A portable intelligent stretching device for treating spasticity and contracture with outcome evaluation

Li-Qun Zhang*, Sun G. Chung, Amanda F. Lin, Elton M. Van Rey, Zhiqiang Bai, Thomas H Grant, Elliot J Roth

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

3 Scopus citations


A portable stretching device with intelligent control was developed to treat the spastic/contractured ankle of neurologically impaired patients and evaluate the outcome. The device stretched the ankle throughout the range of motion (ROM) to extreme dorsiflexion and plantar flexion until a specified peak resistance torque was reached with the stretching velocity controlled based on the resistance torque. Stretching velocity was adjusted constantly. It was slow at the joint extreme positions, making it possible to reach a larger ROM safely, and it was fast in the middle ROM so the majority of the treatment was spent in stretching the problematic extreme ROM. The ankle was held at the extreme position for a period of time to let stress relaxation occur before it was rotated back to the other extreme position. Furthermore, the device evaluated treatment outcome quantitatively in multiple aspects, including active and passive ROM, joint stiffness and viscous damping, and reflex excitability. Combined with ultrasonography, the device was used to evaluate changes in mechanical properties of the achilles tendon-aponeurosis induced by the stretching. The intelligent stretching reduced spasticity and contracture, including increases passive and active ROMs, decreases in elastic stiffness and viscous damping, and increase in muscle force-generating capacity.

Original languageEnglish (US)
Pages (from-to)2453-2454
Number of pages2
JournalAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
StatePublished - Dec 1 2002
EventProceedings of the 2002 IEEE Engineering in Medicine and Biology 24th Annual Conference and the 2002 Fall Meeting of the Biomedical Engineering Society (BMES / EMBS) - Houston, TX, United States
Duration: Oct 23 2002Oct 26 2002


  • Contracture
  • Device
  • Spasticity
  • Stiffness therapy
  • Stretching

ASJC Scopus subject areas

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics


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