Reduction of Shear Forces Using Semi-flexible Sockets on Transtibial Amputees

Loma Linda University (LLU)

Status: Completed

Conditions: Amputation

Treatments: Other: semi flexible socket; Other: rigid fiber socket

Study type: Interventional

Funder types: Other

Identifiers

NCT03390153

5170454

Details and patient eligibility

About

The purpose of this graduate student research study, is to test two different sockets for comfort and test what pressures are created by the socket during daily activities. The objective is to illustrate that semi-flexible sockets will maintain its rigidity and resist progressive shear forces from daily activity, ergo making our prosthetic system a more comfortable experience for the prosthetic user.

Full description

Subjects will immediately be prepared for a casting of their residual limb. On the second visit, subjects will return to be fitted with a definitive rigid carbon fiber socket. At this time, a questionnaire and physical assessments will determine subjects comfort and safety. The physical assessment consists of a ten minute walk on a treadmill, at a self-selected pace. A balancing test on a SMART Balance Master will also be used to assess subject safety, by utilizing the limits of stability protocol. Subjects' will be required to wear the prosthesis given to them for one week before returning for a follow-up appointment. On the third visit, the subjects' will return the first prosthesis to the investigators of the study, where an additional socket will be given to the subject for the second portion of this study. Subjects will be evaluated with a questionnaire and physical assessments to determine comfort and safety. Participants will be required to wear the prosthesis given to them for one week before returning for a follow-up appointment. During the final appointment, the subjects will return all devices given to them to an investigator of the study.

Enrollment: 5 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Transtibial amputee with mature limb
• Minimum of 3-years of prosthetic use
• Capable of ambulating on a treadmill for ten minutes
• Minimum age of 18 years old
• Both Unilateral and Bilateral Amputees
• K-Level K2-K4

Exclusion criteria

• Any open wounds/ulcerations on the residual limb
• Skin allergies to silicone or latex
• Unmanaged co-morbidities such a diabetes and congestive heart failure

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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5 participants in 2 patient groups

semi flexible socket group

Experimental group

Description:

A new form of residuum containment is the semi-flexible carbon fiber prosthetic socket. A semi-flexible carbon fiber socket is constructed with the same security for the subject in mind, and is even more lightweight than a rigid socket. The carbon fiber and resin used in a semi-flexible socket may provide the same durability and stability as previous designs, but will deform, intentionally, without failing (breaking). This distinct feature of semi-flexible sockets makes them a potential option for people living with limb loss. By moving slightly with the residual limb, the socket-user-interface should experience fewer forces/stresses, and yield greater comfort for the prosthetic user.

Treatment:

Other: semi flexible socket

rigid fiber socket group

Active Comparator group

Description:

A rigid carbon fiber socket is constructed for security and is mechanically lightweight to ensure stability and efficient build height. Carbon is used for its durability and stability. It proves to be a detriment in comfort and flexibility. The standard for carbon fiber weaves come in two forms: Unidirectional (UD) and Bidirectional (BD). UD carbon fiber has a zero-degree alignment, which is highly durable when compressed, but has low torsional durability. The BD carbon fibers are aligned in a 90 degree angle allowing for moderate compression and torsional strength. When oriented at 45 degrees to the line of progression, fibers become more flexible and exhibit greater torsional strength. Resins and glass composites are added to ensure security and sturdiness.

Treatment:

Other: rigid fiber socket