scholarly journals Expert Versus Novice Interrater Reliability and Criterion Validity of the Landing Error Scoring System

2010 ◽  
Vol 19 (1) ◽  
pp. 41-56 ◽  
Author(s):  
James Onate ◽  
Nelson Cortes ◽  
Cailee Welch ◽  
Bonnie Van Lunen
Keyword(s):  
Range Of Motion ◽  
Scoring System ◽  
Knee Flexion ◽  
Interrater Reliability ◽  
Assessment Tool ◽  
Outcome Measurement ◽  
Acl Injury ◽  
Initial Contact ◽  
Knee Valgus ◽  
Trunk Flexion

Context:A clinical assessment tool that would allow for efficient large-group screening is needed to identify individuals potentially at risk for anterior cruciate ligament (ACL) injury.Objective:To assess the criterion validity of a jumplanding assessment tool compared with 3-dimensional (3D) motion analysis and evaluate interrater reliability across an expert vs novice rater using the Landing Error Scoring System (LESS).Design:Validity protocol.Setting:Controlled, laboratory.Participants:Nineteen female (age 19.58 ± .84 y, height 1.67 ± .05 m, mass 63.66 ± 10.11 kg) college soccer athletes volunteered.Main Outcome Measurement:Interrater reliability between expert rater (5 y LESS experience) vs novice rater (no LESS experience). LESS scores across 13 items and total score. 3D lower extremity kinematics were reduced to dichotomous values to match LESS items.Interventions:Participants performed drop-box landings from a 30-cm height with standard video-camera and 3D kinematic assessment.Results:Intrarater item reliability, assessed by kappa correlation, between novice and experienced LESS raters ranged from moderate to excellent (κ = .459–.875). Overall LESS score, assessed by intraclass correlation coefficient, was excellent (ICC2,1 = .835, P < .001). Statistically significant phi correlation (P < .05) was found between rater and 3D scores for knee-valgus range of motion; however, percent agreement between expert rater and 3D scores revealed excellent agreement (range of 84–100%) for ankle flexion at initial contact, knee-flexion range of motion, trunk flexion at maximum knee flexion, and foot position at initial contact for both external and internal rotation of tibia. Moderate agreement was found between rater and 3D scores for trunk flexion at initial contact, stance width less than shoulder width, knee valgus at initial contact, and knee-valgus range of motion.Conclusions:Our findings support moderate to excellent validity and excellent expert vs novice interrater reliability of the LESS to accurately assess 3D kinematic motion patterns. Future research should evaluate the efficacy of the LESS to assess individuals at risk for ACL injury.

scholarly journals RELIABILITY OF A NEW LANDING ERROR SCORING SYSTEM: THE LESS-RMC

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0009
Author(s):  
Ryan S. Wexler ◽  
Sean Higinbotham ◽  
Danny Blake ◽  
Carlie Harrison ◽  
Justin Hollenbeck ◽  
...  
Keyword(s):  
Clinical Assessment ◽  
Scoring System ◽  
Injury Risk ◽  
Knee Injury ◽  
Assessment Tool ◽  
Acl Injury ◽  
Knee Valgus ◽  
Jump Landing ◽  
Acl Injury Risk ◽  
The Mean

BACKGROUND Several biomechanical deficits have been shown to increase non-contact knee injury risk of the anterior cruciate ligament (ACL). The Landing Error Scoring System (LESS) is a clinical assessment tool that has been successfully used to predict the individuals that are at a high risk for injury and evaluate changes in landing technique after participation in a neuromuscular preventive training program. The LESS-RT is a shortened version of the LESS and is a method to score landing technique without the use of video. The current study proposes a new tool for the evaluation of landing technique and ACL injury risk that blends the LESS and LESS-RT protocols but emphasizes the movement features that contribute to high knee valgus moments including movement asymmetry. The LESS-RMC (Rocky Mountain Consortium) consists of evaluating 11 comprehensive landing errors that are related to ACL injury risk. Consolidating questions pertaining to the opposite ends of joint motion such as “toe in” and “toe out” into “maximum foot rotation position” and adding a global asymmetry score were performed to reduce the time demands for evaluation yet capture the salient factors of the LESS; whereas the penalty for knee valgus severity was pulled from the LESS-RT but implemented for both knees in the new LESS-RMC to ultimately stratify knee injury risk during the jump landing task. The purpose of this study was to determine the reliability of the new LESS-RMC assessment tool. METHODS Thirty-seven, elite female soccer athletes (13.2 +/- 0.4 y) performed three drop-jumps from a height of 30 cm. Front and side views of the landing were recorded with digital video cameras. Movement quality was rated by 4 researchers evaluating 17 components of the landing with the LESS and a modified, 11 component version of the LESS (LESS-RMC). The 4 raters were novel to the evaluation of both scoring systems. Each rater was trained how to score each test and was instructed to evaluate the landing trials from the first 10 participants. After a group video review and discussion, the raters repeated the scoring procedures for the same 10 participants 48 hours after the original review. After another 48 hours, the raters evaluated the landing trials for all 37 participants (111 trials). Inter-rater reliability of the LESS and LESS-RMC were determined using the ICC (3,1) equations and the output from a two-way ANOVA (SPSS, version 25). RESULTS The mean LESS score was 6.45 +/- 0.55 (rater 1, 6.42; rater 2, 7.15; rater 3, 5.79; rater 4, 6.45). The ICC agreement between raters of scoring the LESS was .389 whereas the ICC agreement for the mean of the four raters was .718. The ICC for scoring consistency was .382 and Cronbach’s a was .735. The mean LESS-RMC score was 6.19 +/- 0.74 (rater 1, 5.65; rater 2, 6.99; rater 3, 5.48; rater 4, 6.64). The ICC agreement of scoring the LESS-RMC was .585 whereas the ICC agreement for the mean of the four raters was .849. The ICC for scoring consistency was .574 and Cronbach’s a was .884. CONCLUSION On average, the raters scored the LESS and the LESS-RMC with moderate reliability across the group of athletes. The LESS-RMC was scored with greater reliability than the LESS for this group of relatively novice raters. This is likely due to the simplification of the overall protocol in terms of quantity of questions, the ability of a novel rater to understand scenarios which elicit specific scores and the clear separation of body segments (e.g. hip and trunk flexion). In conjunction with this, it was reported by the raters that LESS-RMC was less redundant and more effective at assessing crucial aspects of a jump landing pattern. Overall, LESS RMC was objectively and subjectively more reliable and easier to use than the LESS for the four raters involved in this study. It is concluded that the LESS-RMC is a quick, easy and reliable clinical assessment tool that may be used to stratify individuals who may be at risk for ACL injury.

scholarly journals Ankle-Dorsiflexion Range of Motion and Landing Biomechanics

2011 ◽  
Vol 46 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Chun-Man Fong ◽  
J. Troy Blackburn ◽  
Marc F. Norcross ◽  
Melanie McGrath ◽  
Darin A. Padua
Keyword(s):  
Range Of Motion ◽  
Knee Flexion ◽  
Injury Risk ◽  
Acl Injury ◽  
Ankle Dorsiflexion ◽  
Ground Reaction Forces ◽  
Knee Valgus ◽  
Landing Biomechanics ◽  
Reaction Forces ◽  
Acl Injury Risk

Abstract Context: A smaller amount of ankle-dorsiflexion displacement during landing is associated with less knee-flexion displacement and greater ground reaction forces, and greater ground reaction forces are associated with greater knee-valgus displacement. Additionally, restricted dorsiflexion range of motion (ROM) is associated with greater knee-valgus displacement during landing and squatting tasks. Because large ground reaction forces and valgus displacement and limited knee-flexion displacement during landing are anterior cruciate ligament (ACL) injury risk factors, dorsiflexion ROM restrictions may be associated with a greater risk of ACL injury. However, it is unclear whether clinical measures of dorsiflexion ROM are associated with landing biomechanics. Objective: To evaluate relationships between dorsiflexion ROM and landing biomechanics. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Thirty-five healthy, physically active volunteers. Intervention(s): Passive dorsiflexion ROM was assessed under extended-knee and flexed-knee conditions. Landing biomechanics were assessed via an optical motion-capture system interfaced with a force plate. Main Outcome Measure(s): Dorsiflexion ROM was measured in degrees using goniometry. Knee-flexion and knee-valgus displacements and vertical and posterior ground reaction forces were calculated during the landing task. Simple correlations were used to evaluate relationships between dorsiflexion ROM and each biomechanical variable. Results: Significant correlations were noted between extended-knee dorsiflexion ROM and knee-flexion displacement (r  =  0.464, P  =  .029) and vertical (r  =  −0.411, P  =  .014) and posterior (r  =  −0.412, P  =  .014) ground reaction forces. All correlations for flexed-knee dorsiflexion ROM and knee-valgus displacement were nonsignificant. Conclusions: Greater dorsiflexion ROM was associated with greater knee-flexion displacement and smaller ground reaction forces during landing, thus inducing a landing posture consistent with reduced ACL injury risk and limiting the forces the lower extremity must absorb. These findings suggest that clinical techniques to increase plantar-flexor extensibility and dorsiflexion ROM may be important additions to ACL injury-prevention programs.

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.

scholarly journals AGE, BODY MASS INDEX AND SEX RELATED TO DYNAMIC KNEE VALGUS AND SHOCK ABSORPTION DURING SINGLE LEG LANDING IN UNINJURED ADOLESCENT ATHLETES

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0012
Author(s):  
Nicole Mueske ◽  
Bridget G. O’Callahan ◽  
Mia J. Katzel ◽  
Tracy Zaslow ◽  
Bianca Edison ◽  
...  
Keyword(s):  
Risk Factors ◽  
Body Mass Index ◽  
Energy Absorption ◽  
Knee Flexion ◽  
Sagittal Plane ◽  
Acl Injury ◽  
Knee Valgus ◽  
Shock Absorption ◽  
Younger Age ◽  
Hip Abduction

BACKGROUND Dynamic limb valgus and poor shock absorption strategies have been implicated in anterior cruciate ligament (ACL) injuries. Additionally, biomechanics during over ground and double leg landing tasks have been shown to differ depending on sex and age/maturation. However, there is limited evidence evaluating the effect of age, body mass index (BMI) and sex on single leg landing strategies. METHODS 51 uninjured athletes (ages 7-15 years, mean 12.2, SD 2.3; 45% female) completed the single leg hop (SLH) for distance task. 3-D motion analysis using a 6 degree-of-freedom model was used to collect lower extremity kinematics and kinetics from initial foot contact to peak knee flexion of landing limb; for each limb the hop with the longest distance and appropriate landing (stuck for >2 seconds) was used for analysis. Using multivariate regression with standardized coefficients, the effects of age, BMI and sex on biomechanical variables of interest were assessed. RESULTS When considering dynamic valgus components, younger age was associated with higher knee valgus (ß=0.251; p=0.038) and hip abduction (ß=0.250; p=0.038) angles, higher BMI was associated with higher knee valgus angles (ß=0.262; p=0.028), and females tended to have higher hip abduction moments (ß=0.301; p=0.003), but a more abducted (ß=0.281; p=0.005) and internally rotated hip position (ß=0.359; p=0.003) along with higher internal rotation hip moments (ß=0.298; p=0.001) and with higher ankle inversion moments (ß=0.304; p=0.003). Although differences were observed, R2 values were low ranging from 0.191 (hip ab/adduction angles) to 0.053 (knee valgus moment). Sagittal plane components of shock absorption were partially explained by age, BMI and sex (R2 values range from 0.685 to 0.013; vertical ground reaction force (vGRF) in multiples of body weight, ankle dorsi/plantarflexion moment, respectively). Younger age was associated with higher vGRF (ß=-0.520; p<0.0001) and knee flexion moments (ß=-0.225; p=0.034), but with lower knee flexion angles (ß=0.252; p=0.041), ankle dorsiflexion angles (ß=0.322; p=0.003) and hip flexion moments (ß=0.289; p=0.016). Higher BMI was associated with lower GRF (ß=-0.387; p<0.0001), lower knee (ß=-0.277; p=0.009) and hip (ß=-0.289; p=0.043) flexion moments and lower sagittal plane energy absorption at the knee (ß=-0.267; p=0.016). Females tended to have lower vGRF (ß=0.147; p=0.017), more sagittal plane hip (ß=0.282; p=0.007) and knee (ß =0.250; p=0.010) energy absorption and less ankle dorsiflexion (ß=-0.283; p=0.002). CONCLUSION/SIGNIFICANCE Biomechanical risk factors for ACL injury during single leg hop landings are influenced by age, BMI and sex. Female sex and higher BMI are associated with dynamic limb valgus while younger age is associated with both dynamic limb valgus and poor shock absorption during single leg hop landings. These are important findings due to the known ACL injury risk in female athletes and the high re-tear rate in pediatric athletes. Identifying these biomechanical risk factors related to demographics and anthropometrics may provide objective direction needed to contribute to effective intervention strategies and eventual injury reduction in these high risk groups.

scholarly journals Instruction and Jump-Landing Kinematics in College-Aged Female Athletes Over Time

2013 ◽  
Vol 48 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Jena Etnoyer ◽  
Nelson Cortes ◽  
Stacie I. Ringleb ◽  
Bonnie L. Van Lunen ◽  
James A. Onate
Keyword(s):  
Lower Extremity ◽  
Retention Test ◽  
Knee Flexion ◽  
Female Athletes ◽  
Initial Contact ◽  
Knee Valgus ◽  
Drop Jump ◽  
Jump Landing ◽  
Peak Knee ◽  
Hip Flexion

Context: Instruction can be used to alter the biomechanical movement patterns associated with anterior cruciate ligament (ACL) injuries. Objective: To determine the effects of instruction through combination (self and expert) feedback or self-feedback on lower extremity kinematics during the box–drop-jump task, running–stop-jump task, and sidestep-cutting maneuver over time in college-aged female athletes. Design: Randomized controlled clinical trial. Setting: Laboratory. Patients or Other Participants: Forty-three physically active women (age = 21.47 ± 1.55 years, height = 1.65 ± 0.08 m, mass = 63.78 ± 12.00 kg) with no history of ACL or lower extremity injuries or surgery in the 2 months before the study were assigned randomly to 3 groups: self-feedback (SE), combination feedback (CB), or control (CT). Intervention(s): Participants performed a box–drop-jump task for the pretest and then received feedback about their landing mechanics. After the intervention, they performed an immediate posttest of the box–drop-jump task and a running–stop-jump transfer test. Participants returned 1 month later for a retention test of each task and a sidestep-cutting maneuver. Kinematic data were collected with an 8-camera system sampled at 500 Hz. Main Outcome Measure(s): The independent variables were feedback group (3), test time (3), and task (3). The dependent variables were knee- and hip-flexion, knee-valgus, and hip- abduction kinematics at initial contact and at peak knee flexion. Results: For the box–drop-jump task, knee- and hip-flexion angles at initial contact were greater at the posttest than at the retention test (P &lt; .001). At peak knee flexion, hip flexion was greater at the posttest than at the pretest (P = .003) and was greater at the retention test than at the pretest (P = .04); knee valgus was greater at the retention test than at the pretest (P = .03) and posttest (P = .02). Peak knee flexion was greater for the CB than the SE group (P = .03) during the box–drop-jump task at posttest. For the running–stop-jump task at the posttest, the CB group had greater peak knee flexion than the SE and CT (P ≤ .05). Conclusions: Our results suggest that feedback involving a combination of self-feedback and expert video feedback with oral instruction effectively improved lower extremity kinematics during jump-landing tasks.

Reliability of Using a Handheld Tablet and Application to Measure Lower-Extremity Alignment Angles

2015 ◽  
Vol 24 (4) ◽  
Author(s):  
Deborah L. King ◽  
Barbara C. Belyea
Keyword(s):  
At Risk ◽  
Lower Extremity ◽  
Knee Flexion ◽  
Interrater Reliability ◽  
Knee Injury ◽  
Vertical Jump ◽  
Frontal Plane ◽  
Initial Contact ◽  
Experience Level ◽  
Lower Extremity Injuries

Context: Landing kinematics have been identified as a risk factor for knee injury. Detecting atypical kinematics in clinical settings is important for identifying individuals at risk for these injuries. Objective: To determine the reliability of a handheld tablet and application (app) for measuring lower-extremity kinematics during drop vertical-jump landings. Design: Measurement reliability. Setting: Laboratory. Participants: 23 healthy young adults with no lower-extremity injuries and no contraindications for jumping and landing. Intervention: Subjects performed 6 drop vertical jumps that were captured with an iPad2 and analyzed with a KinesioCapture app by 2 novice and 2 experienced raters. Three trials each were captured in the frontal and sagittal planes. Main Outcome Measures: Frontal-plane projection angles, knee flexion, and hip flexion at initial contact and maximum knee flexion were measured. ICC and SEM were calculated to determine intertrial and interrater reliability. One-way ANOVAs were used to examine differences between the measured angles of the raters. Results: Average intertrial reliability ranged from .71 to .98 for novice raters and .77 to .99 for experienced raters. SEMs were 2.3-4.3° for novice raters and 1.6-3.9° for experienced raters. Interrater ICC2,1 was .39-.98 for the novice raters and .69-.93 for the experienced raters. SEMs were smallest with the experienced raters, all less than 1.5°. Conclusion: A handheld tablet and app is promising for evaluating landing kinematics and identifying individuals at risk for knee injury in a clinical setting. Intertrial reliability is good to excellent when using average trial measures. Interrater reliability is fair to excellent depending on experience level. Multiple trials should be assessed by a single rater when assessing lower-extremity mechanics with a handheld tablet and app, and results may vary with experience level or training.

scholarly journals Reliability of the Landing Error Scoring System-Real Time, a Clinical Assessment Tool of Jump-Landing Biomechanics

2011 ◽  
Vol 20 (2) ◽  
pp. 145-156 ◽  
Author(s):  
Darin A. Padua ◽  
Michelle C. Boling ◽  
Lindsay J. DiStefano ◽  
James A. Onate ◽  
Anthony I. Beutler ◽  
...  
Keyword(s):  
At Risk ◽  
Lower Extremity ◽  
Real Time ◽  
Clinical Assessment ◽  
Scoring System ◽  
Interrater Reliability ◽  
Assessment Tool ◽  
Lower Extremity Injuries ◽  
Jump Landing ◽  
Extremity Injuries

Context:There is a need for reliable clinical assessment tools that can be used to identify individuals who may be at risk for injury. The Landing Error Scoring System (LESS) is a reliable and valid clinical assessment tool that was developed to identify individuals at risk for lower extremity injuries. One limitation of this tool is that it cannot be assessed in real time and requires the use of video cameras.Objective:To determine the interrater reliability of a real-time version of the LESS, the LESS-RT.Design:Reliability study.Setting:Controlled research laboratory.Participants:43 healthy volunteers (24 women, 19 men) between the ages of 18 and 23.Intervention:The LESS-RT evaluates 10 jump-landing characteristics that may predispose an individual to lower extremity injuries. Two sets of raters used the LESS-RT to evaluate participants as they performed 4 trials of a jump-landing task.Main Outcome Measures:Intraclass correlation coefficient (ICC2,1) values for the final composite score of the LESS-RT were calculated to assess interrater reliability of the LESS-RT.Results:Interrater reliability (ICC2,1) for the LESS-RT ranged from .72 to .81 with standard error of measurements ranging from .69 to .79.Conclusions:The LESS-RT is a quick, easy, and reliable clinical assessment tool that may be used by clinicians to identify individuals who may be at risk for lower extremity injuries.

scholarly journals The Effects of Injury Prevention Programs on the Biomechanics of Landing Tasks: A Systematic Review With Meta-analysis

2017 ◽  
Vol 46 (6) ◽  
pp. 1492-1499 ◽  
Author(s):  
Thiago Jambo Alves Lopes ◽  
Milena Simic ◽  
Gregory D. Myer ◽  
Kevin R. Ford ◽  
Timothy E. Hewett ◽  
...  
Keyword(s):  
Injury Prevention ◽  
Knee Flexion ◽  
Meta Analysis ◽  
Acl Injury ◽  
Prevention Programs ◽  
Initial Contact ◽  
Landing Biomechanics ◽  
Peak Knee ◽  
Knee Abduction ◽  
Hip Flexion

Background: Anterior cruciate ligament (ACL) tear is a common injury in sports and often occurs during landing from a jump. Purpose: To synthesize the evidence on the effects of injury prevention programs (IPPs) on landing biomechanics as they relate to the ligament, quadriceps, trunk, and leg dominance theories associated with ACL injury risk. Study Design: Meta-analysis. Methods: Six electronic databases were searched for studies that investigated the effect of IPPs on landing task biomechanics. Prospective studies that reported landing biomechanics at baseline and post-IPP were included. Results from trunk, hip, and knee kinematics and kinetics related to the ACL injury theories were extracted, and meta-analyses were performed when possible. Results: The criteria were met by 28 studies with a total of 466 participants. Most studies evaluated young females, bilateral landing tasks, and recreational athletes, while most variables were related to the ligament and quadriceps dominance theories. An important predictor of ACL injury, peak knee abduction moment, decreased ( P = .01) after the IPPs while other variables related to the ligament dominance theory did not change. Regarding the quadriceps dominance theory, after the IPPs, angles of hip flexion at initial contact ( P = .009), peak hip flexion ( P = .002), and peak knee flexion ( P = .007) increased, while knee flexion at initial contact did not change ( P = .18). Moreover, peak knee flexion moment decreased ( P = .005) and peak vertical ground-reaction force did not change ( P = .10). Conclusion: The exercises used in IPPs might have the potential to improve landing task biomechanics related to the quadriceps dominance theory, especially increasing peak knee and hip flexion angles. Importantly, peak knee abduction moment decreased, which indicates that IPPs influence a desired movement strategy to help athletes overcome dangerous ligament dominance loads arising from lack of frontal plane control during dynamic tasks. The lack of findings for some biomechanical variables suggests that future IPPs may be enhanced by targeting participants’ baseline profile deficits, highlighting the need to deliver an individualized and task-specific IPP.

scholarly journals Rapid Posterior Tibial Reduction After Noncontact Anterior Cruciate Ligament Rupture: Mechanism Description From a Video Analysis

2020 ◽  
Vol 12 (5) ◽  
pp. 462-469 ◽  
Author(s):  
Alberto Grassi ◽  
Filippo Tosarelli ◽  
Piero Agostinone ◽  
Luca Macchiarola ◽  
Stefano Zaffagnini ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Video Analysis ◽  
Knee Flexion ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Soccer Players ◽  
Initial Contact ◽  
Acl Injuries ◽  
Posterior Tibial ◽  
Anterior Cruciate

Background: The mechanisms of noncontact anterior cruciate ligament (ACL) injuries are an enormously debated topic in sports medicine; however, the late phases of injury have not yet been investigated. Hypothesis: A well-defined posterior tibial translation can be visualized with its timing and patterns of knee flexion after ACL injury. Study Design: Case series. Level of Evidence: Level 4. Methods: A total of 137 videos of ACL injuries in professional male football (soccer) players were screened for a sudden posterior tibial reduction (PTR) in the late phase of noncontact ACL injury mechanism. The suitable videos were analyzed using Kinovea software for sport video analysis. The time of initial contact of the foot with the ground, the foot lift, the start of tibial reduction, and the end of tibial reduction were assessed. Results: A total of 21 videos exhibited a clear posterior tibial reduction of 42 ± 11 ms, after an average of 229 ± 81 ms after initial contact. The tibial reduction occurred consistently within the first 50 to 60 ms after foot lift (55 ± 30 ms) and with the knee flexed between 45° and 90° (62%) or more than 90° (24%). Conclusion: A rapid posterior tibial reduction is consistently present in the late phases of noncontact ACL injuries in some male soccer players, with a consistent temporal relationship between foot lift from the ground and consistent degrees of knee flexion near or above 90°. Clinical Relevance: This study provides insight into the late phases of ACL injury. The described mechanism, although purely theoretical, could be responsible for commonly observed intra-articular lesions.

Effects of Gender and Foot-Landing Techniques on Lower Extremity Kinematics during Drop-Jump Landings

2007 ◽  
Vol 23 (4) ◽  
pp. 289-299 ◽  
Author(s):  
Nelson Cortes ◽  
James Onate ◽  
João Abrantes ◽  
Linda Gagen ◽  
Elizabeth Dowling ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
The Self ◽  
Initial Contact ◽  
Knee Valgus ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground ◽  
Hip Flexion

The purpose of this study was to assess kinematic lower extremity motion patterns (hip flexion, knee flexion, knee valgus, and ankle dorsiflexion) during various foot-landing techniques (self-preferred, forefoot, and rear foot) between genders. 3-D kinematics were collected on 50 (25 male and 25 female) college-age recreational athletes selected from a sample of convenience. Separate repeated-measures ANOVAs were used to analyze each variable at three time instants (initial contact, peak vertical ground reaction force, and maximum knee flexion angle). There were no significant differences found between genders at the three instants for each variable. At initial contact, the forefoot technique (35.79° ± 11.78°) resulted in significantly (p= .001) less hip flexion than did the self-preferred (41.25° ± 12.89°) and rear foot (43.15° ± 11.77°) techniques. At peak vertical ground reaction force, the rear foot technique (26.77° ± 9.49°) presented significantly lower (p= .001) knee flexion angles as compared with forefoot (58.77° ± 20.00°) and self-preferred (54.21° ± 23.78°) techniques. A significant difference for knee valgus angles (p= .001) was also found between landing techniques at peak vertical ground reaction force. The self-preferred (4.12° ± 7.51°) and forefoot (4.97° ± 7.90°) techniques presented greater knee varus angles as compared with the rear foot technique (0.08° ± 6.52°). The rear foot technique created more ankle dorsiflexion and less knee flexion than did the other techniques. The lack of gender differences can mean that lower extremity injuries (e.g., ACL tears) may not be related solely to gender but may instead be associated with the landing technique used and, consequently, the way each individual absorbs jump-landing energy.

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