Pelvic and shoulder movements in the frontal plane during treadmill walking in adults with stroke

Analysis of lateral displacement (LD) in the frontal plane during gait could provide information about asymmetric impairments and balance disorders for patients with stroke. The purpose of this study was to quantify the LD and lateral acceleration (LA) of the shoulders and pelvis of patients who were hemiparetic and walking at slow, natural, and fast speeds on a treadmill, and to compare the results with those for control subjects walking at similar speeds. A convenience sample of 10 patients with chronic stroke and 10 control subjects participated in this study. A videographic system was used to record the positions in the frontal plane of markers placed on the seventh cervical vertebra (shoulder level) and on the posterior iliac spines (pelvis level). Then, the LDs and LAs were calculated. The temporal parameters of the gait cycle were also determined using foot switches. The symmetry in the LAs and in the time spent in single stance was computed. Results showed that patients with stroke had larger LDs and LAs than the control group when walking at similar speeds. Results for patients with stroke also indicated that LAs were greater on the paretic side, whereas single stance percentages were greater on the nonparetic side. The data were almost symmetric for the control subjects. These findings indicate that the pelvis and shoulder of a patient with stroke have different rhythmic activity in the frontal plane compared with those of control subjects performing at similar speeds.