Muscle Activation Analysis with Kinematic Comparison Between Wind-Up and Stretch Pitching with Respect to the Upper and Lower Extremities

Megan M. Smidebush
2018
Baseball pitching is considered one of the most intense aspects within the game of baseball, as well as the most complicated dynamic throwing task in all of sports. The biomechanics of pitching have been heavily investigated in an attempt to identify optimal pitching mechanics in terms of pitching performance. Previous quantified upper body kinetics research has concluded that improved muscle strength is needed in attempting to achieve adequate upper body kinetics and efficient pitching
more » ... nces. Therefore, it is the purpose of this research study to compare the lower extremity muscle and upper extremity muscle activation patterns and kinematic variables associated with the curveball pitch and the fastball pitch when pitching from the wind-up and stretch position. Methods: Twelve skilled (competed at the NCAA collegiate level) baseball pitchers volunteered to be research subjects for this study. The participants were fitted with six surface electromyography (EMG) bipolar electrodes (Delsys Inc., Boston, Massachusetts) on the stride leg biceps femoris, medial gastrocnemius, ipsilateral side (throwing arm side) lower trapezius, upper trapezius, triceps brachii and biceps brachii. Each participant underwent maximum voluntary isometric contraction (MVIC) testing and then performed a pitching analysis. All EMG variables of interest were normalized using MVIC data and then compared between pitching types and pitch delivery. Shoulder rotation, shoulder abduction, elbow flexion and extension, elbow angular velocity and pelvis rotation were determined using motion capture (Motion Analysis Corp., Santa Rosa, SA) and Visual 3D software (C-Motion Inc., Germantown, MD). Paired t-tests and factorial analyses were performed using SPSS (p ≤ 0.05). Results and Discussion: Significant differences in the peak and mean muscle activity for the fastball and curveball pitched from wind-up and stretch position were observed. Significant differences in the kinematic variables between the fastball and curveball from the [...]
doi:10.13023/etd.2018.085 fatcat:7u2ziai2dnbhbpkjvc6skaqdde