OBJECTIVE: Our objective is to investigate the effects of proprioceptive exercises rehabilitation on isokinetic strength and postural balance in athletes with sprain ankle. MATERIALS AND METHODS: The ankles of 16 subjects were tested: eight in the functional instability (FI) group and eight non-injured (NI) subjects in the control group. Subjects were asked to take part in a testing session. The test order for the postural stability and isokinetic strength tests was randomized to avoid learning or fatigue effects. The testing session started with a 5-minute warm-up. Subjects were then instructed to perform several lower body flexibility exercises. The test procedure consisted in static assessments, where single-limb (right and left) stance postural stability was assessed. Three practice trials were allowed for each subject. The assessment quantifies postural sway velocity while the athlete stands calmly on one foot on the force plate, for each leg. They were asked to stand as still as possible for 30s, upper limbs along the body. The subjects were requested to maintain balance with eyes open and then with the eyes closed on the firm surface. The sway velocity (in degrees per second) is given for all trials. Subjects were allowed a 1-minute rest between tests. The regime of isokinetic evaluation of dorsi-plantar flexions is concentric, with three successive speeds: slow (30°/s, reps 5), average (60°/s, reps 10), and fast (120°/s, reps 15), according to the protocol established by European Group for the development and the isokinetic research and the procedural guidelines. Relative moment of strength and times of acceleration and deceleration were calculated for each set of isokinetic testing repetitions per body side, muscle group and testing speed. RESULTS: The results of tests-retest and between both groups (injured vs. healthy) show that after eight weeks of proprioceptive work, significant increase of maximal strength, decrease in times of acceleration and deceleration at the level of plantar flexors and better stability of the injured limb at slow and average (P<0.05). For the healthy limb, improvements varying from 1 to 39% were obtained between test and retest on all the variables. However, these variations were not statistically significant. CONCLUSION: Proprioceptive training exercises can effectively stabilize an unstable ankle above for muscular and postural control. However, 8 weeks does not assess whether we have achieved maximum effect. In addition, we do not know to what extent these effects will continue over time. It would be interesting to later re-evaluate the athletes for the effect of this treatment, which is based on a proprioceptive training program on a year or more.