Disclosures: Loc Lam, Medical Student: No financial relationships or conflicts of interest
Objective: Over 10,000 amputees in Vietnam have been fitted with the patented Mercer prosthetic devices (MUP) though Mercer on Mission program since 2009. The aims of this study is to analyze the extended muscle activity in the lower extremities of the Transtibial amputees wearing their custom made prosthesis and MUP.
Design: Observational Design Setting : The participants wearing the custom made prosthesis and then MUP were instructed to walk on treadmill at a constant speed while their lower extremities’ muscles were taken using a wireless Noraxon Desktop DTS EMG system. Participants : Twenty Transtibial Vietnamese amputees (32-55 years old) participated in this study.
Interventions: Paired t-test were performed using SPSS program. All P values are the result of two tailed statistical tests, with valued of P < 0.05 regarded as significant.
Main Outcome Measures: The EMG targeting muscles group are lateral gastrocnemius (LG), tibialis anterior (TA) of the residual limbs, rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST) and biceps femoris long head (BF) muscles both residual limb and natural limb.
Results: In generally MUP causes a greater change in mean muscle activity especially in the RF (15%, p=0.762) and VL (9%, p=0.631) of the residual limb. In addition, there is also a significant decrease in the knee flexors activity (-23%, p=0.423 for BF and -17%, p=0.374 for ST) of the residual leg especially in stance phase. Conclusions: These changes in muscle activity pattern of the MUP can be attributed to the ankle propulsion feature of the prosthetic design. MUP obtains the C-shape foot design that provides ankle dorsiflexion/plantarflexion during walking. It also help to absorb energy during stance phase and provide push-off in pre-swing to help in the forward propulsion of the amputee. The lightweight feature of MUP seems to contribute for energy consumption rather than directly affect on muscle activity of the Transtibial amputees fit with the MUP devices.
Level of Evidence: Level IV
To cite this abstract in AMA style:
Lam L, LE TT, Vo H, Nguyen BN. The Study of Muscle Activities of Below Knee Amputee Fit with Mercer® Universal Prosthesis [abstract]. PM R. 2020; 12(S1)(suppl 1). https://pmrjabstracts.org/abstract/the-study-of-muscle-activities-of-below-knee-amputee-fit-with-mercer-universal-prosthesis/. Accessed May 14, 2025.« Back to AAPM&R Annual Assembly 2020
PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/the-study-of-muscle-activities-of-below-knee-amputee-fit-with-mercer-universal-prosthesis/