Objective

To study the acute effect of static and dynamic stretching on the knee muscle strength and postural capacity in athletes.

Patients and methods

Fifteen judokas performed 2 stretching protocols (static and dynamic) on the muscles of both lower limbs with an interval of 48 hours in a random order. An evaluation of the dominant knee muscle strength with an isokinetic dynamometer CybexNormII was performed before and after each stretching protocol in a concentric mode at a speed of 60 and 180°/s.

Each athlete was evaluated on the Satel ^® plateform in static conditions open and closed eyes in the two trials.

This evaluation was performed after a standard warm-up protocol (5 minutes on a bicycle ergometer) and a minute after the stretching protocol.

The parameters were monitored: mediolateral (Long X) anterior-posterior deviations (Long Y) of the plantar center of pressure and the total area.

Results

Five judokas, with mean age of 21.3 ± 2.3 years, mean height of 177.8 ± 8.8 cm, and mean weight of 74.6 ± 14.6 kg participated in this study.

We objectified an increase in the mean peak torque (PC) after the dynamic stretching protocol compared to the initial assessment at the speed of 60°/s in both the flexor ( P < 0.001) and extensor ( P = 0.005) muscles. Furthermore, we found a decrease in the PC after the static stretching protocol at the same speed with a statistically significant difference in both flexor ( P < 0.001) and extensor ( P < 0.001) muscles.

Discussion/Conclusion

On one hand, this study confirms the value of dynamic muscle stretching on the gain of the isokinetic strength of the knee muscles. On the other hand, a deterioration of the postural following capacity after both static and dynamic stretching was observed.