Technique effects on upper limb loading in the tennis serve

2003 ◽  
Vol 6 (1) ◽  
pp. 76-87 ◽  
Author(s):  
B Elliott ◽  
G Fleisig ◽  
R Nicholls ◽  
R Escamilia
Keyword(s):  
1995 ◽  
Vol 11 (4) ◽  
pp. 433-442 ◽  
Author(s):  
Bruce C. Elliott ◽  
Robert N. Marshall ◽  
Guillermo J. Noffal

In the high-velocity tennis serve, the contributions that the upper limb segments' anatomical rotations make to racket head speed at impact depend on both their angular velocity and the instantaneous position of the racket with respect to the segments' axes of rotation. Eleven high-performance tennis players were filmed at a nominal rate of 200 Hz by three Photosonics cameras while hitting a high-velocity serve. The three-dimensional (3-D) displacement histories of 11 selected landmarks were then calculated using the direct linear transformation approach, and 3-D individual segment rotations for the upper limb were calculated using vector equations (Sprigings, Marshall, Elliott, & Jennings, 1994). The major contributors to the mean linear velocity of the center of the racket head of 31.0 m · s-1 at impact were internal rotation of the upper arm (54.2%), flexion of the hand (31.0%), horizontal flexion and abduction of the upper arm (12.9%), and racket shoulder linear velocity (9.7%). Forearm extension at the elbow joint played a negative role (-14.4%) and reduced the forward velocity of the center of the racket at impact.


Author(s):  
Brian D. Lowe ◽  
J. Steven Moore ◽  
Naomi Swanson ◽  
Lisa Perez ◽  
Margit Alderson

2002 ◽  
Vol 88 (1-2) ◽  
pp. 42-49 ◽  
Author(s):  
Ville Leinonen ◽  
Markku Kankaanpää ◽  
Osmo Hänninen ◽  
Olavi Airaksinen ◽  
Simo Taimela

2012 ◽  
Vol 28 (1) ◽  
pp. 93-98 ◽  
Author(s):  
M. M. Reid ◽  
Amity C. Campbell ◽  
B. C. Elliott

Tennis stroke mechanics have attracted considerable biomechanical analysis, yet current filtering practice may lead to erroneous reporting of data near the impact of racket and ball. This research had three aims: (1) to identify the best method of estimating the displacement and velocity of the racket at impact during the tennis serve, (2) to demonstrate the effect of different methods on upper limb kinematics and kinetics and (3) to report the effect of increased noise on the most appropriate treatment method. The tennis serves of one tennis player, fit with upper limb and racket retro-reflective markers, were captured with a Vicon motion analysis system recording at 500 Hz. The raw racket tip marker displacement and velocity were used as criterion data to compare three different endpoint treatments and two different filters. The 2nd-order polynomial proved to be the least erroneous extrapolation technique and the quintic spline filter was the most appropriate filter. The previously performed “smoothing through impact” method, using a quintic spline filter, underestimated the racket velocity (9.1%) at the time of impact. The polynomial extrapolation method remained effective when noise was added to the marker trajectories.


Author(s):  
Makamas Kumprou ◽  
Pipatana Amatachaya ◽  
Thanat Sooknuan ◽  
Preeda Arayawichanon ◽  
Thiwabhorn Thaweewannakij ◽  
...  

Background: Walking devices are frequently prescribed for many individuals, including those with spinal cord injury (SCI), to promote their independence. However, without proper screening and follow-up care, the individuals may continue using the same device when their conditions have progressed, that may possibly worsen their walking ability. Objective: This study developed an upper limb loading device (ULLD), and assessed the possibility of using the tool to determine the optimal walking ability of ambulatory participants with SCI who used a walking device daily ([Formula: see text]). Methods: All participants were assessed for their optimal walking ability, i.e., the ability of walking with the least support device or no device as they could do safely and confidently. The participants were also assessed for their amount of weight-bearing on the upper limbs or upper limb loading while walking, amount of weight-bearing on the lower limbs or lower limb loading while stepping of the other leg, and walking performance. Results: The findings indicated that approximately one third of the participants (31%) could progress their walking ability from their current ability, whereby four participants could even walk without a walking device. The amount of upper limb loading while walking, lower limb loading ability, and walking performance were significantly different among the groups of optimal walking ability ([Formula: see text]). Furthermore, the amount of upper limb loading showed negative correlation to the amount of lower limb loading and walking performance ([Formula: see text] to [Formula: see text]0.493, [Formula: see text]). Conclusion: The findings suggest the potential benefit of using the upper limb loading device and the amount of upper limb loading for walking device prescription, and monitoring the change of walking ability among ambulatory individuals with SCI.


2012 ◽  
Vol 21 (12) ◽  
pp. 2688-2692 ◽  
Author(s):  
H. Watson ◽  
A. Simpson ◽  
P. E. Riches

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