The isolated effect of balance training on muscle strength of the flexors a
nd extensors of the knee, without accompanying strength training, has not b
een addressed in the past. Effects of a balance training program alone were
compared to a strength training program. Balance and strength training wer
e performed by 15 persons each for 6 weeks including 12 training units of 2
5 min. Balance training was performed on instability training devices such
as rolling board, mini trampoline and large rubber ball. The 15 persons of
the strength training group trained on machines for leg curls and on leg pr
esses for 25 min per unit. Measurements for balance were performed with one
-leg balance on a narrow edge and a tilting stabilometer for 30 s; maximum
isometric strength was measured using an isokinetic device for each leg sep
arately. The muscular balance between dominant and non-dominant leg was cal
culated. Strength gain was similar for the flexors and extensors in both gr
oups. One-leg balance improved after balance training (P < 0.01) with a 100
% increase over the strength training group (P < 0.05) and the stabilometer
test for each person in the balance (P < 0.01), but not in the strength tr
aining group. In the balance group the initial difference between right and
left diminished. The results indicate balance training to be effective for
gain in muscular strength, and secondly, in contrast to strength training,
equalisation of muscular imbalances may be achieved after balance training
.