Clustering trunk movements of children and adolescents with neurological gait disorders undergoing robot-assisted gait therapy: the functional ability determines if actuated pelvis movements are clinically useful.

The study was cross-sectional, so it cannot show whether these movement patterns lead to long-term therapy improvement. Participants were recruited by convenience sampling and had a wide range of neurological gait disorders, which makes it difficult to identify the mechanisms behind their reactions. The actuated pelvis movement was set to 2 cm per side for everyone, and timing and magnitude were not individualized; this may have been too much for shorter patients. The harness and bodyweight support may have restricted trunk movement, although the overall range of motion between groups was comparable. The study did not assess leg kinematics or knee stability, which are also relevant when the FreeD module is used with released leg cuffs. Six participants could not perform the Timed Up and Go test, so it was not included in the statistical comparison. Two participants were excluded because of equipment malfunction and one because of poor compliance. Patients received minimal standardized instructions, so the results do not show what happens when therapists actively coach the movement. The reference pattern came from a different study of children walking on a treadmill, not from the same participants walking in the Lokomat. Two participants with poor trunk control were found in clusters other than unstable, suggesting that rigid muscle co-contraction may have made their movement patterns look more stable.

The work was supported by Schweizerische Stiftung für das Cerebral Gelähmte Kind, ACCENTUS Foundation, Switzerland, J and K Wonderland Foundation, Anna Müller Grocholski Stiftung, and Olga Mayenfisch Stiftung. No author conflicts of interest are stated in the supplied text.

Do not conclude that actuated pelvis movement alone improves therapy. It was tested together with released leg cuffs during a single Lokomat session in 35 participants, and the study did not follow patients over time to test long-term function.