Adherence and Perspiration While Wearing Lower Limb Prostheses
Adherence and Perspiration While Wearing Lower Limb Prostheses
Individuals with lower limb amputation often complain about uncomfortable residual limb skin
 temperatures and the accumulation of sweat inside their prostheses. It doesn't take long
 before the presence of sweat on the residual limb leads to a lack of confidence in the
 security of their prosthetic suspension. Some circumstances allow the wearer to doff the
 prosthesis before it falls off, wipe it and the residual limb dry, and then don it again.
 Another option is to simply reduce the intensity of activities before sweat becomes a
 problem. However, the Warfighter amputee may not be afforded such accommodations. For these
 service personnel, inadequate moisture management can significantly limit or inhibit their
 mobility. The objective of the proposed research is to provide lower limb amputees who work
 in demanding environments with a prosthesis that remains secure despite profuse residual limb
 sweating without compromising residual limb health and comfort.

 The aim of this research is to compare three different, lower limb prosthetic suspension
 systems and identify which is most effective at maintaining a secure adherence when worn in
 conditions that result in profuse sweating. The investigators also aim to compare how the
 three study prostheses effect residual limb skin health and comfort when participants pursue
 their usual activities in the home, work, and community environments.

 To achieve these aims, the investigators will to recruit 25 below-knee amputees. Each subject
 will be asked to be asked to wear: (1) their as-prescribed prosthesis, (2) a prosthesis with
 a perforated elastomeric liner that allows sweat to flow away from the skin, and (3) a
 prosthesis that has a battery and body-weight activated pump to flow air between the
 prosthesis and the residual limb skin, allowing expulsion of any accumulated sweat. Subjects
 will wear each of these prostheses in the home, work, and community environments for two
 weeks, after which the investigators will measure their residual limb health and comfort.
 Subjects will then walk on a treadmill in a room whose climate will be set to Middle
 East-like conditions: 35 °C (95 °F) and 50% relative humidity. After 30 minutes, the
 investigators will measure any slippage of their prosthesis relative to their limb and how
 much sweat is expelled. The investigators hypothesize there will be differences in the amount
 of slippage, residual limb health, and comfort between the three prostheses.
Individuals with lower limb amputation often complain about uncomfortable residual limb skin
 temperatures, accumulation of perspiration inside their prostheses, and loss of confidence in
 suspension security that often leads them to cease their activities or, in demanding
 circumstances, may lead to their prosthesis falling off. Most amputees can sense the
 impending loss of suspension during vigorous activities and can stop, doff the prosthesis,
 wipe it and the residual limb dry, and then don it again. However, the Warfighter amputee may
 not be afforded such accommodations.

 The investigators will compare the performance of an individual's as-prescribed suspension
 with two exciting alternatives: a new-to-market liner intended to transport perspiration away
 from the skin and an improved version of the Dynamic Air Exchange (DAE) suspension system the
 investigators developed. The new-to-market suspension system consists of a perforated
 elastomeric liner that allows perspiration to be exuded into the liner-prosthesis space.
 Anecdotal reports suggest this liner (Uniprox's SoftSkin Air), can maintain suspension during
 profuse perspiration, but may result in excessive skin dryness and discomfort. The improved
 Dynamic Air Exchange - Rising Edge Design (DAE-RED) suspension expels accumulated
 perspiration using a vacuum pump like its predecessor, but incorporates hybrid, body-weight
 activated pump to minimize battery consumption and a revised ventilation system obviating the
 need for undesirable exterior tube connections.

 The objective of the proposed research is to provide lower limb amputees who work in
 demanding environments with a prosthesis that remains secure despite profuse residual limb
 perspiration without compromising residual limb health and comfort.

 The proposed research has two specific aims: (1) compare three different, lower limb
 prosthetic suspension systems and identify which is most effective at maintaining a secure
 adherence when worn in conditions that result in profuse perspiration, and (2) compare how
 the three suspension systems effect residual limb skin health and comfort when participants
 pursue their usual activities in the home, work, and community environments.

 The investigators will recruit unilateral transtibial amputees who are successful ambulators
 on their as-prescribed prosthesis and collect baseline data (residual limb skin hydration,
 transepidermal water loss (skin barrier function), and Socket Comfort Score). After fitting
 the participants with Uniprox and DAE-RED prostheses, subjects will wear one of these study
 prostheses (random order) for two weeks, after which the investigators will measure their
 skin hydration, transepidermal water loss, and Socket Comfort Score. The subject will then
 enter our environmental chamber (35° C and 50% relative humidity) and sit for a 30-minute
 acclimation period. The subject will then walk for 30 minutes on a treadmill at their
 self-selected speed. Subjects will then exit the environmental chamber and sit for 30 minutes
 in a comfortable climate (~20° C and 50% relative humidity). The amount of slippage, along
 with the perspiration accumulated/expelled, will be then be measured. Subjects will then be
 fit with their as-prescribed prosthesis and the protocol repeated to washout intervention
 effects. Finally, subjects will be fit with the other study prosthesis (either Uniprox or
 DAE-RED) and repeat the protocol.

 After wearing the prostheses in our environmental chamber set to Middle East-like conditions
 (35 °C and 50% relative humidity), the investigators hypothesize:

 H1.1 The amount of slippage (loss of adherence) will be different between the three
 suspension systems.

 H1.2 The amount of perspiration expelled will be different between the Uniprox and DAE-RED.

 After wearing the study prostheses in the home, work, and community environments for two
 weeks, the investigators hypothesize:

 H2.1 Residual limb skin hydration will be different between the three suspension systems.

 H2.2 Residual limb transepidermal water loss will be different between the three suspension
 systems.

 H2.3 The Socket Comfort Score will be different between the three suspension systems.
Inclusion Criteria:

 -  Unilateral transtibial amputation

 -  Been fit with a prosthesis and used it for at least six months

 -  Wear the prosthesis for four or more ours on an average day

 -  Ambulate without upper extremity aids

 -  Able to walk for 30 minutes on a treadmill

 Exclusion Criteria:

 -  Improper fit and suspension with current prosthesis and one cannot be achieved with
 clinical resources (determined at initial visit)

 -  Current skin irritation or injury on residual limb

 -  Osteoarthritis, injury, or pain that interferes with walking ability

 -  Currently incarcerated

 -  Pregnant (determined via self-report)

 -  Inadequate cognitive function or language proficiency to consent to participate

 -  High (>20%) coronary heart disease risk at 10 years as determined by heir Framingham
 Risk Score