Medical & Biological Engineering & Computing

, Volume 51, Issue 4, pp 377–386 | Cite as

Gait analysis in children with cerebral palsy via inertial and magnetic sensors

  • Josien C. van den Noort
  • Alberto Ferrari
  • Andrea G. Cutti
  • Jules G. Becher
  • Jaap Harlaar
Original Article


3D kinematic measurements in children with cerebral palsy (CP) to assess gait deviations can only be performed in gait laboratories using optoelectronic systems. Alternatively, an inertial and magnetic measurement system (IMMS) can be applied for ambulatory motion-tracking. A protocol named Outwalk has recently been developed to measure the 3D kinematics during gait with IMMS. This study preliminary validated the application of IMMS, based on the Outwalk protocol, in gait analysis of six children with CP and one typically developing child. Reference joint kinematics were simultaneously obtained from a laboratory-based system and protocol. On average, the root mean square error (RMSE) of Outwalk/IMMS, compared to the reference, was less than 17° in the transversal plane, and less than 10° in the sagittal and frontal planes. The greatest differences were found in offsets in the knee and ankle rotation, and in the hip flexion. These offset differences were mainly caused by a different anatomical calibration in the protocols. When removing the offsets, RMSE was always less than 4°. Therefore, IMMS is suitable for gait analysis of major joint angles in a laboratory-free setting. Further studies should focus on improvement of anatomical calibrations of IMMS that can be performed in children with CP.


Cerebral palsy Gait Inertial sensors Rehabilitation Joint kinematics 



This work is part of the FreeMotion project ( funded by the Dutch Ministry of Economic Affairs and Senter Novem. The authors wish to thank all the children and their parents who participated in the study, and Martin Schepers for assistance in data analysis.


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Copyright information

© International Federation for Medical and Biological Engineering 2012

Authors and Affiliations

  • Josien C. van den Noort
    • 1
  • Alberto Ferrari
    • 2
    • 3
    • 4
  • Andrea G. Cutti
    • 3
  • Jules G. Becher
    • 1
  • Jaap Harlaar
    • 1
  1. 1.Department of Rehabilitation Medicine, Research Institute MOVEVU University Medical CenterAmsterdamThe Netherlands
  2. 2.Department of Electronics, Computer Science and SystemsUniversity of BolognaBolognaItaly
  3. 3.Centro Protesi INAIL, Vigorso di Budrio (BO)BolognaItaly
  4. 4.Xsens Technologies B.V.EnschedeThe Netherlands

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