This article and any supplementary material should be cited as follows: Roy A, Forrester LW, Macko RF, Krebs HI. Changes in passive ankle stiffness and

This article and any supplementary material should be cited as follows: Roy A, Forrester LW, Macko RF, Krebs HI. Changes in passive ankle stiffness and its effects on gait function in people with chronic stroke. J Rehabil Res Dev. 2013;50(4):555-72. http://dx.doi.org/10.1682/JRRD.2011.10.0206

Slideshow ProjectDOI:10.1682/JRRD.2011.10.0206JSP

Changes in passive ankle stiffness and its effects on gait function in

people with chronic stroke

Anindo Roy, PhD; Larry W. Forrester, PhD; Richard F. Macko, MD; Hermano I. Krebs, PhD



• Aim– Investigate robot-assisted ankle training in people

with chronic stroke:• Effect on passive ankle stiffness (PAS).• Relationship to overground gait function.

• Relevance– Mechanical impedance of ankle is known to

influence key aspects of ankle function.



Method

• 8 seated participants with residual hemiparetic deficits engaged in visuomotor task over 6 wk:– Performed dorsiflexion (DF) or plantar flexion (PF)

of paretic ankle.– Ankle robot (“anklebot”) assisted as needed.

• PAS was measured in both: – Trained sagittal plane. – Untrained frontal plane.



Results• PAS decreased in both DF and PF. • DF PAS:– Reverted into variability of age-matched controls.

• PF PAS: – Changes correlated strongly with gains in paretic step

length and stride length.– Baseline correlated with gains in paretic step length,

stride length, and single-support stance duration.

• Baseline eversion PAS: – Correlated with gains in cadence.



Conclusion

• Ankle robot-assisted, visually evoked, visually guided ankle training positively affects paretic ankle PAS.– Strongly influences key measures of gait function.

Documents

This article and any supplementary material should be cited as follows: Roy A, Forrester LW, Macko RF, Krebs HI. Changes in passive ankle stiffness and