The Clinical Progression

Gait training is central in the rehabilitation of individuals with neuromotor disabilities. In clinical circles, there is considerable debate over whether gait training is best performed over a treadmill or over ground. Is one intervention more effective than the other? The research on this topic is inconclusive at best. What we do know, however, is that studies comparing the two gait training approaches show that both yield good outcomes. So when and why would you choose one over the other, or is there a place for both?

I like to explore this by drawing from a variety of clinical resources – current knowledge of the principles of motor learning and neuroplasticity, the available research and clinical expertise. Each adds a valuable perspective.

Motor Learning and Neuroplasticity

Motor learning and neuroplasticity are the overarching guides to almost any therapy intervention. Our current understanding of motor learning, especially in children, is based on dynamic systems theory (DST), referred to in practice as the “task-oriented approach.”^1,2,3 This approach recognizes the importance of both the task and the environment in the creation of efficient motor solutions. It also recognizes that we learn best when we work on skills that relate directly to a daily activity or a task that interests us or motivates us.

Additionally the amount of skill practice is of paramount importance.^4,5,6 Schmidt and Lee, who are leaders in the field of neuro-rehabilitation, emphasize what is often taken for granted: “Clearly, more learning will occur if there are more practice trials. Perhaps we do not need to say any more about the amount of practice than this: In structuring the practice session, the number of practice attempts should be maximized.”⁴ Best-selling author and journalist Malcolm Gladwell notes in his book Outliers that the more you practice, the better you get at anything. In fact, he talks about the magic of 10,000; someone who dedicates 10,000 hours to a particular skill, playing the violin, for example, will master it.⁷ In the world of motor learning and function-based programs where we’re not concerned with complete mastery, we speak of 2,000 practice trials in order to learn a new skill.⁸

Learning through practice is also the main way known to science of stimulating neuroplastic changes or reorganizing the remaining healthy tissue in a damaged brain. In their paper, Kleim and Jones describe ten principles of experience-dependent neural plasticity that, when applied in practice sessions, help to guide the formation of new neural connections in the brain. These principles emphasize the importance of continued, intense use of the neural circuitry and task-specific and repetitive skill practice.⁹

Clearly, providing intervention that is true to the principles of DST is essential. So when we think about the best approach to gait training we must consider how to provide the best environment for motor learning and neuroplasticity to take place.

Treadmill Gait Training

The clinical environments for gait training are either on the treadmill or over the ground. An understanding of what each entails is necessary for making the clinical decisions necessary to guide successful gait training.

The idea for using a treadmill to regain ambulation abilities started with research in animal models. Here researchers noted that after months of practice, cats and rats with severed spinal cords were able to take steps with their hind limbs on a treadmill if their hindquarters were supported.¹⁰ Manipulating the intraspinal circuits of cats and rats with repetitive, treadmill driven stepping has since provided a foundation for approaching human gait recovery.^{11,12,13,14, 15}

As with the cat and rat models, body-weight support (BWS) is essential in gait rehabilitation, especially over a treadmill. An individual at the start of gait training is debilitated with weakness, poor coordination and balance issues. In conventional rehab without BWS, these factors contribute to fatigue and fear of falling, therefore limiting the length of the practice session. But harnesses, slings and saddles that support an individual’s weight change this dramatically. By decreasing the load through the lower extremities there is less fatigue and fear of falling which allows longer, more intense practice sessions as well as an earlier start at rehab for individuals with significant disabilities. Off-weighting also gives the individual a chance to concentrate on stepping and less on balance and weight-bearing. Additionally, BWS allows the clinician to step away and focus on guiding a typical gait pattern, reciprocal arm swing and trunk mobility.

Combine BWS with the treadmill and you now have what clinicians recognize as a safe and structured walking environment. The treadmill belt drives the gait cycle affording a high degree of energy-efficient gait repetition and re-patterning work. A patient supported on the treadmill is able to take more steps in the same amount of time and achieve a higher walking velocity compared to over-ground walking. This provides the practice and intensity needed for neuroplastic changes early on in recovery.^{12,16,17,18,19,20,}  

Treadmill training then seems most appropriate for those in the acute and early stages of rehab. Research demonstrates that non-ambulatory individuals, or those with more involved impairments, perform better on a treadmill as opposed to supported over-ground walking.^21,22,23,24 McCain, looking at a group of adults post-stroke concludes: “The application of locomotor treadmill training with partial body weight support before over-ground gait training may be more effective in establishing symmetric and efficient gait in acute rehabilitation.²⁵

Over-ground Gait Training

What then is the role of over-ground gait training? Over-ground gait training involves negotiating an actual environment--rooms, hallways, paths and parks. Stepping is self-generated requiring muscle activation to drive ground-reaction forces and the weight-shifting of limbs resulting in better gait kinematics and functional walking speeds.^26,27,28 This is perfect for individuals in the later stages of rehab who can walk or who have impairments that are less severe. For these people, over-ground gait training is a way to continue motor learning opportunities that are challenging, intense, problem-solving and task-specific in the clinic. It is also a chance to work on balance, postural control and community navigation--opportunities not afforded by treadmill practice.^29,30,31

Clinical Progression

A clinical progression is perhaps the best way to describe the complementary nature of treadmill and over-ground gait training. As we know from motor learning theory and research, gait interventions for people with neurological disabilities should be task-specific and challenging with frequent practice opportunities. As an individual’s capabilities improve, moving from the supported treadmill to over-ground walking provides a perfect way to maintain the level of intensity and practice that motor learning requires.^{12,27, 32} I find the following clinical progression sequence is best supported by the research:

1. Body-weight supported treadmill training for practice re-patterning gait and improving neuromuscular capabilities.

2. Over-ground walking in a clinical environment with over-ground assistive devices to encourage client-initiated movement.

3. Integrating over-ground walking skills into actual task-specific environments such as the home and community. This involves negotiating various environments, changing walking pace and stopping and starting.

Clinical Progression Case Studies

The following case studies--an individual with traumatic brain injury (TBI) and an individual with cerebral palsy (CP)--provide great illustrations of this clinical progression in gait rehabilitation.

Sean Carter

Sean was a teenager when he sustained a TBI from a drunk-driving accident. This left him paralyzed and unable to walk. After four years in a wheelchair he began an aggressive program of gait training. In this short video clip his therapist, Dr. Karen McCain, tells Sean’s recovery story and how he progressed, with intense practice, from the treadmill to over-ground gait training in the clinic. She particularly emphasizes the importance of supported over-ground practice for gait recovery.

In this next video, we can see Sean ambulating over-ground outdoors. It is amazing to see the progress he made with rehabilitation applying the principles of motor learning and neuroplasticity.

Payton White

Payton has a diagnosis of cerebral palsy and initially presented with limited ambulation ability from lower extremity rotational deformities, contractures and spasticity. On first coming to VIP Rehab, a private practice offering intensive 3-hour daily sessions, Payton walked in the Lokomat, a robotic treadmill, for 30 minutes. His therapist, Donna Nasielski, PT noted that the treadmill provided Payton with much needed intense stepping repetition, weight-bearing through the lower extremities and his upright posture improved circulation. Because of Payton’s increased spasticity it was difficult for him to take steps, so the Lokomat was good because it kept him walking. This video clip shows Payton working on stepping in the Lokomat:

After the Lokomat, Payton transferred to the Rifton Pacer, an assistive gait device, for over-ground ambulation. As a result, his hip flexion contractures stretched out and he increased his step length from 3 inches to 10-11 inches. The Pacer’s saddle additionally provided enough separation for his legs that scissoring was no longer an issue.

Now Payton is working on side stepping and walking outdoors using the momentum from a slight downhill ramp seen here:

Conclusion

Demonstrated by the case studies and supported by research, the progression from the treadmill to over-ground gait training is a successful gait rehabilitation approach for individuals with neuromotor disabilities. Through considering the research findings and the premises of motor learning and neuroplasticity, treadmill gait training and over-ground gait training are combined effectively. The work on the treadmill gives an individual the opportunity to learn (re-learn) reciprocal stepping patterns in the acute phases of recovery and disability. The positioning offered by the various body-weight support devices contributes to longer practice sessions and optimal environments for motor learning to take place. As the individual improves, supported over-ground ambulation continues the learning process with increasingly challenging and task-specific environments.

References

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10. Barbeau H, Rossignol S. Recovery of locomotion after chronic spinalization in the adult cat. Brain Res. 1987; 412(1):84-95.

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