Comparative Performance of Dynamic Elastic Response Feet

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02542761

Enrollment

Registered

2015-09-07

Start date

2015-06-30

Completion date

2016-05-31

Last updated

2018-09-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Transtibial Amputation - Unilateral

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.

Interventions

DEVICEFiberglass Composite foot

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

DEVICECarbon Fiber Composite Foot

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

Study design

Allocation

NON_RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

NONE

Intervention model description

This was a repeated measures cross-over trial whereby only the prosthetic foot was changed. Each subject was tested using their current carbon-fiber prosthetic foot (CFPF), and the fiberglass prosthetic foot (FPF). Half of the subjects began the study on the CFPF while the other half began on the FPF. Each subject was given an acclimation period of 4 weeks before testing.

Eligibility

Sex/Gender

ALL

Age

21 Years to No maximum

Healthy volunteers

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)

Design outcomes

Primary

Measure	Time frame	Description
Peak Ankle Dorsiflexion During Stance	After approximate 4 week acclimation period	The peak ankle dorsiflexion is the peak ankle backward flexion or bending when walking.

Secondary

Measure	Time frame	Description
Peak Ankle Plantar Flexor Moment During Stance	After approximate 4 week acclimation period	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).
Peak Ankle Power Generation	After approximate 4 week acclimation period	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.
Peak Knee Flexion During Swing	After approximate 4 week acclimation period	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.
Time of Peak Knee Flexion During Swing	After approximate 4 week acclimation period	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.
Patient Satisfaction as Measured by the Prosthesis Evaluation Questionnaire (PEQ)	After approximate 4 week acclimation period	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.

Countries

United States

Participant flow

Recruitment details

Subjects were recruited at Mayo Clinic in Rochester, Minnesota.

Participants by arm

Arm	Count
Entire Study Population Includes groups studying CFPF first and FPF first.	10
Total	10

Baseline characteristics

Characteristic	Entire Study Population
Age, Categorical <=18 years	0 Participants
Age, Categorical >=65 years	0 Participants
Age, Categorical Between 18 and 65 years	10 Participants
Age, Continuous	49 years STANDARD_DEVIATION 9
Body Mass Index (BMI)	29 kg/m^2 STANDARD_DEVIATION 7
Region of Enrollment United States	10 Participants
Sex: Female, Male Female	0 Participants
Sex: Female, Male Male	10 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	0 / 10	0 / 10
other Total, other adverse events	0 / 10	0 / 10
serious Total, serious adverse events	0 / 10	0 / 10