The goal of neurorehabilitation is to optimize recovery, minimize compensations, and increase the intensity of skill practice¹. The human brain and body are extremely efficient at finding ways to accomplish tasks after an injury. However, even though the task gets accomplished, it might not be the best for your recovery.
For example, if someone is trying to walk after a stroke, they will often lean to their stronger side and then swing their weaker leg forward in order to take a step. This is one way of moving forward, but clearly not the most efficient way to walk.
In order to optimize recovery for a client after a neurological injury, we want to create the right environment and provide the assistance necessary to complete the task without unnecessary movements, in other words, minimize compensations.
Furthermore, it is not enough to accomplish this task once or twice, it requires a high level of repetition and challenge while practicing this skill, in order to make a positive and permanent change towards recovery.
One method used in neurorehabilitation to create a more optimal environment, to provide the appropriate assistance, and to improve a client’s postural control, is the body-weight supported treadmill. The body-weight supported treadmill training allows therapists to give their clients the necessary support when completing many different tasks such as standing, balance training, stepping, reaching and walking.
Walking: A Complex Whole Body Activity
Human locomotion combines multiple body systems and is incredibly complex. Your body unconsciously allows you to do all of the following:
- Bipedal progression of the centre of mass with dynamic equilibrium (i.e. moving your body forward and upright)
- Adapts to destabilizing factors from an anticipatory and reactive perspective (i.e. reacting to things in your way and things you didn’t anticipate)
- Utilizes coordinated synergies of upper limbs, trunk, head and lower limbs
For example, think about the last time you walked from your car to your home. During that walk you stepped out of your car, moved around your vehicle, stepped onto the sidewalk or path, climbed up several steps, and then walked through your front door and into your home.
Think about the amazing number of movements that took place without one conscious thought of how you were moving your legs, placing your steps, or adjusting for different environments.
Here is a schematic representation of gait cycle with stance (red) and swing (yellow) phases showed in the above line, whereas the line drawn in middle reported the gait cycle of the contralateral limb with swing (light blue) and stance (blue) phases.
Posture and Walking
Before you even start walking, your neurological system prepares. We have three ways in which we get ready for movement.
- Early postural adjustments (-600 to -200ms before the movement) help to create adequate mechanical conditions for the expected (planned) perturbation (action)².
- Anticipatory Postural Adjustments (-200ms to 0) minimize the negative consequences of a predicted postural perturbation³.
- Anticipatory Synergy Adjustments (ASA’s) modify the stability (reproducibility) of performance variables4.
All of these anticipatory systems are influenced by body alignment, amount of practice, and velocity of the movement, which are all variables incorporated into body-weight support treadmill training.
Body weight supported treadmill training will directly increase the demand placed on the postural control mechanisms of your body and thus the production of anticipatory postural adjustments. This means that using the body-weight supported treadmill training helps to prepare your body to achieve the right alignment and posture to walk.
The Central Pattern Generator (CPG)
Once you have started walking, your neurological system has a network of neurons within your spinal cord which helps to generate rhythm and the locomotor pattern5.
Sensory information from a variety of sources within the visual, vestibular and proprioceptive systems are utilized by the CPG to keep you walking smoothly6.
Using BWSTT to Improve Walking
During body weight supported treadmill training, the client is partially suspended in a harness either from the ceiling or from an apparatus frame. This helps to reduce the client’s overall weight bearing and provides postural stability.
It also enables the integration of the client’s postural control and stepping in a safe, variable, dynamic task specific environment7 either over the ground or on a treadmill. The amount of support can be gradually decreased as postural control, balance, and coordination begin to improve.
At Propel Physiotherapy, we use the LiteGait system for body weight support in combination with a treadmill, to provide body-weight supported treadmill training for many of our clients with neurological injuries. The effects are safe, cumulative, non-invasive.
The Evidence for Body Weight Supported Treadmill Training
Body weight supported treadmill training is considered one of the newest evidence-based clinical approaches to locomotor rehabilitation, enabling task-specific training, thereby inducing activity-dependent neuroplasticity8. A recent Cochrane Review concluded that body weight support treadmill training improved walking velocity and endurance in individuals post-stroke who were independent ambulators9.
Currently, body weight supported treadmill training lacks statistically significant effect in the randomized controlled trial research literature due to the variability of client populations and treatments used with body weight supported treadmill training. However, prospective observational cohort studies are reporting statistically significant effects and body weight supported treadmill training is supported by neurophysiological evidence.
Research is still needed to define:
- Patient selection criteria and goals for body weight supported treadmill training
- Optimal speeds, duration of treatments, de-weighting amounts, and facilitation used during body weight supported treadmill training
Appropriate Body Weight Loading during BWSTT
In order to optimize the results of BWSTT, we need to know how much of the client’s weight should be supported by the harness. Although there has been no evidence for the ideal de-weighting, it has been shown that less than 30% of body weight support results in the most typical gait pattern10, which is what we are aiming for with this type of treatment.
It is widely accepted that limb loading (i.e. weight-bearing through the legs) plays a role in modulating CPG activity and influencing supraspinal structures11.Thus, we need to ensure that an appropriate amount of weight is being transferred through the client’s legs during BWSTT, so that the neurological systems are getting the full benefits of this training.
One of our primary systems involved in movement, called anticipatory postural adjustments (APA’s), have shown changes associated not only with mechanical aspects of a task but also with its perceptual aspects (i.e. fear of falling)12. By using the BWSTT there is an increased feeling of safety and decreased fear of falling, which allows for appropriate responses by the APA’s.
Using BSWTT to Increase Walking Speed
In addition to de-weighting and providing support to the client, using the BWSTT allows therapists to manually facilitate the client (hands-on assistance) at the feet, knees, and hips. This manual assistance improves the client’s gait patterning and decreases compensatory strategies. Together, these factors allow a client to improve their stepping ability and increase their walking speed.
Strong relationships have been established between walking speed and motor recovery, lower limb strength, and maximal ankle power13. In addition, fast walking improves symmetry in double and single-support proportions in persons post-stroke14.
The Central Pattern Generator (CPG) is speed dependent and has been shown to be inactive when stepping at slow speeds. With increasing walking speed, the CPG is activated and the automaticity of the gait pattern improves.
In a study by Hedel, Tomatis & Muller in 2006, they found that increased walking speed led to the following:
- Increased cadence (steps/minute) & stride length
- Decreased variability (i.e. improved consistency of stepping)
- Swing phase & single stance duration increased
- Double stance decreased
- Increased amplitude of hip joint movement
- Significant differences in ankle movement
Overall, this means that by increasing the client’s walking speed, we can improve a number of factors that help in neurological recovery and functional independence. By using the BWSTT, increasing a client’s gait speed is possible and safe, even for client’s who have begun their neurological recovery.
Although it seems that BWSTT is easy to apply to a wide variety of clients with neurological impairments, there are a number of factors that have a significant effect on the outcome of the BWSTT; and should be considered by the therapist before treatments. These factors include:
- Alignment and body posture / stability
- Upper limb (hand/arm) placement / dependence / role of light touch
- Use of de-weighting
- Footwear and Bracing
- Walking speed
- Manual Facilitation vs external assistance
- Intensity of the training
- Somatosensory information, vision, cutaneous input
- Previous training level of the client
BWSTT: More than just walking!
As with all physiotherapy treatments, the BWSTT needs to be tailored to a client’s specific functional goals and specific therapy treatment plan.
Because BWSTT provides improved safety and stability, it can allow clients to work on a wide variety of goals, such as stepping, balance exercises, and reaching tasks, and can result in numerous benefits.
By increasing time spent in standing and challenging clients in novel ways, BWSTT has been shown to have numerous benefits outside of walking, including modulation of neurologic tone, improving cardiovascular endurance, increased bone density, improved bowel and bladder function, and psychological benefits.
¹ Duncan et al, 2002; Borich et al, 2015; Wonsetler & Bowden 2017, Part 1 & 2
² Krishnan et al. 2011
³ Santos et al. 2010
4 Klous et al. 2011
5 Danner et al. 2015; McLean & Dougherty 2015; Dietz 2003; Brocard & Dubuc 2003
6 Danner at al. 2015; Rossignol, Dubuc et al. 2006; Dietz 2003
7 Barbeau 2003; Fong et al, 2009; Tansey 2010
8 Barbeau 2003)(Burnfield et al, 2016
9 Merholz et al, 2014
10 Hesse, Helm et al. 1997
11 Dietz & Duysens 2000; Barbeau 2003; Rossignol, Dubuc et al. 2006
12 Slijper 2000
13 Dodd & Morris 2003; Pepin, Ladouceur et al. 2003; Pepin, Norman et al. 2003
14 Wonsetler & Bowden 2017; Burnfield et al, 2016; Lamontagne and Fung 2004
- Neurological Injury RehabRedDot2019-03-01T18:32:28+00:00
- Stroke Recovery TherapyPropel Physiotherapy2019-03-01T18:32:37+00:00
Indoor bootcamps at Propel Physiotherapy Etobicoke are led by kinesiologist Sabrina La Rosa. Sabrina incorporates full-body exercises, adapted for people of all levels of fitness into her sessions. Participants work on improving cardiovascular and musculoskeletal fitness in a variety of movements, all while listening to some good music to improve morale.