Contributions of the muscular torques and motion-dependent torques to generate rapid elbow extension during overhand baseball pitching

Abstract

Some studies have reported that overarm baseball pitching shows a proximal to distal sequential joint motion including a rapid extension of the elbow. It has been suggested that the rapid elbow extension just before ball release is not due to the action of the elbow extensor muscles, but the underlying mechanisms are not so clear. The purpose of this study was to determine the contributions of each joint muscular-and motion-dependent torques, including the upper trunk and throwing arm joints to generate the rapid elbow extension during baseball pitching. The right handed throwing motions of three baseball pitchers were recorded using five high-speed video cameras and the positional data were calculated using the direct linear transformation method. A throwing arm dynamic model of the upper trunk and throwing arm joints was then used, including 10 degrees of freedom, to calculate the throwing arm joint muscular-, throwing arm and upper trunk joint motion-, gravity-, and external forcedependent components that contribute to the maximum elbow extension angular velocity. The results showed that the rapid elbow extension was primarily due to the upper trunk counterclockwise rotation and shoulder horizontal adduction angular velocity-dependent torques. This study implied that the trunk counterclockwise rotators and shoulder horizontal adductors generate positive torques to maintain the angular velocities of the upper trunk counterclockwise rotation and shoulder horizontal adduction may play a key role in producing the rapid elbow extension.

Direct and indirect effects of joint torque inputs during an induced speed analysis of a swinging motion

“…The method proposed in this study quantifies both the direct and indirect effects of individual joint torque inputs in the generation of distal-point speed, and their use for evaluating performance, whereas previous studies showed only the direct effect of joint torques in actions such as the generation of elbow extension angular velocity Naito and Maruyama, 2008), of distal-point speed (Naito et al, 2017), and of angular velocities about the longitudinal axes of the upper arm and forearm segments (Naito et al, 2014) during overarm throwing and baseball pitching, and in the generation of knee extension angular velocity during soccer kicking motion (Naito et al, 2010).…”

“…Although previous studies decompose the MDT into several components in order to describe how particular kinematic features of segmental and joint movements affect the MDT contributions (e.g. Hirashima et al, 2008;Naito and Maruyama, 2008;Naito et al, 2010;Naito et al, 2017;Putnam, 1991Putnam, , 1993, kinematic analyses alone cannot reveal the mechanisms by which these movements induce effective joint torques.…”

“…The MDT plays a crucial role in the generation of angular accelerations that influence distal-point speed in high-speed swinging motions (Hirashima, 2008;Hirashima et al, 2008;Koike and Harada, 2014;Mimura, 2016a, 2016b;Naito and Maruyama, 2008;Naito et al, 2017;Putnam, 1991). Since the MDT is caused by product sums of angular velocities of individual segments, the MDT contribution will be relatively large when angular velocities of several segments increase before ball release or ball contact.…”

Development of inertial and novel marker-based techniques and analysis for upper arm rotational velocity measurements in tennis

“…The correlation between the slow motion serve and the normal speed serve was found to have similar trends in upper arm internal rotation (r = 0.8680, p \ 0.0001) using the Pearson's correlation test. The results from the videography, inertial gyroscopes, and MBVGs were time normalized for comparison [19,20] and are presented in the results and discussion section (see Sect. 3.2).…”

Generation Mechanism of Linear and Angular Ball Velocity in Baseball Pitching

“…In order to obtain large ball speed, the pitchers accelerate the ball by rotating their joints through exerting joint torques (e.g., [1]). Previous studies on high-seed swing motions based on multi-body dynamics have reported that motion-dependent term, which contains centrifugal force and Coriolis force, contributes largely to the generation of distal end points such as ball or hand in baseball pitching [2,3], bat head in baseball batting [4,5], racket head in tennis service [6], and so on.…”