1.71]; P = .049) and for the U15 group (IR, 1.49 [95% CI, 1.24-1.79]; P < .001). The overall injury burden was 58.37 injury days per 1000 hours (95% CI, 56.66-60.13). In PHV period 4+5, the injury burden was significantly higher (BR, 1.53 [95% CI, 1.39-1.68]; P < .001) when compared with the overall mean. Also, compared with the overall mean, the injury burden was higher in the U16 (BR, 1.48 [95% CI, 1.39-1.58]; P < .001), U15 (BR, 1.28 [95% CI, 1.19-1.38]; P < .001), and U17 groups (BR, 1.21 [95% CI, 1.13-1.31]; P < .001). Conclusion: Talented young soccer players were more prone to injuries during the 6 months after PHV (31% above overall mean) as well as in the U15 group (49% above overall mean). Based on the higher injury burden in the U16 (48%), U15 (28%), and U17 (21%) groups, we suggest that research on injury risk factors and preventive measures should primarily target these age groups. Additional interventions based on PHV may be of limited value from a screening perspective. Further research is needed on the interaction between age groups and PHV periods.

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