Versatile articulated dynamic response ankle foot orthosis
Inventors
Assignees
United States, Defense, Secretary of • US Department of Defense
Publication Number
US-11980561-B2
Publication Date
2024-05-14
Expiration Date
2037-04-11
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Abstract
An orthotic device including a plurality of posterior dynamic struts and an adjustable posterior multiple strut engager, wherein the plurality of posterior dynamic struts has a first posterior dynamic strut and one or more additional posterior dynamic struts, and wherein the adjustable posterior multiple strut engager is affixed to the first posterior dynamic strut and is adapted to restrain the movement of said one or more additional posterior dynamic struts, and wherein the adjustable posterior multiple strut engager may be adjusted to engage said one or more additional posterior dynamic struts in combination with the first posterior dynamic strut, thereby forming a single posterior dynamic strut assembly of greater rigidity than the first posterior dynamic strut alone.
Core Innovation
The invention relates to an orthotic device designed for patients with lower limb motor dysfunction, including those with calf functional deficiencies due to triceps surae weakness. This device comprises a plurality of posterior dynamic struts, including a first posterior dynamic strut and one or more additional posterior dynamic struts, combined with an adjustable posterior multiple strut engager. The engager is affixed to the first posterior dynamic strut and restrains the movement of the additional struts, forming a single posterior dynamic strut assembly of greater rigidity when engaged together than the first strut alone.
The orthotic device further includes components such as a proximal cuff, distal mechanical ankle joints, and a distal footplate. The proximal cuff may comprise an inner static cuff component and an outer dynamic cuff component, allowing dynamic response and sliding motion to reduce skin friction during use. The device supports natural ankle range of motion by allowing free plantarflexion and controlled dorsiflexion resistance, thereby facilitating a more natural gait progression for patients, including during higher-impact activities such as running.
The background recognizes that many available ankle foot orthotic devices immobilize the ankle, often leading to abnormal gait patterns and unnecessary restrictions for patients with sufficient ankle range of motion. The problem addressed is the need for an improved orthotic device which provides ankle range of motion and plantarflexion freedom while resisting dorsiflexion where pain or dysfunction exists, especially for patients who retain some ankle function but require support. The invention aims to overcome the limitations of prior art by enabling adjustable strut rigidity through multiple struts engaged as needed to assist walking, running, or other activities.
Claims Coverage
The claims define multiple inventive features related to the articulated dynamic ankle foot orthotic device, focusing on its structural components and adjustable engagement system.
Articulated dynamic ankle foot orthotic device structure
An orthotic device comprising multiple posterior dynamic struts, including a primary (first) strut and one or more additional struts, with an adjustable posterior multiple strut engager permanently fastened to the proximal end of the first strut. The struts are attached distally to mechanical ankle joints, and the first strut proximally to a cuff. The engager can adjustably engage the additional struts vertically stacked with the first, forming a single assembly of greater rigidity, with timing control for additional strut engagement relative to the first.
Proximal cuff with static and dynamic components
A proximal cuff comprising an inner static cuff component and an outer dynamic cuff component, wherein the outer dynamic cuff may slidably translate over the inner static cuff during use, enhancing comfort and dynamic fit.
Materials for the cuff and struts
The outer dynamic cuff component comprises materials allowing a dynamic response such as stainless steel, carbon, carbon fiber, titanium, fiberglass, resin, plastic, poly-para-phenylene terephthalamide, aluminum, or composites thereof. The inner static cuff component comprises materials like thermoplastics, carbon fiber, nylon, or their composites.
Bridging piece and strut attachment
A bridging piece angled about 0-15 degrees (preferably about 8 degrees) connects the distal ends of the posterior dynamic struts to the distal mechanical ankle joints, with struts attached by sandwiching distal ends between the bridging piece and a removable faceplate.
Joint stirrups and ankle joint configuration
Joint stirrups connect the distal mechanical ankle joints to the distal footplate, with stirrups angled about 25-35 degrees relative to the talocrural ankle axis, and joints themselves angled similarly. The ankle joints are double action, with preferred use of contoured double action ankle joints.
Adjustable posterior multiple strut engager fasteners
The engager comprises fasteners such as screws, clips, clamps, straps, springs, nuts, bolts, or combinations thereof, including embodiments with a screw clamp and nut whereby tightening or loosening the nut controls the timing of the additional struts' engagement with the first strut.
The claims collectively cover an orthotic device with adjustable stacked posterior dynamic struts connected via mechanical ankle joints and a bridging piece, combined with a specialized proximal cuff and adjustable engagement mechanisms to provide customizable strut rigidity for various patient activities and comfort.
Stated Advantages
Allows a more natural ankle range of motion including free plantarflexion, preserving normal physiological and biomechanical joint benefits.
Provides adjustable stiffness via multiple posterior dynamic struts engaged selectively for different activity levels, such as walking versus running.
Reduces friction and skin shear by incorporating a proximal cuff with an outer dynamic component sliding over an inner static component.
Improves gait dynamics by mimicking triceps surae muscle function with dynamic response struts acting as energy storage and return elements.
Provides patient and clinician control to customize strut rigidity during use for comfort and functional needs.
Documented Applications
Use by patients with lower limb motor dysfunction, especially with functional deficiency due to triceps surae weakness.
Assistance for walking with adjustable strut rigidity to provide sufficient support.
Assistance for running or other high impact activity by engaging additional posterior dynamic struts to increase rigidity.
Orthotic device worn by patients needing ankle foot orthosis that allows dynamic ankle motion while resisting painful dorsiflexion arcs.
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