Extreme Range Of Motion Research Articles

Intelligent stretching of ankle joints with contracture/spasticity

An intelligent stretching device was developed to treat the spastic/contractured ankle of neurologically impaired patients. The device stretched the ankle safely throughout the range of motion (ROM) to extreme dorsiflexion and plantarflexion until a specified peak resistance torque was reached with the stretching velocity controlled based on the resistance torque. 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. Stretching 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. Furthermore, the device evaluated treatment outcome quantitatively in multiple aspects, including active and passive ROM, joint stiffness and viscous damping and reflex excitability. The stretching resulted in considerable changes in joint passive ROM, stiffness, viscous damping and reflex gain. The intelligent control and yet simple design of the device suggest that with appropriate simplification, the device can be made portable and low cost, making it available to patients and therapists for frequent use in clinics/home and allowing more effective treatment and long-term improvement.

Variation in shoulder position sense at mid and extreme range of motion

Janwantanakul P, Magarey ME, Jones MA, Dansie BR. Variation in shoulder position sense at mid and extreme range of motion. Arch Phys Med Rehabil 2001;82:840-4. Objective: To determine the effect of different joint positions on position sense of asymptomatic shoulders. Design: Repeated-measures design. Setting: Laboratory in an educational institution. Participants: Thirty-four asymptomatic, right-handed men. Interventions: The ability of subjects to replicate 3 criterion positions was examined on subjects' right shoulders by using an isokinetic dynamometer. Three criterion positions were the 50th, 75th, and 90th percentiles of each individual's total passive shoulder rotation range measured from the full internal rotation position. Main Outcome Measure: Repositioning accuracy, indicating the difference in degrees between the criterion and matching positions. Results: All subjects were able to reproduce the criterion position near the end of external rotation range more accurately and consistently than in the middle range of motion (ROM). Conclusions: Position sense acuity at the shoulder complex varied across the ROM and may be enhanced near the end of rotation range where there is more tension on the restraints to movement. Therefore, an individual's ROM should be factored into any attempt to assess or rehabilitate shoulder proprioception.