A Prediction Model for Determining Over Ground Walking Speed After Locomotor Training in Persons With Motor Incomplete Spinal Cord Injury

Abstract

Background/Objective: To develop and test a clinically relevant model for predicting the recovery of over ground walking speed after 36 sessions of progressive body weight-supported treadmill training (BWSTT) in individuals with motor incomplete spinal cord injury (SCI). Design: A retrospective review and stepwise regression analysis of a SCI clinical outcomes data set. Setting: Outpatient SCI laboratory. Subjects: Thirty individuals with a motor incomplete SCI who had participated in locomotor training with BWSTT. Eight individuals with similar diagnoses were used to prospectively test the prediction model. Main Outcome Measures: Over ground walking speed was assessed using the 10-m walking test. Methods: The locomotor training program consisted of 36 sessions of sequential comprehensive training comprised of robotic assisted BWSTT, followed by manual assisted BWSTT, and over ground walking. The dose of locomotor training was standardized throughout the protocol. Results: Clinical characteristics with predictive value for walking speed were time from injury onset, the presence or absence of voluntary bowel and bladder voiding, a functional spasticity assessment, and over ground walking speed before locomotor training. The model identified that these characteristics accounted for 78.3% of the variability in the actual final over ground walking speed after 36 sessions of locomotor training. The model was successful in prospectively predicting over ground walking speed in the 8 test participants within 4.15 6 2.22 cm/s in their recovered walking speed.Conclusions: This prediction model can identify individuals who are most likely to experience success using locomotor training by determining an expected magnitude of training effect, thereby allowing individualized decisions regarding the use of this intensive approach to rehabilitation.

Supraspinal Control Predicts Locomotor Function and Forecasts Responsiveness to Training after Spinal Cord Injury

“…In 30 participants with subacute or chronic SCI who took part in a 36-session locomotor training program, the factors associated with fastest post-training walking speeds were pre-training walking speed, voluntary bowel/bladder function, time since injury, and spasticity as assessed by resistive forces generated during robotic stepping. 138 Given that voluntary bowel/bladder function is an indication of supraspinal control over circuits in the lower levels of the spinal cord, as with the studies showing the contribution of LEMS to walking function, this finding supports the role of supraspinal centers in walking after SCI in humans.…”

“…While improvements continue to be possible even in the chronic phase regardless of training approach, 51 there is evidence that training responsiveness is greatest early after SCI. 52,138 During chronic stages, 1-5 years after SCI, recovery of muscle strength slows or regresses. 139 For this reason, studies that include both participants with subacute SCI and those with chronic SCI may offer limited ability to forecast trainingrelated outcomes in either group alone.…”

“…We contend that forecasting responsiveness to training rather than final outcome of training is the more valuable focus, because unsurprisingly, final outcomes of training are invariably tied to initial values; i.e., participants with the fastest pre-training walking speed typically have the fastest post-training walking speeds. 138 Conversely participants with very slow pre-training walking speeds can make large gains relative to initial values, but still walk very slowly after training. 92,140 Third, association models are often based on relatively small samples; forecasts based on small samples may not be representative of the responsiveness or outcomes of persons with SCI in the population as a whole.…”

Leg Strength, Preferred Walking Speed, and Daily Step Activity in Adults With Incomplete Spinal Cord Injuries

“…13,14 The average walking speed for our sample was 0.43 ± 0.21 m•s recorded in other studies of male and female adults with iSCI classified as AIS C and D. 15,16 Viewed collectively, this trio of walking speeds falls below the threshold for independent community ambulation, thus setting the stage for Table 3. Relationships among leg strength, preferred walking speed, and daily step activity an increased reliance on assistive mobility aids to facilitate locomotion.…”

The Ability to Walk After a Spinal Cord Injury with Emphasis on Exoskeletons: A Review

“…Literature suggests that a walking speed of 1.20 to 1.31 m/s is required for independent community ambulation [18]. However, several studies show an average walking speed of patients with SCI around 0.36 m/s [19][20][21]. Together with factors such as the ability to transfer and manage curbs, stairs and crowded areas, this could lead to a reduced independence in walking in the community.…”