Biomechanical Assessment of Gait in Lower-Extremity-Amputees

This study has been completed.
Information provided by (Responsible Party):
Goeran Fiedler, University of Wisconsin, Milwaukee Identifier:
First received: April 6, 2011
Last updated: December 9, 2013
Last verified: December 2013

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.

Condition Intervention
Prosthesis User
Device: Alignment perturbations

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Official Title: Biomechanical Assessment of Gait in Lower-Extremity-Amputees

Resource links provided by NLM:

Further study details as provided by University of Wisconsin, Milwaukee:

Primary Outcome Measures:
  • Gait symmetry [ Time Frame: 10 weeks ] [ Designated as safety issue: No ]
    Gait data will be continuously recorded and will be post processed to determine symmetry between left and right legs

Secondary Outcome Measures:
  • Heart rate [ Time Frame: 1 hour ] [ Designated as safety issue: No ]
    Subjects will wear a wireless heart rate monitor. The respective readings will be noted and assessed during and immediately following the trials

Enrollment: 10
Study Start Date: April 2011
Study Completion Date: August 2012
Primary Completion Date: November 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Alignment perturbations
The following modifications will be applied to the prostheses: increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation, increased foot outward rotation, increased foot inward rotation (always 15 degrees from the neutral position)
Device: Alignment perturbations
Increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation, increased foot outward rotation, increased foot inward rotation (always 15 degrees from the neutral position)

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.


Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

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

Exclusion Criteria:

  • 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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01332123

United States, Wisconsin
USR, 115 E Reindl Way
Milwaukee, Wisconsin, United States, 53211
Sponsors and Collaborators
University of Wisconsin, Milwaukee
Principal Investigator: Brooke A Slavens, PhD UWM CHS
  More Information

Responsible Party: Goeran Fiedler, Student-PI, University of Wisconsin, Milwaukee Identifier: NCT01332123     History of Changes
Other Study ID Numbers: UWM-11.254 
Study First Received: April 6, 2011
Last Updated: December 9, 2013
Health Authority: United States: Institutional Review Board processed this record on May 30, 2016