Three-Dimensional Torso Motion in Tethered Front Crawl Stroke and its Implications on Low Back Pain

Abstract

Low back pain is a common problem among competitive swimmers, and repeated torso hyperextension is claimed to be an etiological factor. The purpose of this study was to describe the three-dimensional torso configurations in the front crawl stroke and to test the hypothesis that swimmers experience torso hyperextension consistently across the stroke cycles. Nineteen collegiate swimmers underwent 2 measurements: a measurement of the active range of motion in 3 dimensions and a measurement of tethered front crawl stroke at their maximal effort. Torso extension beyond the active range of torso motion was defined as torso hyperextension. The largest torso extension angle exhibited during the stroke cycles was 9 ± 11° and it was recorded at or around 0.02 ± 0.08 s, the instant at which the torso attained the largest twist angle. No participant hyperextended the torso consistently across the stroke cycles and subjects exhibited torso extension angles during tethered front crawl swimming that were much less than their active range of motion. Therefore, our hypothesis was rejected, and the data suggest that repeated torso hyperextension during front crawl strokes should not be claimed to be the major cause of the high incidence of low back pain in swimmers.

Proximal to distal sequencing impacts on maximum shoulder joint angles and the risk of impingement in baseball pitching involving a scapular independent thoracohumeral model

“…The temporal variables and kinematic variables determined in the present study are within the ranges reported in literature 26,27,32,34,39 and the scapular motions and shoulder (scapulohumeral) joint angles presented here are consistent with the corresponding values in the literature 15,16 . Furthermore, the validity of measuring the mid‐torso joint angle with the same measurement system was tested and confirmed elsewhere 18 . The good agreement between the numerical results obtained in the present study and those in the literature indicates the validity of the present data collection method and the validity of the results obtained from our kinematic analysis of pitching motion.…”

“…15,16 Furthermore, the validity of measuring the mid-torso joint angle with the same measurement system was tested and confirmed elsewhere. 18 The good agreement between the numerical in the present study and those the literature indicates the validity of the present data collection method and the validity of the results obtained from our kinematic analysis of pitching motion.…”

“…Baseball pitching motion was recorded with an electromagnetic tracking device (Liberty, Polhemus). The procedure for setting up this system was similar to that in our previous studies 15,18 . This system consisted of a control unit, a transmitter, 8 sensors and a pen‐shaped sensor used for measuring its tip position called the stylus.…”

“…The procedure for setting up this system was similar to that in our previous studies. 15,18 This system consisted of a control unit, a transmitter, 8 sensors and a pen-shaped sensor used for measuring its tip position called the stylus. The transmitter generated a hemispheric magnetic field around it and the position and orientation of each sensor located within the field were measured at 240 Hz.…”

Relationship between using tables, chairs, and computers and improper postures when doing VDT work in work from home

“…Body landmarks for the thorax, scapulae, humeri, and joint coordinate systems for the shoulder were defined according to ISB recommendations 16) . Body landmarks for the pelvis and joint coordinate systems for the low back were defined according to a previous study 17) . Body landmarks for the head were chosen as the vertex of the head and the left and right tragions.…”