Abstract - Isokinetic strength of the wrist in male aikido athletes
Background. Physiological research in general on aikido is scarce. Although many aikido techniques use extreme wrist flexion and extension that may lead to injury, no information is available on isokinetic strength of the upper extremities in aikido. Investigations on grip strength in martial arts and combat sports were mainly done in judo.
Aim. The purpose of the current study was to assess isokinetic strength of the wrist in recreational aikido athletes.
Material and Methods. Male aikido practitioners (n=13, 33.23±7.94 years, 180.62±8.03 cm, 80.31±13.10 kg) were recruited from a summer camp organized at Masaryk University. Subjects were tested on a Cybex Humac Norm at 120o, 180o and 240o/sec on both left and right wrists. A 3-way (Side x Movement x Angular Velocity) Anova with repeated measures on the second and third factors was used to assess the differences between right and left wrist extension and flexion by angular velocity. The level of significance for all analyses was set to an effect size of 0.20.
Results. There was a Movement x Angular velocity interaction (partial eta2 = 0.859, 95% CI: 0.451– 0.954). Simple effects analysis showed that wrist extension at 240o/sec (13.27 ± 3.18 Nm) was lower than wrist flexion (23.55 ± 6.66 Nm) at the same angular velocity (d = 2.050, 95% CI: 0.123 – 3.978) but the effect was not clear. Flexion at 120o/sec (31.64 ± 8.06 Nm) was higher than at 180o/s (28.50 ± 7.10 Nm) but the effect was also not clear: d = 0.430 (95% CI: -2.375 – 3.235).
Conclusions. Based on the current results, strength exercises for wrist extension in aikido athletes may be indicated, although a larger sample size will be needed to arrive at a definitive conclusion. More research is required with aikidokas varying in age and experience. Female practitioners should be investigated as well. Future research should also include the positions at peak torque. Aikidokas have weaker handgrip strength than other combat sports/martial arts athletes. Based on the current results, strength exercises for wrist extension in aikido athletes may be indicated, especially when using weapons, where extension is more important in hand techniques.