Comparative Performance of Dynamic Elastic Response Feet

Transtibial Amputation - Unilateral Clinical Trial

Official title:

Comparative Performance of Dynamic Elastic Response Feet

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02542761
• Other study ID #: 15-001367
• Status: Completed
• Phase: N/A
• Start date: June 2015
• Est. completion date: May 2016

Study information

• Verified date: August 2018
• Source: Mayo Clinic
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 10
• Est. completion date: May 2016
• Est. primary completion date: December 2015
• Accepts healthy volunteers: No
• Gender: All
• Age group: 21 Years and older

Eligibility

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)

Related Conditions & MeSH terms

• Transtibial Amputation - Unilateral

Intervention

Device:
• Fiberglass Composite foot
The Rush foot is a fiberglass composite energy storage and return prosthetic foot.
• Carbon Fiber Composite Foot
All types of currently commercially available carbon fiber energy storage and return prosthetic feet will be considered appropriate.

Locations

Country	Name	City	State
United States	Mayo Clinic	Rochester	Minnesota

Sponsors (1)

Lead Sponsor	Collaborator
Mayo Clinic

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Peak Ankle Dorsiflexion During Stance	The peak ankle dorsiflexion is the peak ankle backward flexion or bending when walking.	After approximate 4 week acclimation period
Secondary	Peak Ankle Plantar Flexor Moment During Stance	Peak ankle plantar flexor moment means the peak force of the movement of the foot in which the foot or toes flex downward toward the sole. The unit of measurement for this variable is Nm/kg = 1 nanometer / (kilogram unit).	After approximate 4 week acclimation period
Secondary	Peak Ankle Power Generation	Joint power (P) is the "dot product" of the moment (M) at the joint and the angular velocity (w) of the distal segment with respect to the proximal segment (i.e., P = M · w). Depending on the direction of the moment and the direction of the angular velocity, the power can be positive or negative. If the signs for the moment and angular velocity are both positive or both negative, the power is positive. If the signs for the moment and angular velocity are different, the power is negative. The unit of measurement for this variable is W/kg = watts/kilogram.	After approximate 4 week acclimation period
Secondary	Peak Knee Flexion During Swing	A gait cycle is the period of time for one stride, that is, the time from one event (usually initial foot contact) to the next occurrence of the same event with the same foot. For each leg, the gait cycle can be divided into a stance phase and a swing phase. This variable is measuring the angle of knee flexion during the swing phase.	After approximate 4 week acclimation period
Secondary	Time of Peak Knee Flexion During Swing	A gait cycle is the period of time for one stride, that is, the time from one event (usually initial foot contact) to the next occurrence of the same event with the same foot. For each leg, the gait cycle can be divided into a stance phase and a swing phase. This variable is expressed as a percentage of the gait cycle.	After approximate 4 week acclimation period
Secondary	Patient Satisfaction as Measured by the Prosthesis Evaluation Questionnaire (PEQ)	The PEQ is a self-administered questionnaire composed of nine scales computed from forty-two items (ambulation, appearance, frustration, perceived response, residual limb health, social burden, sounds, utility, well being). Each question uses a visual analog scale format, scored as a continuous numerical variable measured as the distance in millimeters from the left endpoint of the measured from the left (0-100). The 0 side of the scale is very negative (terrible) and the 100 side of the scale is very positive (excellent). Each scale is reported separately, with a higher score indicating more satisfaction with the prosthesis itself or quality of life.	After approximate 4 week acclimation period