Physiologic Range of Step-by-step Variations in Lower Limb Prosthesis Forces During Walking

NCT02234505 | Completed

• 1 other identifier: PRO14040403
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

In human gait there is a certain amount of variation between steps; some considered physiological and owed to variations in environment or posture, and some severe enough to be indicative of gait instabilities that may lead to stumbling and falling. In users of lower limb prosthetics, such gait instabilities are of especially great interest. The study investigates the correlation between socket alignment quality and gait step-by-step variability in users of trans-tibial-prosthetics. It is hypothesized that a clearly defined range of step-by-step variability exists, and that therefore step-by-step variability is suitable as an outcome variable for the assessment of socket alignment. A sample of ten persons with trans-tibial amputation will be recruited for this pilot study. Subjects will be asked to walk on different natural surfaces while the socket alignment is successively perturbed. Step-by-step variations in horizontal ground reaction forces and torsional moments will be measured and statistically compared.

Conditions

Trans-tibial Limb Loss

Keywords

prosthetics; amputation; gait stability; step variability; load cell

Outcome Measures

Primary Outcomes (1)

• Step-by-step variability

  Peak horizontal ground reaction force (Fx and Fy) as well as peak axial torsion moment (Mz) will be extracted for 10 consecutive intermediary steps for each testing condition. Total range in Newtons over the 10 step sample, as well as maximal difference between consecutive steps in Newtons and percent will be reported for statistical analysis.

  2 hours

Study Arms (1)

Trans-tibial prosthesis users

EXPERIMENTAL

prosthetic alignment perturbation

Procedure: Prosthetic alignment perturbation

Interventions

Prosthetic alignment perturbation PROCEDURE

Prosthetic ankle plantar-flexion will be modified in different degrees, devices (prosthetic components) will not be modified from baseline condition

Trans-tibial prosthesis users

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• activity classification of K2 to K4
• experience in prosthesis use of at least one year
• stated ability to walk pain free for at least 30 minutes

You may not qualify if:

• age of less than 18 years
• acute or ongoing residual limb pain
• use of a prosthesis that is not suitable for installation of the load cell (e.g. is too short, or has non-removable cosmesis)

Sponsors & Collaborators

• University of Pittsburgh: lead
• American Orthotic and Prosthetic Association: collaborator

Study Sites (1)

Bakery Square MSPO labs

Pittsburgh, Pennsylvania, 15206, United States

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: August 28, 2014
• First Posted: September 9, 2014
• Study Start: September 1, 2014
• Primary Completion: August 1, 2015
• Study Completion: November 1, 2015
• Last Updated: December 4, 2015

Record last verified: 2015-12

Locations

US (1)