Treadmill Base: A Solution for Gait Practice

Body-weight-supported treadmill training (BWSTT) is widely recognized as a promising intervention to improve ambulation for individuals with neuromotor disability, with diagnoses including cerebral palsy¹, spinal cord injury² and stroke³.

With the external support of a device, we provide the postural control that clients lack so they are able to concentrate their physical energies on reciprocal step-taking. This external support may not only provide balance support but may also decrease the load on the limbs by providing weight bearing assist, thereby reducing energy expenditure and fatigue and enabling increased step-taking practice ⁴. Additionally, body weight support provides a safe support system, decreasing risk of fall and injury, and reducing the strain on the therapist who can focus on the person’s gait rather than on providing physical support. For children with cerebral palsy, BWSTT can be particularly effective for those classified as Level IV and Level V on the Gross Motor Function Classification System (GMFCS)⁵.

One research study documented the effects of exercise training using BWSTT with an 18-year-old non-ambulatory young man with cerebral palsy who was not receiving physical therapy. BWSTT provided him with a safe and feasible option to be physically active on a regular basis. Data showed that both his exercise time and speed increased with practice, and that his physiological cost index decreased. Even self-care and mobility showed improvements.⁶

In another study, a non-ambulatory 9-year-old child with spastic tetraplegic cerebral palsy gained the ability to take up to 60 steps on the treadmill while supported in that position. Additionally, after four months of BWSTT, he could walk short distances with minimal assistance over ground, using a rolling walker.⁷

The Rifton Pacer with dynamic upper frame used in combination with the treadmill base offers the additional benefit of motion in the vertical and horizontal planes. In normal gait, the center of gravity moves side-to-side and up and down as an individual transfers weight between the lower extremities to the stance limb, and to enable clearance of the swing limb. By providing for this motion in the support device this may further reduce the physical effort required to actively shift the center of gravity and achieve steps. Observing a student walking in the Pacer with the dynamic upper frame and multi-position saddle, one therapist commented, “The dynamic body weight seat allowed enough natural gait and rhythmic motion that significant changes in walking patterns were noticed immediately.”

In 2010, the Academy of Pediatric Physical Therapists put together a guideline for BWSTT.⁸ They recommend using the least amount of body weight support required to maintain postural alignment, and the least amount of manual assistance required for stepping. Their recommendations regarding frequency, session length, speed of treadmill, and episodes of treatment, based on the research available at that time, are shown in Table 1. More recent robotics research also suggests the value of adding resistance (counter-forces) to enhance muscle activation.⁹ ¹⁰

Table 1 APTA Guideline for Use of Body-Weight-Supported Treadmill Training

Those of us who are involved in gait practice in the therapy community acknowledge the value of gait training over a treadmill for health benefits and for potentially accelerating motor skill attainment in children with cerebral palsy and general developmental delay ¹¹, and perhaps more so when this is complemented with home-based BWSTT opportunity.¹² Research suggests that BWSTT decreases the overall metabolic cost of walking ¹³. However we must also recognize the role of overground gait practice. A study with healthy adults demonstrates that normal ground reaction forces (GRF) are not present during treadmill walking ¹⁴.

Research confirms that the body weight support and the moving treadmill surface influences muscle activation and timing and the overall gait pattern, such that over ground walking practice may offer a better carryover to functional gait with longer and faster strides. ¹⁵ ¹⁶ ¹⁷ A comparison between treadmill and overground training is offered in Table 2.

As one reviewer states, “Continued emphasis on progressive reduction of body weight support along with adding concurrent overground walking practice to a treadmill training protocol may increase the intensity of training and assist with carryover of improvements to overground walking.” ¹⁸

One distinct advantage of the Rifton Pacer upper frame used in combination with the treadmill base is that it can also be used over ground in the same treatment session, provided there is sufficient space in the exercise room.

Table 2 Comparison between PBWTT and OG