Physical mechanism
The principle of the locomotion/treadmill therapy is based on the plasticity of the central nervous system (CNS) and on the physical mechanism of the neurological gait control.  Cortical plasticity is the ability of the motor cortex to modify neuronal circuits by altering representational maps, changing synapse morphology or changing axonal trajectories, amongst others.1  These changes can be driven by task-oriented therapy or experience.

Neural spinal control circuits (network of interneurons) defined as ‘Central Pattern Generators’ (CPG) are able to activate the muscles of the weight-bearing leg as well as the non-weight-bearing or swinging leg, independent of cortical control.  CPG’s, therefore, control neural gait.

Impulses from the mechanical receptors (pressure/load) in the sole of the foot as well as impulses from the extension and pressure respondent neuromuscular spindles, receptors of joints, and tendons in the hip joint, initiate the main walking pattern or locomotor program.  The impulses are afferently transmitted through sensory nerve fibres, processed by the CPG in the spine and the adequate activity is efferently transmitted through motor nerve fibres to the muscle.  Intensity and temporal sequencing of the muscle activation can be measured and graphed electromyographically (EMG).

For activating the appropriate muscles relevant for walking, it is essential to initiate both the load on the sole of the foot and the afferent input from the hip region.  With the aid of a suspension harness and partial load, even patients without the ability to stand are able to activate the mechanical receptors of the foot soles.  At the same time, the moving surface of the treadmill provokes an extension of the hip region of the weight-bearing leg.  The associated activation of the extension receptors initiates the locomotor program.

Effectiveness
Treadmill training improves both the intensity and coordination of the muscle activations required in incomplete spinal cord injuries.^2,3,4,5 In complete spinal cord injuries, the effectiveness of the training was too marginal to achieve a significant improvement in the EMG-amplitude and in the autonomous gait movement.

In patients with an interference in the gait ability after a stroke or traumatic cerebral injury, the autonomous gait ability can be achieved sooner with treadmill training than with the traditional physiotherapy treatment.^6,7 In patients with hemi-paresis, both course of movement and the gait symmetry as well as the duration of the stance phase are improved with the treadmill training.8  Treadmill training has also been shown to improve the walking pace.⁹

Advancements
In heavily afflicted patients, the traditional treadmill therapy requires physical exertion of the physiotherapist in guiding the feet of the patient, which often results in complaints of back pain as the therapist is constantly in a crouching or crooked posture.  Due to the uncomfortable posture, the therapists are unable to perform treatments in succession. Trials prove that the frequent and repetitive exercise of the locomotor patterns in particular lead to an improvement of the gait ability. LokoHelp has been developed to automatically guide the feet of the patient and is therefore of benefit to both the physiotherapist and the patient.  LokoHelp simulates natural gait ability by guiding the patient’s feet and thus modulating the duration of the stance and swing phases.  The LokoHelp design facilitates a gait typical roll motion and a proper load.  Since balance and posture also play a role in the locomotor program, the therapist should attend to the proper relocation of the centre of gravity and the knee-bend/extension axle. Any corrections can be communicated verbally or implemented manually and do not inflict any physical stress on the therapist.

A completed clinical trial compared the effectiveness of the LokoHelp with the traditional treadmill training, with regards to the posture control of the patient as well as the therapeutic effort. The study shows clear positive results in favour of LokoHelp.

Recently, it has been shown that with regards to the achievement of gait ability and other functional parameters of patients after a stroke, the locomotor training supported by apparatus combined with physiotherapy is significantly superior to a traditional physiotherapeutic treatment of the same duration.^10,11

It is expected that the positive results in favour of the locomotor therapy supported by apparatus are causally ascribed to the higher training intensity.

Literature: