Gait in Children With Down Syndrome While Wearing Orthoses
Condition: Down Syndrome
MeSH terms: Down Syndrome; Syndrome
Study type: Interventional

Summary: 
      On average, Down syndrome (DS) occurs once in every 700 live births and results in life-long
      disability and increased risk for comorbidities.1 Individuals with DS are also susceptible to
      secondary physical impairments and limitations as a result of complications associated with
      joint hypermobility, hypotonicity, and increased ligamentous laxity. Secondary impairments
      such as pes planus (flat feet), weakened muscles, bony abnormalities and arthritis may lead
      to painful joints and feet. Additionally, children with DS often manifest deviations in gait
      as a result of physical limitations imposed by orthopedic and muscular deficiencies that may
      lead to decreased postural stability. These secondary losses in function, which exacerbate
      disabilities, may be preventable with the use of appropriate early interventions aimed at
      correcting abnormal joint alignment. Research exploring effective physical therapy
      interventions for adults and children with DS is currently very limited. However, the use of
      orthotic devices to support lax ligaments and hypotonic muscles, which are common
      manifestations of DS, is one accepted method of intervention for children within this
      population. Orthoses are variable in structure and the degree of support provided to the foot
      and ankle also differ between foot orthoses (FOs) and supramalleolar orthoses (SMOs).
      Previous studies have supported the effectiveness of orthoses on improving ankle and foot
      alignment, as well as gait parameters. However, disagreement currently exists concerning
      which type of orthotic device is most beneficial for the population of children with DS.
      Children with DS express variable degrees of joint laxity and hypotonicity, as well as
      differences in the severity of specific alignment abnormalities such as excessive pronation
      or calcaneal eversion.6 Current literature is insufficient for explaining differences in the
      benefits provided by FOs and SMOs and the specific indications for their use in children with
      DS is unclear.

      Study Aims This study will demonstrate the differences in structural outcomes provided by FOs
      and SMOs and develop specific criterion for matching individuals of differing orthopedic
      impairments with the most beneficial orthotic device.
    

Detailed description: 
      The purpose of this study is to demonstrate the differences in functional outcomes provided
      by supramalleolar orthoses and foot orthoses, as well as develop specific criterion for
      matching individuals with Down syndrome (DS) of differing orthopedic impairments with the
      most beneficial orthotic device.

      Participants must be able to walk independently or with an assistive device, such as a
      walker, for 50 feet at one time, and have at least six months of walking experience.
      Participants must also be able to follow simple verbal instructions. Both males and females
      will be included in this study, and children of any race may participate as long as they meet
      the inclusion criteria and are between three and ten years of age at the time of data
      collection. Exclusion criteria include a history of uncorrected visual and inner ear
      impairments, and lower extremity orthopedic surgical corrections.

      There are no costs associated with participation in this study, and subjects will not be paid
      for their participation.

      Participants in this study will be fitted for the appropriate size orthoses either by
      physical therapists in the participants' school district, or by one of the researchers prior
      to data collection. The correct fitting orthotic will be sized using the sizing guides
      provided by Cascade. These are footplates of various sizes that provide the length of the
      child's foot in inches and the orthosis width that will fit the child. Measurements of
      height, weight, leg length, medial longitudinal arch height, tibial torsion, and calcaneal
      eversion will be taken for each subject. Weight will be measured in kilograms using a scale,
      while height, leg length, and medial longitudinal arch height will be measured using a metric
      tape measure. Tibial torsion will be measured with the participant lying in prone (on their
      stomach) on the plinth with one knee flexed to 90 degrees. The angle of tibial torsion is
      formed by a line perpendicular to the line between the medial and lateral malleoli of the
      ankle, and a line parallel to the femur. This angle will be measured using a goniometer,
      which is an instrument used to measure joint angles and range of motion, and this angle will
      be measured once on each side. Finally, while standing, calcaneal eversion will be measured
      by determining the angle between neutral calcaneal alignment and resting stance. Neutral
      calcaneal alignment is found by palpating the position of the talus, so that the talus bone
      is felt equally on both sides of the foot. Once neutral alignment has been determined a line
      will be drawn with washable marker between the posterior talus and midline of the calf. The
      participant will then be asked to stand in their normal position and a goniometer will be
      used to measure the angle between the neutral alignment and the resting alignment of the
      ankle.

      In addition to these measurements, a hypermobility screen will be performed in which mobility
      of fingers, wrists, elbows, knees, and the spine will be scored. The screen is scored using a
      point system in which one point is given for the ability to perform each of the tasks in the
      screen. These tasks include the ability to actively extend the little fingers 90 degrees at
      the metacarpophalangeal joints, passively touch the thumbs to the volar surface of the
      forearms, extend the wrists more than 90 degrees, extend elbows and knees more than 10
      degrees, and the ability to bend the spine to reach the floor with palms flat on the ground.
      Gait of each participant will be assessed in conditions of shoes only, with foot orthoses,
      and with supramalleolar orthoses. This order will be determined by selecting a condition at
      random from a hat, such that the first condition chosen will be performed and assessed first.

      Gait parameters including step length, step width, walking speed, percentage of time spent in
      single leg support, and variability in gait will be measured using a GAITRite mat. The
      GAITRite measurement system includes an electronic walkway which contains sensor pads, and is
      similar to a roll-out carpet. The GAITRite mat is then linked to a computer, which collects
      information about gait as the participant walks across the mat. The GAITRite mat, which is 20
      feet long, will be set-up as one segment of a circular track so that total walking distance
      of the loop will be 50 feet. Participants will be given an accommodation period of ten
      minutes for both types of orthoses prior to gait assessment in which they will be instructed
      to walk around the room and over the GAITRite mat in order to get comfortable wearing the
      orthoses and walking along the track. Once the accommodation period is complete for one
      orthosis, participants will walk around the track three times. This procedure of
      accommodation and data collection will be repeated for each condition. Participants will be
      given verbal encouragement by the researchers as they walk the track as a means of
      motivation. Rest periods will be given to participants when requested, or when behavioral
      cues displaying discomfort, pain, or frustration occur. Data collection will be stopped
      altogether at the participant's request or if behavioral cues of discomfort persist. Trials
      involving both supramalleolar and foot orthoses are hypothesized to increase step length,
      walking speed, and time spent in single leg support from control trials in the shoes only
      condition. Both orthoses are also expected to decrease step width, and variability in gait
      parameters. Supramalleolar orthoses, which provide above-ankle support, are expected to
      improve gait parameters to a greater magnitude than foot orthoses for participants who score
      higher on the hypermobility screen and have greater tibial torsion and ankle eversion than
      their cohorts. Conversely, foot orthoses are expected to provide greater improvement in gait
      parameters than supramalleolar orthoses for participants who score lower on the hypermobility
      screen and have less tibial torsion and ankle eversion than their cohorts due to the need for
      less external foot and ankle support. An increase in step length, walking speed, time spent
      in single leg support, and a decrease in step width and variability in gait will indicate a
      positive result of orthoses use.

      Students of physical therapy from the University of Puget Sound Physical Therapy Program will
      perform all measurements, with the exception of orthotic size in some cases. One researcher
      will perform all anthropometric measurements and the hypermobility screen on the
      participants. A second researcher will operate the GAITRite mat, while the third researcher
      will guide and instruct the participants along the GAITRite mat course.
    

Intervention name(s): Supramalleolar Orthoses (Cascade)
Intervention type(s): Device
Intervention description(s): Walk wearing supramalleolar orthoses - three trial
Other intervention name(s): Cascade - leap frog
Intervention model: Single Group Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Gait; Orthoses; Down syndrome