Do intermediate- and higher-order principal components contain useful information to detect subtle changes in lower extremity biomechanics during running?

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.

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Lower Extremity Biomechanics Predicts Major League Baseball Player Performance

Orthopaedic Journal of Sports Medicine ◽

10.1177/23259671211015237 ◽

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.

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

PeerJ ◽

10.7717/peerj.9813 ◽

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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Sequential fatigue progressively alters lower extremity biomechanics

British Journal of Sports Medicine ◽

10.1136/bjsm.2011.084038.87 ◽

2011 ◽

Vol 45 (4) ◽

pp. 340-341 ◽

Cited By ~ 2

Author(s):

N. Cortes ◽

E. Greska ◽

R. Kollock ◽

J. Onate

Keyword(s):

Lower Extremity ◽

Lower Extremity Biomechanics

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Foot and Lower Extremity Biomechanics II: Precision Intricast Newsletters, 1997–2003.

Journal of the American Podiatric Medical Association ◽

10.7547/87507315-93-6-503 ◽

2003 ◽

Vol 93 (6) ◽

pp. 503-503 ◽

Cited By ~ 2

Author(s):

William H. Sanner

Keyword(s):

Lower Extremity ◽

Lower Extremity Biomechanics

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Effect of Anticipation on Lower Extremity Biomechanics During Side- and Cross-Cutting Maneuvers in Young Soccer Players

The American Journal of Sports Medicine ◽

10.1177/0363546514531578 ◽

2014 ◽

Vol 42 (8) ◽

pp. 1985-1992 ◽

Cited By ~ 27

Author(s):

Jin Hyun Kim ◽

Ki-Kwang Lee ◽

Se Jin Kong ◽

Keun Ok An ◽

Jin Hwa Jeong ◽

...

Keyword(s):

Lower Extremity ◽

Soccer Players ◽

Lower Extremity Biomechanics

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Lower Extremity Biomechanics During a Drop-Vertical Jump and Muscle Strength in Women With Patellofemoral Pain

Journal of Athletic Training ◽

10.4085/1062-6050-476-18 ◽

2020 ◽

Vol 55 (6) ◽

pp. 615-622

Author(s):

Andrea Baellow ◽

Neal R. Glaviano ◽

Jay Hertel ◽

Susan A. Saliba

Keyword(s):

Lower Extremity ◽

Knee Flexion ◽

Vertical Jump ◽

Gluteus Maximus ◽

Biceps Femoris ◽

Trunk Flexion ◽

Healthy Group ◽

Lower Extremity Biomechanics ◽

Hip Internal Rotation ◽

Kinematics And Kinetics

Context Patellofemoral pain (PFP) is one of the most prevalent knee conditions observed in women. Current research suggests that individuals with PFP have altered muscle activity, kinematics, and kinetics during functional tasks. However, few authors have examined differences in lower extremity biomechanics in this population during the drop-vertical jump (DVJ). Objective To determine how lower extremity electromyography, kinematics, and kinetics during a DVJ and lower extremity isometric strength differed between women with and those without PFP. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants Fifteen healthy women (age = 20.23 ± 1.39 years, height = 169.32 ± 5.38 cm, mass = 67.73 ± 9.57 kg) and 15 women with PFP (age = 22.33 ± 3.49 years, height = 166.42 ± 6.01 cm, mass = 65.67 ± 13.75 kg). Intervention(s) Three trials of a DVJ. Main Outcome Measure(s) Surface electromyography, kinematics, and kinetics were collected simultaneously during a DVJ. Lower extremity strength was measured isometrically. Independent-samples t tests were performed to assess group differences. Results Normalized muscle activity in the vastus medialis (healthy group = 120.84 ± 80.73, PFP group = 235.84 ± 152.29), gluteus maximus (healthy group = 43.81 ± 65.63, PFP group = 13.37 ± 13.55), and biceps femoris (healthy group = 36.68 ± 62.71, PFP group = 11.04 ± 8.9) during the landing phase of the DVJ differed between groups. Compared with healthy women, those with PFP completed the DVJ with greater hip internal-rotation moment (0.04 ± 0.28 N/kg versus 0.06 ± 0.14 N/kg, respectively) and had decreased knee-flexion excursion (76.76° ± 7.50° versus PFP = 74.14° ± 19.85°, respectively); they took less time to reach peak trunk flexion (0.19 ± 0.01 seconds versus 0.19 ± 0.02 seconds, respectively) and lateral trunk flexion (0.12 ± 0.07 seconds versus 0.11 ± 0.04 seconds, respectively). Conclusions During the DVJ, women with PFP had increased hip internal-rotation moment and decreased knee-flexion excursion with less time to peak trunk flexion and lateral flexion. Muscle activation was increased in the vastus medialis but decreased in the gluteus maximus and biceps femoris. This suggests that altered motor-unit recruitment in the hip and thigh may result in changes in biomechanics during a DVJ that are often associated with an increased risk of injury.

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Acute Effects of Midsole Bending Stiffness on Lower Extremity Biomechanics during Layup Jumps

Applied Sciences ◽

10.3390/app10010397 ◽

2020 ◽

Vol 10 (1) ◽

pp. 397

Author(s):

Zhiqiang Zhu ◽

Weijie Fu ◽

En Shao ◽

Lu Li ◽

Linjie Song ◽

...

Keyword(s):

Lower Extremity ◽

Ankle Joint ◽

Jump Height ◽

Acute Effects ◽

Kinetic Chain ◽

Joint Power ◽

Joint Biomechanics ◽

Reaction Forces ◽

Lower Extremity Biomechanics ◽

And Control

Purpose: This study aims to investigate the acute effects of shoe midsole stiffness on the joint biomechanics of the lower extremities during specific basketball movements. Methods: Thirty participants wearing stiff midsole shoes (SS) and control shoes (CS) performed layup jumps (LJs) while the kinematics and ground reaction forces were simultaneously collected via the Vicon motion capture system and Kistler force plates. Furthermore, the joint angles, range of motion (ROM), joint power, joint energy, and jump height were calculated. Results: No significant differences were observed between SS and CS conditions for both jump height and the metatarsophalangeal (MTP) joint biomechanics except that the minimum angular velocity of the MTP joint was significantly lower in SS the condition. However, the ROM in the ankle joint was significantly greater in the SS condition than in the CS condition (p < 0.05). Additionally, the maximum plantarflexion power, energy absorption (EA), and energy generation (EG) in the ankle joint were significantly greater in the SS condition than in the CS condition (p < 0.05). Compared with the CS condition, jump height in the SS condition did not increase. Conclusion: During a single LJ, the longitudinal midsole stiffness did not influence the jump height and MTP joint biomechanical patterns but significantly increased the maximum power, EA, and EG during the push-off phase of the ankle joint. These preliminary results indicate that wearing SS could change the ankle joint mechanical patterns by modulating the lower extremity kinetic chain, and may enhance muscle strength in the ankle.

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