Cerebral Palsy and Lokomat – Learning to Walk!

Robotic Assisted Body Weight Supported Treadmill Training (Lokomat) Of Neurologic Impaired Patients

'Children with normal development learn to walk; children with development delay and cerebral palsy states have to ‘learn’ to walk!'  - Dr Mal Hooper

Lokomat (Robotic Gait Assisted Walking) treadmill training is a task-specific rehabilitation strategy that enhances functional locomotion in patients with neurological impairments.

Gait ability is a complex motor activation pattern organized hierarchically, with the uppermost level (initiation of the movement) mediated through the primary cortex and the lowest levels (organization and execution of the movement) mediated through the spinal motor neurons.

There is evidence that innate pattern generators in the spine produce the newborn stepping. During the first year of development the corticospinal tracts growth, there is a transformation of this innate ability towards a normal plantigrade stepping.

The deficit induced by a central nervous system lesion depends on which group of cells is damaged: lesions of the upper motor neuron let some muscle contractions even with an altered highest cortical control. Lesions of the lower motor neuron result in flaccid paresis without the ability to recover some movements.  

Experiments conducted on spinalized cats demonstrated that treadmill walk was possible in this animal model suggesting evidence of a central gait pattern generator. Therefore central nervous system lesions produce different symptoms: paresis, somatosensory deficits which induce inactivity and loss of function. This inability to realize a movement combined with the neuroplasticity of the central nervous system may induce a secondary functional incapacity called the “learning non use”. Active repetitive stimulation is required! 

The Lokomat produces a constraint-induced movement therapy of a specific task the gait training with a pattern of muscle activation as physiologic as possible. The alternating ‘stance and swing phase’ of the Lokomat generates afferent inputs which stimulate the spinal gait generator inducing a motor reorganization and acquisition of forgotten skills. The partial body weight support allows patients to stand even with very weak muscles.  

The device includes a treadmill, a body weight support system and two lightweight robotic arms strapped to the patients legs. The Lokomat is fully programmable, hip and knee joint angles trajectories are permanently controlled by software to achieve a gait pattern as physiological and comfortable as possible. Treadmill speed and guidance assistance provided to the patient are also adaptable. Many repetitions are known to improve necessary to perfect a movement if the motor system is intact.

It should be more accentuated if the motor system is damaged and more repetitive movements are necessary to restore activity especially walking function.  

We reported the preliminary results of patients; we found that reflex stiffness and spasticity are significantly reduced; that range of motion, peak velocity and acceleration of voluntary movements are increased. Therefore the walking ability improves as well as independence.