Partial Weight Bearing Gait Therapy and Use of LiteGait Training

By: Amir H. Seif-Naraghi, PhD

The most exciting technique aimed at recovery of locomotor behavior following neurological damage combines the benefits of repetitive task specific training with stimulation of spinal stepping generators. Supported or lite gait therapy has been called by many names and successfully applied to a variety of disorders and patient functional levels in both chronic and acute settings.

It has been referred to as Body Weight Supported Treadmill Training (BWS-TT)1, Partial Weight Bearing Gait Therapy (PWB-GT) 5, Laufband Therapy2 and more recently Partial Body Weight Support (PBWS)4.

Despite the name changes, the techniques remain the best alternative for retraining walking after most neurological disorders such as patients post CVA1,3, TBI5, SCI2, and CP. The techniques simply involve provision of corrected upright position and the stimulus of a treadmill. The therapist may facilitate corrected gait patterns to generate afference inputs that stimulate both spinal processes and cortical regions involved in control of walking.

Partial Weight Bearing (or Lite) Gait Therapy requires a supportive fall-free environment that corrects posture, assists with balance, and reduces weight bearing. Coupled to the stimulus of a motorized treadmill and facilitated by the therapist, patient experiences many repetitions of well-formed gait patterns.

Both spinal and cortical processes are expected to be stimulated by the resulting rhythmic sensory input that closely resembles that of proper walking. The walking speed dictated by the treadmill is increased, the support decreased and facilitation from the therapist reduced, as therapy progresses and the patient can be challenged incrementally more.

GaitKeeper walking surface is raised to allow therapist to sit in an integrated chair and easily reach the patient limbs to facilitate while LiteGait supports the patient.

Figure 1. GaitKeeper walking surface is raised to allow therapist to sit in an integrated chair and easily reach the patient limbs to facilitate while LiteGait supports the patient.

Animal and human studies on spinal cord injury has resulted in an understanding of spinal rhythm generators or central pattern generators (CPG)(6,7). The severed spinal cord of cats can be stimulated to generate the stepping portion of walking in the absence of cortical input. The key factor in successful activation of CPG appears to be afference input which results from intensive repetition of well formed gait patterns.

The first clinical protocol is extracted from the notion that passive imposition of proper gait patterns on a patient will stimulate well coordinated stepping at the spinal level. This author calls it, Protocol C for CPG based protocol. The patient is supported over a treadmill in a manner that allows the therapist(s) to passively guide his/her legs through walking movements at a pace close to normal walking rates of about 2 mph.

The increased training speed allows for an increase in the magnitude and intensity of the main trigger of CPG (i.e., elongation of Iliopsoas at the end of the stance phase) and hence a stronger stimulus to the spinal locomotor mechanism.

While position sensors measure this velocity dependent afference, the force sensors measure the loading and unloading during the middle of the stance phase. Proper weight shifting and loading of the weak side is also necessary for the success of this therapeutic approach. While some reserchers suggest this fast paced protocol as the only use of PWB-GT, others reserve this fast paced passive protocol for complete or near complete SCI patients.

On the other end of the spectrum of protocols, is Protocol B for ‘Brain Learns’ or motor learning. This requires setting up an environment in which the desired motor behavior could be practiced repeatedly and progressively more challenging and complete. The goal of all over-ground traditional gait therapy for nearly all patients is to allow them to practice walking as close to normal as possible given their specific condition.

While traditional gait therapy may lead to compensatory patterns of walking for a patient with a weak side or excessive use of an assistive device, PWB Gait Therapy provides the environment for safe and supported yet rhythmic and upright ambulation to be practiced repeatedly. Even without the benefit of the therapist’s intervention, the stabilization of the upper body and relief of weight bearing improves the many patients’ ability to take more steps with better step-through patterns.

This aspect of PWB-GT, i.e., improvement of patient output both in quantity and quality of practice, provides the basis for a different use of Lite Gait therapy than that based on stimulation of CPG. While Protocol B maybe applied by many clinicians to all diagnosis including TBI, this author believe it to be most appropriate to deal with muscle weaknesses, posture and balance deficit, orthopeutic issues and prosthetic retraining.

Since the patient is provided the support and correction of the device but left to walk at his/her own speed on the treadmill as he/she would have over ground, this protocol counts on the repetition and shear increase in the output of the patient due to reduced degree of difficulty, fear and safety concerns, to improve outcome

The vast difference between the two protocols of use only emphasizes the value of this environment. On one hand, supported patients could be subjected to facilitated treadmill walking at near normal rates in order to stimulate spinal processes.

On the other hand, patients walk at their selected rate while safely supported over a slow moving treadmill which provides enough of a stimulation to challenge them to improve gait function though motor learning and forced use concepts. The most commonly used PWB-GT protocol is protocol A, as in the best protocol for neurological patients. It bridges the gap between these two extremes.

In many CVA, TBI, and SCI patients with gait deficits, the patient selected rate of walking is accompanied by patient’s inefficient patterns of ambulation. In order to teach correct walking patterns, the patient is challenged with a speed above the selected rate so as to modify or break down any existing abnormal patterns. Considering the need for active participation by the patient in order to benefit from motor learning and the task specificity of the PWB-GT environment, clinicians facilitate or passively move only when patient’s own functional level fails him/her.

Although the speed is increased toward the normal walking rates of CPG protocol, it is only when the patient level of participation allows it. The guiding principal in Protocol A is that the patient must practice good gait patterns with the help of the device, the stimulus of the treadmill and the help of a therapist. Clinically resources for protocol C (often three therapist to stabilize and move patient limbs) are not available. Protocol A offers a successfully tested compromise for neurological patient.

Describing these techniques with terms such as weight support or patial weight has led to some confusion with the orthopedic concepts of unloading or de-weighting. The orthopedic devices need only reduce the weight bearing and joint loading. These devices can readily be used for performance enhancement as in sport medicine and orthopedic patients to increase intensity of practice without the impact or joint loading.

The patient’s posture is not controlled. The limb loading is reduced and kept at a constant level. The patient is free to climb stairs, sit down or lose balance, while having less loading on the joints. The environment described by the Barbeau and colleagues1 is a positional control device with the weight support changing during the dynamics of gait so that the upper body position can be maintained.

LiteGait is used to transfer the skilled learned over treadmill to over-ground without the improper biomechanics of a walker or a can

Figure 2. LiteGait is used to transfer the skilled learned over treadmill to over-ground without the improper biomechanics of a walker or a cane.

LiteGait by Mobility Research is the means to provide posture, balance, and weight bearing assistance to neurological patients of any functional level so that they can obtain proper upright position for ambulation on and off the treadmill (refered to GaitKeeper walking surface). LiteGait is designed to allow correction of the biomechanics by providing asymmetric support where the patient needs it.

Two rigid independent double support points, one above each shoulder, allows asymmetric support of right and left as well as front and back of the body. These can be used to enforce a corrected walking position on nearly all neurological patients.

A lift mechanism allows for handling of the more difficult patients as well as modulation of the amount of support and weight bearing. As patient progresses, the rigidity o the arms can also be reduced. The unique FlexAble support allows the clinician to dial in a travel range for the center-of-mass from 0 to 5 inches. This allows a gradual increase of demand on posture and balance mechanism.

The GaitKeeper walking surface is specially designed high torque motorized treadmill with a movable control panel. The zero start high torque feature means it is strong enough to start slow with the patient standing on the belt and work through patient’s tone. The movable controls allows a single clinician access not just to the patient but also to the controls of the treadmill.

LiteGait sets up a controlled walking environment for the patient and the therapist. It allows a gradual increase in the degree of difficulty of walking. In its easy mode, patient is supported sufficiently to achieve upright position, GaitKeeper belt moves slowly and the therapist assists (facilitates or passively moves) the patient so that good gait patterns can be formed.

As the patient improves, the bar is set higher by increasing the speed of the treadmill, decreasing the support, and reducing the therapist input. At every stage, the common factor is that the patient must be practicing good gait patterns. This form of intervention provides the best chance for patients of any diagnosis and functional level to improve their gait.

For more information, contact:
Amir H. Seif-Naraghi, PhD
VP of Research & Education
www.litegait.com
www.litegait.org
Mobility Research
444 West Geneva
Tempe, AZ 85282
480-829-1727

 

References:

  1. Visintin M, Barbeau H, Korner-Bitensky N, Mayo NE. A new approach to retrain gait in stroke patients through body weight support and treadmill stimulation. Stroke 1998; 29: 1122-1128
  2. Wernig A, Muller S, Nanassy A, Cagol E. Laufband therapy based on "Rules of Spinal Locomotion" is effective in spinal cord injured persons. European Journal of Neuroscience 1995; 7: 823-829
  3. Hesse S, Bertelt C, Jahnke, MT, Schaffrin A, Baake P, Malezic M, Mauritz KH.. Treadmill training with partial body weight support compared with physiotherapy in nonambulatory hemiparetic patients. Stroke1995; 26: 976-981
  4. Trueblood PR. Partial body weight treadmill training in persons with chronic stroke. NeuroRehabilitation. 2001;16(3):141-53
  5. Seif-Naraghi AH, Herman RM. A novel method for locomotion training. Journal of Head Trauma Rehabilitation 1999; 14: 146-162.
  6. Barbeau H, McCrea DA, O’Donovan MJ, Rossignol S, Grill WM, Lemay MA. Tapping into spinal circuits to restore motor function. Brain Research Reviews 1999; 30: 27-51.
  7. Barbeau H, Rossignol S. Recovery of locomotion after chronic spinalization in the adult cat. Brain Research 1987; 412: 84-95.
  8. for a complete bibliography visit www.LiteGait.com