scholarly journals ANALYSIS OF TRUNK POWER AND JOINT STRESSES BETWEEN PROFESSIONAL AND COLLEGIATE PITCHERS

2021 ◽  
Vol 57 (2) ◽  
pp. 121-127
Author(s):  
Maxwell L. Albiero ◽  
◽  
Cody Dziuk ◽  
Janelle A. Cross
Keyword(s):  
External Rotation ◽  
Camera Motion ◽  
Joint Stress ◽  
Joint Torques ◽  
Dynamic Motion ◽  
Shoulder External Rotation ◽  
Analysis System ◽  
Set Up ◽  
3D Software ◽  
Camera Motion Analysis

The dynamic motion of a baseball pitch generates high elbow and shoulder torques that can result in injury. Previous research has noted the importance of properly transferring energy from the lower extremities through the throwing arm to decrease joint stress. The goal of this study was to compare segmental powers between two levels of pitchers at various moments throughout the pitching cycle and observe their influence on upper extremity torques. Thirteen professional and thirteen collegiate pitchers participated in this study. Forty-seven reflective markers were attached to the subjects at specific landmarks. An 8-camera motion analysis system was set up surrounding an artificial pitching mound, where participants threw 10 fastballs. Data were exported and processed using Visual 3D software. Welch’s T-tests compared the means between groups with a significance set at p < 0.05. Professional pitchers were found to have significantly greater torso power at foot contact, maximum shoulder external rotation, ball release, and overall peak torso power. They also demonstrated significantly greater pitch velocity. Professional pitchers generated similar elbow varus torque and shoulder internal rotation torque compared to collegiate pitchers. These findings suggest professional pitchers more effectively use torso power to help increase pitch speed without increasing overall joint torques.

Dancers’ Joint Strategies for Achieving Turnout in Low and High Friction Conditions

2020 ◽  
Vol 35 (2) ◽  
pp. 96-102
Author(s):  
Rebekha Duncan ◽  
Catherine Wild ◽  
Leo Ng ◽  
Danica Hendry ◽  
Sarah Carter ◽  
...  
Keyword(s):  
Repeated Measures ◽  
External Rotation ◽  
Injury Rate ◽  
Camera Motion ◽  
Joint Angles ◽  
Low Friction ◽  
Training Tool ◽  
Analysis System ◽  
Lumbar Extension ◽  
Camera Motion Analysis

BACKGROUND: Dancing with legs externally rotated (turnout) is a fundamental element of ballet technique. A reliance on floor friction to achieve turnout may contribute toward the high injury rate in dancers. Joint strategies used by dancers in high and low friction turnout conditions are not well understood. OBJECTIVES: To quantify the lower limb and lumbar spine joint strategies used by female pre-professional dancers to achieve turnout in low-friction (rotation discs) and high-friction (functional and forced) conditions. METHODS: Twenty-three pre-professional female dancers participated in the study. A 12-camera motion analysis system collected hip and knee external rotation (ER), ankle abduction, and lumbar extension angles in three turnout conditions and passive hip ER range of motion angles. Repeated measures ANOVA analysed the differences between joint angles, maximum turnout angle (foot relative to pelvis), and available hip ER. RESULTS: Dancers demonstrated lower knee ER (18.5±4.8°) and ankle abduction (6.0±7.7°) angles during low-friction turnout compared to higher friction conditions (p<0.05). Dancers utilised between 70–83% of available hip ER within all conditions. Low-friction turnout demonstrated greater hip ER contribution within maximum turnout (43%) compared to higher friction conditions. Dancers demonstrated greater lumbar extension angles in low-friction turnout compared to higher friction conditions (p<0.05). CONCLUSIONS: Further hip ER strength training is required to promote greater hip ER range within the position. Rotation discs may be a valuable training tool as dancers demonstrated greater hip ER utilisation with less knee ER and ankle abduction; however, this position did promote undesirable lumbar extension.

The relationship of hip rotation range, hip rotator strength and balance in healthy individuals

2020 ◽  
Vol 33 (5) ◽  
pp. 761-767
Author(s):  
Yongwook Kim ◽  
Seungmook Kang
Keyword(s):  
Motion Analysis ◽  
External Rotation ◽  
Dynamic Balance ◽  
Three Dimensional ◽  
Camera Motion ◽  
3D Motion ◽  
3D Motion Analysis ◽  
Balance Ability ◽  
Analysis System ◽  
The Relationship

BACKGROUND: Few studies have explored the relationship between muscle strength, range of motion (ROM), and balance in the horizontal plane of the hip joint using three-dimensional (3D) motion analysis. OBJECTIVE: We investigate the relationships of hip internal rotation (IR) and external rotation (ER) ROM, measured using a 3D motion capture system, with hip internal and external rotator strength and single-leg standing balance. METHODS: The participants were 40 healthy adults. Kinematic data on hip ROM were collected using an eight-camera motion analysis system. Hip rotational strength measurements were obtained using hand-held isometric dynamometry. A Single-leg standing test and a pendular test were conducted to evaluate static and dynamic balance ability using BioRescue. RESULTS: Significant correlations were found between hip strength and each variable measured during hip ROM assessments (p< 0.05). Significant positive correlations were found between the hip IR/ER strength ratio and the IR/ER ROM ratio (r= 0.72, p< 0.01). The subgroup with a normal IR/ER ratio of hip rotator strength and ROM showed significantly better dynamic balance ability than the subgroup with a hip rotator muscle imbalance (p< 0.05). CONCLUSIONS: There is a significant relationship between hip IR/ER strength and IR/ER ROM with a normal hip IR/ER strength and ROM ratio positively affecting dynamic balance ability.

scholarly journals Baseball Pitchers’ Kinematic Sequences and Their Relationship to Elbow and Shoulder Torque Production

2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0042
Author(s):  
Donna Moxley Scarborough ◽  
Shannon E. Linderman ◽  
Javier E. Sanchez ◽  
Eric M. Berkson
Keyword(s):  
Upper Extremity ◽  
External Rotation ◽  
Kinetic Chain ◽  
Joint Torques ◽  
Ball Velocity ◽  
Collegiate Baseball ◽  
Angular Velocities ◽  
Shoulder External Rotation ◽  
Baseball Pitchers ◽  
The Ideal

Objectives: Ball velocity is generated during the overhead baseball pitch via efficient force transmission up the kinetic chain, from the lower body up and outward to the throwing hand. The kinematic sequence, or the sequential timing pattern of peak angular velocities of body segments during a pitch, provides insight to segment position and motion control that drives the kinetic chain (Putnam CA, 1993). Previous publications report an ideal kinematic sequence (KS) where the timing of each body segment’s peak angular velocity occurs in a proximal-to-distal (PDS) pattern resulting in greater ball velocity and reduction in throwing arm injury risk (Fortenbaugh D, et.al, 2009). A recent study revealed that baseball pitchers perform a variety of KSs (Scarborough DM et.al, 2018). There is no known investigation of the relationship of kinematic sequences and throwing arm joint torques. The purpose of this study was to 1) identify the number of different KSs performed by each pitcher and 2) compare elbow valgus and shoulder external rotation (ER) and extension (Ext) torques between the 3 primary KSs performed during the fastball pitch. Methods: Fourteen collegiate baseball pitchers (20.57 ± 1.91 yr) underwent 3D biomechanical pitch analysis using 20 motion-capture Vicon MX™ cameras (360 Hz). A total of 119 fastball pitches with an average of 8.5 ± 2.71 pitches per player were analyzed. Elbow valgus and shoulder external rotation and extension torques were calculated. The timing of peak angular velocities for the pelvis, trunk, arm, forearm and hand body segments were recorded to generate each pitch’s KS. KSs were then divided into groups based on similarities to the ideal PDS pattern. ANCOVA statistical analyses were performed to compare joint torques across these KS groups with ball velocity as a covariate. Results: A total of 13 different KSs were observed across the 14 pitchers resulting in an average of 3 ± 1.41 different KSs per pitcher. Three different primary KS groups were identified: (1) PDS group: with a KS closest to the ideal PDS pattern (2) the Altered Distal Upper Extremity segment: with the forearm peaking after the hand (the most common group) and (3) Altered Proximal Upper Extremity segment order with the arm segment peaking after the hand (2nd most common). Across these three primary KS patterns, statistically significant differences were noted for elbow valgus torque [F(62,2) = 8.785, ɳ2 = .221, p < 0.00], shoulder external rotation (ER) torque [F(62,2) = 14.127, ɳ2 = .313, p < 0.00] and shoulder extension (Ext) torque [F(62,2) = 13.237, ɳ2 = .299, p < 0.00] (Figure 1). Conclusion: Our findings demonstrate that collegiate baseball pitchers performed an average of 3 different kinematic sequence patterns during fastball pitching. This is the first study to demonstrate a relationship between KSs and elbow and shoulder torque production. As anticipated, the PDS KSs produced the least torque across the elbow and shoulder joints. Alterations in Distal Upper Extremity KS was most common and generated the greatest shoulder Ext torques. Alterations in the Proximal Upper Extremity KS demonstrated the greatest elbow valgus and shoulder ER. Further study of the influence of kinematic sequence on joint torques in the baseball pitch may provide insight into pitching injuries and injury avoidance programs.

scholarly journals Impact of Engaging the Nonthrowing Arm on Maximal Ball Velocity From an Overhand Throw With Both the Dominant and Nondominant Arms: A Pilot Study

2021 ◽  
pp. 1-18
Author(s):  
Alanna Weisberg ◽  
Hyun Suk Lee ◽  
Tak Fung ◽  
Larry Katz
Keyword(s):  
The Body ◽  
Whole Body ◽  
Camera Motion ◽  
Ball Speed ◽  
Kinematic Data ◽  
Overhand Throw ◽  
Ball Velocity ◽  
Analysis System ◽  
The Impact ◽  
Camera Motion Analysis

The overhand throw is a complex whole-body motor skill that is fundamental to many sports and activities. When throwing properly, the momentum generated to complete the movement begins in the lower body and transfers through the trunk to the throwing arm. This proof-of-concept study’s primary purpose was to evaluate the impact of the nonthrowing arm on the ball speed during an overhand throw with both the dominant and nondominant arms. Eighteen participants (age: 20.20 ± 2.90 years, nine women) were divided into two intervention groups: a pulling group taught to engage the nonthrowing arm through a pull toward the body and a nonpulling group taught the overhand throw using a component-based physical education curriculum. Each participant completed 12 total throws, six for each side (dominant and nondominant arm). Ball speed and kinematic data were collected using an eight-camera motion analysis system and were assessed using a pre–post study design. The two groups showed significant improvements pre–post when throwing with both the dominant and nondominant arms. Based on effect size comparisons, engaging the nonthrowing arm makes a meaningful difference in maximal ball velocity.

scholarly journals O processo de fadiga pode alterar a estratégia motora de velocidade de golpes no karate: um estudo de caso

2016 ◽  
Vol 85 (3) ◽  
Author(s):  
Keith Sato Urbinati ◽  
Matheus Aguiar ◽  
Juarez Trancoso ◽  
Caluê Papcke ◽  
Percy Nohama ◽  
...  
Keyword(s):  
Biomechanical Model ◽  
Left Knee ◽  
Black Belt ◽  
South American ◽  
Camera Motion ◽  
Vo2 Max ◽  
Motor Strategy ◽  
Analysis System ◽  
Camera Motion Analysis ◽  
Motor Strategies

Introdução: Devido às novas exigências nas regras competitivas com maiores pontuações, o karate vem se tornando um esporte com altas demandas da variável velocidade. Dentre diversos fatores que podem afetar a velocidade de golpes, o processo de fadiga exaustão é uma importante variável interveniente. Logo, como ocorre o controle motor para a manutenção de velocidade de golpes em situação de fatigabilidade?Objetivo: Identificar as estratégias motoras na manutenção de velocidade do gyako zuki no processo de fadiga.Métodos: Foi avaliado o atual campeão sul-americano da categoria -78 kg, sub 21 do sistema World Karate Federation (WKF). O atleta prática karate por 7 anos, é faixa preta, nível internacional, com 78 kg, 1,82m, 14,4% de gordura, VO2 máx = 55 kg.ml-1.min-1. O atleta realizou um protocolo de carga progressiva denominado Karate Specific Aerobic Test (KSAT) até a exaustão. Para o modelo biomecânico foi utilizado um sistema de análise de movimento de seis câmeras (Sistema Vicon).Resultados: As diferentes contribuições de velocidade de segmentos para a manutenção de vP (velocidade de pico) do gyako zuki ocorre uma vez que protocolos de fadiga comumente atribuem adaptações funcionais para superar o efeito da fadiga e continuar executando a ação técnica da ‘melhor’ forma possível.Conclusão: A principal estratégia motora adotada no processo de fadiga é a diminuição do deslocamento de tornozelo e joelho esquerdos à frente, o que diminui a vP do gyako zuki. O deslocamento do segmento de quadril ocorre em situação de homeostase e não necessariamente em situação de fadiga.The process of fatigue can change the motor strategy in velocities of strokes in karate: a case studyIntroduction: Because of the new requirements in the competitive rules with higher scores, karate has become a sport with high demands of speed. Among many factors that can affect the speed of strokes, the process of fatigue exhaustion is an important intervening variable. How the motor control for maintaining speed in strokes fatigability situation?Objective: Identify the motor strategies in maintaining gyako zuki speed in the fatigue process.Methods: We evaluated the current South American champion of the category -78 kg, under 21 years of age, World Karate Federation system (WKF). The karate athlete practice for 7 years, is a black belt, internationally, with 78 kg, 1.82m, 14.4% fat, VO2 max = 55 kg.ml -1 .min -1. The athlete made a progressive load protocol called Karate Specific Aerobic Test (KSAT) until exhaustion. For biomechanical model was used a six camera motion analysis system (Vicon system).Results: Different contributions segments speed to maintain Vp (peak velocity) gyako zuki occurs because fatigue protocols commonly assigned functional adaptations to overcome the effects of fatigue and continue running the technical action as 'better' as possible.Conclusion: The main motor strategy adopted in the fatigue process is the reduction of ankle dislocation and left knee forwarding, which reduces the vP of gyako zuki. The displacement of the hip segment occurs in homeostasis position and not necessarily by fatigue condition.

Influence of cross-fit footwear on patellofemoral kinetics during running activities

2017 ◽  
Vol 13 (2) ◽  
pp. 105-111 ◽  
Author(s):  
J.K. Sinclair ◽  
P.J. Taylor ◽  
B. Sant
Keyword(s):  
Repeated Measures ◽  
Camera Motion ◽  
Repeated Measures Anova ◽  
Joint Pathology ◽  
Limb Kinematics ◽  
Analysis System ◽  
Camera Motion Analysis ◽  
Lower Limb Kinematics ◽  
Reduced Risk ◽  
Modelling Approach

The aim of this work was to examine the effects of barefoot, cross-fit, minimalist and conventional footwear on patellofemoral loading during running. Twelve cross-fit athletes ran at 4.0 m/s in each of the four footwear conditions. Lower limb kinematics were collected using an 8 camera motion analysis system and patellofemoral loading was estimated using a mathematical modelling approach. Differences between footwear were examined using one-way repeated measures ANOVA. The results showed the peak patellofemoral force and stress were significantly reduced when running barefoot (force = 3.42 BW & stress = 10.71 MPa) and in minimalist footwear (force = 3.73 BW & stress = 11.64 MPa) compared to conventional (force = 4.12 BW & stress = 12.69 MPa) and cross-fit (force = 3.97 BW & stress = 12.30 MPa) footwear. In addition, the findings also showed that patellofemoral impulse was significantly reduced when running barefoot (0.35 BW·s) and in minimalist footwear (0.36 BW·s) compared to conventional (0.42 BW·s) and cross-fit (0.38 BW·s) footwear. Given the proposed association between patellofemoral loading and patellofemoral disorders, the outcomes from the current investigation suggest that cross-fit athletes who select barefoot and minimalist footwear for their running activities may be at reduced risk from patellofemoral joint pathology in comparison to conventional and cross-fit footwear conditions.

scholarly journals Changes in Youth Baseball Pitching Biomechanics: A 7-Year Longitudinal Study

2017 ◽  
Vol 46 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Glenn S. Fleisig ◽  
Alek Z. Diffendaffer ◽  
Brett Ivey ◽  
Kyle T. Aune ◽  
Tony Laughlin ◽  
...  
Keyword(s):  
External Rotation ◽  
Mixed Linear Model ◽  
Foot Placement ◽  
Honestly Significant Difference ◽  
Significant Difference ◽  
Youth Baseball ◽  
Shoulder External Rotation ◽  
Analysis System ◽  
Kinematics And Kinetics ◽  
Difference Test

Background: Pitching biomechanics are associated with performance and risk of injury in baseball. Previous studies have identified biomechanical differences between youth and adult pitchers but have not investigated changes within individual young pitchers as they mature. Hypothesis: Pitching kinematics and kinetics will change significantly during a youth pitcher’s career. Study Design: Descriptive laboratory study. Methods: Pitching biomechanics were captured in an indoor laboratory with a 12-camera, 240-Hz motion analysis system for 51 youth pitchers who were in their first season of organized baseball with pitching. Each participant was retested annually for the next 6 years or until he was no longer pitching. Thirty kinematic and kinetic parameters were computed and averaged for 10 fastballs thrown by each player. Data were statistically analyzed for the 35 participants who were tested at least 3 times. Within-participant changes for each kinematic and kinetic parameter were tested by use of a mixed linear model with random effects ( P < .05). Least squares means for sequential ages were compared via Tukey’s honestly significant difference test ( P < .05). Results: Three kinematic parameters that occur at the instant of foot contact—stride length, lead foot placement to the closed side, and trunk separation—increased with age. With age, shoulder external rotation at foot contact decreased while maximum shoulder external rotation increased. Shoulder and elbow forces and torques increased significantly with age. Year-to-year changes were most significant between 9 and 13 years of age for kinematics and between 13 and 15 years for normalized kinetics (ie, scaled by bodyweight and height). Conclusion: During their first few years, youth pitchers improve their kinematics. Elbow and shoulder kinetics increase with time, particularly after age 13. Thus, prepubescent pitchers may work with their coaches to improve the motions and flexibility of the players’ bodies and the paths of their arms. Once proper mechanics are developed, adolescent pitchers can focus more on improving strength and power.

Comparison of Foot Pronation and Lower Extremity Rotation in Persons With and Without Patellofemoral Pain

2002 ◽  
Vol 23 (7) ◽  
pp. 634-640 ◽  
Author(s):  
Christopher M. Powers ◽  
Pon-Yo Chen ◽  
Stephen F. Reischl ◽  
Jaquelin Perry
Keyword(s):  
Lower Extremity ◽  
Internal Rotation ◽  
Three Dimensional ◽  
Patellofemoral Pain ◽  
Group Differences ◽  
Camera Motion ◽  
Foot Pronation ◽  
Analysis System ◽  
Camera Motion Analysis ◽  
Female Subjects

Abnormal foot pronation and subsequent rotation of the lower extremity has been hypothesized as being contributory to patellofemoral pain (PFP). The purpose of this study was to test the hypothesis that subjects with PFP would exhibit larger degrees of foot pronation, tibia internal rotation, and femoral internal rotation compared to individuals without PFP. Twenty-four female subjects with a diagnosis of PFP and 17 female subjects without PFP participated. Three-dimensional kinematics of the foot, tibia, and femur segments were recorded during self-selected free-walking trials using a six-camera motion analysis system (VICON). No group differences were found with respect to the magnitude and timing of peak foot pronation and tibia rotation. However, the PFP group demonstrated significantly less femur internal rotation compared the comparison group. These results do not support the hypothesis that individuals with PFP demonstrate excessive foot pronation or tibial internal rotation compared to nonpainful individuals. The finding of decreased internal rotation in the PFP group suggests that this motion may be a compensatory strategy to reduce the quadriceps angle.

scholarly journals The Test-Retest Reliability of Anatomical Co-Ordinate Axes Definition for the Quantification of Lower Extremity Kinematics During Running

2012 ◽  
Vol 35 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Jonathan Sinclair ◽  
Paul John Taylor ◽  
Andrew Greenhalgh ◽  
Christopher James Edmundson ◽  
Darrell Brooks ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Lower Extremities ◽  
Camera Motion ◽  
Anatomical Landmarks ◽  
Kinematic Parameters ◽  
Paired Samples ◽  
Kinematic Analyses ◽  
Analysis System ◽  
Test Retest Reliability ◽  
Camera Motion Analysis

Three-dimensional (3-D) kinematic analyses are used widely in both sport and clinical examinations. However, this procedure depends on reliable palpation of anatomical landmarks and mal-positioning of markers between sessions may result in improperly defined segment co-ordinate system axes which will produce in-consistent joint rotations. This had led some to question the efficacy of this technique. The aim of the current investigation was to assess the reliability of the anatomical frame definition when quantifying 3-D kinematics of the lower extremities during running. Ten participants completed five successful running trials at 4.0 m·s-1 ± 5%. 3-D angular joint kinematics parameters from the hip, knee and ankle were collected using an eight camera motion analysis system. Two static calibration trials were captured. The first (test) was conducted prior to the running trials following which anatomical landmarks were removed. The second was obtained following completion of the running trials where anatomical landmarks were re-positioned (retest). Paired samples t-tests were used to compare 3-D kinematic parameters quantified using the two static trials, and intraclass correlations were employed to examine the similarities between the sagittal, coronal and transverse plane waveforms. The results indicate that no significant (p>0.05) differences were found between test and retest 3-D kinematic parameters and strong (R2≥0.87) correlations were observed between test and retest waveforms. Based on the results obtained from this investigation, it appears that the anatomical co-ordinate axes of the lower extremities can be defined reliably thus confirming the efficacy of studies using this technique.

The Stance Phase of Walking During Late Pregnancy

2005 ◽  
Vol 95 (3) ◽  
pp. 247-253 ◽  
Author(s):  
Janelle K. Lymbery ◽  
Wendy Gilleard
Keyword(s):  
Ground Reaction Force ◽  
Stance Phase ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Late Pregnancy ◽  
Camera Motion ◽  
Motion Analysis System ◽  
Step Width ◽  
Analysis System ◽  
Camera Motion Analysis

The purpose of this study was to investigate temporospatial and ground reaction force variables in the stance phase of walking during late pregnancy. An eight-camera motion-analysis system was used to record 13 pregnant women at 38 weeks’ gestation and again 8 weeks after birth. In late pregnancy, there was a wider step width, and mediolateral ground reaction force tended to be increased in a medial direction. The center of pressure moved more medially initially and less anteriorly at 100% of stance in late pregnancy. The differences suggest that women may adapt their gait to maximize stability in the stance phase of walking and to control mediolateral motion. (J Am Podiatr Med Assoc 95(3): 247–253, 2005)

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