Impact of Powered Knee-Ankle Prosthesis on Low Back Muscle Mechanics in Transfemoral Amputees: A Case Series

Abstract

Regular use of prostheses is critical for individuals with lower limb amputations to achieve everyday mobility, maintain physical and physiological health, and achieve a better quality of life. Use of prostheses is influenced by numerous factors, with prosthetic design playing a critical role in facilitating mobility for an amputee. Thus, prostheses design can either promote biomechanically efficient or inefficient gait behavior. In addition to increased energy expenditure, inefficient gait behavior can expose prosthetic user to an increased risk of secondary musculoskeletal injuries and may eventually lead to rejection of the prosthesis. Consequently, researchers have utilized the technological advancements in various fields to improve prosthetic devices and customize them for user specific needs. One evolving technology is powered prosthetic components. Presently, an active area in lower limb prosthetic research is the design of novel controllers and components in order to enable the users of such powered devices to be able to reproduce gait biomechanics that are similar in behavior to a healthy limb. In this case series, we studied the impact of using a powered knee-ankle prostheses (PKA) on two transfemoral amputees who currently use advanced microprocessor controlled knee prostheses (MPK). We utilized outcomes pertaining to kinematics, kinetics, metabolics, and functional activities of daily living to compare the efficacy between the MPK and PKA devices. Our results suggests that the PKA allows the participants to walk with gait kinematics similar to normal gait patterns observed in a healthy limb. Additionally, it was observed that use of the PKA reduced the level of asymmetry in terms of mechanical loading and muscle activation, specifically in the low back spinae regions and lower extremity muscles. Further, the PKA allowed the participants to achieve a greater range of cadence than their predicate MPK, thus allowing them to safely ambulate in variable environments and dynamically control speed changes. Based on the results of this case series, it appears that there is considerable potential for powered prosthetic components to provide safe and efficient gait for individuals with above the knee amputation.

Multidimensional Approach to Frailty

“…Depending on the tool used to assess the nutritional status, the percentage of malnourished patients before cardiac surgery varies between 4.6 and 19.1% (Lomivorotov et al, 2013). In patients qualified for cardiac surgery, abnormal nutrition correlates with increased morbidity, mortality, prolonged hospitalization, abnormal wound healing, and delayed benefits of postoperative cardiac rehabilitation (Arai et al, 2018;Jayaraman et al, 2018). Pre-operative identification of nutritional risk is extremely important for predicting complications and surgical results in cardiac surgery (Ringaitiene et al, 2016).…”

A Phase Variable Approach for Improved Rhythmic and Non-Rhythmic Control of a Powered Knee-Ankle Prosthesis

“…For comparing the joint angle trajectories of the prosthetic legs with those of the reference able-bodied subjects (adopted from [8]), we computed the Pearson correlation coefficient for each case, as in [25]. In the ideal case (trajectories identical to reference able-bodied trajectories), this coefficient would be equal to 1.…”

“…In [25], the positive effects of a powered leg on back muscles and gait energy expenditure were investigated. Such symptoms often originate from compensations that amputees adopt to overcome the lack of power in passive prostheses [26]- [29].…”

Modeling the Kinematics of Human Locomotion Over Continuously Varying Speeds and Inclines

“…One example is the Vanderbilt Generation 3 powered knee and ankle prosthesis. This device has been shown to allow amputees to walk with gait kinematics that are similar to the normal gait kinematics of subjects with healthy limbs, and is showing promising results in terms of metabolic performance and minimizing back muscle activation related to the risk of low back pain [1].…”