The impact of centre of mass kinematics and ground reaction forces on ball release speeds in cricket fast bowling

2014 ◽  
Vol 7 (1-2) ◽  
pp. 4-11 ◽  
Author(s):  
Paul S. Glazier ◽  
Peter J. Worthington
Keyword(s):  
Ground Reaction Forces ◽  
Centre Of Mass ◽  
Ball Release ◽  
Reaction Forces ◽  
The Impact

Footwear and Elevated Heel Influence On Barbell Back Squat: a Review

2021 ◽  
Author(s):  
Aaron Michael Pangan ◽  
Matthew J Leineweber
Keyword(s):  
Ground Reaction Forces ◽  
Specific Effects ◽  
Back Squat ◽  
Running Shoes ◽  
Different Types ◽  
Reaction Forces ◽  
Joint Loads ◽  
The Impact ◽  
Kinematics And Kinetics ◽  
Full Body

Abstract The back squat is one of the most effective exercises in strengthening the muscles of the lower extremity. Understanding the impact of footwear has on the biomechanics is imperative for maximizing the exercise training potential, preventing injury, and rehabilitating from injury. This review focuses on how different types of footwear affect the full-body kinematics, joint loads, muscle activity, and ground reaction forces in athletes of varying experience performing the weighted back squat. The literature search was conducted using three databases, and fourteen full-text articles were ultimately included in the review. The majority of these studies demonstrated that the choice of footwear directly impacts kinematics and kinetics. Weightlifting shoes were shown to decrease trunk lean and generate more plantarflexion relative to running shoes and barefoot lifting. Elevating the heel through the use of external squat wedges is popular clinical exercise during rehabilitation and was shown to provide similar effects to WLS. Additional research with a broader array of populations, particularly novice and female weightlifters, should be conducted to generalize the research results to non-athlete populations. Further work is also needed to characterize the specific effects of sole stiffness and heel elevation height on squatting mechanics.

Associations between ground reaction force waveforms and sprint start performance

2019 ◽  
Vol 14 (5) ◽  
pp. 658-666 ◽  
Author(s):  
Steffi L Colyer ◽  
Philip Graham-Smith ◽  
Aki IT Salo
Keyword(s):  
Reaction Force ◽  
Statistical Parametric Mapping ◽  
Force Production ◽  
Mass Motion ◽  
Ground Reaction Forces ◽  
Centre Of Mass ◽  
Specific Training ◽  
Force Vector ◽  
Reaction Forces ◽  
External Power

Ground reaction forces produced on the blocks determine an athlete’s centre of mass motion during the sprint start, which is crucial to sprint performance. This study aimed to understand how force waveforms are associated with better sprint start performance. Fifty-seven sprinters (from junior to world elite) performed a series of block starts during which the ground reaction forces produced by the legs and arms were separately measured. Statistical parametric mapping (linear regression) revealed specific phases of these waveforms where forces were associated with average horizontal external power. Better performances were achieved by producing higher forces and directing the force vector more horizontally during the initial parts of the block phase (17–34% and 5–37%, respectively). During the mid-push (around the time of rear block exit: ∼54% of the block push), magnitudes of front block force differentiated performers, but orientation did not. Consequently, the ability to sustain high forces during the transition from bilateral to unilateral pushing was a performance-differentiating factor. Better athletes also exhibited a higher ratio of forces on the front block in the latter parts of unilateral pushing (81–92% of the block push), which seemed to allow these athletes to exit the blocks with lower centre of mass projection angles. Training should reflect these kinetic requirements, but also include technique-based aspects to increase both force production and orientation capacities. Specific training focused on enhancing anteroposterior force production during the transition between double- to single-leg propulsion could be beneficial for overall sprint start performance.

Magnitude and Spatial Distribution of Impact Intensity Under the Foot Relates to Initial Foot Contact Pattern

2017 ◽  
Vol 33 (6) ◽  
pp. 431-436 ◽  
Author(s):  
Bastiaan Breine ◽  
Philippe Malcolm ◽  
Veerle Segers ◽  
Joeri Gerlo ◽  
Rud Derie ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Loading Rate ◽  
Ground Reaction Forces ◽  
Contact Pattern ◽  
Intensity Measure ◽  
Foot Kinematics ◽  
Contact Patterns ◽  
Reaction Forces ◽  
Local Impact ◽  
The Impact

In running, foot contact patterns (rear-, mid-, or forefoot contact) influence impact intensity and initial ankle and foot kinematics. The aim of the study was to compare impact intensity and its spatial distribution under the foot between different foot contact patterns. Forty-nine subjects ran at 3.2 m·s−1 over a level runway while ground reaction forces (GRF) and shoe-surface pressures were recorded and foot contact pattern was determined. A 4-zone footmask (forefoot, midfoot, medial and lateral rearfoot) assessed the spatial distribution of the vertical GRF under the foot. We calculated peak vertical instantaneous loading rate of the GRF (VILR) per foot zone as the impact intensity measure. Midfoot contact patterns were shown to have the lowest, and atypical rearfoot contact patterns the highest impact intensities, respectively. The greatest local impact intensity was mainly situated under the rear- and midfoot for the typical rearfoot contact patterns, under the midfoot for the atypical rearfoot contact patterns, and under the mid- and forefoot for the midfoot contact patterns. These findings indicate that different foot contact patterns could benefit from cushioning in different shoe zones.

scholarly journals Spring-like leg behaviour, musculoskeletal mechanics and control in maximum and submaximum height human hopping

2011 ◽  
Vol 366 (1570) ◽  
pp. 1516-1529 ◽  
Author(s):  
Maarten F. Bobbert ◽  
L. J. Richard Casius
Keyword(s):  
Energy Expenditure ◽  
Muscle Activation ◽  
Mechanical Energy ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Centre Of Mass ◽  
Leg Stiffness ◽  
Reaction Forces ◽  
And Control ◽  
The Relationship

The purpose of this study was to understand how humans regulate their ‘leg stiffness’ in hopping, and to determine whether this regulation is intended to minimize energy expenditure. ‘Leg stiffness’ is the slope of the relationship between ground reaction force and displacement of the centre of mass (CM). Variations in leg stiffness were achieved in six subjects by having them hop at maximum and submaximum heights at a frequency of 1.7 Hz. Kinematics, ground reaction forces and electromyograms were measured. Leg stiffness decreased with hopping height, from 350 N m −1 kg −1 at 26 cm to 150 N m −1 kg −1 at 14 cm. Subjects reduced hopping height primarily by reducing the amplitude of muscle activation. Experimental results were reproduced with a model of the musculoskeletal system comprising four body segments and nine Hill-type muscles, with muscle stimulation STIM( t ) as only input. Correspondence between simulated hops and experimental hops was poor when STIM( t ) was optimized to minimize mechanical energy expenditure, but good when an objective function was used that penalized jerk of CM motion, suggesting that hopping subjects are not minimizing energy expenditure. Instead, we speculated, subjects are using a simple control strategy that results in smooth movements and a decrease in leg stiffness with hopping height.

The influence of boot longitudinal flexural stiffness on external mechanical work and running economy during skate roller-skiing: A case study

2019 ◽  
Vol 233 (4) ◽  
pp. 548-558
Author(s):  
Jurij Hladnik ◽  
Matej Supej ◽  
Janez Vodičar ◽  
Boris Jerman
Keyword(s):  
Rolling Resistance ◽  
Forward Direction ◽  
Running Economy ◽  
Mechanical Work ◽  
Flexural Stiffness ◽  
Centre Of Mass ◽  
Reaction Forces ◽  
The Impact ◽  
Derivatives Of

This case study examines the impact of boot longitudinal flexural stiffness on the total external mechanical work of a skier’s centre of mass per distance travelled in the forward direction ([Formula: see text] EX (J/m)) and on running economy during skate roller-skiing under submaximal steady-state conditions. Moreover, it analyses time derivatives of total W EX, of W EX performed by the roller-skis and poles, respectively, and of the directly useful mechanical work (the sum of the work to overcome centre of mass’ gravity and rolling resistance) within a typical roller-skiing cycle. Multiple roller-skiing trials (G3 technique) were performed by one subject on an inclined treadmill with boots of soft, intermediate, and stiff flexural stiffness. The orientation and magnitude of the roller-ski and pole ground reaction forces, body kinematics, VO2, and lactic acid concentration were monitored. The stiff boots had 13.4% ( p < 0.01) lower [Formula: see text] EX compared to the intermediate boots, and 20.7% ( p < 0.001) lower [Formula: see text] EX compared to the soft boots. Regarding running economy, the soft boots had 2.2% ( p < 0.05) higher VO2 compared to the intermediate boots, but the same VO2 compared to the stiff boots. In conclusion, the soft boots had significantly higher [Formula: see text] EX and running economy, while stiff boots had significantly lower [Formula: see text] EX and intermediate boots significantly lower running economy. Moreover, [Formula: see text] EX appears to be a better indicator of the boot flexural stiffness impact on energy efficiency than running economy.

The effects of strength training upon front foot contact ground reaction forces and ball release speed among high-level cricket pace bowlers

2021 ◽  
pp. 1-17
Author(s):  
Samuel J. Callaghan ◽  
Robert G. Lockie ◽  
Jamie Tallent ◽  
Robert F. Chipchase ◽  
Warren A. Andrews ◽  
...  
Keyword(s):  
Strength Training ◽  
Ground Reaction Forces ◽  
Ball Release ◽  
Reaction Forces ◽  
High Level ◽  
Release Speed

scholarly journals Changes in Ground Reaction Forces, Joint Mechanics, and Stiffness during Treadmill Running to Fatigue

2019 ◽  
Vol 9 (24) ◽  
pp. 5493 ◽  
Author(s):  
Zhen Luo ◽  
Xini Zhang ◽  
Junqing Wang ◽  
Yang Yang ◽  
Yongxin Xu ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Treadmill Running ◽  
Ground Reaction Forces ◽  
Joint Mechanics ◽  
Soft Landing ◽  
Ankle Stiffness ◽  
Impact Forces ◽  
Reaction Forces ◽  
The Impact ◽  
Kinematics And Kinetics

Purpose: This study aimed to determine the changes in lower extremity biomechanics during running-induced fatigue intervention. Methods: Fourteen male recreational runners were required to run at 3.33 m/s until they could no longer continue running. Ground reaction forces (GRFs) and marker trajectories were recorded intermittently every 2 min to quantify the impact forces and the lower extremity kinematics and kinetics during the fatiguing run. Blood lactate concentration (BLa) was also collected before and after running. Results: In comparison with the beginning of the run duration, (1) BLa significantly increased immediately after running, 4 min after running, and 9 min after running; (2) no changes were observed in vertical/anterior–posterior GRF and loading rates; (3) the hip joint range of motion (θROM) significantly increased at 33%, 67%, and 100% of the run duration, whereas θROM of the knee joint significantly increased at 67%; (4) no changes were observed in ankle joint kinematics and peak joint moment at the ankle, knee, and hip; and (5) vertical and ankle stiffness decreased at 67% and 100% of the run duration. Conclusion: GRF characteristics did not vary significantly throughout the fatiguing run. However, nonlinear adaptations in lower extremity kinematics and kinetics were observed. In particular, a “soft landing” strategy, achieved by an increased θROM at the hip and knee joints and a decreased vertical and ankle stiffness, was initiated from the mid-stage of a fatiguing run to potentially maintain similar impact forces.

scholarly journals Impacto producido por la técnica seoi-otoshi. Relación con años de práctica y grado en judo

2014 ◽  
Vol 9 (1) ◽  
pp. 32 ◽  
Author(s):  
Carlos Montero Carretero ◽  
José Luis López Elvira
Keyword(s):  
Body Weight ◽  
Potential Risk ◽  
The Other ◽  
Ground Reaction Forces ◽  
Expert Group ◽  
Risk Of Injury ◽  
Force Peak ◽  
Reaction Forces ◽  
The Mean ◽  
The Impact

Judokas commonly train the <em>seoi-otoshi</em> technique (aka, drop-knee <em>seoi-nage</em>). A controversy exists about the convenience of its use by the younger judokas due to the risk of high loads produced by the impacts on their growing structures. The aim of the present paper was to measure the impacts against the tatami when executing the knee <em>seoi-otoshi</em> technique and its relationship with the years of practice and the degree or level (color of the belt). Thirty-three judokas from different years and degree volunteered to participate. Two force plates covered by standard tatami, registered the ground reaction forces while five consecutive repetitions were executed. We measured the mean and maximum peaks of force relative to their own body weight (BW). The results show peaks of more than 10 BW, which can be considered a potential risk of injury in the younger judokas, especially when repeated in time. In addition, a tendency to decrease the impact as the years of practice increase is observed (potential function; R<sup>2</sup>= 0.41, p&lt;0.000 in the force peak), and the force in the expert group has been significantly lower than in the other groups (p&lt;0.001). On the other hand, the degree (belt color) shows a quadratic relationship (R<sup>2</sup>= 0.45, p&lt;0.000 in the force peak). The lack of agreement between the years of practice and the degree shows that the promotion criteria does not appear to be a valid one from a preventive viewpoint, especially in the lower degrees which would correspond to younger practitioners whose locomotor structures are still not fully developed.

A Technique to Evaluate Foot Function During the Stance Phase of Gait

1995 ◽  
Vol 16 (12) ◽  
pp. 764-770 ◽  
Author(s):  
Karen Lohmann Siegel ◽  
Thomas M. Kepple ◽  
Paul G. O'Connell ◽  
Lynn H. Gerber ◽  
Steven J. Stanhope
Keyword(s):  
Stance Phase ◽  
Center Of Pressure ◽  
Three Dimensional ◽  
Ground Reaction Forces ◽  
Coordinate Systems ◽  
Future Studies ◽  
Case Examples ◽  
Reaction Forces ◽  
Foot Function ◽  
The Impact

A technique to measure foot function during the stance phase of gait is described. Advantages of the method include its three-dimensional approach with anatomically based segment coordinate systems. This allows variables such as ground reaction forces and center of pressure location to be expressed in a local foot coordinate system, which gives more anatomical meaning to the interpretation of results. Application of the measurement technique to case examples of patients with rheumatoid arthritis demonstrated its ability to discriminate normal from various levels of pathological function. Future studies will utilize this technique to study the impact of pathology and treatment on foot function.

scholarly journals Race Walking Ground Reaction Forces at Increasing Speeds: A Comparison with Walking and Running

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 873
Author(s):  
Gaspare Pavei ◽  
Dario Cazzola ◽  
Antonio La Torre ◽  
Alberto E. Minetti
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
The Body ◽  
Ground Reaction Forces ◽  
Centre Of Mass ◽  
Walking Gait ◽  
Wide Range ◽  
Reaction Forces ◽  
Race Walking ◽  
Walking Speeds

Race walking has been theoretically described as a walking gait in which no flight time is allowed and high travelling speed, comparable to running (3.6–4.2 m s−1), is achieved. The aim of this study was to mechanically understand such a “hybrid gait” by analysing the ground reaction forces (GRFs) generated in a wide range of race walking speeds, while comparing them to running and walking. Fifteen athletes race-walked on an instrumented walkway (4 m) and three-dimensional GRFs were recorded at 1000 Hz. Subjects were asked to performed three self-selected speeds corresponding to a low, medium and high speed. Peak forces increased with speeds and medio-lateral and braking peaks were higher than in walking and running, whereas the vertical peaks were higher than walking but lower than running. Vertical GRF traces showed two characteristic patterns: one resembling the “M-shape” of walking and the second characterised by a first peak and a subsequent plateau. These different patterns were not related to the athletes’ performance level. The analysis of the body centre of mass trajectory, which reaches its vertical minimum at mid-stance, showed that race walking should be considered a bouncing gait regardless of the presence or absence of a flight phase.

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