No abstract

Background: Recreational athletes can select their desired footwear based on personal preferences of shoe properties such as comfort and weight. Commonly worn running shoes and cleated footwear with similar stud geometry and distribution are worn when performing sport-specific tasks such as a side-step cutting maneuver (SCM) in soccer and American football (hereafter, referred to as football). The effects of such footwear on injury mechanics have been documented with less being known regarding their effect on performance. Objective: The purpose of this study was to examine performance differences including peak ground reaction forces (pGRF), time-to-peak ground reaction forces (tpGRF) and the rate of force development (RFD) between football cleats (FB), soccer cleats (SOC), and traditional running sneakers (RUN) during the braking and propulsive phases of a SCM. Methodology: Eleven recreationally active males who participated in football and/or soccer-related activities at the time of testing completed the study. A 1 x 3 [1 Condition (SCM) x 3 Footwear (RUN, FB, SOC)] repeated measures ANOVA was utilized to analyze the aforementioned variables. Results: There were no significant differences (p > 0.05) between footwear conditions when comparing pGRF, tpGRF, or RFD in either the braking or propulsive phases. Conclusion: The results suggest that the studded and non-studded footwear allowed athletes to generate similar forces over a given time frame when performing a SCM.

Background: According to the National Collegiate Athletic Association (NCAA) there are over 34,000 athletes who compete in baseball at the collegiate level. These individuals spend countless hours training to improve their ability at bat performance by use of a batting tee and their position preference. However, during a game situation an athlete may swing a bat through their strike zone depending on the pitch thrown by an opposing pitcher. Objective: The aim of this investigation was to examine changes in swing kinematics throughout an individual’s strike zone in collegiate baseball players. Variables of interest included resultant velocity at ball contact (RVBC) and the angle of the bat at ball contact (BABC). Methodology: A series of markers were placed on the tee and bat to record swing kinematic variables of interest. Participants completed a brief two-minute on-deck warm-up protocol before being counterbalanced into completing 15 swing trials in various regions of their respective strike zone. A ten-minute washout period was completed followed by another 15 swing trials throughout their strike zone until there was a total of 45 swing trials, having 5 swing trials completed in each of the nine regions of the strike zone. Results: Repeated measures analysis of variance were used to examine swing kinematic variables of interest. Significant differences were found in RVBC along with significant differences in BABC (p<.05). Conclusions: Knowledge of this information can allow both athlete and sport coach to identify areas of weakness when addressing their hitting performance in preparation for an at bat situation during a game.

The use of vibrating platforms has become increasingly available, and popular at sports and rehabilitation institutes. Given the discrepancies in the literature regarding whole body vibration (WBV) and human reflexive responses, the purpose of this study was to examine the acute effects of WBV on postural response latencies, as well as associated electromyography measures of the lower extremities during balance perturbations. Reflexive responses during backward and forward balance perturbations were examined before, after, and 10 min after a bout of WBV. The findings suggest that following an acute bout of whole body vibration, muscle activity of the lower extremities is decreased during a reflexive response to an unexpected perturbation, and may be associated with faster reaction time.

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 0.05). The turf shoe x pitching mound interaction elicited significantly (P 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.