Lower limb amputation has been associated with secondary impairments such as knee osteoarthritis in the uninvolved limb. Greater knee loading in the frontal plane has been related to severity and rate of progression in knee osteoarthritis. Reduced push-off work from the involved limb can increase uninvolved limb knee loading. However, little is known about specific effects that prosthetic foot damping may have on uninvolved limb loading. We hypothesized that uninvolved limb peak knee internal abduction moment (IAM) and loading rates would be greater when using a high-damping foot compared with a low-damping foot, across walking speeds. Eight healthy, young subjects walked in a prosthesis simulator boot using the experimental feet. Greater uninvolved limb first peak IAM (+16% in fast speed, P = .002; +11% in slow speed, P = .001) and loading rates (+11% in fast speed, P = .003) were observed when using the high-damping foot compared with low-damping foot. Within each foot, uninvolved limb first peak IAM and loading rates had a trend to increase with increased walking speed. These findings suggest that damping properties of prosthetic feet are related to uninvolved limb peak knee IAM and loading rates.
Search Results
The Effect of High- and Low-Damping Prosthetic Foot Structures on Knee Loading in the Uninvolved Limb Across Different Walking Speeds
Li Jin, Peter G. Adamczyk, Michelle Roland, and Michael E. Hahn
Does Decreasing Below-Knee Prosthesis Pylon Longitudinal Stiffness Increase Prosthetic Limb Collision and Push-Off Work During Gait?
Matthew J. Major, José L. Zavaleta, and Steven A. Gard
impact of prosthetic foot properties on user performance, no studies to date have systematically investigated the effects of modifications in prosthesis longitudinal stiffness. This variable is uniquely relevant to commonly prescribed shock-absorbing pylons (SAPs). The longitudinal stiffness of SAPs can
Daily Activity of Individuals With an Amputation Above the Knee as Recorded From the Nonamputated Limb and the Prosthetic Limb
Kerstin Hagberg, Roland Zügner, Peter Thomsen, and Roy Tranberg
amputation are not physically active enough to meet health recommendations ( Langford et al., 2019 ), increasing the risk of developing metabolic syndrome ( Bhatnagar et al., 2019 ). Among amputees, positive relationships have been reported between prosthetic mobility and quality of life and general
Self-Reported Functional Mobility, Balance Confidence, and Prosthetic Use Are Associated With Daily Step Counts Among Individuals With a Unilateral Transtibial Amputation
Jaclyn Megan Sions, Elisa Sarah Arch, and John Robert Horne
sedentary behavior are independent predictors of morbidity and subsequent mortality. 4 , 5 Nonmodifiable factors, such as sex, 6 , 7 age, 7 time since the amputation, 8 and comorbidities (regardless of the cause of the amputation) 8 – 13 have been found to impact prosthetic use and/or physical activity
Effects of Prosthetic Mass Distribution on Metabolic Costs and Walking Symmetry
Jeremy D. Smith and Philip E. Martin
Unilateral, transtibial amputees exhibit walking asymmetries and higher metabolic costs of walking than nonamputees walking at similar speeds. Using lightweight prostheses has previously been suggested as a contributing factor to walking asymmetries. The purpose was to investigate the effects of prosthesis mass and mass distribution on metabolic costs and walking asymmetries among six unilateral, transtibial amputees. Kinematic and temporal symmetry did not improve when mass was added at different locations on the limb. Stance and swing time asymmetries increased by 3.4% and 7.2%, respectively, with loads positioned distally on the limb. Maximum knee angular velocity asymmetries increased by 6% with mass added to the thigh, whereas maximum thigh angular velocity asymmetries increased by approximately 10% with mass positioned near the prosthetic ankle. Adding 100% of the estimated mass difference between intact and prosthetic legs to the ankle of the prosthesis increased energy costs of walking by 12%; adding the same mass to the prosthesis center of mass or thigh center of mass increased metabolic cost by approximately 7% and 5%, respectively. Unless other benefits are gained by increasing prosthesis mass, this should not be considered as a possible alternative to current lightweight prosthesis designs currently being prescribed to unilateral amputees.
Pedaling Asymmetries in Cyclists With Unilateral Transtibial Amputation: Effect of Prosthetic Foot Stiffness
W. Lee Childers, Robert S. Kistenberg, and Robert J. Gregor
Cyclists with unilateral transtibial amputation (CTA) provide a unique model to study integration of the neuromuscular and bicycle systems while having the option to modify this integration via the properties of the prosthesis. This study included eight CTA and nine intact cyclists. The cyclists pedaled on a stationary bicycle with instrumented force pedals. The CTA group pedaled with a stiff or flexible prosthetic foot during a simulated time trial and a low difficulty condition. During the time trial condition, pedaling with the flexible foot resulted in force and work asymmetries of 11.4% and 30.5%, the stiff foot displayed 11.1% and 21.7%, and the intact group displayed 4.3% and 4.2%, respectively. Similar trends were shown in the low difficulty condition. These data suggest foot stiffness has an effect on cycling symmetry in amputees.
Prosthetic Devices and Performance Enhancement
Monique Mokha and Richard Conrey
Column-editor : G. Monique Mokha
Robotic Devices to Enhance Human Movement Performance
Daniel P. Ferris and Bryan R. Schlink
Robotic exoskeletons and bionic prostheses have moved from science fiction to science reality in the last decade. These robotic devices for assisting human movement are now technically feasible given recent advancements in robotic actuators, sensors, and computer processors. However, despite the ability to build robotic hardware that is wearable by humans, we still do not have optimal controllers to allow humans to move with coordination and grace in synergy with the robotic devices. We consider the history of robotic exoskeletons and bionic limb prostheses to provide a better assessment of the roadblocks that have been overcome and to gauge the roadblocks that still remain. There is a strong need for kinesiologists to work with engineers to better assess the performance of robotic movement assistance devices. In addition, the identification of new performance metrics that can objectively assess multiple dimensions of human performance with robotic exoskeletons and bionic prostheses would aid in moving the field forward. We discuss potential control approaches for these robotic devices, with a preference for incorporating feedforward neural signals from human users to provide a wider repertoire of discrete and adaptive rhythmic movements.
Foot Orthoses: Materials and Manufacturers
Dan Minert
Optimal Starting Block Configuration in Sprint Running: A Comparison of Biological and Prosthetic Legs
Paolo Taboga, Alena M. Grabowski, Pietro Enrico di Prampero, and Rodger Kram
In the 2012 Paralympic 100 m and 200 m finals, 86% of athletes with a unilateral amputation placed their unaffected leg on the front starting block. Can this preference be explained biomechanically? We measured the biomechanical effects of starting block configuration for seven nonamputee sprinters and nine athletes with a unilateral amputation. Each subject performed six starts, alternating between their usual and unusual starting block configurations. When sprinters with an amputation placed their unaffected leg on the front block, they developed 6% greater mean resultant combined force compared with the opposite configuration (1.38 ± 0.06 vs 1.30 ± 0.11 BW, P = .015). However, because of a more vertical push angle, horizontal acceleration performance was equivalent between starting block configurations. We then used force data from each sprinter with an amputation to calculate the hypothetical starting mechanics for a virtual nonamputee (two unaffected legs) and a virtual bilateral amputee (two affected legs). Accelerations of virtual bilateral amputees were 15% slower compared with athletes with a unilateral amputation, which in turn were 11% slower than virtual nonamputees. Our biomechanical data do not explain the starting block configuration preference but they do explain the starting performance differences observed between nonamputee athletes and those with leg amputations.
