Comparative Performance of Dynamic Elastic Response Feet

NCT ID: NCT02542761

Last Updated: 2018-09-20

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2015-06-30
• Study Completion Date: 2016-05-31

Brief Summary

The purpose of this study was to compare the functional performance of individuals with transtibial amputation using two types of prosthetic foot designs: carbon fiber vs. fiberglass composite.

Detailed Description

Recently, a new type of prosthetic foot has appeared on the market. This device is composed of a fiberglass composite material. Knowledge is lacking regarding the performance characteristics of this new device. Comprehensive studies are needed to form a solid basis for prosthetic prescription. The current study sought to understand the experience of community-living, transtibial amputees using this prosthetic foot. Specifically, the biomechanical performance of this device were compared to existing conventional dynamic elastic response (DER) technology in a controlled laboratory setting. The investigators hypothesized that the fiberglass composite material provided more energy return and improved ankle kinematics performance.

The study design was a repeated measures cross-over trial whereby only the prosthetic foot was changed. Each subject was tested using their current carbon-fiber energy storage and return prosthetic foot (CFPF) and the fiberglass composite energy storage and return prosthetic foot (Rush, Ability Dynamics) (FPF). Half of the subjects began the study on the CFPF while the other half began on the FPF. All types of CFPF were used in this study. Each subject was given an acclimation period (about 4 weeks) before testing, which was consistent with other similar studies. The same socket and suspension were used throughout the study in order to eliminate these confounding variables.

A 10 camera, high resolution motion capture system with a set of 51 reflective markers was used to capture whole-body motion. Three-dimensional marker trajectory data was collected at 120 Hz and filtered using a fourth-order Butterworth low-pass filter with a cutoff frequency of 8 Hz. The standard Helen Hayes marker set and some additional markers were applied to the subject. Additional markers included an anterior pylon marker, medial pylon marker, lateral pylon marker, right and left medial calcaneus markers, and right and left lateral calcaneus markers. In addition, left and right medial knee markers were used for establishing the knee joint centers and were then removed for the walking trails. Subjects wore standard laboratory athletic shoes for all walking trials. All of the markers associated with the foot were placed on the outside of the subject's shoes.

Following the application of the reflective marker set, the subject performed tests while walking over level ground at a self-selected and normalized speed as well as up and down a 10 degree inclined ramp. The normalized speed controlled for leg length by normalizing to a Froude (Fr) number of 0.25 where Fr = v^2/gl, and v is the walking speed, g is the gravitational constant, and l is the leg length using the greater trochanter height as leg length. Timing gates were used to control the walking speed. Simultaneously, ground reaction force data was collected from force plates at a sampling rate of 600 Hz. Data from these force plates was time-synchronized with the motion cameras. The ramp had a force plate embedded within the ramp.

Conditions

Transtibial Amputation - Unilateral

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

CFPF first, then FPF

After a 4 week acclimation period, subjects were studied on their current carbon fiber composite foot (CFPF), followed by another 4 week acclimation period, then studied on the study provided fiberglass composite foot (FPF).

Group Type: EXPERIMENTAL

Fiberglass Composite foot

Intervention Type: DEVICE

The Rush foot is a fiberglass composite energy storage and return prosthetic foot.

Carbon Fiber Composite Foot

Intervention Type: DEVICE

All types of currently commercially available carbon fiber energy storage and return prosthetic feet will be considered appropriate.

FPF first, then CFPF

After a 4 week acclimation period, subjects were studied on the study provided fiberglass composite foot (FPF), followed by another 4 week acclimation period, then studied on their current carbon fiber composite foot (CFPF).

Group Type: EXPERIMENTAL

Fiberglass Composite foot

Intervention Type: DEVICE

The Rush foot is a fiberglass composite energy storage and return prosthetic foot.

Carbon Fiber Composite Foot

Intervention Type: DEVICE

All types of currently commercially available carbon fiber energy storage and return prosthetic feet will be considered appropriate.

Interventions

Fiberglass Composite foot

The Rush foot is a fiberglass composite energy storage and return prosthetic foot.

Intervention Type: DEVICE

Carbon Fiber Composite Foot

All types of currently commercially available carbon fiber energy storage and return prosthetic feet will be considered appropriate.

Intervention Type: DEVICE

Other Intervention Names

Rush Foot; Otto Bock Triton; Ossur Variflex; Ossur Variflex EVO; Ossur Reflex Shock; Freedom Renegade; Freedom Pacifica; Freedom Thrive with Vertical Shock; Freedom Highlander; Freedom Agilix

Eligibility Criteria

Inclusion Criteria

• Unilateral transtibial amputee
• Currently using a carbon fiber prosthetic (DER) foot for at least the last 6 months
• Stable stump volume over the past 6 months
• Medicare Functional Classification Level K3 or K4

Exclusion Criteria

• Neuromuscular problems such as previous stroke or contralateral amputation
• Use of gait aids for ambulation
• Undergoing dialysis
• Poor prosthetic socket fit or stump problems (e.g., skin breakdown)

• Minimum Eligible Age: 21 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Mayo Clinic

OTHER

Sponsor Role: lead

Responsible Party

Kenton R. Kaufman, Ph.D.

PI

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Kenton R Kaufman, PhD

Role: PRINCIPAL_INVESTIGATOR

Mayo Clinic

Locations

Mayo Clinic

Rochester, Minnesota, United States

Countries

United States

References

Kaufman KR, Bernhardt K. Functional performance differences between carbon fiber and fiberglass prosthetic feet. Prosthet Orthot Int. 2021 Jun 1;45(3):205-213. doi: 10.1097/PXR.0000000000000004.

Reference Type: DERIVED

PMID: 33856155 (View on PubMed)

Other Identifiers

15-001367

Identifier Type: -

Identifier Source: org_study_id