Using Motion-Capture Technology to Guide Treatment in Cerebral Palsy

March 2008 Issue of Cerebral Palsy Magazine: State-of-the-art technology using computerized three-dimensional (3D) motion analysis is not only reserved for Hollywood movies, video-gaming, professional athletes, the aviation industry, or high-tech businesses,* but is also within reach for local therapists and doctors to help guide treatment for children and adults with cerebral palsy (CP).  Clinical Motion Analysis Laboratories (MALs), which are located throughout the country, can assist when navigating the treatment options available to improve movement in individuals with CP.  Often housed within children’s hospitals, these clinical labs can also be found at independent sites.  Many motion labs are located within university settings, however these labs are usually research-oriented and do not “see patients.” By Kimberly Wesdock, PT, MS, PCS, BioMotion of America LLC

Using evidenced-based practice and cutting edge motion-capture technology, physical therapist movement specialists, kinesiologists, bioengineers, physical medicine & rehabilitation doctors (physiatrists), and pediatric orthopedic surgeons evaluate movement in a very comprehensive way using computerized 3D motion analysis.  Both walking (gait) patterns as well as hand and arm (upper limb) movements can be evaluated in the MAL, although not all labs do upper limb analysis.

In the MAL, physical therapists place a myriad of special reflective markers (using stickers) and sensors on an individual’s body at strategic anatomic points.  Large amounts of information are then collected by special cameras mounted on the walls when the individual either walks down a walkway across force plates imbedded into the floor (for gait analysis), or performs functional tasks using both hands (for upper limb analysis).  This objective information (data) consists of kinematics (3D movement at each body joint), kinetics (forces responsible for joint movement), and electromyography or EMG (muscle activity related to joint movement).

Another critical part of the evaluation includes a detailed physical therapy baseline examination also done the same day.  During this exam, physical therapists measure joint range of motion, muscle length and strength, classify muscle tone (spasticity, dystonia, athetosis, ataxia, or combinations), perform other neurological and orthopedic screening tests, and classify walking and functional status using standardized scales.

By combining the dynamic motion data together with the physical therapy exam findings, a complex picture is created, kind of like a very big jigsaw puzzle.  It is not until the puzzle is completely assembled that the complete picture of an individual with CP can be seen – how one moves and why one moves in a certain way.  The “fully-assembled puzzle” combines the display of all data in the form of graphs, along with an interpretation that logically lists treatment options, based on the data gathered.

While only a highly-trained clinician with motion analysis and clinical expertise can interpret and assemble the motion analysis evaluations, the final written report contains recommendations aimed at the treating physical or occupational therapist, and/or physician.

The 2 to 3-hour long evaluation sessions consist of the most comprehensive services available to gather the evidence for figuring out the causes and compensations in CP in order to make the best decisions about how to improve movement and function.  While many insurance companies cover motion analysis for the diagnosis of CP, a few companies continue to incorrectly insist that motion analysis technology is only a research tool.

Laura is a beautiful 8-year-old girl with CP affecting her left side.  She had recently returned to the Spasticity Clinic at her local hospital for a multi-disciplinary approach to decide how to improve her gait.  Laura had been seen in the Motion Analysis Laboratory two years prior for both upper limb and gait evaluations.  However, her gait pattern had changed considerably since that evaluation, which was done before two rounds of Botox injections, casting, and aggressive physical therapy including kinesiotaping and functional weight-bearing activities.

Discussion proceeded in clinic with consideration of the following options: orthopedic surgery, rhizotomy, more Botox and casting, or more physical therapy.  When the team members, who included a physiatrist, neurosurgeon, neurosurgery nurse practitioner, neurologist, orthopedic surgeon, and two physical therapists, could not agree on the best course of action to improve Laura’s gait, the decision was made to “level the playing field” and have her return to the Motion Analysis Laboratory for a re-evaluation.

This turned out to be a very wise decision as it was the only way to objectively compare her gait pattern from two years ago to her current gait pattern, which had changed.   Documenting her gait using 3D motion analysis at this point in time was useful before any further treatment options were pursued.

The findings from her Motion Analysis Re-Evaluation, which could not be quantified during her clinic visit, actually demonstrated multiple improvements in her gait from two years ago.  These improvements included 1) a reduction in her left foot drop, 2) a reduction in her equinus (toe-walking), 3) a changed foot posture from a previous cavus (high-arched) foot with inverted heel to a flattened-arch foot with everted heel and abducted forefoot (out-toeing), 4) a reduction in her right-sided compensations, 5) improved dynamic balance as she went from falling twice daily to only tripping once per week, and 6) overall, an improved gait pattern that was smoother, more consistent, and demonstrated more control than two years ago.

Motion analysis evaluations such as Laura’s can be instrumental in determining which treatment options not to pursue, for the reason that certain options may cause more harm than good.  Because of Laura’s secondary dystonia (a specific type of increased muscle tone), which was more pronounced than her spasticity, it was determined that she was not a candidate for rhizotomy surgery, and that tendon transfers were not indicated at the present time.  Additional interventions to be avoided, according to the motion analysis data, included surgical hamstring lengthening, or any more Botox to her left posterior tibialis or gastrocnemius (calf muscles).

While Motion Analysis can pinpoint which procedures to avoid, thus preventing unnecessary interventions, these evaluations can be helpful with planning treatments as well.  Treatment options resulting from Laura’s repeat gait analysis included 1) Botox to the left ankle everter (peroneus longus) muscle, 2) consideration of Botox to the left medial hamstrings, 3) continuation of very aggressive and targeted physical therapy including trials with electrical stimulation and continued kinesiotaping, 4) continued daytime use of her left supramalleolar orthosis (SMO), and 5) consideration of medication trials to manage her dystonia if desired by her parents.  Re-evaluation in the Motion Analysis Lab was recommended in 1-2 years to compare results again, and determine the next course of action for Laura.  Both Laura and her mother were very satisfied with the outcome of this visit to the Motion Analysis Lab!

When selecting a Motion Analysis Lab, you can ask about gait and upper limb analysis, if you are interested in both.  You can also ask if a “new generation” foot model will be used, which looks at both hindfoot and forefoot motion (the multi-segment foot) in a more anatomic way.  If you are an adult seeking a motion analysis evaluation, you need to make sure the lab you choose will see adults!  Some health care providers advertise “motion analysis” or “gait analysis” when they are only using conventional videotaping on a treadmill.  While these applications may work for a healthy runner, or a straightforward orthopedic injury, computerized 3D motion analysis is necessary to evaluate individuals with CP.  In the near future, motion analysis laboratories will be accredited through the Commission for Motion Laboratory Accreditation, Inc. (www.cmlainc.org) after meeting all requirements including submission of an extensive application packet.

Motion Analysis Evaluations can help guide treatment in CP including:

  • Physical Therapy (PT)
  • Occupational Therapy (OT)
  • Alternative Treatments in conjunction with PT/OT such as: Intensive Suit Therapy, Constraint Induced Movement Therapy, Hand Arm Bimanual Intensive Therapy, Hippotherapy, SaeboFlex(R), Conductive Education
  • Orthoses - AFO Braces, DAFO's, Splints
  • Botox Injections
  • Medication Trials - usually done by a physiatrist or neurologist using Oral baclofen, Sinemet(R) and Artane(R)
  • Orthopedic Surgery - muscle/tendon lengthenings, tendon transfers, bony work
  • Neurosugery - Intrathecal baclofen (ITB), Intraventricular baclofen (IVB), Deep Brain Stimulation (DBS), Dorsal or Ventral Rhizotomy, Cervical/Lumbar Rhizotomy

 

 * Beyond Virtual Reality in BusinessWeek, April 2, 2007

 

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