scholarly journals Cricket Biomechanics Analysis of Skilled and Amateur Fast Bowling Techniques

2015 ◽  
Vol 49 (4) ◽  
pp. 173-181
Author(s):  
KA Thiagarajan ◽  
Tvisha Parikh ◽  
Anees Sayed ◽  
MB Gnanavel ◽  
S Arumugam
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Three Dimensional ◽  
The Body ◽  
Vertical Ground Reaction Force ◽  
Ball Release ◽  
Equality Of Means ◽  
Counter Rotation ◽  
Vertical Ground ◽  
Release Speed

ABSTRACT Cricket fast bowling action involves complex three-dimensional (3D) motion of the body and poses a high risk of injury more so in schoolboys. It is not known how the bowling technique varies between skilled and less skilled fast bowlers. The aim of this study is to compare the differences in bowling technique between young sub-elite (skilled) and amateur university level cricketers. Twelve players, 6 skilled and six amateur, were attached with 35 retro-reflective markers using the full body Plug-in-Gait marker set and asked to bowl 6 deliveries at a good length. Their bowling action was captured with 12 Vicon 3D cameras and the ground reaction force was measured using AMTI force plates. The best delivery from each bowler was selected. Their bowling action types were classified and parameters like shoulder counter rotation (scr), pelvicshoulder separation angle at back foot contact, trunk lateral flexion, front knee angle, front foot vertical ground reaction force (vGRF) and ball release speed were measured. The results were analyzed with Levene's test for Equality of Variances and a t-test for equality of means. The skilled bowlers showed faster ball release speed and experienced larger vGRF while the other parameters did not show any significant differences. How to cite this article Thiagarajan KA, Parikh T, Sayed A, Gnanavel MB, Arumugam S. Cricket Biomechanics Analysis of Skilled and Amateur Fast Bowling Techniques. J Postgrad Med Edu Res 2015;49(4):173-181.

scholarly journals Acute fatigue effects on ground reaction force of lower limbs during countermovement jumps

2013 ◽  
Vol 19 (4) ◽  
pp. 737-745
Author(s):  
Carlos Gabriel Fábrica ◽  
Paula V. González ◽  
Jefferson Fagundes Loss
Keyword(s):  
Body Weight ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
The Body ◽  
Lower Limbs ◽  
Vertical Ground Reaction Force ◽  
External Work ◽  
Jumping Performance ◽  
Vertical Ground ◽  
The Relationship

Parameters associated with the performance of countermovement jumps were identified from vertical ground reaction force recordings during fatigue and resting conditions. Fourteen variables were defined, dividing the vertical ground reaction force into negative and positive external working times and times in which the vertical ground reaction force values were lower and higher than the participant's body weight. We attempted to explain parameter variations by considering the relationship between the set of contractile and elastic components of the lower limbs. We determined that jumping performance is based on impulsion optimization and not on instantaneous ground reaction force value: the time in which the ground reaction force was lower than the body weight, and negative external work time was lower under fatigue. The results suggest that, during fatigue, there is less contribution from elastic energy and from overall active state. However, the participation of contractile elements could partially compensate for the worsening of jumping performance.

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.

scholarly journals The Effects of Posture on the Three-Dimensional Gait Mechanics of Human Walking in Comparison to Bipedal Chimpanzees

2021 ◽  
Author(s):  
Russell T. Johnson ◽  
Matthew C. O'Neill ◽  
Brian R. Umberger
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Three Dimensional ◽  
Bipedal Walking ◽  
Human Walking ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Gait Mechanics ◽  
Reaction Forces ◽  
Vertical Ground

Humans walk with an upright posture on extended limbs during stance and with a double-peaked vertical ground reaction force. Our closest living relatives, chimpanzees, are facultative bipeds that walk with a crouched posture on flexed, abducted hind limbs and with a single-peaked vertical ground reaction force. Differences in human and bipedal chimpanzee three-dimensional kinematics have been well quantified; however, it is unclear what the independent effects of using a crouched posture are on three-dimensional gait mechanics for humans, and how they compare with chimpanzees. Understanding the relationships between posture and gait mechanics, with known differences in morphology between species, can help researchers better interpret the effects of trait evolution on bipedal walking. We quantified pelvis and lower limb three-dimensional kinematics and ground reaction forces as humans adopted a series of upright and crouched postures and compared them with data from bipedal chimpanzee walking. Human crouched posture gait mechanics were more similar to bipedal chimpanzee gait than normal human walking, especially in sagittal plane hip and knee angles. However, there were persistent differences between species, as humans walked with less transverse plane pelvis rotation, less hip abduction, and greater peak horizontal ground reaction force in late stance than chimpanzees. Our results suggest that human crouched posture walking reproduces only a small subset of the characteristics of three-dimensional kinematics and ground reaction forces of chimpanzee walking, with the remaining differences likely due in large part to the distinct musculoskeletal morphologies of humans and chimpanzees.

Simulation of the Vertical Ground Reaction Force on Sport Surfaces during Landing

2002 ◽  
Vol 18 (2) ◽  
pp. 122-134 ◽  
Author(s):  
Klaus Peikenkamp ◽  
Martin Fritz ◽  
Klaus Nicol
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
The Body ◽  
Overuse Injuries ◽  
Surface Model ◽  
Vertical Ground Reaction Force ◽  
Surface Mass ◽  
Maximum Deformation ◽  
Linear Spring ◽  
Vertical Ground

The surface-athlete interaction is discussed as one possible factor in overuse injuries, as the ground reaction force does not depend only on the athlete’s movement during surface contact but also on the mechanical properties of the playing surface. Since it is extremely difficult to measure the ground reaction force on an area-elastic surface, two damped linear-spring models were combined to calculate both the vertical ground reaction force on area-elastic surfaces and their deformations during the athlete’s landing from a jump height of 0.45 m. The athlete model consists of 4 segments (feet, shanks, thighs, and rest of the body) and the surface model consists of 5 segments each connected (a) to the concrete and (b) to each other via an additional imaginary segment. While the connections to the concrete were kept constant, the surface mass and the connections between the segments were varied in order to consider different degrees of area-elasticity of the simulated surfaces. With this approach it was shown that both the passive and active maximum of the vertical ground reaction force depend only on the maximum deformation of the surface, whereas the force rates vary greatly for identical maximum deformations. It appears that these differences increase with increasing maximum deformation. Therefore, in constructing area-elastic sport surfaces, the maximum deformation allowed should be as large as would coincide with other functions the surface must fulfill. Subsequently, the surface mass interacting with the athlete during landing should be large and the damping properties between these mass-segments should be very small.

scholarly journals Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Time Patterns ◽  
Foot Strike ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

Carrying loads with springy poles

1991 ◽  
Vol 71 (3) ◽  
pp. 1119-1122 ◽  
Author(s):  
R. Kram
Keyword(s):  
Oxygen Consumption ◽  
Ground Reaction Force ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Reaction Force ◽  
Load Carriage ◽  
Vertical Ground Reaction Force ◽  
Suspension Systems ◽  
Vertical Ground ◽  
Male Subjects

People throughout Asia use springy bamboo poles to carry the loads of everyday life. These poles are a very compliant suspension system that allows the load to move along a nearly horizontal path while the person bounces up and down with each step. Could this be an economical way to carry loads inasmuch as no gravitational work has to be done to lift the load repeatedly? To find out, an experiment was conducted in which four male subjects ran at 3.0 m/s on a motorized treadmill with no load and while carrying a load equal to 19% body wt with compliant poles. Oxygen consumption rate, vertical ground reaction force, and the force exerted by the load on the shoulders were measured. Oxygen consumption rate increased by 22%. The same increase has previously been observed when loads are carried with a backpack. Thus compliant poles are not a particularly economical method of load carriage. However, pole suspension systems offer important advantages: they minimize peak shoulder forces and loading rates. In addition, the peak vertical ground reaction force is only slightly increased above unloaded levels when loads are carried with poles.

scholarly journals The Relationship Between Vertical Loadrates and Tibial Acceleration Across Footstrike Patterns

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0020 ◽  
Author(s):  
Irene Davis ◽  
Todd Hayano ◽  
Adam Tenforde
Keyword(s):  
Impact Loading ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Force Plate ◽  
Correlation Coefficients ◽  
Strongly Correlated ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground ◽  
Tibial Acceleration ◽  
The Relationship

Category: Other Introduction/Purpose: While the etiology of injuries is multifactorial, impact loading, as measured by the loadrate of the vertical ground reaction force has been implicated. These loadrates are typically measured with a force plate. However, this limits the measure of impacts to laboratory environments. Tibial acceleration, another measure of running impacts, is considered a surrogate for loadrate. It can be measured using new wearable technology that can be used in a runner’s natural environment. However, the correlation between tibial acceleration measured from mobile devices and vertical ground reaction force loadrates, measured from forceplates, is unknown. The purpose of this study was to determine the correlation between vertical and resultant loadrates to vertical and resultant tibial acceleration across different footstrike patterns (FSP) in runners. Methods: The study involved a sample of convenience made up of 169 runners (74 F, 95 M; age: 38.66±13.08 yrs) presenting at a running injury clinic. This included 25 habitual forefoot strike (FFS), 17 midfoot strike (MFS) and 127 rearfoot strike (RFS) runners. Participants ran on an instrumented treadmill (average speed 2.52±0.25 m/s), with a tri-axial accelerometer attached at the left distal medial tibia. Only subjects running with pain <3/10 on a VAS scale during the treadmill run were included to reduce the confounding effect of pain. Vertical average, vertical instantaneous and resultant instantaneous loadrates (VALR, VILR and RILR) and peak vertical and resultant tibial accelerations (VTA, RTA) were averaged for 8 consecutive left steps. Correlation coefficients (r) were calculated between tibial accelerations and loadrates. Results: All tibial accelerations were significantly correlated across all loadrates, with the exception of RTA with VILR for FFS (Table 1) which was nearly significant (p=0.068). Correlations ranged from 0.37-0.82. VTA was strongly correlated with all loadrates (r = 0.66). RTA was also strongly correlated with both loadrates for RFS and MFS, but only moderately correlated with loadrates for FFS (r = 0.47). Correlations were similar across the different loadrates (VALR, VILR, RILR). Conclusion: The stronger correlation between vertical tibial acceleration and all loadrates (VALR, VILR, RILR) suggests that it may be the best surrogate for loadrates when studying impact loading in runners.

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