Effects of Malleo-Lok Stiffness on Lower Limb Mechanics
Condition: Adult ALL; Healthy
Study type: Interventional

Summary: 
      The primary purpose of this research study is to determine if the stiffness of a commercially
      available ankle foot orthosis (Malleo-Lok, Bio-Mechanical Composites, Des Moines IA) impacts
      gait biomechanics and overall joint level stiffness. Previously published research suggests
      that AFO stiffness can affect gait biomechanics and patient preference. However, previous
      studies have focused on traditional posterior strut devices with the strut aligned in the
      frontal plane to allow sagittal plane deflection. The Malleo-Lok is a novel, low-profile
      carbon fiber device with two laterally positioned struts aligned in the sagittal plane. The
      proposed study will provide insight that can be used by certified prosthetists orthotists
      (CPOs), physical therapists, and physicians to select the device that bests meets their
      patients' needs.
    

Detailed description: 
      Healthy adult individuals will be invited to participate in this study, at the University of
      Iowa, that involves one visit lasting 3-4 hours. The primary purpose of this work is to
      determine the effects of Malleo-Lok stiffness on gait biomechanics and ankle joint stiffness.
      Previous work has highlighted the effects of ankle foot orthosis stiffness on gait using
      devices with a traditional single posterior strut opposed to the Malleo-Lok, which has two
      laterally positioned struts. Orthosis stiffness is an important factor to consider during
      device prescription and manufacturing. The ability to tune overall joint level stiffness by
      determining the combined effects of biological limb stiffness and orthosis stiffness will
      enhance precision medicine when treating individuals who require an orthosis for daily
      activities. The secondary purpose of this research study is to determine the within session
      repeatability of a novel approach for in-vivo AFO stiffness testing. AFO stiffness testing is
      typically performed using mechanical testing systems without accounting for the interaction
      of the individual and the device.

      During the visit to the University of Iowa campus participants will review a list of
      inclusion and exclusion criteria to determine their eligibility for this study. Eligible
      participants will review an informed consent document and have the chance to ask any
      questions they may have. Study staff will thoroughly explain the informed consent document
      and answer all questions. Upon signing the informed consent document study activities will
      begin. Participants will complete all study activities wearing no brace and two braces of
      differing stiffness's. Anthropometric and demographic information will be collected from each
      participant. The investigators will also use a motion capture system to evaluate gait
      biomechanics and ankle joint stiffness. Participants will walk at a self-selected and a
      controlled speed to evaluate gait biomechanics, and will stand in the motion capture system
      and bring their knee forward over the foot to evaluate ankle joint stiffness. Participants
      will be provided visual feedback of muscle activity to minimize lower limb muscle activity
      during ankle stiffness testing.

      Results from the proposed study will provide information about the effects of orthosis
      stiffness on gait biomechanics and ankle joint stiffness. Study results will be made
      available to clinicians to use when prescribing and fitting individuals with ankle foot
      orthoses.
    

Intervention name(s): Malleo-Lok
Intervention type(s): Device
Intervention description(s): The Malleo-Lok is a novel, low-profile carbon fiber device with two laterally positioned struts aligned in the sagittal plane.
Other intervention name(s): Ankle Foot Orthosis; Carbon Fiber Custom Dynamic Orthosis
Intervention MeSH terms: Carbon Fiber
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: All participants will be tested wearing no brace and two braces of differing stiffness's. The testing order will be randomized for each participant to prevent testing order from influencing study results.
Masking: Single (Participant)
Primary purpose: Basic Science
Keywords: Gait Analysis; Ankle Foot Orthosis; Carbon Fiber; Biomechanics