This article describes a new portable digital data acquisition module, which has been developed for the measurement and temporary storage of signals from mobile biomechanical phenomena in the field. The module’s performance capabilities include 32 available analog input channels, a 12-bit analog-to-digital converter, maximum throughput of 57,040 samples per second, and a temporary storage capacity of up to 253,000 samples. The portable power source is a rechargeable battery pack, and the appropriate sensors and sensor signal conditioning circuits are supplied by the user to meet the particular needs of the phenomena under study. The size of the signal conditioning, battery pack, and data acquisition module is such that it can be carried in a belt pack worn by a subject under study and weighs less than 3 kgf. To facilitate the use of the module, operating software complements the hardware. The software is comprehensive functionally in that routines are provided for acquiring data, for transferring acquired data serially to a general purpose microcomputer for storage on magnetic media, and for monitoring equipment setup. Further, the software is versatile in that the various parameters necessary to customize the operation to a particular application may be readily set. Finally, the menu-driven structure ensures that the software is easy to use.
Jeff Newmiller and Maury L. Hull
Arnel L. Aguinaldo, Janet Buttermore and Henry Chambers
High rotational torques during baseball pitching are believed to be linked to most overuse injuries at the shoulder. This study investigated the effects of trunk rotation on shoulder rotational torques during pitching. A total of 38 pitchers from the professional, college, high school, and youth ranks were recruited for motion analysis. Professional pitchers demonstrated the least amount of rotational torque (p = .001) among skeletally mature players, while exhibiting the ability to rotate their trunks significantly later in the pitching cycle, as compared to other groups (p = .01). It was concluded that the timing of their rotation was optimized as to allow the throwing shoulder to move with decreased joint loading by conserving the momentum generated by the trunk. These results suggest that a specific pattern in throwing can be utilized to increase the efficiency of the pitch, which would allow a player to improve performance with decreased risk of overuse injury.
Bing Yu and James G. Andrews
The purpose of this study was to investigate relationships between free limb motions and triple jump performance. The subjects were 13 elite male triple jumpers. Three-dimensional videographic data were collected using a direct linear transformation technique with panning cameras. Changes in the velocity of the whole body center of gravity (G), changes in the whole body angular momentum about G, changes in the velocity of G due to free limb motions, and changes in the whole body angular momentum about G due to free limb motions were determined for each of the three support phases. Free limb motions were associated with decreases in the forward horizontal velocity of G and increases in the vertical velocity of G and significantly influenced changes of the corresponding velocity components of G when the changes were large. The free limb motions also created some angular momentum components about G during each support phase but did not significantly influence the changes of the corresponding angular momentum components of the whole body. Neither the changes in the three velocity components of G nor the changes in the three angular momentum components of the whole body about G due to free limb motions were significantly related to the actual distance of the triple jump.
The purpose of the study was to determine the mechanical variables that are related to successful post-flight somersaulting performance of the Roche vault. The 23 Roche vaults performed during the 2000 Olympic Games were filmed by a 16-mm camera operating at 100 Hz. The 2-D direct linear transformation technique was used for spatial calibration. Approximately 60 frames were digitized per vault. The method of Hay and Reid (1988) was used to develop a deterministic model to identify the mechanical variables that govern linear and angular motions of the vault. Correlational analysis was used to establish the strength of the relationship between the mechanical variables identified and the judges’ scores. Significant correlations indicated that the higher judges’ scores were negatively related to five mechanical variables and positively related to seventeen variables in the model. The normalized horizontal displacement of body center of mass (CM) from the knee grasp to the peak of post-flight was the best single predictor of the judges’ score and accounted for 50% of variation in the judges’ score. Finally, the landing point deductions and the official horizontal distance of post-flight collectively accounted for 86% of the variance in the judges’ scores.
Brock Laschowski, Naser Mehrabi and John McPhee
Paralympic wheelchair curling is an adapted version of Olympic curling played by individuals with spinal cord injuries, cerebral palsy, multiple sclerosis, and lower extremity amputations. To the best of the authors’ knowledge, there has been no experimental or computational research published regarding the biomechanics of wheelchair curling. Accordingly, the objective of the present research was to quantify the angular joint kinematics and dynamics of a Paralympic wheelchair curler throughout the delivery. The angular joint kinematics of the upper extremity were experimentally measured using an inertial measurement unit system; the translational kinematics of the curling stone were additionally evaluated with optical motion capture. The experimental kinematics were mathematically optimized to satisfy the kinematic constraints of a subject-specific multibody biomechanical model. The optimized kinematics were subsequently used to compute the resultant joint moments via inverse dynamics analysis. The main biomechanical demands throughout the delivery (ie, in terms of both kinematic and dynamic variables) were about the hip and shoulder joints, followed sequentially by the elbow and wrist. The implications of these findings are discussed in relation to wheelchair curling delivery technique, musculoskeletal modeling, and forward dynamic simulations.
. Broker * Robert J. Gregor * 11 1990 6 4 394 403 10.1123/ijsb.6.4.394 Research A Compact Portable Data Acquisition Module for Sports Biomechanics Research Jeff Newmiller * Maury L. Hull * 11 1990 6 4 404 414 10.1123/ijsb.6.4.404 Intrasubject Variability of Upper Extremity Angular Kinematics in the
Jill L. McNitt-Gray
, in particular, sports biomechanics. I would like to thank the American Society of Biomechanics for the 2016 Jim Hay Memorial Award and the Journal of Applied Biomechanics for this opportunity to share some of the insights we, as members of the University of Southern California Biomechanics Research
/author level ( HEFCE, 2015 ). In sports biomechanics, Knudson ( 2013a ) reported 25% agreement between international scholars’ nominations of influential research and most highly cited (total citations and citations per year) review and research articles. Individual Publication Metrics The growing rejection of
Scott W. Ducharme and Richard E.A. van Emmerik
important for the development of adaptive movement behaviors. Recent reviews on variability in sports biomechanics have provided clear evidence for the role of variability in optimizing performance ( Bartlett, Wheat, & Robins, 2007 ; Davids, Glazier, Araujo, & Bartlett, 2003 ; Preotoni et al., 2013
Ben Serrien, Maggy Goossens and Jean-Pierre Baeyens
.M. , & Bartlett , R.M. ( 1990 ). A kinematic comparison between elite fast bowlers and college fast-medium bowlers . Proceedings of the sports biomechanics section of the British Association of Sports Sciences . Leeds, UK . Glazier , P.S. ( 2017a ). Could sports biomechanics provide the missing pieces to