Planned Gait Termination in Cerebellar Ataxias

This study set out to characterise the pattern of planned gait termination in a sample of patients with cerebellar diseases. The gait termination phase was recorded, using a motion analysis system, in ten patients with primary degenerative cerebellar disease and in ten controls. The subjects were instructed to walk at different gait speeds and to stop in response to an acoustic signal. Time\u2013distance parameters (step length, step width, double support duration, time-to-slow, stopping time, centre of mass velocity and number of steps) and stability index-related parameters (distance between the \u201cextrapolated centre of mass\u201d (XCoM) and centre of pressure (CoP)) were measured at both matched and self-selected gait speeds. At matched speed the patients, compared with the controls, showed a reduced step length, a greater first and second step width and used more steps to stop. At self-selected speed, almost all the parameters differed from those of the controls. Furthermore, the patients showed an increased stability index, suggesting that they need to maintain a \u201csafety margin\u201d between the XCoM and CoP during the gait termination. Patients develop a series of compensatory strategies in order to preserve balance during planned gait termination, e.g. increasing their step width and number of steps. Ataxic patients need to maintain a safety margin in order to avoid instability when stopping. Given the potential risk of falls when stopping, walking ataxic patients may benefit from a rehabilitation treatment focused on preserving and improving their ability to terminate gait safely

Turning strategies in patients with cerebellar ataxia

Turning while walking is a common but demanding task requiring modification of the motor program from linear walking to lateral turning and it is associated with a high risk of falls. Patients with cerebellar ataxia have unstable gait and report a high incidence of falls. In the present study, we investigated the motor strategies adopted by ataxic patients when performing turns of different degrees and directions of rotation. Ten ataxic patients and 10 controls were analyzed while performing 30\ub0/90\ub0 turns to the right/left. We recorded the number of completed turn tasks, the number of steps needed, and the time taken to complete the task, time\u2013distance parameters and the onset of head, trunk and pelvis reorientation. The ataxic patients were less able to complete 90\ub0 turns, displayed a greater stride width, shorter step length, and greater number of steps when turning, and were unable to flexibly adjust their stride width across the turning task. The duration of the turning task and of the segmental reorientation did not differ from control values. Our findings indicate that ataxic patients have more difficulties in performing large turns and adopt a series of compensatory strategy aimed at reducing the instability associated with turning, such as enlarge the base of support, shorten the step length, increase the number of steps, and use the \u201cmulti-step\u201d rather than the \u201cspin-turn\u201d strategy. Given the high risk of falls related to this task, it would be useful to include turning training in the rehabilitation protocol of ataxic patients