We examined whether pediatric prosthetic single-axis knees can theoretically provide the beneficial functional characteristics of polycentric knees and the design considerations needed to realize this. Five children and their parents provided subjective opinions of the relative importance of functional requirements (FRs) for the knee. FRs related to comfort, fatigue, stability, and falling were found to be of high importance, while sitting appearance and adequate knee flexion were of lower importance. Relationships were drawn between these FRs and deductions were made regarding the importance of associated design parameters. Stance-phase control was rated to be of greatest importance followed by toe clearance. Models were developed for five knees including four- and six-bar knees, corresponding to two commercially available components, and for three configurations of a single-axis knee. Stance-phase control, specifically stability after heel-strike and swing-phase initiation at push-off, and toe clearance were simulated. The results suggest that a single-axis knee design incorporating stance-phase control will mutually satisfy the identified set of highly and moderately important FRs.
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http://dx.doi.org/10.1109/TNSRE.2004.838444 | DOI Listing |
Arthroplast Today
December 2024
Südtiroler Sanitätsbetrieb, Department Orthopaedic Surgery, Brixen, Italy.
Background: Unrestricted kinematic alignment (uKA) in total knee arthroplasty (TKA) has the theoretical advantage of reproducing patients' constitutional alignment and restoring the pre-arthritic joint line position and obliquity. However, modifications of the original uKA technique have been proposed due to the potential risk of mechanical failure and instability. Given the significant variability in soft tissue behavior within the same bony morphology group, uKA pure knee resurfacing could be occasionally detrimental.
View Article and Find Full Text PDFMuscle Nerve
December 2024
Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa, Japan.
Introduction/aims: VAChT-Cre is a transgenic mouse line targeting slow-twitch fatigue-resistant and fast-twitch fatigue-resistant motor neurons that innervate oxidative type I and type IIa muscle fibers. To ablate these neurons, VAChT-Cre mice were crossbred with NSE-DTA mice, leading to the expression of diphtheria toxin A after Cre-mediated excision. The resulting VAChT-Cre;NSE-DTA mice exhibited motor deficits, abnormal locomotion, muscular atrophy, and tremor, making them a useful model for studying motor neuron physiology and pathology.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Department of Information Engineering, Università Politecnica delle Marche, 60131 Ancona, Italy.
The volitional control of powered assistive devices is commonly performed by mapping the electromyographic (EMG) activity of the lower limb to joints' angular kinematics, which are then used as the input for regulation. However, during walking, the ground reaction force (GRF) plays a central role in the modulation of the gait, providing dynamic stability and propulsion during the stance phase. Including this information within the control loop of prosthetic devices can improve the quality of the final output, providing more physiological walking dynamics that enhances the usability and patient comfort.
View Article and Find Full Text PDFGait Posture
December 2024
Laboratory of Technology and Sport Performance, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil. Electronic address:
Background: Examining movement patterns in athletic activities is crucial for understanding the mechanisms and contributing factors linked to lower limb injuries, with the knee joint being particularly vulnerable in team sports like handball.
Research Question: How does a handball-specific fatigue protocol affect trunk-knee and hip-knee intersegmental coordination during the drop vertical jump (DVJ) and sidestep cutting maneuver (SCM) in handball players?
Methods: Twenty female handball athletes participated, performing three trials of each task before and after undergoing the fatigue protocol. Using a motion capture system, the trunk, hip, and knee joint angles were recorded in all three planes and time-normalized to 100 % of the stance phase.
PLoS One
December 2024
Division of Orthopedic Surgery and Musculoskeletal Trauma Care, Geneva University Hospitals and University of Geneva, Geneva, Switzerland.
Total Knee Arthroplasty has well-established success in relieving knee pain and improving function but patients do not reach functional levels of control groups after surgery and 20% of patients remain unsatisfied. To understand the different patient profiles and develop patient-specific approaches of care, functional phenotypes based on knee biomechanics during gait have been evaluated. To widen the understanding of patient's function, it seems crucial to consider the gait devieations at the whole body level.
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