Clinical trial NCT04806100: Effects of Malleo-Lok Stiffness on Lower Limb Mechanics
Official title: Effects of Malleo-Lok Stiffness on Lower Limb Mechanics
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Adult ALL
Healthy
Keywords: Gait Analysis
Ankle Foot Orthosis
Carbon Fiber
Biomechanics
Lead sponsor: University of Iowa
Sponsor class: OTHER
First posted: 2021-03-19
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
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.
Primary purpose: BASIC_SCIENCE

Brief 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.

Eligibility criteria: Inclusion Criteria:

* Between the ages of 18 and 45
* Healthy without current complaint of lower extremity pain, spine pain, open wounds or active infections, or medical or neuromusculoskeletal disorders that have limited their participation in work or exercise in the last 6 months
* Able to hop without pain
* Able to perform a full squat without pain
* Ability to speak and understand English

Exclusion Criteria:

* Diagnosed with a moderate or severe brain injury
* Lower extremity injury resulting in surgery or limiting function for greater than 6 weeks
* Injuries that would limit performance in this study
* History of recurrent ankle sprains or chronic ankle instability
* Diagnosed with a physical or psychological condition that would preclude functional testing (e.g. cardiac condition, clotting disorder, pulmonary condition)
* Uncorrected visual or hearing impairment(s)
* Require use of an assistive device
* Unhealed wounds (cuts/abrasions) that would prevent AFO use
* BMI \> 35
* Pregnancy

Primary outcomes:
measure: Ankle Joint Stiffness
timeFrame: In-vivo ankle joint stiffness was measured for each condition before and after short bouts of walking (~15-20 minutes).
measure: Ankle Joint Power
timeFrame: Ankle joint power was measured for each condition during short bouts of walking (~15-20 minutes).
measure: Ankle Joint Moment
timeFrame: Ankle joint moment was measured for each condition during short bouts of walking (~15-20 minutes).
Secondary outcomes:
measure: Numerical Pain Rating Scale
timeFrame: Participants were asked to rate their pain after completing in-vivo ankle stiffness testing and walking trials in all conditions.
measure: Modified Socket Comfort Score: Comfort
timeFrame: Participants were asked to rate their comfort after completing in-vivo ankle stiffness testing and walking trials in Compliant and Stiff conditions.
measure: Modified Socket Comfort Score: Smoothness
timeFrame: Participants were asked to rate the orthosis smoothness after completing in-vivo ankle stiffness testing and walking trials in Compliant and Stiff conditions.
Other outcomes:
measure: Center of Pressure Velocity Magnitude
timeFrame: Baseline
measure: Center of Pressure Velocity Timing
timeFrame: Baseline
measure: Soleus Muscle Activity (Electromyography)
timeFrame: Baseline
measure: Medial Gastrocnemius Muscle Activity (Electromyography)
timeFrame: Baseline
measure: Tibialis Anterior Muscle Activity (Electromyography)
timeFrame: Baseline
measure: Peroneus Longus Muscle Activity (Electromyography)
timeFrame: Baseline
Locations:
city: Iowa City
country: United States
facility: University of Iowa
state: Iowa
Study officials:
affiliation: University of Iowa
name: Jason M Wilken, PT, PhD
role: PRINCIPAL_INVESTIGATOR
References: