scholarly journals Sagittal-Plane Trunk Position, Landing Forces, and Quadriceps Electromyographic Activity

2009 ◽  
Vol 44 (2) ◽  
pp. 174-179 ◽  
Author(s):  
J. Troy Blackburn ◽  
Darin A. Padua
Keyword(s):  
Risk Factors ◽  
Repeated Measures ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Acl Injury ◽  
Electromyographic Activity ◽  
Trunk Flexion ◽  
Repeated Measures Design ◽  
Peak Knee

Abstract Context: Researchers have suggested that large landing forces, excessive quadriceps activity, and an erect posture during landing are risk factors for anterior cruciate ligament (ACL) injury. The influence of knee kinematics on these risk factors has been investigated extensively, but trunk positioning has received little attention. Objective: To determine the effect of trunk flexion on landing forces and quadriceps activation during landing. Design: Two (sex) × 2 (task) repeated-measures design. Setting: Research laboratory. Patients or Other Participants: Forty healthy, physically active volunteers (20 men, 20 women). Intervention(s): Participants performed 2 drop-landing tasks. The first task represented the natural, or preferred, landing strategy. The second task was identical to the first except that participants flexed the trunk during landing. Main Outcome Measure(s): We measured peak vertical and posterior ground reaction forces and mean quadriceps electromyographic amplitude during the loading phase of landing (ie, the interval from initial ground contact to peak knee flexion). Results: Trunk flexion decreased the vertical ground reaction force (P < .001) and quadriceps electromyographic amplitude (P < .001). The effect of trunk flexion did not differ across sex for landing forces or quadriceps electromyographic activity. Conclusions: We found that trunk flexion during landing reduced landing forces and quadriceps activity, thus potentially reducing the force imparted to the ACL. Research has indicated that trunk flexion during landing also increases knee and hip flexion, resulting in a less erect landing posture. In combination, these findings support emphasis on trunk flexion during landing as part of ACL injury-prevention programs.

scholarly journals Gender, Vertical Height and Horizontal Distance Effects on Single-Leg Landing Kinematics: Implications for Risk of non-contact ACL Injury

2013 ◽  
Vol 37 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Nicholas Ali ◽  
Gholamreza Rouhi ◽  
Gordon Robertson
Keyword(s):  
Reaction Force ◽  
Injury Rate ◽  
Acl Injury ◽  
Flexion Angle ◽  
Whole Body ◽  
Horizontal Distance ◽  
Trunk Flexion ◽  
Peak Knee ◽  
Knee Abduction ◽  
Vertical Height

There is a lack of studies investigating gender differences in whole-body kinematics during single-leg landings from increasing vertical heights and horizontal distances. This study determined the main effects and interactions of gender, vertical height, and horizontal distance on whole-body joint kinematics during single-leg landings, and established whether these findings could explain the gender disparity in non-contact anterior cruciate ligament (ACL) injury rate. Recreationally active males (n=6) and females (n=6) performed single-leg landings from a takeoff deck of vertical height of 20, 40, and 60 cm placed at a horizontal distance of 30, 50 and 70 cm from the edge of a force platform, while 3D kinematics and kinetics were simultaneously measured. It was determined that peak vertical ground reaction force (VGRF) and the ankle flexion angle exhibited significant gender differences (p=0.028, partial η2=0.40 and p=0.035, partial η2=0.37, respectively). Peak VGRF was significantly correlated to the ankle flexion angle (r= -0.59, p=0.04), hip flexion angle (r= -0.74, p=0.006), and trunk flexion angle (r= -0.59, p=0.045). Peak posterior ground reaction force (PGRF) was significantly correlated to the ankle flexion angle (r= -0.56, p=0.035), while peak knee abduction moment was significantly correlated to the knee flexion angle (r= -0.64, p=0.03). Rearfoot landings may explain the higher ACL injury rate among females. Higher plantar-flexed ankle, hip, and trunk flexion angles were associated with lower peak ground reaction forces, while higher knee flexion angle was associated with lower peak knee abduction moment, and these kinematics implicate reduced risk of non-contact ACL injury.

Examining the Dynamic Nature of Anterior Cruciate Ligament Injury Risk Factors in Women’s Collegiate Soccer

2021 ◽  
pp. 1-8
Author(s):  
Elena M. D’Argenio ◽  
Timothy G. Eckard ◽  
Barnett S. Frank ◽  
William E. Prentice ◽  
Darin A. Padua
Keyword(s):  
Risk Factors ◽  
Anterior Cruciate Ligament ◽  
Range Of Motion ◽  
Injury Risk ◽  
External Rotation ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Dynamic Risk Factors ◽  
Dynamic Risk ◽  
Anterior Cruciate

Context: Anterior cruciate ligament (ACL) injuries are a common and devastating injury in women’s soccer. Several risk factors for ACL injury have been identified, but have not yet been examined as potentially dynamic risk factors, which may change throughout a collegiate soccer season. Design: Prospective cohort study. Methods: Nine common clinical screening assessments for ACL injury risk, consisting of range of motion, movement quality, and power, were assessed in 29 Division I collegiate women’s soccer players. Preseason and midseason values were compared for significant differences. Change scores for each risk factor were also correlated with cumulative training loads during the first 10 weeks of a competitive soccer season. Results: Hip external rotation range of motion and power had statistically significant and meaningful differences at midseason compared with preseason, indicating they are dynamic risk factors. There were no significant associations between the observed risk factor changes and cumulative training load. Conclusions: Hip external rotation range of motion and power are dynamic risk factors for ACL injury in women’s collegiate soccer athletes. Serial screening of these risk factors may elucidate stronger associations with injury risk and improve prognostic accuracy of screening tools.

scholarly journals Longitudinal Assessment of Noncontact Anterior Cruciate Ligament Injury Risk Factors During Maturation in a Female Athlete: A Case Report

2009 ◽  
Vol 44 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Gregory D. Myer ◽  
Kevin R. Ford ◽  
Jon G. Divine ◽  
Eric J. Wall ◽  
Leamor Kahanov ◽  
...  
Keyword(s):  
Risk Factors ◽  
Anterior Cruciate Ligament ◽  
Body Mass ◽  
Female Athlete ◽  
Injury Risk ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Knee Abduction ◽  
Injury Risk Factors ◽  
Anterior Cruciate

Abstract Objective: To present a unique case of a young pubertal female athlete who was prospectively monitored for previously identified anterior cruciate ligament (ACL) injury risk factors for 3 years before sustaining an ACL injury. Background: In prospective studies, previous investigators have examined cross-sectional measures of anatomic, hormonal, and biomechanical risk factors for ACL injury in young female athletes. In this report, we offer a longitudinal example of measured risk factors as the participant matured. Differential Diagnosis: Partial or complete tear of the ACL. Measurements: The participant was identified from a cohort monitored from 2002 until 2007. No injury prevention training or intervention was included during this time in the study cohort. Findings: The injury occurred in the year after the third assessment during the athlete's club basketball season. Knee examination, magnetic resonance imaging findings, and arthroscopic evaluation confirmed a complete ACL rupture. The athlete was early pubertal in year 1 of the study and pubertal during the next 2 years; menarche occurred at age 12 years. At the time of injury, she was 14.25 years old and postpubertal, with closing femoral and tibial physes. For each of the 3 years before injury, she demonstrated incremental increases in height, body mass index, and anterior knee laxity. She also displayed decreased hip abduction and knee flexor strength, concomitant with increased knee abduction loads, after each year of growth. Conclusions: During puberty, the participant increased body mass and height of the center of mass without matching increases in hip and knee strength. The lack of strength and neuromuscular adaptation to match the increased demands of her pubertal stature may underlie the increased knee abduction loads measured at each annual visit and may have predisposed her to increased risk of ACL injury.

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.

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.

Evaluating the Spectrum of Cognitive-Motor Relationships During Dual-Task Jump Landing

2021 ◽  
pp. 1-8
Author(s):  
Patrick D. Fischer ◽  
Keith A. Hutchison ◽  
James N. Becker ◽  
Scott M. Monfort
Keyword(s):  
Working Memory ◽  
Cognitive Function ◽  
Visual Attention ◽  
Dual Task ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Neuromuscular Control ◽  
Task Demands ◽  
Jump Landing ◽  
Peak Knee

Cognitive function plays a role in understanding noncontact anterior cruciate ligament injuries, but the research into how cognitive function influences sport-specific movements is underdeveloped. The purpose of this study was to determine how various cognitive tasks influenced dual-task jump-landing performance along with how individuals’ baseline cognitive ability mediated these relationships. Forty female recreational soccer and basketball players completed baseline cognitive function assessments and dual-task jump landings. The baseline cognitive assessments quantified individual processing speed, multitasking, attentional control, and primary memory ability. Dual-task conditions for the jump landing included unanticipated and anticipated jump performance, with and without concurrent working memory and captured visual attention tasks. Knee kinematics and kinetics were acquired through motion capture and ground reaction force data. Jumping conditions that directed visual attention away from the landing, whether anticipated or unanticipated, were associated with decreased peak knee flexion angle (P < .001). No interactions between cognitive function measures and jump-landing conditions were observed for any of the biomechanical variables, suggesting that injury-relevant cognitive-motor relationships may be specific to secondary task demands and movement requirements. This work provides insight into group- and subject-specific effects of established anticipatory and novel working memory dual-task paradigms on the neuromuscular control of a sport-specific movement.

Change in Drop-Landing Mechanics Over 2 Years in Young Athletes After Anterior Cruciate Ligament Reconstruction

2019 ◽  
Vol 47 (11) ◽  
pp. 2608-2616 ◽  
Author(s):  
Matthew P. Ithurburn ◽  
Mark V. Paterno ◽  
Staci Thomas ◽  
Michael L. Pennell ◽  
Kevin D. Evans ◽  
...  
Keyword(s):  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Knee Extension ◽  
Trunk Flexion ◽  
Young Athletes ◽  
Vertical Ground Reaction Force ◽  
Drop Landing ◽  
Vertical Ground ◽  
Anterior Cruciate

Background: While between-limb landing asymmetries after anterior cruciate ligament reconstruction (ACLR) are linked with poor function and risk of additional injury, it is not currently understood how landing symmetry changes over time after ACLR. Purpose/Hypothesis: The purpose was to investigate how double-legged drop vertical jump (DVJ) landing and single-legged drop-landing symmetry changed from the time of return-to-sport (RTS) clearance to 2 years later in a prospective cohort of young athletes after ACLR. It was hypothesized that double-legged DVJ landing and single-legged drop-landing symmetry would improve from the time of RTS to 2 years later. Study Design: Descriptive laboratory study. Methods: The authors followed 64 young athletes with primary, unilateral ACLR for 2 years after RTS clearance. At the time of RTS and 2 years later, between-limb symmetry values for biomechanical variables of interest (VOIs) were calculated with 3-dimensional motion analysis during double-legged DVJ and single-legged drop-landing tasks. VOIs included knee flexion excursion, peak internal knee extension moment, peak vertical ground-reaction force, and peak trunk flexion (for single-legged task only). Symmetry values and proportions of participants meeting 90% symmetry cutoffs were compared between time points. Results: For double-legged DVJ landing, symmetry values for all VOIs and the proportions meeting 90% cutoffs for peak internal knee extension moment and peak vertical ground-reaction force were higher at 2 years after RTS as compared with RTS. For single-legged drop-landing, symmetry values were higher for knee flexion excursion and lower for peak trunk flexion at 2 years after RTS as compared with RTS, but the proportions meeting 90% cutoffs for all VOIs did not differ between time points. Conclusion: Double-legged DVJ landing symmetry improved across VOIs over the 2 years after RTS following ACLR, while single-legged drop-landing did not improve as consistently. The implications of longitudinal landing asymmetry after ACLR should be further studied.

Preliminary Evaluation of Knee Kinetics in Female Athletes on Hormonal Contraceptives

2019 ◽  
Vol 41 (02) ◽  
pp. 113-118
Author(s):  
Gabrielle Gilmer ◽  
Gretchen D. Oliver
Keyword(s):  
Injury Risk ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Acl Injury ◽  
Hormonal Contraceptives ◽  
Preliminary Evaluation ◽  
Knee Valgus ◽  
Time Points ◽  
Acl Injury Risk

AbstractRecently, an emphasis has been placed on understanding how ovarian sex hormones and hormonal contraceptives affect risk for anterior cruciate ligament (ACL) injury. The literature presents large discrepancies in whether or not hormonal contraceptives affect ACL injury risk; therefore, the purpose of this study was to evaluate whether vertical ground reaction force (GRF) and knee valgus force are different between athletes who do and do not use hormonal contraceptives. Twenty-two female athletes volunteered to participate and were divided into two groups based on their answers to a health history questionnaire: those who use hormonal contraceptives and those who do not. Participants performed a drop vertical jump (DVJ) and single leg crossover dropdown (SCD) at two different time points in their menstrual cycle (pre-ovulatory phase and mid-luteal phase). Kinetic data were collected at 1000 Hz. Independent samples t-tests revealed no significant differences between groups in vertical GRF and knee valgus force at both time points. Findings from this study suggest that hormonal contraceptives do not elicit detectable changes in vertical GRF and knee valgus force. Ultimately, this calls for further studies on the relationship between hormones and ACL injury risk and physicians to consider hormonal screening in addition to neuromuscular and biomechanical screening.

Quadriceps and Hamstrings Fatigue Alters Hip and Knee Mechanics

2010 ◽  
Vol 26 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Abbey C. Thomas ◽  
Scott G. McLean ◽  
Riann M. Palmieri-Smith
Keyword(s):  
Repeated Measures ◽  
Injury Risk ◽  
Mixed Model ◽  
External Rotation ◽  
Reaction Force ◽  
Acl Injury ◽  
Knee Extension ◽  
Initial Contact ◽  
Knee Mechanics ◽  
Acl Injury Risk

Neuromuscular fatigue exacerbates abnormal landing strategies, which may increase noncontact anterior cruciate ligament (ACL) injury risk. The synergistic actions of quadriceps and hamstrings (QH) muscles are central to an upright landing posture, though the precise effect of simultaneous fatigue of these muscles on landing and ACL injury risk is unclear. Elucidating neuromechanical responses to QH fatigue thus appears important in developing more targeted fatigue-resistance intervention strategies. The current study thus aimed to examine the effects of QH fatigue on lower extremity neuromechanics during dynamic activity. Twenty-five healthy male and female volunteers performed three single-leg forward hops onto a force platform before and after QH fatigue. Fatigue was induced through sets of alternating QH concentric contractions, on an isokinetic dynamometer, until the first five repetitions of a set were performed at least 50% below QH peak torque. Three-dimensional hip and knee kinematics and normalized (body mass × height) kinetic variables were quantified for pre- and postfatigue landings and subsequently analyzed by way of repeated- measures mixed-model ANOVAs. QH fatigue produced significant increases in initial contact (IC) hip internal rotation and knee extension and external rotation angles (p< .05), with the increases in knee extension and external rotation being maintained at the time of peak vertical ground reaction force (vGRF) (p< .05). Larger knee extension and smaller knee fexion and external rotation moments were also evident at peak vGRF following fatigue (p< .05). Females landed with greater hip fexion and less abduction than males at both IC and peak vGRF as well as greater knee fexion at peak vGRF (p< .05). The peak vGRF was larger for females than males (p< .05). No sex × fatigue effects were found (p> .05). Fatigue of the QH muscles altered hip and knee neuromechanics, which may increase the risk of ACL injury. Prevention programs should incorporate methods aimed at countering QH fatigue.

scholarly journals Effects of Sex and Fatigue on Biomechanical Measures During the Drop-Jump Task in Children

2017 ◽  
Vol 5 (1) ◽  
pp. 232596711667964 ◽  
Author(s):  
Kristín Briem ◽  
Kolbrún Vala Jónsdóttir ◽  
Árni Árnason ◽  
Þórarinn Sveinsson
Keyword(s):  
Knee Flexion ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Pearson Correlation ◽  
Reaction Force ◽  
Acl Injury ◽  
Initial Contact ◽  
Drop Jump ◽  
Increased Risk ◽  
Movement Strategies

Background: Female athletes have a higher rate of anterior cruciate ligament (ACL) injury than males from adolescence and into maturity, which is suggested to result from sex-specific changes in dynamic movement patterns with maturation. Few studies have studied movement strategies and response to fatigue in children. Purpose: To evaluate the effect of fatigue on biomechanical variables associated with increased risk for ACL injury during a drop-jump (DJ) performance in children. Study Design: Controlled laboratory study. Methods: A total of 116 children (mean age, 10.4 years) were recruited from local sports clubs and performed 5 repetitions of a DJ task before and after a fatigue protocol. Kinematic and kinetic data from initial contact (IC) to the first peak vertical ground reaction force (vGRF) were analyzed for both limbs, including limb and fatigue as within-subject factors for analyses between boys and girls. Pearson correlation coefficients were calculated to identify associations between variables of interest. Results: Girls demonstrated greater peak vGRF values than boys (by 8.1%; P < .05), there were greater peak vGRF values for the right limb than the left (by 6.2%; P < .001), and fatigue led to slightly greater values ( P < .05). Although weak, the correlation between peak vGRF values and knee flexion excursion was stronger for girls ( r = –0.20) than boys ( r = –0.08) ( P < .006). Fatigue resulted in greater knee flexion angles at IC and less excursion during landing, more so for girls (by 6.1° vs 1.4°; interaction, P < .001), although the knee flexion moment was generally lowered by fatigue ( P < .001). Limb asymmetry in knee flexion moments was more pronounced for boys than for girls (interaction, P < .05), contrary to that seen in frontal plane knee moments, where asymmetry was much greater in girls than boys (interaction, P < .001). Conclusion: Even as young athletes, girls and boys seem to adopt dissimilar movement strategies and are differently affected by fatigue. Clinical Relevance: Injury prevention programs should be considered at an earlier age in an effort to lower the risk of ACL injury in athletes.

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