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Prosthesis UserNCT01332123

Biomechanical Assessment of Gait in Lower-Extremity-Amputees

A study testing Alignment perturbations in people with Prosthesis User, run by University of Wisconsin, Milwaukee at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study is investigating the influence of several simulated real life conditions on the symmetry of gait with trans-tibial prostheses Hypotheses: It is hypothesized that the observable differences in gait pattern between amputees can be detected by a combination of forces and moments that are measured internally in… Read more about this study

Who is it for?
Ages 18 to 80 yearsHealthy volunteers can take part
Conditions the study is for
Prosthesis User
What is being tested?
Alignment perturbations
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
10 participants
Where
1 siteUnited States
Study dates
Apr 2011to Aug 2012
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 80 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Trans tibial amputation
  • Able to walk 30 minutes comfortably
  • Modular prosthesis

Who cannot join

  • Prosthesis does not provide enough space between socket and foot module to fit the mobile measuring unit
  • Physically or mentally unable to perform the required tasks

Trial locations and contacts

1 site in 1 country.

United States1 site
  • USR, 115 E Reindl Way

    Milwaukee, Wisconsin, 53211

Other trials in United States

About this study

This study is investigating the influence of several simulated real life conditions on the symmetry of gait with trans-tibial prostheses

Hypotheses: It is hypothesized that the observable differences in gait pattern between amputees can be detected by a combination of forces and moments that are measured internally in the prosthesis, and electromyography data. It is further hypothesized that changing conditions such as uneven walking surface, prosthetic misalignment or user fatigue are characterized by typical values in the measured data or combinations thereof.

Read the detailed description

In amputee walking, an optimal static alignment of the artificial leg is important in order to achieve the best possible performance. Comfort, energy expenditure, mobility and walking speed should ideally be similar to those of able bodied persons. Of course, amputation level, overall health status and other factors often pose certain individual limitations that may prevent an amputee from reaching this goal.

Irrespective of that, the artificial leg must be aligned properly to eliminate unnecessary inhibitions. Apart from manufacturing a well fitting socket, and selecting the appropriate functional components of the prosthesis, the prosthetist has to routinely optimize the static alignment during the fitting process. Hereby, objective measures and guidelines are scarce. Despite various more or less useful tools that are available, the alignment optimization in praxis is often based on subjective gait assessment and rules of thumb. Commonly accepted is the notion, that the gait pattern should be most symmetrically, that is step lengths, stance times, knee angles etc. should be identical between sound and prosthetic leg.

There are different questions that our study wants to address: Is gait symmetry indeed a valid measure of prosthetic performance (e.i. is it the most energy efficient way to walk)? How does the gait pattern change when the prosthesis user walks on different surfaces, becomes tired or tries to compensate for a less-than-optimal prosthesis fit? How can gait symmetry be objectively assessed without using an expensive motion analysis laboratory? We hope that our findings will provide practically useful information that can help improve prosthetic fittings in the field.

The study will be based on data from up to 15 trans-tibial prosthesis users. Participants will walk with their standard prosthesis, which will be equipped with a small sensor unit for the measurement of forces and moments during walking. The muscle activity of the thigh muscles will be measured using surface EMG sensors. All of the data collection will take place at the USR facilities (115 E Reindl Way, Milwaukee), where a multi camera motion analysis system is set up. Trials will require an overall time commitment of 5 hours at most, and will include normal walking, walking on carpet and gravel, walking up and down stairs, walking with fatigued thigh muscles.

Conditions
Prosthesis User
Being tested
Alignment perturbations

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Alignment perturbationsDevice

    Increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation (always 2 degrees from the neutral position)

Study groups in NCT01332123
Study groupRoleWhat they receive
Alignment perturbationsExperimentalThe following modifications will be applied to the prostheses: increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation (always 2 degrees from the neutral position)
Receives: Device: Alignment perturbations

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Overall Asymmetry Index

    Gait data was continuously recorded and was post processed to determine symmetry between left and right legs. Symmetry was computed by dividing the difference between legs by the average of both legs. 0 marks perfect symmetry and greater values higher asymmetry. There is no maximum limit.

    The overall asymmetry index was calculated as the mean of the following: max knee flex, dorsi flexion, plantar flexion (1st and 2nd peak), knee moment, dorsi-flexion moment, plantar-flexion moment, times of max in % of the gait cycle, Stance phase % of gait cycle and step length.

    The kinematics asymmetry index was calculated as the mean of the following: maximal knee flex, dorsi flexion, plantar flexion (1st and 2nd peak), the times of max in % of the gait cycle, Stance phase % of gait cycle and step length.

    The kinetics asymmetry index was calculated as the mean of the following variables: knee moment, dorsi-flexion moment, plantar-flexion moment, the times of max in % of the gait cycle.

    Measured: 1 hour

Secondary outcomes (1)
  1. Heart Rate Change

    Subjects were wearing a wireless heart rate monitor. The respective readings were noted and assessed during and immediately following the trials to estimate individual exertion rates. Changes in heart rate between resting and exertion across the sample were investigated to be able to interpret the primary outcome measures and to discuss limitations of the protocol. Unequal exertion rates within the sample would cause uneven trends biomechanical changes that are related to exertion.

    Measured: 1 hour

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Apr 2011 (estimated)
  2. Study startApr 2011
  3. Primary completionNov 2011
  4. Study completionAug 2012

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
10 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01332123
Sponsor's protocol ID
UWM-11.254
Status last verified
Jun 2016
First submitted
6 Apr 2011
Last updated
9 Jun 2016
Data monitoring committee
No

Questions about this trial

What is this clinical trial studying?

A study testing Alignment perturbations in people with Prosthesis User, run by University of Wisconsin, Milwaukee at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 9 Jun 2016. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 9 Jun 2016). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Overall Asymmetry Index (time frame: 1 hour). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Jun 2016.

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