Application of external socket reaction moments to quantify uni-lateral transtibial prosthetic alignment

Alignment of the prosthesis is currently an un-quantified iterative process,
based on observation and communication between certified prosthetist and
patient. Inadequate alignment results in compensatory mechanisms of the
amputee. Assessment of symmetrical walking by exclusively looking at kinematic
gait deviations, excludes the adaptability of the human body. Recently the
moments working at the base of the socket are used in an effort to quantify
prosthetic alignment, with promising results. There is a necessity for
evidence-based clinical practice in relation to prosthetic alignment and
quantification, enabling prosthetists to provide evidence based clinical
interventions.

The primary objective of this study is to investigate whether computer assisted
prosthetic alignment can influence the average external socket reaction moments
in the frontal plane during stance phase for transtibial amputees. The
secondary objective is to investigate whether an external socket reaction
moment can be altered to an standardized mean external socket reaction moment
during stance for different amputees.

The patient*s comfortable walking speed will be determined on their daily
prosthetic and used for further testing. A certified prosthetist (CP) will
receive all the prosthetic components, i.e. prosthetic foot, tube, adapter,
Intelligent Prosthetic Endo-Skeletal Component System (iPecs-system),
pin-system, prosthetic socket, shoes and will be asked to do a bench alignment.
Where after, a prosthetic dynamic alignment will be preformed. Gait data will
be measurement by the Gait Real-time Analysis Interactive Lab (GRAIL) and
iPecs. After dynamic alignment the real-time external socket reaction moment
(ESRM) will be shown on the GRAIL*s screen. The CP will fine-tune the
prosthetic alignment by the mean external socket reaction moment during stance
phase.

The burdens or risks associated with this research are not different from the
risks and burdens of patients normally visiting a Prosthetics and Orthotics
facility. A better understanding of alignment and achieving a more quantifiable
approach will result in a more reliable alignment session inside prosthetic
facilities. Where after, evidenced based alignment could reduce the risk on
secondary condition, associated with a wrong alignment.