Front Foot Contact Research Articles

Analysis of Front Leg Kinematics of Cricket Bowler Using Wearable Sensors and Machine Learning

A fast bowler in the game of cricket is exposed to high-intensity actions and is more prone to lumbar stress fractures, ankle sprains, and knee, shoulder, and lower back injuries. There are different phases of bowling, from running to ball release, viz., run-up, predelivery stride (PDS), mid-bound (MB), front foot contact (FFC), ball release, and follow through. The front leg motion of the bowler plays a crucial role in delivering the ball efficiently. An improper landing after the jump causes most of the injuries as more strain is induced on the knee, ankle, and groin region. Loss of balance during the follow-through is the other most common reason for injury. A braced front leg at FFC helps the bowler transfer the momentum gained during the run-up into a fast-bowling action. For a refined understanding of the motion of the bowler and the causes of injuries, the identification of bowling phases is crucial. This article proposes the design of a miniature and economical wearable sensor unit using a Bosch BNO055 inertial measurement unit (IMU) sensor that the players can comfortably wear during the game. A novel method for calculating knee flexion of bowlers at FFC using quaternion data gathered from sensors is presented. Two wearable units were placed on the bowler’s front leg to collect motion data. Supervised machine-learning algorithms have been evaluated for classifying bowling phases using statistical features extracted from the sensor data to assist coaches and players with data-driven and evidence-based bowlers’ training.

Characteristics of elite cricket fast bowlers who do and do not sustain a lumbar bone stress injury: Multifactorial analysis over 4 years

Introduction: Lumbar bone stress injuries (LBSI) are the highest time-loss injury among cricket fast bowlers. Previous studies have identified risk factors such as shoulder counter rotation and lateral flexion during bowling delivery, lumbar extension endurance on screening, and high bowling loads. However, findings tend to be unidimensional, inconsistent, and limited to a short time-frame. The purpose of this study was to address these limitations by retrospectively reviewing 4-seasons of data across multiple domains. Methods: Data of elite male fast bowlers was retrieved from Cricket Australia’s Athlete Management System for the seasons 2016-17 to 2019-20. Bowlers who sustained a LBSI during a season, denoted “injured” (n=32, 22.8 ± 4.3 years) were compared to bowlers who did not sustain a LBSI in the previous 5 years, denoted “non-injured” (n=18, 25.8 ± 4.2 years). Bowling biomechanics, musculoskeletal screening, fitness tests, and bowling loads were compared between injured and non-injured bowlers using univariate and multivariate analyses. Results: Injured bowlers were younger than non-injured (p=0.026). Injured and non-injured bowlers had similar biomechanics, with the exception of a possible larger amount of lumbar extension at front foot contact (FFC) (d = 0.6) and a straighter front knee at FFC (d = 0.5) in the injured group. There was no difference in musculoskeletal screening and fitness tests between groups. Injured and non-injured bowlers had similar bowling loads over the 4 weeks preceding injury (or equivalent time-point for non-injured group). Non-injured bowlers bowled more balls over 12 weeks (1499, p=0.007) and more balls (5137, p=0.001) and more days over 1 year (113, p=0.012). Discussion: This study adds to the existing literature, supporting younger age as a risk factor for LBSI. Bowling biomechanics and bowling loads evidently contribute to LBSI risk, however there is not a clear delineation for increased risk. These findings emphasise the complexity of LBSI in elite male fast bowlers. An individualised and adaptive approach to managing the preparation of fast bowlers is recommended. Conflict of interest statement: My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.

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

ABSTRACT The effects of an eight-week off-season strength training program upon lower-body strength, power, eccentric capacity, front foot contact (FFC) kinetics, and ball release speed (BRS) in pace bowlers were investigated. Ten elite-academy pace bowlers completed the intervention, and pre- and post-testing. Pre- and post-testing included: double (DLDL) and single leg (SLDL) drop landings; isometric mid-thigh pull (IMTP); countermovement jump; and pace bowling performance (two-over bowling spell measuring BRS and FFC kinetics). Changes from pre- to post-testing were assessed with paired sample t tests (p≤ 0.01), effects sizes and statistical parametrical mapping. Post-testing revealed a significant decrease in peak normalised vertical force during DLDL and SLDL with large effects and a significant, moderate effect increase in IMTP. There was no significant changes in BRS. Concomitantly, neither discrete scalar (p= 0.15-0.58) nor vector field analysis kinetics during FFC indicated significant changes. No significant alterations in FFC kinetics may explain the lack of improvement in BRS (pre = 31.55 ± 1.44 m/s; post = 31.79 ± 1.33 m/s). This study indicated an eight-week strength training program can improve strength and eccentric capacity in pace bowlers, and these changes when developed in the absence of skills training neither improved nor decreased pace bowling performance.

The influence of technique and physical capacity on ball release speed in cricket fast-bowling

ABSTRACT This study examined the relationships between physical capacity, bowling technique and ball speed in 20 fast-bowlers. Technique factors correlated with ball speed were; bowling action duration (r = -0.639, p = 0.002), run-up velocity (r = 0.616, p = 0.004), back foot contact (BFC) time (r = -0.608, p = 0.004), front foot contact (FFC)-ball release (BR) duration (r = -0.602, p = 0.005), delivery stride phase acceleration (r = -0.582, p = 0.007), delivery stride duration (r = -0.547, p = 0.012), time of peak horizontal braking force (r = -0.538, p=0.014), peak pelvis COM velocity (BFC-BR) (r = 0.469, p = 0.037) and peak vertical GRF time (r = -0.461, p = 0.041). Physical capacities were; 10-30 m split (r = -0.554, p = 0.011), 30 m sprint (r = -0.482, p = 0.031) and IMTP (r = 0.471, p = 0.036). Stepwise regression showed bowling action duration and 10-30 m split explained 54% (p = 0.001) of ball speed variation. Ball speed was associated with faster run-ups, shorter BFC times and abrupt FFC GRF application. Coaches should also consider sprint speed and lower-body strength as important modifiable factors for fast-bowlers.

Not as simple as it seems: Front foot contact kinetics, muscle function and ball release speed in cricket pace bowlers

ABSTRACT This study investigated the relationship between front foot contact (FFC) ground reaction forces (GRF) during the delivery stride, lower-limb strength, eccentric dexterity and power, and ball release speed (BRS) among pace bowlers. Thirteen high-level male pace bowlers performed double and single leg drop landings; isometric mid-thigh pull; countermovement jump; and pace bowling (two-over bowling spell measuring BRS and FFC GRF). The relationship between assessed variables and BRS was determined via frequentist and Bayesian multiple linear regression. The model including peak braking force was the most probable given the data (Bayes Factor=1.713) but provided only weak evidence in comparison to the null model. The results of frequentist and Bayesian modelling were comparable with peak braking force explaining 23.3% of the variance in BRS (F (1, 11)=4.64, P=0.054). Results indicate pace bowlers with greater peak braking GRF during FFC generally elicit higher BRS. However, the weak relationship between peak braking force and BRS, and the lack of a linear relationship between BRS and other variables, highlights the complexities and inter-individual variability inherent to pace bowling at a high-level. A more individual-focused analysis revealed varied strategies within pace bowlers to deliver the outcome (e.g., BRS) and should be considered in future study designs.

Does Delivery Length Impact Measures of Whole-Body Biomechanical Load During Pace Bowling?

To investigate whether changes in delivery length (ie,short, good, and full) lead to alterations in whole-body biomechanical loading as determined by ground reaction force during front-foot contact of the delivery stride for pace bowlers. Current load-monitoring practices of pace bowling in cricket assume equivocal biomechanical loading as only the total number of deliveries are monitored irrespective of delivery length. A total of 16 male pace bowlers completed a 2-over spell at maximum intensity while targeting different delivery lengths (short, 7-10m; good, 4-7m; and full, 0-4m from the batter's stumps). In-ground force plates were used to determine discrete (vertical and braking force, impulse, and loading rates) and continuous front-foot contact ground reaction force. Repeated-measures analysis of variance (P < .05), effects size, and statistical parametrical mapping were used to determine differences between delivery lengths. There were no significant differences between short, good, and full delivery lengths for the discrete and continuous kinetic variables investigated (P = .19-1.00), with trivial to small effect sizes. There were minimal differences in front-foot contact biomechanics for deliveries of different lengths (ie,short, good, and full). These data reinforce current pace bowling load-monitoring practices (ie,counting the number of deliveries), as changes in delivery length do not affect the whole-body biomechanical loading experienced by pace bowlers. This is of practical importance as it retains simplicity in load-monitoring practice that is used widely across different competition levels and ages.

Modifying bowling kinematics in cricket pace bowlers with exercise-based injury prevention: A cluster-randomised controlled trial

ObjectivesUndesirable bowling kinematics can increase the risk of low back injury. This study investigated if an exercise-based injury prevention program (IPP) could modify bowling kinematics in community-level adolescent pace bowlers. DesignCluster-randomised controlled trial. MethodsPace bowlers from eight cricket organisations were cluster-randomised into an intervention or control group. At baseline and follow-up sessions biomechanical bowling data were collected. Between sessions, the intervention group completed an eight-week IPP while the control continued their normal cricket activity. Treatment effects (95% CI) were estimated with linear mixed models. ResultsThere were significant treatment effects favouring the intervention group for shoulder counter-rotation (−3.8°; −7.2° to −0.3°) and lateral trunk flexion relative to the pelvis (−2.2°; −4.0° to −0.5°). Shoulder counter-rotation also increased in the control group by 2.2° (Cohen’s d=0.22). There were no effects of the intervention on: lateral trunk flexion at front foot contact (FFC) (1.2°; −2.5° to 4.8°), lateral trunk flexion at ball release (BR) (−0.5°; −3.0° to 2.0°), pelvis rotation at FFC (0.9°; −4.0° to 2.2°), pelvis rotation at BR (−1.1°; −5.7° to 3.6°), front hip angle at FFC (1.6°; −3.6° to 6.7°), front hip angle at BR (−1.6°; −5.0° to 1.9°), front knee angle at FFC (−1.1°; −4.5° to 2.3°), front knee angle at BR (1.7°; −5.6° to 9.1°), or ball velocity (1.1kmh−1; −7.5kmh−1 to 9.7kmh−1). ConclusionsThe IPP maintained shoulder counter-rotation and lateral trunk flexion relative to the pelvis in the intervention group and this could attenuate injury risk. No treatment effects were observed for lower-limb kinematics.

A biomechanical comparison of conventional classifications of bowling action-types in junior fast bowlers

ABSTRACT Fast bowling is categorised into four action types: side-on, front-on, semi-open and mixed; however, little biomechanical comparison exists between action types in junior fast bowlers. This study investigated whether there are significant differences between action-type mechanics in junior fast bowlers. Three-dimensional kinematic and kinetic analyses were completed on 60 junior male fast bowlers bowling a five-over spell. Mixed-design factorial analyses of variance were used to test for differences between action-type groups across the phases of the bowling action. One kinetic difference was observed between groups, with a higher vertical ground reaction force loading rate during the front-foot contact phase in mixed and front-on compared to semi-open bowlers; no other significant group differences in joint loading occurred. Significant kinematic differences were observed between the front-on, semi-open and mixed action types during the front-foot contact phase for the elbow and trunk. Significant kinematic differences were also present for the ankle, T12-L1, elbow, trunk and pelvis during the back-foot phase. Overall, most differences in action types for junior fast bowlers occurred during the back-foot contact phase, particularly trunk rotation and T12-L1 joint angles/ranges of motion, where after similar movement patterns were utilized across groups during the front-foot contact phase.

The Effects of an Eight over Cricket Bowling Spell upon Pace Bowling Biomechanics and Performance within Different Delivery Lengths.

Pace bowlers must often perform extended bowling spells with maximal ball release speed (BRS) while targeting different delivery lengths when playing a multi-day match. This study investigated the effect of an eight over spell upon pace bowling biomechanics and performance at different delivery lengths. Nine male bowlers (age = 18.8 ± 1.7 years) completed an eight over spell, while targeting different lengths (short: 7–10 m, good: 4–7 m, full: 0–4 m from the batter’s stumps, respectively) in a randomized order. Trunk, knee and shoulder kinematics and ground reaction forces at front foot contact (FFC), as well as run-up velocity and BRS were measured. Paired sample t-tests (p ≤ 0.01), Hedges’ g effect sizes, and statistical parametrical mapping were used to assess differences between mean variables from the first and last three overs. No significant differences (p = 0.05–0.98) were found in any discrete or continuous variables, with the magnitude of difference being trivial-to-medium (g = 0.00–0.73) across all variables. Results suggest pace bowlers sustain BRS through a single eight over spell while tolerating the repeatedly high whole-body biomechanical loads as suggested by maintaining the kinematics or technique at the assessed joints during FFC. Practically, the findings are advantageous for bowling performance and support current bowling load monitoring practices.

Induced Power Analysis Of Sequential Body Motion And Elbow Valgus Load During Baseball Pitching

The flow of mechanical energy of segmental motion provides a mechanism by which the throwing arm is accelerated during baseball pitching. Muscles can indirectly influence the energy level of distal segments to which they are not attached by way of the interaction torques transferring energy up the kinetic chain. No study to date, however, has addressed these causal components of mechanical power, specifically in relation to valgus loading at the elbow, which is prone to pitching-related injuries. PURPOSE: To determine the components of muscle and velocity-dependent torques that contribute to the power of throwing arm segments when the elbow is under valgus load during pitching. METHODS: The throwing motions of 10 adult pitchers (age = 22.9 ± 4.1 years, height = 1.87 ± 4.93 m, and mass = 86.5 ± 7.4 kg) were biomechanically measured using 3D motion capture after written informed consents were provided by the participants. The resulting kinematic and kinetic data were included in a state-space power analysis using a 10-DOF model. The contributions of the torque-induced components to the mechanical work of the forearm were determined by integrating the power curves in time between the instants of front foot contact (FC) and maximum external rotation (MER) of the throwing shoulder. RESULTS: Pitchers threw with a maximum elbow valgus torque of 70.1 ± 2.2 N•m. The trunk flexion (r1) and rotation (r3) components of the muscle-induced torque were the greatest positive contributors to the work of the forearm. Muscle torques contributed a total of 44.5 ± 23.4 J while velocity-dependent torques absorbed 69.6 ± 37.1 J, representing 61% of the total work (114.1 J) of the distal arm segments during the arm-cocking phase (Figure 1). CONCLUSIONS: Trunk motion in the early part of the arm-cocking phase appears to drive the power of accelerating the throwing elbow in valgus via velocity-dependent torques.

The effects of a resistance training program on strength, eccentric capacity, and front foot bowling kinetics in fast bowlers

Introduction: Fast bowlers (FBs) will often attempt to maximise ball release velocity (BRV) to assist in dismissing opposing batsman. The ground reaction force (GRF) generated during front foot contact (FFC) can contribute to increased BRV. Consequently, FBs must ensure they have the necessary lower-limb strength and eccentric capacity to appropriately attenuate and utilise the forces experienced during FFC. Despite this link between physical capacity (strength) and expression of force (GRF at FFC), there has been limited analysis of training interventions in FBs.

Comparison of biomechanical characteristics between male and female elite fast bowlers

ABSTRACTThis study investigated ball release speed and performance kinematics between elite male and female cricket fast bowlers. Fifty-five kinematic parameters were collected for 20 male and 20 female elite fast bowlers. Group means were analysed statistically using an independent samples approach to identify differences. Significant differences were found between: ball release speed; run-up speed; the kinematics at back foot contact (BFC), front foot contact (FFC), and ball release (BR); and the timings between these key instants. These results indicate that the female bowlers generated less whole body linear momentum during the run-up than the males. The male bowlers also utilised a technique between BFC and FFC which more efficiently maintained linear momentum compared to the females. As a consequence of this difference in linear momentum at FFC, the females typically adopted a technique more akin to throwing where ball release speed was contributed to by both the whole body angular momentum and the large rotator muscles used to rotate the pelvis and torso segments about the longitudinal axis. This knowledge is likely to be useful in the coaching of female fast bowlers although future studies are required to understand the effects of anthropometric and strength constraints on fast bowling performance.

The relationship between inertial measurement unit-derived ‘force signatures’ and ground reaction forces during cricket pace bowling

This study assessed the reliability and validity of segment measured accelerations in comparison to front foot contact (FFC) ground reaction force (GRF) during the delivery stride for cricket pace bowlers. Eleven recreational bowlers completed a 30-delivery bowling spell. Trunk- and tibia-mounted inertial measurement units (IMUs) were used to measure accelerations, converted to force, for comparisons to force plate GRF discrete measures. These measures included peak force, impulse and the continuous force–time curve in the vertical and braking (horizontal) planes. Reliability and validity was determined by intra-class correlation coefficients (ICC), coefficient of variation (CV), Bland–Altman plots, paired sample t-tests, Pearson’s correlation and one-dimensional (1D) statistical parametrical mapping (SPM). All ICC (0.90–0.98) and CV (4.23–7.41%) were acceptable, except for tibia-mounted IMU braking peak force (CV = 12.44%) and impulse (CV = 18.17%) and trunk vertical impulse (CV = 17.93%). Bland–Altman plots revealed wide limits of agreement between discrete IMU force signatures and force plate GRF. The 1D SPM outlined numerous significant (p < 0.01) differences between trunk- and tibia-located IMU-derived measures and force plate GRF traces in vertical and braking (horizontal) planes. The trunk- and tibia-mounted IMUs appeared to not represent the GRF experienced during pace bowling FFC when compared to a gold-standard force plate.

Epidemiologic Comparison of Pitching Mechanics, Pitch Type, and Pitch Counts Among Healthy Pitchers at Various Levels of Youth Competition

To determine differences among healthy pitchers at various levels of competition regarding pitching history, pitching mechanics, and prevalence of breaking pitches. Demographic, anthropometric, pitching history, and kinematic data were collected on healthy youth pitchers using dual orthogonal high-speed video analysis. Players were grouped by maturity level (9 to 12 [prepubescent], 13 to 15 [pubescent], 16 to 17 [mature], and 18 to 22years [adult]). Groups were compared regarding pitch counts, pitching mechanics, and use of breaking pitches. Mechanics were assessed for favorable observational parameters (e.g., closed foot orientation at foot-strike) and measurable parameters at cocking, foot-strike, and ball release (e.g., knee flexion). Two hundred ninety-five pitchers were included. Sixty-three were 9 to 12, 130 were 13 to 15, 78 were 16 to 17, and 24 were 18 to 22years of age. Older pitchers threw more pitches per game (41, 52, 69, and 50 by age group; P < .001), per season (766, 975, 1,079, and 881; P= .017), and per year (901, 1,343, 2,064, and 1,302; P < .001). They were more likely to pitch for multiple teams, for more than 9months, in showcases, and in violation of pitch count recommendations. Older pitchers were more likely to maintain their hand on top of the ball, maintain closed shoulders at foot-strike, achieve hip and shoulder separation, and lead with their hips. Older pitchers achieved greater relative stride-length, greater knee flexion at front-foot contact, and increased lead hip flexion at ball release. Pitchers began throwing curveballs and sliders at 12.6 and 13.5years, respectively. As pitchers age, they throw more pitches per game, per season, and per year and are more likely than younger pitchers to violate pitch count recommendations. Older pitchers tend to pitch with improved mechanics and velocity. The proportion of pitchers throwing breaking pitches increases with age, with the greatest increase occurring between ages 12 and13. Level II, cross-sectional study.

Determination of the vertical ground reaction forces acting upon individual limbs during healthy and clinical gait

In gait lab, the quantification of the ground reaction forces (GRFs) acting upon individual limbs is required for dynamic analysis. However, using a single force plate, only the resultant GRF acting on both limbs is available.The aims of this study are (a) to develop an algorithm allowing a reliable detection of the front foot contact (FC) and the back foot off (FO) time events when walking on a single plate, (b) to reconstruct the vertical GRFs acting upon each limb during the double contact phase (DC) and (c) to evaluate this reconstruction on healthy and clinical gait trials.For the purpose of the study, 811 force measurements during DC were analyzed based on walking trials from 27 healthy subjects and 88 patients. FC and FO are reliably detected using a novel method based on the distance covered by the centre of pressure. The algorithm for the force reconstruction is a revised version of the approach of Davis and Cavanagh [24]. In order to assess the robustness of the algorithm, we compare the resulting GRFs with the real forces measured with individual force plates. The median of the relative error on force reconstruction is 1.8% for the healthy gait and 2.5% for the clinical gait. The reconstructed and the real GRFs during DC are strongly correlated for both healthy and clinical gait data (R2=0.998 and 0.991, respectively).

Kinematics of Baseball and Softball Catchers Throwing Down to Second Base

PURPOSE: To determine differences in torso and shoulder kinematics in baseball and softball catchers when throwing to second base from their stance or knees. METHODS: Nineteen baseball and softball catchers volunteered to participate (15.63 + 3.47 years; 165.91 + 12.50 cm; 67.71 +17.86 kg). Ten electromagnetic sensors were attached to participants to determine joint positions throughout the throwing motion. Participants were allotted an unlimited time to warm-up, in their catching gear to gain familiarity with the throwing surface. Each participant received a pitch from a pitcher and then completed a series of 10 (5 from knees and 5 from stance) throws to second base located regulation distance from home plate (25.6 m/38.8 m). The kinematic variables analyzed included trunk axial rotation, trunk lateral flexion, shoulder rotation, shoulder elevation, shoulder plane of elevation, pelvis axial rotation, and pelvis lateral flexion. Kinematic variables were analyzed at front foot contact (FC), maximum external rotation (MER), ball release (BR), and maximum internal rotation (MIR). RESULTS: Significant kinematic differences, at each event mark, were identified using a MANOVA followed by paired sample t test, p <.05, to determine the variables that were different between the two types of throws. At FC, trunk axial rotation, shoulder plane of elevation, shoulder elevation, pelvis lateral flexion, and pelvis axial rotation were significantly different. During MER significant differences occurred with trunk flexion, trunk lateral flexion, and pelvis lateral flexion. Ball release produced significant differences in trunk flexion, trunk lateral flexion, and pelvis lateral flexion. Differences at MIR included trunk flexion and trunk lateral flexion. CONCLUSIONS: When the catchers threw from the stance they had a greater degree of shoulder plane of elevation as well as shoulder elevation. Throwing from the stance allowed them to position their throwing arm in a more biomechanically efficient position of shoulder elevation and abduction. It is often assumed that catchers throw from the knees in attempt to produce a quicker release. The results of this study demonstrate that throwing from the knees results in significantly different kinematics than throwing from the stance which could ultimately predispose injury.

Correlation of Throwing Mechanics With Elbow Valgus Load in Adult Baseball Pitchers

Background Studies have shown that various biomechanical factors affect valgus extension overload during baseball pitching; yet, their relationships are not clearly defined, and factors such as trunk rotation and arm slot have not been investigated. Hypothesis The onset of trunk rotation, with other biomechanical variables that define sequential body motion, will significantly predict elbow valgus loading. Study Design Descriptive laboratory study. Methods Sixty-nine adult baseball players pitched off an indoor mound during 3-dimensional motion analysis to measure whole body kinematics and kinetics at 240 Hz. Thirteen biomechanical variables were calculated and extracted for regression analysis to investigate their associations with elbow valgus load. A 2-way analysis of variance compared valgus torques between pitchers with 2 onsets of trunk rotation (before and after front-foot contact) and 2 arm slot positions (overhand and sidearm). Results Six biomechanical variables had significant correlations (P < .02) with elbow valgus torque—with maximum shoulder external rotation, elbow flexion at peak valgus torque, and elbow valgus loading rate accounting for 68% of its variance. Reduced elbow valgus torques were associated with increased elbow flexion (P < .01). Players who initiated trunk rotation before front-foot contact had significantly higher elbow valgus torques than did those who rotated afterward (P = .02). Fourteen pitchers displayed a sidearm delivery and had significantly higher elbow valgus torques than did those with an overhand arm slot position. Conclusion Valgus torque at the elbow during baseball pitching is associated with 6 biomechanical variables of sequential body motion. A condition of late trunk rotation, reduced shoulder external rotation, and increased elbow flexion appeared to be most closely related to valgus torque. Sidearm pitchers appeared to be more susceptible than overhand pitchers to reduced elbow valgus torque. Clinical Relevance The biomechanical findings of this study offer scientific feedback for developing methods used to minimize the effects of valgus load on pitching-related elbow injuries.

Biomechanical Comparison of the Fastball from Wind-up and the Fastball from Stretch in Professional Baseball Pitchers

Background It has long been thought by many baseball coaches and players that throwing the fastball from the stretch is more stressful to the shoulder and elbow than throwing the fastball from the wind-up. However, no research has compared the biomechanics of these 2 pitch variations. Hypothesis There are differences in shoulder and elbow kinetics, kinematic position at front-foot contact, timing, and ball velocity between the 2 pitching variations. Study Design Controlled laboratory study. Methods Twenty-eight professional baseball pitchers (aged 22.1 ± 2.8 years) pitched fastballs from both the wind-up and stretch positions in an indoor laboratory setting. Three-dimensional motion-analysis systems were employed to capture the pitching motion. Kinetic variables, kinematic variables at lead-foot contact, and temporal variables of the 2 pitching variations were compared. Results There was no significant difference between the 2 pitch variations for the kinetic, kinematic, or temporal variables. The difference between the ball velocities was statistically significant, but the mean difference was only 0.2 m/s. Conclusions The pitching biomechanics between the wind-up and stretch fastball showed no statistical differences in joint kinetics, kinematics, or timing, and clinically insignificant differences in ball velocity. Clinical Relevance The current results suggest that pitching the fastball from the stretch is not necessarily more stressful to the shoulder and elbow.