GAIT SYMMETRY AFTER STROKE: DO CEREBRAL HEMISPHERES INFLUENCE EQUALLY?

Abstract

Stroke responds to a high death rate and is the world major impairment cause. The risk of going through this condition increases 22% after the age of 55 years and increases further 13% every 5 years. The brain damage brings loss of selective muscle control and primitive locomotor patterns may arise to reinforce stability. This adaptation causes asymmetry and is related to the constant postural balance compensation need. It is known that the cerebral hemispheres have different motor tasks. The right one is responsible for the motor control while the left one controls the spacial orientation. The aim of this cross-sectional 3D gait analysis study was to assess stride width and gait speed symmetry among stroke survivors (SS), using the Symmetry Index (SI), and compare those with left (LBD) from those with right brain damage (RBD). A sample of 32 SS (47yo±17,32) and 32 able-bodied (25,09yo±3,77) were divided in three groups: LBD (16, 43,87yo±17,90), RBD (18, 49,76yo±16,83) and Able-bodied (32). Results showed less stride width symmetry and slower gait (0,5m/s±0,2) at RBD while LBD symmetry was not different from Able-bodied (p=0,074). The LBD group showed better recovery and motor compensation bringing their symmetry next to those able-bodied. Less stride width asymmetry leads to less center of mass sway and benefits dynamic postural balance. The more asymmetrical LBD group showed a slower gait as a compensation. Differences in symmetry bring diferente level of stability challenges. It is important to keep that in mind when managing stroke survivors in rehabilitation programmes.