Postural muscle responses in the spinal cord injured persons during forward reaching

To compensate for postural muscle function loss spinal cord injured (SCI) p eople have to use parts of the sensorimotor system which are still intact. In this study, postural control was investigated in high and low thoracic S CI people and in able-bodied controls, using a bimanual forward-reaching ta sk. Muscle activity was recorded bilaterally from the erector spinae (ES) a t level L3, T9 and T3, latissimus dorsi (LD), ascending part of the trapezi us muscle (TPA), serratus anterior (SA), sternocostal head of the pectorali s major (PM) and the oblique abdominal muscles (OA) by means of surface ele ctromyography. Sitting balance was monitored by measuring the changes in th e location of the centre of pressure (CP) using a force platform. Muscle ac tivity analyzed in different phases of the movement showed that SCI people adopt different postural adjustments to face the balance changes due to the reaching movement. SCI people make alternative use of non-postural muscles like the LD and TPA to maintain their sitting balance.