A bit newer publication
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A Comparison of Wrist Angular Kinematics and Forearm
EMG Data for an Elite, Intermediate and Novice Standard
Tennis Player Performing a One-handed Backhand
Groundstroke
Jonathan A. Glynn 1
, Behzat B. Kentel 2
, Mark A. King 1+
and Sean R. Mitchell 2
1
School of Sport and Exercise Sciences, Loughborough University, Loughborough, LE11 3TU, UK.
2
Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough,
LE11 3TU, UK.
(Received August 12 2007, accepted September 2 2007)
Abstract. Wrist angular kinematics (flexion/extension) and electromyography (EMG) data of a one-handed
tennis backhand groundstroke were compared for an elite, intermediate and novice standard tennis player.
For this purpose, synchronisation of the data with respect to ball impact time was achieved by a system of
wireless and wired triggers and receivers. All three players maintained wrist extension for the 0.6 second
period centred on ball impact. The elite and intermediate player struck the ball with the wrist extended by an
average of 10o
from neutral alignment whilst moving towards flexion. After ball impact the wrist moved
back towards and further into extension. The novice player was characterised by fluctuations in the wrist
flexion/extension angle prior to ball impact with the wrist extended on average by 30o
from neutral alignment
at impact. The wrist of the novice palyer moved back towards and further into extension after ball impact,
although less than for intermediate and elite players. For the elite player, peak EMG levels for the wrist
flexors and extensors were reached consistently 0.05-0.1 seconds prior to ball impact. Wrist flexor EMG
levels for the intermediate and novice players peaked on average 0.02 seconds after ball impact and extensor
EMG levels peaked at ball impact. For the novice player, both flexor and extensor EMG data exhibited
fluctuations consistent with the wrist kinematics data. Previously cited conditions that predispose a novice
player to injury were not observed in this study. Given current injury mechanism theories, the data from this
study suggests that the susceptibility of a player to tennis elbow injury cannot be established by generic skill
level alone. Tennis players need to analysed as individuals.
Keywords: backhand, tennis, elite, intermediate, novice, wrist kinematics, EMG.