Verheyden et al conducted trunk exercise on a stable support surface with subacute stroke patients and reported that the functions of their trunks improved.
Bayouk et al observed that exercise on different support surfaces had a positive influence on subacute stroke patients.
Shumway- Cook et al noted that an unstable support surface stimulated the sensory system and the motor system more than a stable support surface, effectively changing postural ori- entation ability and aiding postural strategies. Until now,clinical evaluation tools for the assessment of stroke patients’ trunks have been used. However, changes in scores are difficult to interpret. And an additional problem is the potential subjectivity of the evaluators. In contrast, morphological study through computed tomography (CT) enables visual identification of muscles and is quantitative and objective.