Previous studies have shown that the effective rocker shape of the physiologic ankle-foot system during standing and fore-aft swaying is much flatter than that used during walking, which indicates a more stable base of support for the standing/swaying activity. Previous work suggests that flat regions within the effective rocker shapes of prosthetic ankle-foot systems could provide enhanced sta...

The need for simulation of human foot mechanism has made researchers and engineers move towards different patterns to describe this movement. In this regard, optimal solutions such as energy consumption, accuracy, etc. are of utmost importance. In this paper, efforts have been made to present a new solution by designing a fully two-dimensional six-bar mechanism with one degree of freedom so tha...

This report describes the construction and evaluation of an ankle-foot prosthesis using human cadaveric bones as the endoskeleton inside a fiber-reinforced vulcanized rubber shell. Cadaveric bones and exhumed skeletal bones were used. Three designs were fabricated, subjected to radiographic evaluation, and underwent 4-week field trials of normal daily use by a unilateral below-knee amputee. The...

People with a transtibial amputation using passive-elastic prostheses exhibit reduced prosthetic ankle power and push-off work compared to non-amputees and compensate by increasing their affected leg (AL) hip joint work and unaffected leg (UL) ankle, knee, and hip joint and leg work during level-ground walking. Use of a powered ankle–foot prosthesis normalizes step-to-step transition work durin...

OBJECTIVE To describe the technique used for total ossiculoplasty with the Fisch titanium total prosthesis and evaluate the 1-year postoperative functional results in patients presenting with the stapes (or footplate) without the malleus handle. STUDY DESIGN Prospective trial with preoperative and postoperative comparison. SETTING Academic and private practice tertiary care center for otolo...

The swing-phase motion of the shank of an above-knee prosthesis has been modelled mathematically. An inexpensive endoskeletal prosthesis was designed using the Jaipur foot and conduit pipes with a hinge joint for the knee. Results of field trials and the modelling indicate that a very simple above-knee prosthesis can give near normal gait at "normal" walking speeds on flat surfaces. The swing o...

Foot length discrepancy may result from congenital or acquired causes. If the absence of the foot is more proximal than the metatarsal level, push off and foot resilience will be disturbed and rapid walking and spring will be awkward. Those patients have to be fitted with a prosthesis extending above the ankle to the distal leg. The functional impairment and poor cosmetic appearance become soci...

This paper describes the design of an ankle-foot robotic prosthesis controllable in the sagittal and frontal planes. The prosthesis was designed to meet the mechanical characteristics of the human ankle including power, range of motion, and weight. To transfer the power from the motors and gearboxes to the ankle-foot mechanism, a Bowden cable system was used. The Bowden cable allows for optimal...

Unilateral lower limb prosthesis users display temporal, kinematic, and kinetic asymmetries between limbs while ascending and descending stairs. These asymmetries are due, in part, to the inability of current prosthetic devices to effectively mimic normal ankle function. The purpose of this study was to provide a comprehensive set of biomechanical data for able-bodied and unilateral transtibial...

One of the challenges in the development of prostheses is the testing and tuning of the mechanism before testing with human subjects. It is a common practice in the industry to use testing platforms to tests new products for different properties such as strength and fatigue; however, few platforms have been developed for testing and tuning of ankle–foot prosthesis. Before testing the lower extr...