scholarly journals The Effect of an Isometric Hip Muscle Strength Training Protocol on Valgus Angle During a Drop Vertical Jump in Competitive Female Volleyball Players

2017 ◽  
Vol 5 (4) ◽  
pp. 1 ◽  
Author(s):  
Kaitlin M. Jackson ◽  
Tyson A. C. Beach ◽  
David M. Andrews
Keyword(s):  
Muscle Strength ◽  
Injury Risk ◽  
Acl Injury ◽  
Group Level ◽  
Hip Muscle ◽  
Peak Knee ◽  
Volleyball Players ◽  
Acl Injury Risk ◽  
Muscle Groups ◽  
External Rotator

Background: Hip muscle weakness is associated with higher peak knee valgus angles (VA) during drop vertical jumps (DVJ) and linked to ACL injury risk. Objective: To determine if isometric strengthening (IST) of the hip extensor, abductor, and external rotator muscle groups would reduce VA exhibited during a DVJ. Methodology:  Fourteen female volleyball players (7 training (TG), 7 control (CG), VA≥9˚ during DVJ) participated. Pre- and post-test gluteal, quadriceps and hamstring strength were measured with a digital force gauge. Three-dimensional kinematics were collected during 15 DVJ trials. TG participated in a 6-week IST program that targeted the hip extensor, abductor, and external rotator muscle groups. Two-way mixed ANOVAs compared mean differences of VA and strength. Single-participant analyses examined if athlete-specific adaptations went undetected in the analyses of aggregated data. Results: TG hip extension, abduction, and knee flexion strength increased, respectively, by 20.5%, 27.5% and 23.5% (P<0.05). No group-level changes in VA were detected. Unilateral VA decreased for 5 TG participants, and bilateral VA decreased in 2 TG participants. Conclusions: IST increased isometric hip muscle strength, but its effect on VA is inconclusive based on group-level analyses. Using single-participant designs, future studies should assess IST and/or dynamic resistance/neuromuscular training in a larger sample to determine its effect on ACL injury risk factors.

scholarly journals NEURAL ACTIVITY PROFILES ASSOCIATED WITH ACL INJURY-RISK MECHANICS IN ECOLOGICAL SPORT SPECIFIC VIRTUAL REALITY

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0015
Author(s):  
Dustin R. Grooms ◽  
Jed A. Diekfuss ◽  
Alexis B. Slutsky-Ganesh ◽  
Cody R. Criss ◽  
Manish Anand ◽  
...  
Keyword(s):  
Motor Control ◽  
Neural Activity ◽  
Injury Risk ◽  
Neural Control ◽  
Acl Injury ◽  
Initial Contact ◽  
Leg Press ◽  
Visual Spatial ◽  
Peak Knee ◽  
Acl Injury Risk

Background: Anterior cruciate ligament (ACL) injury is secondary to a multifactorial etiology encompassing anatomical, biological, mechanical, and neurological factors. The nature of the injury being primarily due to non-contact mechanics further implicates neural control as a key injury-risk factor, though it has received considerably less study. Purpose: To determine the contribution of neural activity to injury-risk mechanics in ecological sport-specific VR landing scenarios. Methods: Ten female high-school soccer players (15.5±0.85 years; 165.0±6.09 cm; 59.1±11.84 kg) completed a neuroimaging session to capture neural activity during a bilateral leg press and a 3D biomechanics session performing a header within a VR soccer scenario. The bilateral leg press involved four 30 s blocks of repeated bilateral leg presses paced to a metronome beat of 1.2 Hz with 30 s rest between blocks. The VR soccer scenario simulated a corner-kick, requiring the participant to jump and head a virtual soccer ball into a virtual goal (Figure 1A-E). Initial contact and peak knee flexion and abduction angles were extracted during the landing from the header as injury-risk variables of interest and were correlated with neural activity. Results: Evidenced in Table 1 and Figure 1 (bottom row), increased initial contact abduction, increased peak abduction, and decreased peak flexion were associated with increased sensory, visual-spatial, and cerebellar activity (r2= 0.42-0.57, p corrected < .05, z max > 3.1, table & figure 1). Decreased initial contact flexion was associated with increased frontal cortex activity (r2= 0.68, p corrected < .05, z max > 3.1). Conclusion: Reduced neural efficiency (increased activation) of key regions that integrate proprioceptive, visual-spatial, and neurocognitive activity for motor control may influence injury-risk mechanics in sport. The regions found to increase in activity in relation to higher injury-risk mechanics are typically activated to assist with spatial navigation, environmental interaction, and precise motor control. The requirement for athletes to increase their activity for more basic knee motor control may result in fewer neural resources available to maintain knee joint alignment, allocate environmental attention, and handle increased motor coordination demands. These data indicate that strategies to enhance efficiency of visual-spatial and cognitive-motor control during high demand sporting activities is warranted to improve ACL injury-risk reduction. [Figure: see text][Table: see text]

Optimizing Whole-Body Kinematics During Single-Leg Jump Landing to Reduce Peak Abduction/Adduction and Internal Rotation Knee Moments: Implications for Anterior Cruciate Ligament Injury Risk

2021 ◽  
pp. 1-8
Author(s):  
Dhruv Gupta ◽  
Jeffrey A. Reinbolt ◽  
Cyril J. Donnelly
Keyword(s):  
Internal Rotation ◽  
Injury Risk ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Whole Body ◽  
Jump Landing ◽  
Peak Knee ◽  
Knee Abduction ◽  
Acl Injury Risk ◽  
Anterior Cruciate

Knee abduction/adduction moment and knee internal rotation moment are known surrogate measures of anterior cruciate ligament (ACL) load during tasks like sidestepping and single-leg landing. Previous experimental literature has shown that a variety of kinematic strategies are associated or correlated with ACL injury risk; however, the optimal kinematic strategies needed to reduce peak knee moments and ACL injury are not well understood. To understand the complex, multifaceted kinematic factors underpinning ACL injury risk and to optimize kinematics to prevent the ACL injury, a musculoskeletal modeling and simulation experimental design was used. A 14-segment, 37-degree-of-freedom, dynamically consistent skeletal model driven by force/torque actuators was used to simulate whole-body single-leg jump landing kinematics. Using the residual reduction algorithm in OpenSim, whole-body kinematics were optimized to reduce the peak knee abduction/adduction and internal/external rotation moments simultaneously. This optimization was repeated across 30 single-leg jump landing trials from 10 participants. The general optimal kinematic strategy was to bring the knee to a more neutral alignment in the transverse plane and frontal plane (featured by reduced hip adduction angle and increased knee adduction angle). This optimized whole-body kinematic strategy significantly reduced the peak knee abduction/adduction and internal rotation moments, transferring most of the knee load to the hip.

The Effect of Abdominal Muscle Activation Techniques on Trunk and Lower Limb Mechanics During the Single-Leg Squat Task in Females

2018 ◽  
Vol 27 (5) ◽  
pp. 438-444
Author(s):  
Lukas D. Linde ◽  
Jessica Archibald ◽  
Eve C. Lampert ◽  
John Z. Srbely
Keyword(s):  
Lower Limb ◽  
Injury Risk ◽  
Muscle Activation ◽  
Acl Injury ◽  
Abdominal Muscle ◽  
Abduction Angle ◽  
Peak Knee ◽  
Knee Abduction ◽  
Acl Injury Risk ◽  
Healthy Females

Context: Females suffer 4 to 6 times more noncontact anterior cruciate ligament (ACL) injuries than males due to neuromuscular control deficits of the hip musculature leading to increases in hip adduction angle, knee abduction angle, and knee abduction moment during dynamic tasks such as single-leg squats. Lateral trunk displacement has been further related to ACL injury risk in females, leading to the incorporation of core strength/stability exercises in ACL preventative training programs. However, the direct mechanism relating lateral trunk displacement and lower limb ACL risk factors is not well established. Objective: To assess the relationship between lateral trunk displacement and lower limb measures of ACL injury risk by altering trunk control through abdominal activation techniques during single-leg squats in healthy females. Design: Interventional study setting: movement and posture laboratory. Participants: A total of 13 healthy females (21.3 [0.88] y, 1.68 [0.07] m, and 58.27 [5.46] kg). Intervention: Trunk position and lower limb kinematics were recorded using an optoelectric motion capture system during single-leg squats under differing conditions of abdominal muscle activation (abdominal hollowing, abdominal bracing, and control), confirmed using surface electromyography. Main Outcome Measures: Lateral trunk displacement, peak hip adduction angle, peak knee abduction angle/moment, and average muscle activity from bilateral internal oblique, external oblique, and erector spinae muscles. Results: No differences were observed for peak lateral trunk displacement, peak hip adduction angle, or peak knee abduction angle/moment. Abdominal hollowing and bracing elicited greater muscle activation than the control condition, and bracing was greater than hollowing in 4 of 6 muscles recorded. Conclusion: The lack of reduction in trunk, hip, and knee measures of ACL injury risk during abdominal hollowing and bracing suggests that these techniques alone may provide minimal benefit in ACL injury prevention training.

scholarly journals Stiff Landings Are Associated With Increased ACL Injury Risk in Young Female Basketball and Floorball Players

2016 ◽  
Vol 45 (2) ◽  
pp. 386-393 ◽  
Author(s):  
Mari Leppänen ◽  
Kati Pasanen ◽  
Urho M. Kujala ◽  
Tommi Vasankari ◽  
Pekka Kannus ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Injury Risk ◽  
Acl Injury ◽  
Young Female ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Acl Injuries ◽  
Increased Risk ◽  
Peak Knee ◽  
Acl Injury Risk

Background: Few prospective studies have investigated the biomechanical risk factors of anterior cruciate ligament (ACL) injury. Purpose: To investigate the relationship between biomechanical characteristics of vertical drop jump (VDJ) performance and the risk of ACL injury in young female basketball and floorball players. Study Design: Cohort study; Level of evidence, 3. Methods: At baseline, a total of 171 female basketball and floorball players (age range, 12-21 years) participated in a VDJ test using 3-dimensional motion analysis. The following biomechanical variables were analyzed: (1) knee valgus angle at initial contact (IC), (2) peak knee abduction moment, (3) knee flexion angle at IC, (4) peak knee flexion angle, (5) peak vertical ground-reaction force (vGRF), and (6) medial knee displacement. All new ACL injuries, as well as match and training exposure, were then recorded for 1 to 3 years. Cox regression models were used to calculate hazard ratios (HRs) and 95% CIs. Results: Fifteen new ACL injuries occurred during the study period (0.2 injuries/1000 player-hours). Of the 6 factors considered, lower peak knee flexion angle (HR for each 10° increase in knee flexion angle, 0.55; 95% CI, 0.34-0.88) and higher peak vGRF (HR for each 100-N increase in vGRF, 1.26; 95% CI, 1.09-1.45) were the only factors associated with increased risk of ACL injury. A receiver operating characteristic (ROC) curve analysis showed an area under the curve of 0.6 for peak knee flexion and 0.7 for vGRF, indicating a failed-to-fair combined sensitivity and specificity of the test. Conclusions: Stiff landings, with less knee flexion and greater vGRF, in a VDJ test were associated with increased risk of ACL injury among young female basketball and floorball players. However, although 2 factors (decreased peak knee flexion and increased vGRF) had significant associations with ACL injury risk, the ROC curve analyses revealed that these variables cannot be used for screening of athletes.

scholarly journals Associations Among Eccentric Hamstrings Strength, Hamstrings Stiffness, and Jump-Landing Biomechanics

2020 ◽  
Vol 55 (7) ◽  
pp. 717-723 ◽  
Author(s):  
Derek R. Dewig ◽  
Jonathan S. Goodwin ◽  
Brian G. Pietrosimone ◽  
J. Troy Blackburn
Keyword(s):  
Ground Reaction Force ◽  
Injury Risk ◽  
Reaction Force ◽  
Acl Injury ◽  
Ground Contact ◽  
Vertical Ground Reaction Force ◽  
Landing Biomechanics ◽  
Peak Knee ◽  
Acl Injury Risk ◽  
Vertical Ground

Context Anterior cruciate ligament (ACL) injury risk can be assessed from landing biomechanics. Greater hamstrings stiffness is associated with a landing-biomechanics profile consistent with less ACL loading but is difficult to assess in the clinical setting. Eccentric hamstrings strength can be easily evaluated by clinicians and may provide a surrogate measure for hamstrings stiffness. Objective To examine associations among eccentric hamstrings strength, hamstrings stiffness, and landing biomechanics linked to ACL injury risk. Design Cross-sectional study. Setting Research laboratory. Patients or Other Participants A total of 34 uninjured, physically active participants (22 women, 12 men; age = 20.2 ± 1.6 years, height = 171.5 ± 9.7 cm, mass = 67.1 ± 12.7 kg). Intervention(s) We collected eccentric hamstrings strength, active hamstrings stiffness, and double- and single-legged landing biomechanics during a single session. Main Outcome Measure(s) Bivariate associations were conducted between eccentric hamstrings strength and hamstrings stiffness, vertical ground reaction force, internal knee-extension moment, internal knee-varus moment, anterior tibial shear force, knee sagittal-plane angle at initial ground contact, peak knee-flexion angle, knee frontal-plane angle at initial ground contact, peak knee-valgus angle, and knee-flexion displacement using Pearson product moment correlations or Spearman rank-order correlations. Results We observed no association between hamstrings stiffness and eccentric hamstrings strength (r = 0.029, P = .44). We also found no association between hamstrings stiffness and landing biomechanics. However, greater peak eccentric strength was associated with less vertical ground reaction force in both the double-legged (r = −0.331, P = .03) and single-legged (r = −0.418, P = .01) landing conditions and with less internal knee-varus moment in the single-legged landing condition (r = −0.326, P = .04). Conclusions Eccentric hamstrings strength was associated with less vertical ground reaction force during both landing tasks and less internal knee-varus moment during the single-legged landing but was not an acceptable clinical estimate of active hamstrings stiffness.

scholarly journals Electromyographic Assessment of Anterior Cruciate Ligament Injury Risk in Male Tennis Players: Which Role for Visual Input? A Proof-of-Concept Study

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 997
Author(s):  
Alessandro de Sire ◽  
Nicola Marotta ◽  
Andrea Demeco ◽  
Lucrezia Moggio ◽  
Pasquale Paola ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Injury Risk ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Visual Input ◽  
Proof Of Concept ◽  
Tennis Players ◽  
Concept Study ◽  
Acl Injury Risk ◽  
Anterior Cruciate

Anterior cruciate ligament (ACL) injury incidence is often underestimated in tennis players, who are considered as subjects conventionally less prone to knee injuries. However, evaluation of the preactivation of knee stabilizer muscles by surface electromyography (sEMG) showed to be a predictive value in the assessment of the risk of ACL injury. Therefore, this proof-of-concept study aimed at evaluating the role of visual input on the thigh muscle preactivation through sEMG to reduce ACL injury risk in tennis players. We recruited male, adult, semiprofessional tennis players from July to August 2020. They were asked to drop with the dominant lower limb from a step, to evaluate—based on dynamic valgus stress—the preactivation time of the rectus femoris (RF), vastus medialis, biceps femoris, and medial hamstrings (MH), through sEMG. To highlight the influence of visual inputs, the athletes performed the test blindfolded and not blindfolded on both clay and grass surfaces. We included 20 semiprofessional male players, with a mean age 20.3 ± 4.8 years; results showed significant early muscle activation when the subject lacked visual input, but also when faced with a less-safe surface such as clay over grass. Considering the posteromedial–anterolateral relationship (MH/RF ratio), tennis players showed a significant higher MH/RF ratio if blindfolded (22.0 vs. 17.0% not blindfolded; p < 0.01) and percentage of falling on clay (17.0% vs. 14.0% in grass; p < 0.01). This proof-of-principle study suggests that in case of absence of visual input or falling on a surface considered unsafe (clay), neuro-activation would tend to protect the anterior stress of the knee. Thus, the sEMG might play a crucial role in planning adequate athletic preparation for semiprofessional male athletes in terms of reduction of ACL injury risk.

scholarly journals Is Hip Muscle Strength Associated with Dynamic Knee Valgus in a Healthy Adult Population? A Systematic Review

2021 ◽  
Vol 18 (14) ◽  
pp. 7669
Author(s):  
Ali Mohammed Alzahrani ◽  
Msaad Alzhrani ◽  
Saeed Nasser Alshahrani ◽  
Wael Alghamdi ◽  
Mazen Alqahtani ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Adult Population ◽  
Knee Valgus ◽  
Journal Articles ◽  
Hip Muscle ◽  
Hip Abductor ◽  
Hip Muscles ◽  
Analysis System ◽  
The Relationship ◽  
External Rotator

This study aimed to systematically review research investigating the association between hip muscle strength and dynamic knee valgus (DKV). Four databases (MEDLINE, PubMed, CINAHL, and SPORTDiscus) were searched for journal articles published from inception to October 2020. Seven studies investigating the association between hip muscle strength and DKV using a two-dimensional motion analysis system in healthy adults were included. The relationship between hip abductor muscle strength and DKV was negatively correlated in two studies, positively correlated in two studies, and not correlated in three studies. The DKV was associated with reduced hip extensor muscle strength in two studies and reduced hip external rotator muscle strength in two studies, while no correlation was found in three and five studies for each muscle group, respectively. The relationship between hip muscle strength, including abductors, extensors, and external rotators and DKV is conflicting. Considering the current literature limitations and variable methodological approaches used among studies, the clinical relevance of such findings should be interpreted cautiously. Therefore, future studies are recommended to measure the eccentric strength of hip muscles, resembling muscular movement during landing. Furthermore, high-demand and sufficiently challenging functional tasks revealing lower limb kinematic differences, such as cutting and jumping tasks, are recommended for measuring the DKV.

scholarly journals Do ACL Injury Risk Reduction Exercises Reflect Common Injury Mechanisms? A Scoping Review of Injury Prevention Programs

2021 ◽  
pp. 194173812110379
Author(s):  
Steven L. Dischiavi ◽  
Alexis A Wright ◽  
Rachel A. Heller ◽  
Claire E. Love ◽  
Adam J. Salzman ◽  
...  
Keyword(s):  
Risk Reduction ◽  
Scoping Review ◽  
Injury Risk ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Flight Phase ◽  
Targeted Interventions ◽  
Injury Mechanisms ◽  
Acl Injury Risk

Context: Anterior cruciate ligament (ACL) injury risk reduction programs have become increasingly popular. As ACL injuries continue to reflect high incidence rates, the continued optimization of current risk reduction programs, and the exercises contained within them, is warranted. The exercises must evolve to align with new etiology data, but there is concern that the exercises do not fully reflect the complexity of ACL injury mechanisms. It was outside the scope of this review to address each possible inciting event, rather the effort was directed at the elements more closely associated with the end point of movement during the injury mechanism. Objective: To examine if exercises designed to reduce the risk of ACL injury reflect key injury mechanisms: multiplanar movement, single limb stance, trunk and hip dissociative control, and a flight phase. Data Sources: A systematic search was performed using PubMed, Medline, EBSCO (CINAHL), SPORTSDiscus, and PEDro databases. Study Selection: Eligibility criteria were as follows: (1) randomized controlled trials or prospective cohort studies, (2) male and/or female participants of any age, (3) exercises were targeted interventions to prevent ACL/knee injuries, and (4) individual exercises were listed and adequately detailed and excluded if program was unable to be replicated clinically. Study Design: Scoping review. Level of Evidence: Level 4. Data Extraction: A total of 35 studies were included, and 1019 exercises were extracted for analysis. Results: The average Consensus on Exercise Reporting Template score was 11 (range, 0-14). The majority of exercises involved bilateral weightbearing (n = 418 of 1019; 41.0%), followed by single limb (n = 345 of 1019; 33.9%) and nonweightbearing (n = 256 of 1019; 25.1%). Only 20% of exercises incorporated more than 1 plane of movement, and the majority of exercises had sagittal plane dominance. Although 50% of exercises incorporated a flight phase, only half of these also involved single-leg weightbearing. Just 16% of exercises incorporated trunk and hip dissociation, and these were rarely combined with other key exercise elements. Only 13% of exercises challenged more than 2 key elements, and only 1% incorporated all 4 elements (multiplanar movements, single limb stance, trunk and hip dissociation, flight phase) simultaneously. Conclusion: Many risk reduction exercises do not reflect the task-specific elements identified within ACL injury mechanisms. Addressing the underrepresentation of key elements (eg, trunk and hip dissociation, multiplanar movements) may optimize risk reduction in future trials.

scholarly journals Relationship between BMI and hip muscle strength in young female athletes to prevent lower extremity injury risk: A pilot study

2021 ◽  
Vol 9 (1) ◽  
pp. 3754-3758
Author(s):  
Akshaya M V ◽  
◽  
Abhilash P V ◽  
Priya S ◽  
◽  
...  
Keyword(s):  
Muscle Strength ◽  
Lower Extremity ◽  
Injury Risk ◽  
Female Athletes ◽  
Young Female ◽  
Acute Injury ◽  
Lower Extremity Injury ◽  
College Level ◽  
Extremity Injury ◽  
Hip Muscle

Background: Early identification of the BMI and muscle weakness, can be promoted for developing future rehabilitation by giving proper training in athletes to reduce chance of injuries especially in female athletes. There-for the purpose of this study was to determine the correlation between BMI and hip muscle strength in young female athletes. Materials and Methods: study was conducted among college level female athletes from different colleges of Mangalore, Karnataka, India. 20 college level female athletes between 18-25 years with free from injury and involved at least 2 hrs. per week training session were included in this study. Athletes were excluded if participant had an acute injury during previous six months, had musculoskeletal surgery within the past year. Results: The total number of 20 young female athletes aged between 18- 25 were included in this study. Detailed results enumerated in detail in the results section. Discussion and Conclusion: There was no relationship between BMI and hip muscle strength. Identifying the relationship between BMI and hip muscle strength may help to prevent lower extremity injury risk in female athletes and specific muscle group training can be given as rehabilitation protocol. KEY WORDS: BMI, Hip Muscle Strength, Female Athletes, Lower Extremity Injury.

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