Effects of External Load on Sagittal and Frontal Plane Lower Extremity Biomechanics During Back Squats

2021 ◽  
Author(s):  
Eva M. U. Maddox ◽  
Hunter J. Bennett
Keyword(s):  
Lower Extremity ◽  
Transition Period ◽  
Statistical Parametric Mapping ◽  
Frontal Plane ◽  
Vertical Acceleration ◽  
Hip Strength ◽  
Protocol Testing ◽  
Testing Protocol ◽  
Early Peak ◽  
Lower Extremity Biomechanics

Abstract Previous literature suggests the sticking region, the transition period between an early peak concentric velocity to a local minimum, in barbell movements may be the reason for failing repeated submaximal and maximal squats. This study determined the effects of load on lower extremity biomechanics during back squats. Twenty participants performed the NSCA's one-repetition maximum (1RM) testing protocol, testing to supramaximum loads (failure). After completing the protocol and a 10-minute rest, 80% 1RM squats were performed. Statistical parametric mapping was used to determine vertical velocity, acceleration, ankle, knee, and hip sagittal and frontal plane biomechanics differences between 1RM, submaximum, and supramaximum squats (105% 1RM). Vertical acceleration was a better discriminative measure than velocity, exibiting differences across all conditions. Supramaximum squats emphasized knee moments, whereas 1RM emphasized hip moments during acceleration. Submaximum squats had reduced hip and knee moments compared to supramaximum squats, but similar knee moments to 1RM squats. Across all conditions, knee loads mirrored accelerations and a prominent knee (acceleration) to hip (sticking) transition existed. These results indicate that 1) submaximum squats performed at increased velocities can provide similar moments at the ankle and knee, but not hip, as maximal loads and 2) significant emphasis on hip strength is necessary for heavy back squats.

Running Biomechanics of Adolescents with Autism Spectrum Disoder

2021 ◽  
Author(s):  
Hunter J. Bennett ◽  
Justin Haegele
Keyword(s):  
Lower Extremity ◽  
Sagittal Plane ◽  
Statistical Parametric Mapping ◽  
Frontal Plane ◽  
Autism Spectrum ◽  
Initial Contact ◽  
Hip Abduction ◽  
Knee Abduction ◽  
Running Biomechanics ◽  
Adolescents With Asd

Abstract Research examining gait biomechanics of persons with autism spectrum disorder (ASD) has grown significantly in recent years and has demonstrated that persons with ASD walk at slower self-selected speeds and with shorter strides, wider step widths, and reduced lower extremity range of motion and moments compared to neurotypical controls. In contrast to walking, running has yet to be examined in persons with ASD. The purpose of this study was to examine lower extremity running biomechanics in adolescents (13-18-year-olds) with ASD and matched (age, sex, and body mass index) neurotypical controls. Three-dimensional kinematics and ground reaction forces (GRF) were recorded while participants ran at two matched speeds: self-selected speed of adolescents with ASD and at 3.0m/s. Sagittal and frontal plane lower extremity biomechanics and vertical GRFs were compared using two-way ANOVAs via statistical parametric mapping. Adolescents with ASD ran with reduced stride length at self-selected speed and reduced vertical displacement, loading-propulsion GRFs, propulsion plantarflexion moments, loading-propulsion hip abduction moments, and loading knee abduction moments at both speeds. Running at 3.0m/s increased sagittal plane hip and knee moments surrounding initial contact and frontal plane knee angles during mid stance and propulsion compared to self-selected speeds. Reduced contributions from primarily the ankle plantarflexion but also knee abduction and hip abduction moments likely reduced the vertical GRF and displacement. As differences favored reduced loading, youth with ASD can safely be encouraged to engage in running as a physical activity.

Resistance training is accompanied by increases in hip strength and changes in lower extremity biomechanics during running

2009 ◽  
Vol 24 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Kelli R. Snyder ◽  
Jennifer E. Earl ◽  
Kristian M. O’Connor ◽  
Kyle T. Ebersole
Keyword(s):  
Resistance Training ◽  
Lower Extremity ◽  
Hip Strength ◽  
Lower Extremity Biomechanics

Frontal Plane Lower Extremity Biomechanics During Walking in Boys Who Are Overweight Versus Healthy Weight

2009 ◽  
Vol 21 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Amy Gross McMillan ◽  
Nancy L. Auman ◽  
David N. Collier ◽  
D S. Blaise Williams
Keyword(s):  
Lower Extremity ◽  
Frontal Plane ◽  
Healthy Weight ◽  
Lower Extremity Biomechanics

Statistical Parametric Mapping as a Measure of Differences Between Limbs: Applications to Clinical Populations

2019 ◽  
Vol 35 (6) ◽  
pp. 377-387
Author(s):  
Cherice N. Hughes-Oliver ◽  
Kathryn A. Harrison ◽  
D.S. Blaise Williams ◽  
Robin M. Queen
Keyword(s):  
Anterior Cruciate Ligament ◽  
Lower Extremity ◽  
Ligament Reconstruction ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Statistical Parametric Mapping ◽  
Frontal Plane ◽  
Parametric Mapping ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

In healthy individuals, symmetrical lower-extremity movement is often assumed and calculated using discrete points during various tasks. However, measuring overall movement patterns using methods such as statistical parametric mapping (SPM) may allow for better interpretation of human movement. This study demonstrated the ability of SPM to assess interlimb differences in lower-extremity movement during 2 example tasks: running and landing. Three-dimensional motion analysis was used to determine sagittal and frontal plane lower-extremity joint angles in (1) young and older individuals during running and (2) patients with anterior cruciate ligament reconstruction and uninjured control athletes during landing. Interlimb differences within each group were compared using SPM and paired t tests on peak discrete angles. No differences between limbs were found between young and older runners using SPM. Peak ankle eversion and plantar flexion angles differed between limbs in young and older runners. Sagittal plane hip angle varied between limbs in uninjured control athletes. Frontal plane ankle angle and sagittal plane knee and hip angles differed between limbs in patients with anterior cruciate ligament reconstruction using SPM and discrete analysis. These data suggest that SPM can be useful to determine clinically meaningful interlimb differences during running and landing in multiple populations.

Measurement Properties of Clinically Accessible Movement Assessment Tools for Analyzing Single-Leg Squats and Step-Downs: A Systematic Review

2021 ◽  
pp. 1-14
Author(s):  
Erin M. Lally ◽  
Hayley Ericksen ◽  
Jennifer Earl-Boehm
Keyword(s):  
Lower Extremity ◽  
Reliability And Validity ◽  
Frontal Plane ◽  
Assessment Tools ◽  
Measurement Properties ◽  
Health Measurement ◽  
Movement Assessment ◽  
Projection Angle ◽  
Plane Projection ◽  
Lower Extremity Biomechanics

Context: Poor lower-extremity biomechanics are predictive of increased risk of injury. Clinicians analyze the single-leg squat (SLS) and step-down (SD) with rubrics and 2D assessments to identify these poor lower-extremity biomechanics. However, evidence on measurement properties of movement assessment tools is not strongly outlined. Measurement properties must be established before movement assessment tools are recommended for clinical use. Objective: The purpose of this study was to systematically review the evidence on measurement properties of rubrics and 2D assessments used to analyze an SLS and SD. Evidence Acquisition: The search strategy was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The search was performed in PubMed, SPORTDiscus, and Web of Science databases. The COnsensus-based Standards for the selection of health Measurement INstruments multiphase procedure was used to extract relevant data, evaluate methodological quality of each study, score the results of each movement assessment, and synthesize the evidence. Evidence Synthesis: A total of 44 studies were included after applying eligibility criteria. Reliability and construct validity of knee frontal plane projection angle was acceptable, but criterion validity was unacceptable. Reliability of the Chmielewski rubric was unacceptable. Content validity of the knee-medial-foot and pelvic drop rubrics was acceptable. The remaining rubrics and 2D measurements had inconclusive or conflicting results regarding reliability and validity. Conclusions: Knee frontal plane projection angle is reliable for analyzing the SLS and SD; however, it does not serve as a substitute for 3D motion analysis. The Chmielewski rubric is not recommended for assessing the SLS or SD as it may be unreliable. Most movement assessment tools yield indeterminate results. Within the literature, standardized names, procedures, and reporting of movement assessment tool reliability and validity are inconsistent.

scholarly journals Lower Extremity Biomechanics Predicts Major League Baseball Player Performance

2021 ◽  
Vol 9 (7) ◽  
pp. 232596712110152
Author(s):  
Lucas G. Teske ◽  
Edward C. Beck ◽  
Garrett S. Bullock ◽  
Kristen F. Nicholson ◽  
Brian R. Waterman
Keyword(s):  
Lower Extremity ◽  
Major League Baseball ◽  
Reaction Force ◽  
Regression Trees ◽  
Minimal Detectable Change ◽  
Vertical Force ◽  
Baseball Players ◽  
Major League ◽  
Lower Extremity Biomechanics ◽  
Statistical Metrics

Background: Although lower extremity biomechanics has been correlated with traditional metrics among baseball players, its association with advanced statistical metrics has not been evaluated. Purpose: To establish normative biomechanical parameters during the countermovement jump (CMJ) among Major League Baseball (MLB) players and evaluate the relationship between CMJ-developed algorithms and advanced statistical metrics. Study Design: Cohort study; Level of evidence, 3. Methods: MLB players in 2 professional organizations performed the CMJ at the beginning of each baseball season from 2013 to 2017. We collected ground-reaction force data including the eccentric rate of force development (“load”), concentric vertical force (“explode”), and concentric vertical impulse (“drive”) as well as the Sparta Score. The advanced statistical metrics from each baseball season (eg, fielding independent pitching [FIP], weighted stolen base runs [wSB], and weighted on-base average) were also gathered for the study participants. The minimal detectable change (MDC) was calculated for each CMJ variable to establish normative parameters. Pearson coefficient analysis and regression trees were used to evaluate associations between CMJ data and advanced statistical metrics for the players. Results: A total of 151 pitchers and 138 batters were included in the final analysis. The MDC for “load,” “explode,” “drive,” and the Sparta Score was 10.3, 8.1, 8.7, and 4.6, respectively, and all demonstrated good reliability (intraclass correlation coefficient > 0.75). There was a weak but statistically significant correlation between the Sparta Score and wSB ( r = 0.23; P = .007); however, there were no significant correlations with any other advanced metrics. Regression trees demonstrated superior FIP with higher Sparta Scores in older pitchers compared with younger pitchers. Conclusion: There was a positive but weak correlation between the Sparta Score and base-stealing performance among professional baseball players. Additionally, older pitchers with a higher Sparta Score had statistically superior FIP compared with younger pitchers with a similar Sparta Score after adjusting for age.

Lower-Extremity Biomechanics and Maintenance of Vertical-Jump Height During Prolonged Intermittent Exercise

2014 ◽  
Vol 23 (4) ◽  
pp. 319-329
Author(s):  
Randy J. Schmitz ◽  
John C. Cone ◽  
Timothy J. Copple ◽  
Robert A. Henson ◽  
Sandra J. Shultz
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Principal Components ◽  
Intermittent Exercise ◽  
Vertical Jump ◽  
The Body ◽  
Rating Of Perceived Exertion ◽  
Jump Height ◽  
Lower Extremity Biomechanics ◽  
Biomechanical Factors

Context:Potential biomechanical compensations allowing for maintenance of maximal explosive performance during prolonged intermittent exercise, with respect to the corresponding rise in injury rates during the later stages of exercise or competition, are relatively unknown.Objective:To identify lower-extremity countermovement-jump (CMJ) biomechanical factors using a principal-components approach and then examine how these factors changed during a 90-min intermittent-exercise protocol (IEP) while maintaining maximal jump height.Design:Mixed-model design.Setting:Laboratory.Participants:Fifty-nine intermittent-sport athletes (30 male, 29 female) participated in experimental and control conditions.Interventions:Before and after a dynamic warm-up and every 15 min during the 1st and 2nd halves of an individually prescribed 90-min IEP, participants were assessed on rating of perceived exertion, sprint/cut speed, and 3-dimensional CMJ biomechanics (experimental). On a separate day, the same measures were obtained every 15 min during 90 min of quiet rest (control).Main Outcome Measures:Univariate piecewise growth models analyzed progressive changes in CMJ performance and biomechanical factors extracted from a principal-components analysis of the individual biomechanical dependent variables.Results:While CMJ height was maintained during the 1st and 2nd halves, the body descended less and knee kinetic and energetic magnitudes decreased as the IEP progressed.Conclusions:The results indicate that vertical-jump performance is maintained along with progressive biomechanical changes commonly associated with decreased performance. A better understanding of lower-extremity biomechanics during explosive actions in response to IEP allows us to further develop and individualize performance training programs.

scholarly journals Effects of 12-week cadence retraining on impact peak, load rates and lower extremity biomechanics in running

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9813
Author(s):  
Junqing Wang ◽  
Zhen Luo ◽  
Boyi Dai ◽  
Weijie Fu
Keyword(s):  
Lower Extremity ◽  
Impact Force ◽  
Peak Load ◽  
Control Group ◽  
Initial Contact ◽  
Vertical Load ◽  
Impact Peak ◽  
Peak Knee ◽  
Running Injuries ◽  
Lower Extremity Biomechanics

Background Excessive impact peak forces and vertical load rates are associated with running injuries and have been targeted in gait retraining studies. This study aimed to determine the effects of 12-week cadence retraining on impact peak, vertical load rates and lower extremity biomechanics during running. Methods Twenty-four healthy male recreational runners were randomised into either a 12-week cadence retraining group (n = 12), which included those who ran with a 7.5% increase in preferred cadence, or a control group (n = 12), which included those who ran without any changes in cadence. Kinematics and ground reaction forces were recorded simultaneously to quantify impact force variables and lower extremity kinematics and kinetics. Results Significantly decreased impact peak (1.86 ± 0.30 BW vs. 1.67 ± 0.27 BW, P = 0.003), vertical average load rates (91.59 ± 18.91 BW/s vs. 77.31 ± 15.12 BW/s, P = 0.001) and vertical instantaneous load rates (108.8 ± 24.5 BW/s vs. 92.8 ± 18.5 BW/s, P = 0.001) were observed in the cadence retraining group, while no significant differences were observed in the control group. Foot angles (18.27° ± 5.59° vs. 13.74° ± 2.82°, P = 0.003) and vertical velocities of the centre of gravity (CoG) (0.706 ± 0.115 m/s vs. 0.652 ± 0.091 m/s, P = 0.002) significantly decreased in the cadence retraining group at initial contact, but not in the control group. In addition, vertical excursions of the CoG (0.077 ± 0.01 m vs. 0.069 ± 0.008 m, P = 0.002) and peak knee flexion angles (38.6° ± 5.0° vs. 36.5° ± 5.5°, P < 0.001) significantly decreased whilst lower extremity stiffness significantly increased (34.34 ± 7.08 kN/m vs. 38.61 ± 6.51 kN/m, P = 0.048) in the cadence retraining group. However, no significant differences were observed for those variables in the control group. Conclusion Twelve-week cadence retraining significantly increased the cadence of the cadence retraining group by 5.7%. This increased cadence effectively reduced impact peak and vertical average/instantaneous load rates. Given the close relationship between impact force variables and running injuries, increasing the cadence as a retraining method may potentially reduce the risk of impact-related running injuries.

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