Thermoregulation in Individuals With a Leg Amputation

Thermoregulation in Individuals With a Leg Amputation: Mechanics and Vascular Physiology Factors to Understand Risks for Tissue Complications

The goal of this project is to understand the factors that affect skin temperature (e.g., tissue above amputation site, and opposite foot) in people with amputation and diabetes. This project will also test the effects of 'shock-absorbing' prosthesis on skin temperature responses.

Study Overview

• Status: Enrolling by invitation
• Conditions: Diabetes; Amputation
• Intervention / Treatment: Device: shock-absorbing prosthesis

Detailed Description

The overall goal of this project is to understand the factors that affect impaired temperature control in individuals with a leg amputation for areas vulnerable to damage, such as the tissue above the amputation site and the opposite intact foot. Abnormal tissue temperature is associated with risks for tissue damage, such as ulcers and pressure sores, especially in people with diabetes. In this study, we aim to study the effects of biomechanics and vascular physiology on tissue temperature responses. We will also determine the effectiveness of prosthetic shock-absorbing components in protecting the tissue from damage.

It is hypothesized that the temperatures of tissues above the amputation site and in the opposite intact foot are associated with mechanical factors during walking, such as shear forces and work (i.e., energy). It is also hypothesized that impaired temperature regulation, especially in people with diabetes, is associated with poor vascular function that inhibits effective blood circulation and oxygen delivery to affected tissues. Lastly, it is hypothesized that walking with a shock-absorbing prosthetic component can improve comfort and improve temperature regulation of tissues above the amputation site.

This project will recruit 40 individuals with a unilateral transtibial (below-knee) amputation, divided into two groups: with and without diabetes. All individuals will be given two sets of prostheses: with and without a shock-absorbing pylon (SAP). SAP is a modular prosthetic component that connects the socket and the foot components and allows added compression and twisting along the pylon. In both sets of prostheses conditions, the participants will wear the same foot component provided by the research team. For each of the two sets of prostheses (with and without SAP), the participants will make up to 5 visits to the laboratory (i.e., up to 10 total visits for the entire protocol). Each visit will involve data collections under a variety of walking tasks, such as walking on various slopes and turning. The same data collections will be repeated with the other set of prostheses.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Utah
    • Salt Lake City, Utah, United States, 84112-0920
      • University of Utah

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Individuals with a unilateral transtibial amputation, divided into two groups (with and without diabetes)
• Participants must classify as Medicare class K2 or higher (who can traverse low-level environmental barriers such as curbs, stairs or uneven surfaces).
• Participants must have undergone amputation at least 6 months prior.
• They must have the ability to walk for at least 10 continuous minutes without undue fatigue.

Exclusion Criteria:

• Neurological impairment that may affect walking function, such as stroke, severe traumatic brain injury, Parkinson's disease, and multiple sclerosis.
• History of inflammatory diseases, such as Raynaud's syndrome or rheumatoid arthritis.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Rigid Pylon; The prosthesis will be given a commercial prosthetic foot and a rigid pylon that connects the prosthetic foot to the socket.	Device: shock-absorbing prosthesis; the intervention will test the difference between rigid and shock-absorbing pylons, while the same prosthetic foot is applied in each condition.
Experimental: Shock-absorbing Pylon; The prosthesis will be given a commercial prosthetic foot and a compressive 'shock-absorbing' pylon that connects the prosthetic foot to the socket.	Device: shock-absorbing prosthesis; the intervention will test the difference between rigid and shock-absorbing pylons, while the same prosthetic foot is applied in each condition.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Walking mechanics	Mechanics of walking will be collected using a high-speed motion capture system and force-sensing platforms, which will quantify the motion of the legs and forces acting on the legs, respectively.	during the intervention/procedure/surgery
Vascular physiology - macrocirculation	Macrocirculation of the legs (i.e.,blood flow) will be recorded using a Doppler ultrasound probe secured over the thigh during walking	during the intervention/procedure/surgery
Vascular physiology - microcirculation	Microcirculation of the legs (i.e.,oxygen utility) will be recorded using near-infrared spectroscopy sensors placed on the thighs, calf, and top surface of the foot.	during the intervention/procedure/surgery
Temperature in lower limb	Temperatures of the skin above the amputation site and the opposite intact foot will be recorded using thermistors and a thermal imaging camera.	during the intervention/procedure/surgery
Comfort	Participants will complete a self-reported questionnaire to indicate comfort while walking with a prosthesis.	during the intervention/procedure/surgery

Collaborators and Investigators

• Sponsor: University of Utah
• Investigators: Principal Investigator: Kota Takahashi, University of Utah

Study record dates

Study Major Dates

• Study Start (Actual): May 7, 2024
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): July 31, 2027

Study Registration Dates

• First Submitted: June 6, 2024
• First Submitted That Met QC Criteria: June 11, 2024
• First Posted (Actual): June 13, 2024

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 12, 2026
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Nutritional and Metabolic Diseases; Diabetes Mellitus
• Other Study ID Numbers: 00155345

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No