INVESTIGATION OF THE EFFECTS OF PROSTHETIC KNEE CONDITION FOR INDIVIDUALS WITH TRANSFEMORAL AMPUTATION DURING ATTEMPTED RUNNING

BACKGROUND: A number of individuals with unilateral transfemoral amputation (TFA) run in a prosthesis with an unlocked prosthetic knee, while others choose to run with a locked prosthetic knee to increase stability. Research regarding running with an unlocked knee (UK) versus a locked knee (LK), with respect to energy efficiency, is limited and might be enhanced by characterization of the impact of knee condition on kinematics. OBJECTIVE: To investigate the effect of an UK versus LK on hip kinematics, energy efficiency, and running speed. METHODOLOGY: Five male novice runners with unilateral TFA completed one three-minute self-selected running speed (SSRS) trial and three peak speed trials per knee condition. Hip kinematics, energy efficiency, and running speed were compared between conditions. FINDINGS: Four of the five subjects exhibited a fast walk, rather than a consistent run. Hip flexion increased for all subjects and hip abduction decreased for four subjects during swing phase for the UK condition. Hip kinematic asymmetry was reduced for the UK condition in the sagittal plane for four individuals; hip kinematic asymmetry was also reduced in the frontal plane for the UK condition for three of these individuals. Mean energy efficiency was better for the UK condition (UK: 0.282 mLO2/kg/m, LK: 0.328 mLO2/kg/m). Peak running speed did not differ significantly between knee conditions (UK: 1.47 m/s, LK:1.32 m/s). CONCLUSIONS: For novice recreational runners with unilateral transfemoral amputation, the UK condition resulted in improved energy efficiency and enhanced kinematic symmetry, despite comparable peak speed relative to the LK condition. Therefore the UK condition may be advantageous for mid-range distance running. Layman's Abstract Runners with above-knee amputation may run with a prosthetic leg. Some runners prefer to run with their prosthetic knee unlocked, able to flex and extend, while others prefer to run with the prosthetic knee locked. The purpose of this study was to determine the effects of unlocked and locked knee conditions on hip motion, energy efficiency, and running speed during attempted running. Five male novice runners with an amputation above the knee attempted running for three-minutes at a comfortable speed, followed by three fast walks/sprints with the prosthetic knee unlocked and then locked. Most of the novice runners exhibited more symmetric hip motion while fast walking/running with an unlocked prosthetic knee. All our subjects were more energy efficient or exerted less energy with the unlocked prosthetic knee. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/34481/26590 How To Cite: Blakeley N., Silver-Thorn B., Cross J.A. Investigation of the effects of prosthetic knee condition for individuals with transfemoral amputation during attempted running. Canadian Prosthetics & Orthotics Journal. 2020; Volume 3, Issue 2, No.3. https://doi.org/10.33137/cpoj.v3i2.34481 Corresponding Author:Natalie Blakeley, Department of Biomedical Engineering, Marquette University, Milwaukee, USA. E-mail: Blakeley.natalie@gmail.comORCID: https://orcid.org/0000-0002-2066-4096