The Effects of Footwear on Stride Length in Adolescent Baseball Pitchers

The baseball pitch is considered one of the most dynamic athletic motions. Due to its complexity, multiple variables are taken into consideration for risk of injury. Previous studies have investigated variables that influence factors of a baseball pitch such as fatigue and stride length; however, footwear has not been considered. This study’s objective was to examine whether or not baseball footwear on different surface inclinations altered stride length. Eleven adolescent pitchers (Age: 13.18 ± 1.72 yrs.; Height: 179.01 ± 15.72 cm.; Mass: 61.00 ± 14.66 kg) participated in this study throwing in four shoe-surface conditions: flat ground (FG) x molded cleat (MC), flat ground x turf shoe (TS), pitching mound (PM) x molded cleat, and pitching mound x turf shoe. A 2x2 repeated measure analysis of variance (ANOVA) was used to determine stride length with an alpha level set at p < 0.05

Effects of Playing Surface and Shoe Type of ACL Tears in Soccer Players

Anterior Cruciate Ligament injuries have become more common in athletes over the past decade which is believed to result from playing on more artificial turf surfaces. This study tested the playing surface theory by building upon a previous study conducted with Albany Medical Center which tested surface samples using an axial-torsion load frame located at Union College. The motion that causes most ACL noncontact injuries is replicated by the load frame which pushes and rotates a shoe against the playing surface and measures the torque it experiences. The foot position, normal load, degree of rotation and rate of rotation were set to comply with ASTM standards. Four types of soccer shoes: round studded, bladed studded, soft ground, and turf shoes were fit on to a prosthetic foot to be tested. Kentucky bluegrass, new and old artificial turf with rubber infill, and gym turf were the playing surfaces considered. Each combination of shoe type and playing surface was tested five times and the average of those five trials was analyzed. It was determined that natural grass provides the traction needed for game play without reaching dangerous torque levels and has appropriate cushion to limit impact joint injuries in players. In addition, round studded cleats provide traction and relatively low torque on both natural and artificial turf surfaces. The results will allow players to choose an appropriate shoe for the surface being played on and influence what types of playing surfaces are installed, ideally reducing the number of ACL injuries in soccer players

THE EFFECT OF TWO SPORT-SPECIFIC CLEAT PATTERNS ON PEAK PLANTAR PRESSURES DURING TWO RUNNING TASKS ON FIELDTURFTM

The purpose of this investigation was to examine the effect of two sport-specific cleat patterns (used interchangeably on FieldTurf ) on peak plantar pressures during two running tasks (side cut and cross cut) on FieldTurfTM. Protocols were designed to determine if the turf-specific outsole effectively dispersed peak pressures on certain regions of the foot to a greater degree than a multi-stud outsole. This study was also used to determine if one shoe type would produce faster times during maximal effort sprint trials. Testing was performed on volunteer collegiate and amateur level football and soccer players from The University of Western Ontario. A pressure distribution measuring system for monitoring loads between the foot and the shoe known as the Pedar Mobile System was used in this study to measure peak pressure and maximum force exerted during the cutting motions. Differences between the testing conditions were determined using paired samples t-tests. The analyses demonstrated significant differences between the turf shoe and the multi-stud shoe in peak pressure during both the side cut and the cross cut. The turf-specific shoe was found to reduce the loads in both tasks. No difference was found in maximal sprint effort trials. While the clinical significance of the differences found requires further study, the present findings suggest that turf-specific cleats do, in fact, reduce peak pressure in the forefoot to a greater extent than other types of cleated footwear on FieldTurfT

BIOMECHANICAL DIFFERENCES OF TWO COMMON FOOTBALL MOVEMENT TASKS IN STUDDED AND NON-STUDDED SHOE CONDITIONS ON INFILLED SYNTHETIC TURF

The purpose of this study was to examine kinematic and kinetic differences in three shoe conditions (traditional football shoes with natural and synthetic turf studs and a neutral running shoe) during two common football movements (a 180° cut and a land-cut movement) on infilled synthetic turf. Fourteen recreational male football players performed five trials in all three shoe conditions for a 180° cut as well as a land-cut maneuver. The kinematic and kinetic variables were analyzed with a 3 x 2 (shoe x movement) repeated measures analysis of variance (ANOVA, p\u3c0.05). Peak free moment was significantly greater for the land-cut trials (p\u3c0.001). Vertical GRFs were significantly greater for the land-cut trials (p\u3c0.001). A cleat x movement interaction was seen for time to vertical impact GRF (p=0.048). A cleat main effect was found for time to vertical impact between natural turf cleat and synthetic turf cleat (p=0.019). Vertical loading rate was significantly greater in land-cut trials. Peak medial GRFs showed a significant cleat x movement interaction (p=0.002). The results from this study suggest that land-cut movement elicit greater vertical GRF and vertical impact loadings rates. The running shoe had significantly less dorsiflexion range of motion (ROM) than the synthetic turf studs. A significant cleat main effect was found for peak eversion velocity (p=0.005). Post hoc comparisons showed that it was significantly smaller in shoe than that natural turf stud (p=0.016) and synthetic turf stud (p=0.002). In general, there was a lack of differences between the shoe conditions for GRFs and kinematic variables. For the 180° cut movement, natural turf studs produced lowest peak medial GRF compared to the synthetic turf studs and the shoe. The results from this study suggest that land-cut movement elicit greater vertical GRF and vertical impact loadings rates. In general, there was a lack of differences of GRFs and kinematic variables between the shoe conditions. For the 180° cut movement, natural turf studs produced lowest peak medial GRF compared to the synthetic turf studs and the shoe. Overall, increased GRFs, especially in combination with rapid change of direction and deceleration may increase the chance of injury

The Influence of Shoe and Cleat Type on Lower Extremity Muscle Activation in Youth Baseball Pitchers

Background: Baseball pitching is a dynamic movement where the lower extremities generate and sequentially transfer energy to the upper extremities to maximize ball velocity. The need for lower body muscular strength to produce adequate push-off and landing forces has been documented; however, the influence footwear and surface inclination has on muscle activation remains unknown. Objectives: Determine how pitching in molded cleats and turf shoes from a pitching mound and flat ground affects stride-leg muscle activation in youth baseball pitchers while determining percent activation during each pitching phase. Methods: Cross – sectional study analyzing mean muscle activity and percent activation of the vastus medialis, semitendinosus, tibialis anterior, and medial gastrocnemius on the stride-leg of 11 youth baseball pitchers when pitching fastballs. Results: Footwear did not significantly alter vastus medialis or semitendinosus muscle activation (P \u3e 0.05). The turf shoe x pitching mound interaction elicited significantly (P \u3c 0.05) greater mean muscle activity in the medial gastrocnemius and tibialis anterior from stride foot contact to maximum glenohumeral internal rotation. Molded cleats produced greater activation levels in the tibialis anterior on flat ground from stride foot contact (0.374 ± 0.176 mV) to ball release (0.469 ± 0.150 mV). Conclusion: Findings suggest footwear significantly alters the activity level of the ankle stabilizing musculature. Youth baseball pitchers and coaches should be cognizant of what footwear is worn on a pitching surface. Maximal activation of the tibialis anterior and medial gastrocnemius can ensure the stride leg is adequately stabilized to absorb the momentum generated by trail leg

Traction Characteristics of Cleated Athletic Shoes at Various Angles of Internal Rotation on Artificial Turf

As an alternative to natural grass playing fields, the installation of artificial turf surfaces has grown exponentially over the past several decades. Despite the growing popularity of artificial turf, little is known about the interaction between the player’s shoe and the turf surface. Previous research has sited the difficulty in maximizing performance (high traction), yet minimizing the risk of injury (low traction). Due to seemingly countless factors that affect the turf-shoe interaction, determining safe traction ranges for artificial turf is very difficult. Safe ranges between performance and risk of injury need to be found. The purpose of this study was to investigate whether traction characteristics vary based on a particular cleated athletic shoe on artificial turf at various angles of internal rotation during a linear translational motion. 4 U.S. Men’s size 12 cleated athletic shoes with a variety of stud styles from several different commonly used brands were tested on the artificial turf. Each cleated athletic shoe was set at various angles (0º, 30º, 60º, 90º) of internal rotation, and experienced linear translational motion while data was being collected. Significant differences were found within each cleated athletic shoe at various angles of internal rotation across all dependent variables (p=0.000). This could be attributed to a phenomenon termed the trench effect. There were no significant differences between cleated athletic shoes on artificial turf. Shoe-turf interactions are a very important consideration in athletics. This interaction is a determinant of the level of athletic performance and risk of injury. Shoe-turf interaction is a very stochastic process, and results should only be evaluated within the context of the test conditions

A Kinematic Comparison Of Shoulder And Elbow Dynamics Influenced By The Shoe-Surface Interface In Youth And Adolescent Baseball Pitchers

From 1994-2006, 1.5 million baseball injuries were treated within emergency departments across the United States while the upper extremity was the second most commonly injured body part. Although it has been determined that pitch count, pitch type and pitching mechanics are the main contributors to upper extremity pain in baseball pitchers, footwear has not been considered a potential factor. Therefore, the purpose of this study was to determine how baseball-specific footwear [turf shoes (ts) and molded cleats (mc)] affects the shoulder and elbow dynamics of youth and adolescent pitchers during an overhead pitch on various surface inclinations [flat ground (fg) and pitching mound (pm)]. The aims of the study were to investigate the effect of wearing baseball footwear on (1) upper extremity kinematic variables, (2) lower extremity muscle activity, and (3) torso and pelvis kinematics while on various inclined surfaces. Eleven healthy male right-handed baseball pitchers (age: 13.18 â± 1.72 years; height: 179.01 â± 15.72 cm; mass: 61.00 â± 14.66 kg) who wore baseball footwear for 1 hour per week while actively playing completed the study. Participants threw ten fastballs in all counterbalanced conditions (mc x fg, mc x pm, ts x fg, ts x pm). A 3d motion capture system collected full-body kinematics and electromyography (emg) data. Three pitches thrown without marker obstruction in each condition were analyzed and averaged for each participant. A 2x2 [2 surfaces (fg, pm) x 2 footwear (ts, mc)] repeated measures anova was used to compare the variables of interest. Results shono significant differences were seen for ball velocity. Significant differences were seen across surface conditions and footwear conditions (p\u3c0.05). Pitching in ts elicited a greater amount of shoulder external rotation while mc increased the amount of shoulder internal rotation. Pitching from a mound also placed more stress on the shoulder and elbow relative to flat ground. Stride leg ankle plantarflexion (pf) exhibited significant differences across surface and footwear. The ts shoa greater pf position relative to the mc. These results are consistent in the ankle stabilization muscles (g & ta) showing significantly greater muscle activity in the ts versus mc

Effect of soccer footwear on landing mechanics

Lower-extremity injury is common in soccer. A number of studies have begun to assess why specific lower-extremity injuries occur. However, currently few studies have examined how footwear affects lower-extremity mechanics. In order to address this question, 14 male (age: 22.1±3.9 years, height: 1.77±0.06m, and mass: 73.3±11.5kg) and 14 female (age: 22.8±3.1 years, height: 1.68±0.07m and mass: 64.4±9.2kg) competitive soccer players underwent a motion analysis assessment while performing a jump heading task. Each subject performed the task in three different footwear conditions (running shoe, bladed cleat, and turf shoe). Two-way analyses of variance were used to examine statistical differences in landing mechanics between the footwear conditions while controlling for gender differences. These comparisons were made during two different parts (prior to and following) of a soccer-specific jump heading task. A statistically significant interaction for the peak dorsiflexion angle (P=0.02) and peak knee flexion angle (P=0.05) was observed. Male soccer players exhibited a degree increase in dorsiflexion in the bladed cleat while female soccer players exhibited a three-degree reduction in peak knee flexion in the bladed cleat condition. Other main effects for gender and footwear were also observed. The results suggest that landing mechanics differ based upon gender, footwear, and the type of landing. Therefore, training interventions aimed at reducing lower-extremity injury should consider utilizing sport-specific footwear when assessing movement patterns. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Using the Continuous Wavelet Transform to Characterize Differences Between Impact Signals from Non-Cleated and Cleated Turf Shoes

The continuous wavelet transform was used to characterize the time-frequency differences between impact forces from non-cleated and cleated turf shoes among male football athletes who perform cut and run activities. This research is significant because it elucidates how athletes experience different impact force and torque frequency content based on the type of shoe they are wearing. The complex Morlet mother wavelet was used to analyze all ground reaction force and vertical ground reaction moment signals to create time-frequency power spectrum plots. For each signal, a statistical confidence interval was calculated and displayed along with the cone of influence caused by edge effects. These methods were used to ensure the results to be analyzed were genuine and not a result of edge effects due to the use of the wavelet transform technique or noise from the data acquisition system. To compare and contrast the power spectrum of both cleated and non-cleated turf shoes, a phase angle relationship was computed to find the correlation between the two signals, and then each wavelet transform was sliced at particular frequencies ranging from 11 Hz to 65 Hz to view this correlation at 5 Hz intervals. By calculating the percent difference between the maximum peaks along frequency slices ranging from 11 Hz to 65 Hz, it was possible to identify and characterize differences and similarities between force and moment signals. In general, but not always, results show that the magnitudes of impact forces are directly related to the magnitudes of low frequency content between 11 Hz and 60 Hz, and the maximum values of the frequency percent differences vary within each GRF component and the vertical moment plots. For this study, non-cleated turf shoes increase the magnitude and duration of the response from the vertical ground reaction force and this is also particularly true for the medio-lateral ground reaction force and the ground reaction vertical moment of the same style of shoe

Development and Evaluation of Instrumented Soccer Equipment to Collect Ankle Joint Kinematics in the Field

Ankle sprains commonly occur during athletic competition and result in traumatic injury to the lateral ligament complex. Ankle ligament sprains are the most common injury type for intercollegiate soccer players and athletes that sustain lateral ankle sprains may lose game and/or practice time, have recurrent sprains due to ankle instability, incur proprioceptive deficits, and be at an increased risk of ankle osteoarthritis. The high rate of ankle injuries among soccer athletes demonstrates a need for novel and advanced data collection methodologies to reduce the incidence of lateral ankle sprains and improve injury prevention interventions. The purposes of this study were to develop instrumented soccer equipment to collect ankle joint kinematics in the field; establish the reliability and validity of a kinematic assessment using instrumented equipment during athletic maneuvers; and identify laboratory maneuvers that elicited game-like demands from athletes. Wireless orientation sensors were integrated into soccer shin guards and turf shoes. The instrumented equipment collected ankle joint kinematics during simulated athletic maneuvers in the laboratory and field. The simulated athletic maneuvers in the laboratory are commonly performed by soccer players and have been previously studied. Maneuvers included drop landing, drop jump, stop jump, and jump-stop cut. Drop landing and drop jump maneuvers resulted in poor to excellent reliability and very good to excellent validity. The stop jump maneuver resulted in poor to fair reliability and excellent validity. The jump-stop cut maneuver resulted in poor to excellent reliability and very good validity. The soccer-specific field maneuvers were jump header, moving jump header, and slalom. All maneuvers resulted in poor to good reliability. To identify laboratory maneuvers that elicited game-like demands, laboratory maneuvers of varied demand were compared to field maneuvers. Drop landing and drop jump maneuvers from a 60 cm platform elicited a similar response to the jump header maneuver. A jump distance recommendation for the stop jump maneuver was not warranted because jump distance did not significantly alter landing biomechanics. The instrumented equipment collected reliable and valid ankle joint kinematics in the sagittal plane and are a promising technology for in-game data collection and injury prevention