The main purpose of the specific balance training was to
improve balance ability through training with unstable
surfaces, such as the Swiss-Ball (Perform Better Inc.) and
the Trial-T1 half-sphere (TRIAL s.r.l., Forlı`, Italy,
45 9 23 cm). The following balance training was performed by all of the subjects. First, subjects performed 8
sets of 20 s of Swiss-Ball kneeling hold balancing with
30 s of recovery; subjects were told to maintain balance on
the Swiss-Ball while keeping their knee at an approximate
angle of 90 . Then, they performed 6 sets of 20 repetitions
of the two-handed chest pass balance exercise with 30 s of
recovery; subjects were instructed to maintain balance on
the Trial-T1 half-sphere while performing 20 chest passes
to a teammate in front of them at a distance of approximately 10 m. Finally, subjects performed 10 sets of 30 s
per limb of the single-leg balance, with 10 s of recovery
between repetitions and alternating the supporting lower
limb. Subjects were instructed to maintain balance on the
Trial-T1 half-sphere while keeping a knee angle of
approximately 120 .