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Updated: Apr 20, 2026
Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI
Published on: April 18, 2011
Interventions to Reduce Spasticity and Improve Function in People With Chronic Incomplete Spinal Cord Injury:
Lynsey D Duffell1, Geoffrey L Brown2, Mehdi M Mirbagheri3
1Northwestern University, Chicago, IL, USA lynsey.duffell@northwestern.edu mehdi@northwestern.edu.
Background:
Spinal cord injury (SCI) results in impaired function, and ankle joint spasticity is a common secondary complication. Different interventions have been trialed with variable results.
Objective:
We investigated the effects of pharmacological and physical (locomotor training) interventions on function in people living with incomplete motor function loss caused by SCI and used different analytical techniques to understand whether functional levels affect recovery with different interventions.
Methods:
Participants with an incomplete SCI were assigned to 3 groups: no intervention, Lokomat, or tizanidine. Outcome measures were the 10-m walk test, 6-minute walk test, and the Timed Up and Go. Participants were classified in 2 ways: (1) based on achieving an improvement above the minimally important difference (MID) and (2) using growth mixture modeling (GMM). Functional levels of participants who achieved the MID were compared and random coefficient regression (RCR) was used to assess recovery in GMM classes.
Results:
Overall, walking speed and endurance improved, with no difference between interventions. Only a small number of participants achieved the MID. Both MID and GMM-RCR analyses revealed that tizanidine improved endurance in high-functioning participants. GMM-RCR classification also showed that speed and mobility improved after locomotor training.
Conclusions:
Improvements in function were achieved in a limited number of people with SCI. Using the MID and GMM techniques, differences in responses to interventions between high-and low-functioning participants could be identified. These techniques may, therefore, have potential to be used for characterizing therapeutic effects resulting from different interventions.
