scholarly journals Kinematic Analyses of Parkour Landings From as High as 2.7 Meters

2020 ◽  
Vol 72 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Boyi Dai ◽  
Jacob S. Layer ◽  
Taylour J. Hinshaw ◽  
Ross F. Cook ◽  
Janet S. Dufek
Keyword(s):  
Lower Extremity ◽  
Injury Prevention ◽  
Vertical Velocity ◽  
Injury Risk ◽  
Three Dimensional ◽  
Initial Contact ◽  
Joint Angles ◽  
Performance Training ◽  
Kinematic Analyses ◽  
And Performance

AbstractDeveloping effective landing strategies has implications for both injury prevention and performance training. The purpose was to quantify the kinematics of Parkour practitioners’ landings from three heights utilizing four techniques. Seventeen male and three female Parkour practitioners landed from 0.9, 1.8, and 2.7 m utilizing the squat, forward, roll, and stiff landing techniques when three-dimensional kinematics were collected. The stiff landing demonstrated the shortest landing time, and the roll landing showed the longest landing time for 1.8 and 2.7 m. Roll landings demonstrated the greatest forward velocities at initial contact and at the end of the landing. Stiff landings showed the greatest changes in vertical velocity during the early landing, while roll landings showed the least changes for 0.9 and 1.8 m. Both roll and stiff landings generally resulted in decreased changes in horizontal velocity during the early landing compared to squat and forward landings. The four landing techniques also demonstrated different lower extremity joint angles. Stiff landings may increase injury risk because of the quick decrease of vertical velocities. Roll landings allow individuals to decrease vertical and horizontal velocities over a longer time, which is likely to decrease the peak loading imposed on the lower extremities.

Lower Extremity Joint Moments of Collegiate Soccer Players Differ between Genders during a Forward Jump

2008 ◽  
Vol 17 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Joseph M. Hart ◽  
J. Craig Garrison ◽  
Riann Palmieri-Smith ◽  
D. Casey Kerrigan ◽  
Christopher D. Ingersoll
Keyword(s):  
Lower Extremity ◽  
Internal Rotation ◽  
Outcome Measures ◽  
Cruciate Ligament ◽  
Ligament Injury ◽  
Initial Contact ◽  
Joint Angles ◽  
Joint Moments ◽  
Heel Contact ◽  
Hip Internal Rotation

Context:Lower extremity kinetics while performing a single-leg forward jump landing may help explain gender biased risk for noncontact anterior cruciate ligament injury.Objective:Gender comparison of lower extremity joint angles and moments.Design:Static groups comparison.Setting:Motion analysis laboratory.Patients or Other Participants:8 male and 8 female varsity, collegiate soccer athletes.Intervention:5 single-leg landings from a 100cm forward jump.Main Outcome Measures:Peak and initial contact external joint moments and joint angles of the ankle, knee, and hip.Results:At initial heel contact, males exhibited a adduction moment whereas females exhibited a abduction moment at the hip. Females also had significantly less peak hip extension moment and significantly less peak hip internal rotation moment than males had. Females exhibited greater knee adduction and hip internal rotation angles than men did.Conclusions:When decelerating from a forward jump, gender differences exist in forces acting at the hip.

scholarly journals Biomechanical Analysis of Running in Shoes with Different Heel-to-Toe Drops

2021 ◽  
Vol 11 (24) ◽  
pp. 12144
Author(s):  
Masen Zhang ◽  
Huijuan Shi ◽  
Hui Liu ◽  
Xinglong Zhou
Keyword(s):  
Lower Extremity ◽  
Repeated Measures ◽  
Impact Force ◽  
Three Dimensional ◽  
Knee Extension ◽  
Biomechanical Analysis ◽  
Initial Contact ◽  
Vertical Loading ◽  
Peak Knee ◽  
Running Shoes

The heel-to-toe drop of running shoes is a key parameter influencing lower extremity kinematics during running. Previous studies testing running shoes with lower or larger drops generally used minimalist or maximalist shoes, where the factors outside of the drop may lead to the observed changes in running biomechanics. Therefore, our aim was to compare the strike patterns, impact force, and lower extremity biomechanics when running in shoes that varied only in their drops. Eighteen habitual rearfoot strikers performed trials wearing running shoes with four drop conditions: 15 mm, 10 mm, 5 mm, and without a drop. Three-dimensional (3D) tracks of the reflective markers and impact force were synchronously collected using a video graphic acquisition system and two force plates. The biomechanical parameters were compared among the four drop conditions using one-way ANOVA of repeated measures. A greater foot inclination angle (p = 0.001, ηp2 = 0.36) at initial contact and a lower vertical loading rate (p = 0.002, ηp2 = 0.32) during the standing phase were found when running in shoes with large drops compared with running in shoes without a drop. Running in shoes with large drops, as opposed to without, significantly increased the peak knee extension moment (p = 0.002, ηp2 = 0.27), but decreased the peak ankle eversion moment (p = 0.001, ηp2 = 0.35). These findings suggest that the heel-to-toe drop of running shoes significantly influences the running pattern and the loading on lower extremity joints. Running shoes with large drops may be disadvantageous for runners with knee weakness and advantageous for runners with ankle weakness.

Influence of Footwear on Posture and Comfort in Elite Rugby Players

2021 ◽  
Author(s):  
Sylvain Blanchard ◽  
Laurence Bellaïche ◽  
Zbigniew Kuliberda ◽  
Michel Behr
Keyword(s):  
Injury Prevention ◽  
Injury Risk ◽  
Center Of Pressure ◽  
Dual Purpose ◽  
Spinal Posture ◽  
Foot Arch ◽  
Arch Support ◽  
Potential Impact ◽  
And Performance ◽  
Rugby Players

AbstractInfluence of footwear on posture in athletes is poorly documented despite its potential impact on biomechanics and injury risk. The aim of this study was to investigate effects of different footwear geometries on comfort and posture on a cohort of 48 elite rugby players. Spine posture was characterized by photogrammetry, while center of pressure was measured by means of a force platform. Three different footwear outsoles architectures (one rugby shoe with flat outsole, one rugby shoe with a 10 mm heel rise and foot arch support, and a running shoe with a 10mm heel rise and foot arch support) were compared to non-shod in randomized order. Then comfort felt at the level of foot and spine was also estimated by subjective questionnaires. Compared to the flat rugby model, both other models induced significantly (p<0.05) greater comfort at the level of foot and spine, a slight shift toward of center of pressure and a spinal posture closer to that observed when non-shod. The footwear geometry influences comfort and posture at the level of the foot as well as spine and should be considered in a dual purpose of injury prevention and performance.

scholarly journals Effect of Injury Prevention Programs on Lower Extremity Performance in Youth Athletes: A Systematic Review

2019 ◽  
Vol 12 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Colleen Hanlon ◽  
Joseph J. Krzak ◽  
Janey Prodoehl ◽  
Kathy D. Hall
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Lower Extremity ◽  
Injury Prevention ◽  
Injury Risk ◽  
Prevention Programs ◽  
Force Generation ◽  
Level Of Evidence ◽  
Youth Athletes ◽  
Lower Extremity Performance

Background: Understanding how existing youth injury prevention programs affect specific modifiable injury risk factors will inform future program development for youth athletes. Objective: To comprehensively evaluate the effects of injury prevention programs on the modifiable intrinsic risk factors associated with lower extremity performance in youth athletes. Data Sources: This systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A systematic search of the literature was performed using multiple databases (PubMed, EBSCOhost [including CINAHL, Medline, and SPORTDiscus], and PEDro). Secondary references were appraised for relevant articles. Article types included randomized or cluster randomized controlled trials and randomized cohort designs with youth athletes engaged in organized sports, along with outcomes that included at least 1 physical performance outcome measure. Study Selection: Eight studies met inclusion and exclusion criteria and were reviewed by 2 independent reviewers, with a third consulted in the case of disagreement, which was not needed. Study Design: Systematic review. Level of Evidence: Level 3. Data Extraction: Included studies underwent review of methodological quality using the Physiotherapy Evidence Database scale. Results: Studies included mixed-sex samples of youth athletes who predominantly participated in soccer at different skill levels. The FIFA 11+ series was the most commonly used injury prevention program. Among studies, the mean percentage of improvement identified was 11.3% for force generation, 5.7% for coordination, 5.2% for posture, and 5.2% for balance. The lowest mean percentage improvement was in speed (2.2%). Endurance was not significantly affected by any of the programs. Conclusion: This systematic review shows that injury prevention programs improve several modifiable intrinsic risk factors of lower extremity performance among youth athletes, particularly force generation. However, several intrinsic risk factors were either not significantly affected or specifically addressed by existing programs.

Ankle Dorsiflexion Displacement During Landing is Associated With Initial Contact Kinematics but not Joint Displacement

2015 ◽  
Vol 31 (4) ◽  
pp. 205-210 ◽  
Author(s):  
Rebecca L. Begalle ◽  
Meghan C. Walsh ◽  
Melanie L. McGrath ◽  
Michelle C. Boling ◽  
J. Troy Blackburn ◽  
...  
Keyword(s):  
Injury Risk ◽  
Sagittal Plane ◽  
Plantar Flexion ◽  
Three Dimensional ◽  
Contact Angles ◽  
Ankle Dorsiflexion ◽  
Lower Extremity Injury ◽  
Initial Contact ◽  
Joint Displacement ◽  
Jump Landings

The ankle, knee, and hip joints work together in the sagittal plane to absorb landing forces. Reduced sagittal plane motion at the ankle may alter landing strategies at the knee and hip, potentially increasing injury risk; however, no studies have examined the kinematic relationships between the joints during jump landings. Healthy adults (N = 30; 15 male, 15 female) performed jump landings onto a force plate while three-dimensional kinematic data were collected. Joint displacement values were calculated during the loading phase as the difference between peak and initial contact angles. No relationship existed between ankle dorsiflexion displacement during landing and three-dimensional knee and hip displacements. However, less ankle dorsiflexion displacement was associated with landing at initial ground contact with larger hip flexion, hip internal rotation, knee flexion, knee varus, and smaller plantar flexion angles. Findings of the current study suggest that restrictions in ankle motion during landing may contribute to contacting the ground in a more flexed position but continuing through little additional motion to absorb the landing. Transverse plane hip and frontal plane knee positioning may also occur, which are known to increase the risk of lower extremity injury.

Effects of Volitional Spine Stabilization and Lower-Extremity Fatigue on the Knee and Ankle During Landing Performance in a Population With Recurrent Low Back Pain

2017 ◽  
Vol 26 (5) ◽  
pp. 329-338 ◽  
Author(s):  
Ram Haddas ◽  
Steven F. Sawyer ◽  
Phillip S. Sizer ◽  
Toby Brooks ◽  
Ming-Chien Chyu ◽  
...  
Keyword(s):  
Back Pain ◽  
Lower Extremity ◽  
Injury Risk ◽  
Outcome Measure ◽  
Reaction Force ◽  
Initial Contact ◽  
Vastus Medialis ◽  
Semitendinosus Muscle ◽  
Main Outcome Measure ◽  
Spine Stabilization

Introduction:Recurrent lower back pain (rLBP) and neuromuscular fatigue are independently thought to increase the risk of lower extremity (LE) injury. Volitional preemptive abdominal contraction (VPAC) is thought to improve lumbar spine and pelvis control in individuals with rLBP. The effects of VPAC on fatigued landing performance in individuals with rLBP are unknown.Objectives:To determine the effects of VPAC and LE fatigue on landing performance in a rLBP population.Design:Cross-sectional pretest-posttest cohort control design.Setting:A clinical biomechanics laboratory.Subjects:32 rLBP (age 21.2 ± 2.7 y) but without current symptoms and 33 healthy (age 20.9 ± 2.3 y) subjects.Intervention(s):(i) Volitional preemptive abdominal contraction using abdominal bracing and (ii) fatigue using submaximal free-weight squat protocol with 15% body weight until task failure was achieved.Main Outcome Measure(s):Knee and ankle angles, moments, electromyographic measurements from semitendinosus and vastus medialis muscles, and ground reaction force (GRF) were collected during 0.30 m drop-jump landings.Results:The VPAC resulted in significantly earlier muscle onsets across all muscles with and without fatigue in both groups (mean ± SD, 0.063 ± 0.016 s earlier; P ≤ .001). Fatigue significantly delayed semitendinosus muscle onsets (0.033 ± 0.024 s later; P ≤ .001), decreased GRF (P ≤ .001), and altered landing kinematics in a variety of ways. The rLBP group exhibited delayed semitendinosus and vastus medialis muscle onsets (0.031 ± 0.028 s later; P ≤ .001) and 1.8° less knee flexion at initial contact (P ≤ .008).Conclusion:The VPAC decreases some of the detrimental effects of fatigue on landing biomechanics and thus may reduce LE injury risk in a rLBP population.

The Relationship between Free Limb Motions and Performance in the Triple Jump

1998 ◽  
Vol 14 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Bing Yu ◽  
James G. Andrews
Keyword(s):  
Angular Momentum ◽  
Vertical Velocity ◽  
Three Dimensional ◽  
Whole Body ◽  
Transformation Technique ◽  
Jump Performance ◽  
Body Center ◽  
And Performance ◽  
The Relationship ◽  
Support Phase

The purpose of this study was to investigate relationships between free limb motions and triple jump performance. The subjects were 13 elite male triple jumpers. Three-dimensional videographic data were collected using a direct linear transformation technique with panning cameras. Changes in the velocity of the whole body center of gravity (G), changes in the whole body angular momentum about G, changes in the velocity of G due to free limb motions, and changes in the whole body angular momentum about G due to free limb motions were determined for each of the three support phases. Free limb motions were associated with decreases in the forward horizontal velocity of G and increases in the vertical velocity of G and significantly influenced changes of the corresponding velocity components of G when the changes were large. The free limb motions also created some angular momentum components about G during each support phase but did not significantly influence the changes of the corresponding angular momentum components of the whole body. Neither the changes in the three velocity components of G nor the changes in the three angular momentum components of the whole body about G due to free limb motions were significantly related to the actual distance of the triple jump.

Associations between player age and club soccer coaches’ perceptions of injury risk and lower extremity injury prevention program use

2017 ◽  
Vol 13 (1) ◽  
pp. 122-128 ◽  
Author(s):  
Elle A Morgan ◽  
Samuel T Johnson ◽  
Viktor E Bovbjerg ◽  
Marc F Norcross
Keyword(s):  
Lower Extremity ◽  
Injury Prevention ◽  
Prevention Program ◽  
Injury Risk ◽  
Prevention Programs ◽  
Soccer Players ◽  
Lower Extremity Injury ◽  
Injury Prevention Program ◽  
Program Awareness

The use of a lower extremity injury prevention program by female soccer players before the completion of puberty may mitigate movement changes that develop during puberty and contribute to post-pubescent females’ greater anterior cruciate ligament-injury risk. It is unknown whether club soccer coaches are using injury prevention programs with younger athletes and if player age is associated with soccer coaches’ knowledge, attitudes, and behaviors surrounding injury prevention programs. Fifty-four coaches of female soccer teams from Oregon and Washington states (USA) completed a web-based survey. Associations between team age (U9–U14 teams = 57 and U15–U19 teams = 19 teams) and coaches’ (a) attitudes and perceptions; and (b) injury prevention program awareness, adoption, and implementation fidelity were assessed. Coaches of U15–U19 teams perceived injuries to be more of a problem and soccer to present a high risk of injury. Coaches of older teams more strongly agreed that preventive exercises should be performed by their players during training. Injury prevention program awareness among coaches of U15–U19 and U9–U14 age groups was 79% and 60%, respectively. Injury prevention program-aware coaches of U15–U19 teams were more likely to use an injury prevention program than injury prevention program-aware coaches of U9–U14 teams (67% vs. 38%), but they were not more likely to do so with high fidelity (60% vs. 54%). Team age is associated with coaches’ short-term perceptions of injury risk, but not perceptions about the long-term ramifications of injury. Educating coaches about the potential benefits of injury prevention programs for mitigating injury-related maturational changes and the long-term ramifications of lower extremity injuries may facilitate greater use of injury prevention programs by coaches of younger female soccer players.

scholarly journals Digital Filtering of Three-Dimensional Lower Extremity Kinematics: an Assessment

2013 ◽  
Vol 39 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Jonathan Sinclair ◽  
Paul John Taylor ◽  
Sarah Jane Hobbs
Keyword(s):  
Lower Extremity ◽  
Repeated Measures ◽  
Three Dimensional ◽  
Digital Filtering ◽  
Camera Motion ◽  
Optimal Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Kinematic Analyses ◽  
Analysis System

Abstract Errors in kinematic data are referred to as noise and are an undesirable portion of any waveform. Noise is typically removed using a low-pass filter which removes the high frequency components of the signal. The selection of an optimal frequency cut-off is very important when processing kinematic information and a number of techniques exists for the determination of an optimal frequency cut-off. Despite the importance of cut-off frequency to the efficacy of kinematic analyses there is currently a paucity of research examining the influence of different cut-off frequencies on the resultant 3-D kinematic waveforms and discrete parameters. Twenty participants ran at 4.0 m•s-1 as lower extremity kinematics in the sagittal, coronal and transverse planes were measured using an eight camera motion analysis system. The data were filtered at a range of cut-off frequencies and the discrete kinematic parameters were examined using repeated measures ANOVA’s. The similarity between the raw and filtered waveforms were examined using intra-class correlations. The results show that the cut-off frequency has a significant influence on the discrete kinematic measure across displacement and derivative information in all three planes of rotation. Furthermore, it was also revealed that as the cut-off frequency decreased the attenuation of the kinematic waveforms became more pronounced, particularly in the coronal and transverse planes at the second derivative. In conclusion, this investigation provides new information regarding the influence of digital filtering on lower extremity kinematics and re-emphasizes the importance of selecting the correct cut-off frequency.

Lower Extremity Mechanics in Runners with a Converted Forefoot Strike Pattern

2000 ◽  
Vol 16 (2) ◽  
pp. 210-218 ◽  
Author(s):  
Dorsey S. Williams ◽  
Irene S. McClay ◽  
Kurt T. Manal
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Injury Risk ◽  
Reaction Force ◽  
Three Dimensional ◽  
Vertical Ground Reaction Force ◽  
Running Performance ◽  
Vertical Ground ◽  
The Impact

Runners are sometimes advised to alter their strike pattern as a means of increasing performance or in response to injury. The purpose of this study was to compare lower extremity mechanics of rearfoot strikers (RFS), who were instructed to run with a forefoot strike pattern (CFFS) to those of a preferred forefoot striker (FFS). Three-dimensional mechanics of 9 FFS and 9 CFFS were evaluated. Peak values for most kinematic and kinetic variables and all patterns of movement were not found to be statistically different between CFFS and FFS. Only peak vertical ground reaction force and peak ankle plantarflexion moment were found to be significantly lower (p ≤ .05) in the CFFS group. This suggests that RFS are able to assume a FFS pattern with very little practice that is very similar to that of a preferred FFS. The impact of changing one's strike pattern on injury risk and running performance needs further study.

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