scholarly journals Comparison of the Angular Compartment of Hip Flexion Before and After Training in 11 to 12-Year-old Soccer Players.

2019 ◽  
Vol 1 (1) ◽  
pp. 4-10
Author(s):  
Jair Burboa G ◽  
Mauricio Inostroza M ◽  
Matías Bahamondes F ◽  
Paloma Lillo U ◽  
Jaime Hinzpeter C
Keyword(s):  
Inertial Sensors ◽  
Cruciate Ligament ◽  
Training Session ◽  
Neuromuscular Control ◽  
School Students ◽  
Acl Injuries ◽  
Randomized Clinical Study ◽  
Jump Test ◽  
Before And After ◽  
Hip Flexion

An anterior cruciate ligament (ACL) injury is an important cause of rest in athletes. In most cases, ACL injuries do not require external contact and they are associated with biomechanical risk factors that increase ACL tension. The increase of the hip flexion angle (HF) is included within these. The ACL requires cooperation of the periarticular musculature of the knee, muscle groups, hip stabilizers and CORE muscles; consequently, fatigue caused by exercise would alter the balance and put this ligament at risk. The objective of the study is to determine the angular behavior for HF before and after a physical load (a standardized training) in children between 11 and 12 years old. A non-randomized clinical study was carried out. The sample consisted of 50 soccer school students born between 11 and 12 years old. The angular behavior of HF was compared before and after performing a training session. The angular behavior was measured through the Drop Jump test (DJ), with data obtained by inertial sensors. After the exercise, there was a significant increase in HF. It was concluded that the angular behavior of HF increases significantly in both extremities after training and that preventive measures must be applied for neuromuscular control of the hip.

scholarly journals Hip Angle Behavior in Landing After Drop Jump in Children; and their Implicance in Prevention Programs

2019 ◽  
Vol 1 (1) ◽  
pp. 11-21
Author(s):  
Jair Burboa G ◽  
Matias Bahamondes F ◽  
Mauricio Inostroza M ◽  
Paloma Lillo U ◽  
Jaime Hinzpeter
Keyword(s):  
Risk Factors ◽  
Cruciate Ligament ◽  
Training Session ◽  
Acl Injury ◽  
Physical Load ◽  
Drop Jump ◽  
Protective Capacity ◽  
Level Of Evidence ◽  
Before And After ◽  
Hip Flexion

Background The Anterior Cruciate Ligament (ACL) injury is uncommon, but constitutes an important percentage of the lesions requiring more than 8 weeks of recovery in sports. Most ACL injuries do not require external contact and are associated with biomechanical risk factors that stress this ligament ACL: like an increase in knee valgus angle (KV) and hip flexion (HF) and a decreased in knee flexion (KF). The ACL requires muscle cooperation to resist the load; however, when there is fatigue, the protective capacity of the musculature would decrease. The objective of the study is to analyze the angular behavior before and after a physical load for HF in children of 14-15 years old. Hypothesis The physical load applied in a single training session is enough to change some biomechanical risk factors of ACL injury. Study Design Experimental study Level of Evidence 2b Methods The sample consisted of 50 students from different soccer schools between 14-15 years old. We analyzed the hip angular behavior of hip flexion before and after a training session. The angles where obtained from inertioal sensor while the students performed a Drop Jump test from a 30 centimeters drawer. Results Statistically significant differences were found in the differences between pre physical load HF / post-load HF (p = 0.00053), right pre physical load HF / right post- load HF (p = 0.0086) and left post- load (p = 0.0248206). Conclusions It was concluded that the angular behavior of HF increases significantly in both post-training limbs, after performing a physical load. Clinical Relevance This study analyzed the importance of using prevention injury programs since early stages, and give importance to the eccentric role of hamstring, gluteus and core exercises.

Experiences of returning to elite alpine skiing after ACL injury and ACL reconstruction

2014 ◽  
Vol 26 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Birgitta Nordahl ◽  
Rita Sjöström ◽  
Maria Westin ◽  
Suzanne Werner ◽  
Marie Alricsson
Keyword(s):  
High School Students ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Alpine Skiing ◽  
Structured Interviews ◽  
School Students ◽  
Physical Ability ◽  
Acl Injuries ◽  
Elite Level ◽  
Passive Strategies

Abstract Aim: To explore the experiences of alpine skiing at the elite level after anterior cruciate ligament (ACL) injury and reconstruction. Design: A qualitative approach where semi-structured interviews were conducted, and an analysis of the manifest content was performed. Participants: Five ski high school students, two male and three female skiers, who had suffered ACL injuries and undergone ACL reconstructions. Results: Seven categories were identified. The participants described their perceived opportunities with regard to returning to alpine skiing after ACL injury and reconstruction as something positive to do with self-belief, being mentally and physically prepared, regaining confidence in their own ability, being given time and using active strategies. In contrast, perceived barriers to a return to elite alpine skiing gave rise to negative feelings, for example, fear, disheartenment, a total lack of or ambivalent confidence in their own ability and the use of passive strategies. Conclusion: The two male skiers returned to alpine skiing. They reported confidence in their own ability, active strategies and support on all levels, as well as enhanced physical ability. The female skiers did not return to their pre-injury level of competitive alpine skiing. They stated a lack of support on all levels, deterioration in their physical ability and two out of three reported passive strategies and no or ambivalent confidence in their own ability. The most important factors were family support, support on all levels, access to a physiotherapist and time given.

Reading Comprehension Instruction: Summarization and Self-Monitoring Training for Students with Learning Disabilities

1991 ◽  
Vol 58 (3) ◽  
pp. 270-279 ◽  
Author(s):  
Linda Duncan Malone ◽  
Margo A. Mastropieri
Keyword(s):  
Learning Disabilities ◽  
Reading Comprehension ◽  
Training Session ◽  
Students With Learning Disabilities ◽  
School Students ◽  
Self Monitoring ◽  
Think Aloud Protocols ◽  
Reading Comprehension Instruction ◽  
Before And After ◽  
Monitoring Training

Forty-five middle-school students with learning disabilities were randomly assigned to one of three reading-comprehension training conditions: (a) summarization training, (b) summarization training with a self-monitoring component, or (c) traditional instruction. All students were interviewed before and after training regarding the strategies they typically employ during reading comprehension; during one training session, “think aloud” protocols were collected. Results indicated that students with learning disabilities trained in summarization procedures performed statistically higher on all dependent measures. In addition, on some transfer measures, students who were trained in the monitoring component statistically outperformed those with only the summarization training.

scholarly journals Temporal Kinematic Differences between Forward and Backward Jump-Landing

2020 ◽  
Vol 17 (18) ◽  
pp. 6669 ◽  
Author(s):  
Datao Xu ◽  
Xuanzhen Cen ◽  
Meizi Wang ◽  
Ming Rong ◽  
Bíró István ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Cruciate Ligament ◽  
Statistical Parametric Mapping ◽  
Time Frame ◽  
Biomechanical Analysis ◽  
Acl Injuries ◽  
Jump Landing ◽  
Vertical Ground ◽  
Anterior Cruciate ◽  
Hip Flexion

Backward jump-landing during sports performance will result in dynamic postural instability with a greater risk of injury, and most research studies have focused on forward landing. Differences in kinematic temporal characteristics between single-leg and double-leg backward jump-landing are seldom researched and understood. The purpose of this study was to compare and analyze lower extremity kinematic differences throughout the landing phases of forward and backward jumping using single-leg and double-leg landings (FS and BS, FD and BD). Kinematic data were collected during the landing phases of FS and BS, FD and BD in 45 participants. Through statistical parametric mapping (SPM) analysis, we found that the BS showed smaller hip and knee flexion and greater vertical ground reactive force (VGRF) than the FS during 0–37.42% (p = 0.031), 16.07–32.11% (p = 0.045), and 23.03–17.32% (p = 0.041) landing phases. The BD showed smaller hip and knee flexion than the FD during 0–20.66% (p = 0.047) and 0–100% (p < 0.001) landing phases. Most differences appeared within a time frame during the landing phase at 30–50 ms in which non-contact anterior cruciate ligament (ACL) injuries are thought to occur and are consistent with the identification of risk in biomechanical analysis. A landing strategy that consciously increases the knee and hip flexion angles during backward landing should be considered for people as a measure to avoid injury during the performance of this type of physical activity.

scholarly journals Sagittal Plane Hip, Knee, and Ankle Biomechanics and the Risk of Anterior Cruciate Ligament Injury: A Prospective Study

2017 ◽  
Vol 5 (12) ◽  
pp. 232596711774548 ◽  
Author(s):  
Mari Leppänen ◽  
Kati Pasanen ◽  
Tron Krosshaug ◽  
Pekka Kannus ◽  
Tommi Vasankari ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Young Female ◽  
Roc Curve Analysis ◽  
Acl Injuries ◽  
Increased Risk ◽  
Flexion Moment ◽  
Hip Flexion

Background: Stiff landings with less knee flexion and high vertical ground-reaction forces have been shown to be associated with an increased risk of anterior cruciate ligament (ACL) injury. The literature on the association between other sagittal plane measures and the risk of ACL injuries with a prospective study design is lacking. Purpose: To investigate the relationship between selected sagittal plane hip, knee, and ankle biomechanics and the risk of ACL injury in young female team-sport athletes. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 171 female basketball and floorball athletes (age range, 12-21 years) participated in a vertical drop jump test using 3-dimensional motion analysis. All new ACL injuries, as well as match and training exposure data, were recorded for 1 to 3 years. Biomechanical variables, including hip and ankle flexion at initial contact (IC), hip and ankle ranges of motion (ROMs), and peak external knee and hip flexion moments, were selected for analysis. Cox regression models were used to calculate hazard ratios (HRs) with 95% CIs. The combined sensitivity and specificity of significant test variables were assessed using a receiver operating characteristic (ROC) curve analysis. Results: A total of 15 noncontact ACL injuries were recorded during follow-up (0.2 injuries/1000 player-hours). Of the variables investigated, landing with less hip flexion ROM (HR for each 10° increase in hip ROM, 0.61 [95% CI, 0.38-0.99]; P < .05) and a greater knee flexion moment (HR for each 10-N·m increase in knee moment, 1.21 [95% CI, 1.04-1.40]; P = .01) was significantly associated with an increased risk of ACL injury. Hip flexion at IC, ankle flexion at IC, ankle flexion ROM, and peak external hip flexion moment were not significantly associated with the risk of ACL injury. ROC curve analysis for significant variables showed an area under the curve of 0.6, indicating a poor combined sensitivity and specificity of the test. Conclusion: Landing with less hip flexion ROM and a greater peak external knee flexion moment was associated with an increased risk of ACL injury in young female team-sport players. Studies with larger populations are needed to confirm these findings and to determine the role of ankle flexion ROM as a risk factor for ACL injury. Increasing knee and hip flexion ROMs to produce soft landings might reduce knee loading and risk of ACL injury in young female athletes.

scholarly journals Return to Play (RTP) and Performance in the Women’s National Basketball Association (WNBA) Following Anterior Cruciate Ligament (ACL) Reconstruction (194)

2021 ◽  
Vol 9 (10_suppl5) ◽  
pp. 2325967121S0030
Author(s):  
Joseph Tramer ◽  
Lafi Khalil ◽  
Alexander Ziedas ◽  
Muhammad Abbas ◽  
Nima Mehran ◽  
...  
Keyword(s):  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Return To Play ◽  
Post Injury ◽  
Acl Injuries ◽  
Post Surgery ◽  
Before And After ◽  
Playing Time ◽  
Anterior Cruciate ◽  
And Performance

Objectives: The incidence of ACL injuries in WNBA athletes has been on the rise, despite the high rates of ACL injury there is a paucity of recent research examining the effect of ACL reconstruction on RTP and performance in these athletes. This cohort study seeks to quantify the effect of ACL reconstruction on RTP and performance on WNBA athletes. Methods: All ACL tears sustained in the WNBA from 1997-2018 were identified. BMI, age and position at the time of injury were collected for each player. RTP rates were calculated and performance data was collected for each player before and after injury to determine changes in playing time and statistical performance. Players who successfully RTP after ACL reconstruction were compared to a group of healthy controls who were matched by age, years of experience, position, height, and BMI. Statistics at one year and three years’ post-injury were compared to assess acute and longitudinal changes in performance relative to pre-injury baseline. Results: A total of fifty-nine WNBA players sustained an isolated ACL tear during the study period. Forty-one (69.5%) were able to RTP. There was no difference in demographic characteristics between forty-one players and matched controls. Following RTP athletes played an average of 7.5±12.8 fewer games, 5.1±9.2 fewer minutes per game, and scored 3.7±5.0 less points per game in their first year compared to the year prior to injury. (Table1) When compared to matched controls, WNBA players returning from ACL reconstruction demonstrated a significant decline in games played, games started, minutes per game, rebounds, assists, and blocks per game in their first season after RTP. These differences resolved by year three post-surgery (Table 2). Conclusions: There is a high RTP rate following ACL reconstruction in WNBA athletes. Players may experience a decrease in playing time and performance initially when returning to play, however these variables were found to return to baseline over time.

scholarly journals Can Technique Modification Training Reduce Knee Moments in a Landing Task?

2014 ◽  
Vol 30 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Alasdair R. Dempsey ◽  
Bruce C. Elliott ◽  
Bridget J. Munro ◽  
Julie R. Steele ◽  
David G. Lloyd
Keyword(s):  
Internal Rotation ◽  
Injury Risk ◽  
Cruciate Ligament ◽  
Three Dimensional ◽  
Inverse Dynamic ◽  
Acl Injuries ◽  
Can Technique ◽  
Before And After ◽  
Reaction Forces ◽  
Anterior Cruciate

Anterior cruciate ligament (ACL) injuries are costly. Sidestep technique training reduces knee moments that load the ACL. This study examined whether landing technique training alters knee moments. Nineteen team sport athletes completed the study. Motion analysis and ground reaction forces were recorded before and after 6 weeks of technique modification. An inverse dynamic model was used to calculate three-dimensional knee loading. Pre- and postintervention scores were compared using pairedttests. Maximal knee flexion angle during landing was increased following training. There was no change in valgus or flexion moments, but an increase in peak internal rotation moment. This increase in internal rotation moment may increase the risk of ACL injury. However, the increased angle at which the peak internal rotation moment occurred at follow up may mitigate any increase in injury risk by reducing load transmission.

Knee ligament mechanical properties are not influenced by estrogen or its receptors

2006 ◽  
Vol 290 (5) ◽  
pp. E1034-E1040 ◽  
Author(s):  
Stuart J. Warden ◽  
Leanne K. Saxon ◽  
Alesha B. Castillo ◽  
Charles H. Turner
Keyword(s):  
Mechanical Properties ◽  
Cruciate Ligament ◽  
Neuromuscular Control ◽  
High Rate ◽  
Null Mutation ◽  
Sprague Dawley ◽  
Gene Encoding ◽  
Acl Injuries ◽  
Knee Ligament ◽  
Anterior Cruciate

Women are at greater risk of tearing their knee anterior cruciate ligament (ACL) than men participating in similar athletic activities. There is currently no conclusive explanation for this disparity; however, as ACL injuries in women have been linked with estrogen fluctuations during the menstrual cycle, one hypothesis is that estrogen has a direct detrimental effect on knee ligament mechanical properties. This study investigated the influence of estrogen and its receptors (ERα and ERβ) on knee ligament mechanical properties. This was achieved by testing the viscoelastic and tensile mechanical properties of knee medial collateral ligaments (MCL) and ACLs from: 1) male Sprague-Dawley rats treated with either estrogen (17α-ethynylestradiol; 0.03 mg/kg) or an ERα-specific agonist (propyl pyrazole triol; 2 mg/kg), and 2) female mice with a null mutation of the gene encoding for ERβ. Estrogen treatment had no significant effects on the viscoelastic or tensile mechanical properties of the rat MCL or ACL. Similarly, pharmacological stimulation of ERα using a selective agonist in rats and genetic modulation of ERβ by null mutation of its gene in mice did not influence MCL or ACL properties. These data indicate that estrogen does not have a major direct effect on ligament mechanical properties. Energies for the prevention of the disproportionately high rate of knee ligament injuries in women may be better spent focusing on more established and modifiable risk factors, such as abnormalities in neuromuscular control about the knee.

scholarly journals The Effect of a Pace Training Session on Internal Load and Neuromuscular Parameters in Taekwondo Athletes

2021 ◽  
Vol 12 ◽  
Author(s):  
Jader Sant' Ana ◽  
Raphael Luiz Sakugawa ◽  
Fernando Diefenthaeler
Keyword(s):  
Heart Rate ◽  
Motor Response ◽  
Training Session ◽  
Wilcoxon Test ◽  
Specific Test ◽  
Internal Load ◽  
Load Response ◽  
Jump Test ◽  
Before And After ◽  
Response Performance

This study aimed to verify the effect of a pace training session at an intensity corresponding to the kick frequency at the anaerobic threshold (KFAT) on the internal load response and motor response performance of the roundhouse kick. Twelve black belt taekwondo athletes underwent two evaluation sessions: (1) performed the progressive specific test for taekwondo (PSTT) to identify the heart rate deflection point (HRDP) and the KFAT; (2) performed three 2-min rounds with a 1-min interval. Heart rate (HR) throughout each round and motor response performance before and after sessions were measured. The Student's T-test or Wilcoxon test was used, and p &lt; 0.05 was adopted. During round 1, a lower internal load was observed (167 ± 10 bpm) compared with HRDP (179 ± 8 bpm; p = 0.035). During rounds 2 (178 ± 10 bpm; p = 0.745) and 3 (179 ± 8 bpm; p = 1), no differences were observed for an internal load and HRDP. Motor response performance showed no differences. However, a potentiation in the post countermovement jump test compared with rounds 1 (p = 0.012) and 2 (p = 0.028) was observed. The internal load (HR) observed at the intensity corresponding to KFAT can be considered in the prescription of training when the aim is to control the internal load responses without inducing fatigue.

scholarly journals Ball heading and subclinical concussion in soccer as a risk factor for anterior cruciate ligament injury

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
George Kakavas ◽  
Nikolaos Malliaropoulos ◽  
Wieslaw Blach ◽  
Georgios Bikos ◽  
Filippo Migliorini ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Neuromuscular Control ◽  
Acl Injury ◽  
Soccer Players ◽  
Ligament Injury ◽  
Neurocognitive Performance ◽  
Acl Injuries ◽  
Anterior Cruciate ◽  
The Impact

AbstractSoccer players have a high risk of anterior cruciate ligament (ACL) injury, a potentially career-ending event. ACL rupture has been linked with abnormal neuromuscular control in the lower limb. Additionally, heading the ball with the unprotected head during game play is increasingly recognized as a major source of exposure to concussive and sub-concussive repetitive head impacts. This article provides a hypothesis of potential connection of ACL injury with ball heading in soccer players. The study reviews literature sources regarding the impact of neurocognitive alterations after ball headings in ACL injuries. Poor baseline neurocognitive performance or impairments in neurocognitive performance via sleep deprivation, psychological stress, or concussion can increase the risk for subsequent musculoskeletal injury.

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