scholarly journals The influence of passive-dynamic ankle-foot orthosis bending axis location on gait performance in individuals with lower-limb impairments

2016 ◽  
Vol 37 ◽  
pp. 13-21 ◽  
Author(s):  
Ellyn C. Ranz ◽  
Elizabeth Russell Esposito ◽  
Jason M. Wilken ◽  
Richard R. Neptune
Keyword(s):  
Lower Limb ◽  
Gait Performance ◽  
Ankle Foot Orthosis ◽  
Foot Orthosis

Defining the Mechanical Properties of a Spring-hinged Ankle Foot Orthosis to Assess its Potential Use in Children With Spastic Cerebral Palsy

2014 ◽  
Vol 30 (6) ◽  
pp. 728-731 ◽  
Author(s):  
Yvette L. Kerkum ◽  
Merel-Anne Brehm ◽  
Annemieke I. Buizer ◽  
Josien C. van den Noort ◽  
Jules G. Becher ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cerebral Palsy ◽  
Knee Flexion ◽  
Spastic Cerebral Palsy ◽  
Gait Performance ◽  
Ankle Foot Orthosis ◽  
The Moment ◽  
Potential Use ◽  
Foot Orthosis ◽  
Walking Energy Cost

A rigid ventral shelf ankle foot orthosis (AFO) may improve gait in children with spastic cerebral palsy (SCP) whose gait is characterized by excessive knee flexion in stance. However, these AFOs can also impede ankle range of motion (ROM) and thereby inhibit push-off power. A more spring-like AFO can enhance push-off and may potentially reduce walking energy cost. The recent development of an adjustable spring-hinged AFO now allows adjustment of AFO stiffness, enabling tuning toward optimal gait performance. This study aims to quantify the mechanical properties of this spring-hinged AFO for each of its springs and settings. Using an AFO stiffness tester, two AFO hinges and their accompanying springs were measured. The springs showed a stiffness range of 0.01−1.82 N·m·deg−1. The moment-threshold increased with increasing stiffness (1.13–12.1 N·m), while ROM decreased (4.91–16.5°). Energy was returned by all springs (11.5–116.3 J). These results suggest that the two stiffest available springs should improve joint kinematics and enhance push-off in children with SCP walking with excessive knee flexion.

scholarly journals Newly designed computer controlled knee-ankle-foot orthosis (Intelligent Orthosis)

1998 ◽  
Vol 22 (3) ◽  
pp. 230-239 ◽  
Author(s):  
T. Suga ◽  
O. Kameyama ◽  
R. Ogawa ◽  
M. Matsuura ◽  
H. Oka
Keyword(s):  
Lower Limb ◽  
Stance Phase ◽  
Gait Cycle ◽  
Normal Subjects ◽  
Swing Phase ◽  
Ankle Foot Orthosis ◽  
Normal Gait ◽  
Heel Contact ◽  
Computer Controlled ◽  
Foot Orthosis

The authors have developed a knee-ankle-foot orthosis with a joint unit that controls knee movements using a microcomputer (Intelligent Orthosis). The Intelligent Orthosis was applied to normal subjects and patients, and gait analysis was performed. In the gait cycle, the ratio of the stance phase to the swing phase was less in gait with the knee locked using a knee-ankle-foot orthosis than in gait without an orthosis or gait with the knee controlled by a microcomputer. The ratio of the stance phase to the swing phase between controlled gait and normal gait was similar. For normal subjects the activity of the tibialis anterior was markedly increased from the heel-off phase to the swing phase in locked gait. The muscle activities of the lower limb were lower in controlled force in locked gait showed spikes immediately after heel-contact in the vertical at heel-contact in the sagittal to locked gait, gait with the Intelligent Orthosis is smooth and close to normal gait from the viewpoint of biomechanics. Even in patients with muscle weakness of the quadriceps, control of the knee joint using the Intelligent Orthosis resulted in a more smooth gait with low muscle discharge.

Preliminary Evaluation of a Knee-Ankle-Foot Orthosis for the Emulation of Transfemoral Prosthesis Socket Loads

2011 ◽  
Author(s):  
James A. Dawley ◽  
Andrew M. Romanazzi ◽  
Kevin B. Fite
Keyword(s):  
Lower Limb ◽  
Myoelectric Control ◽  
Preliminary Evaluation ◽  
Residual Limb ◽  
Direct Control ◽  
Ankle Foot Orthosis ◽  
Prosthetic Limbs ◽  
Transfemoral Prosthesis ◽  
Socket Interface ◽  
Foot Orthosis

Control of prosthetic limbs using myoelectric muscle potentials from the wearer’s residual limb enables direct control of artificial limb behavior. The typical approach entails the integration of surface electromyogram (sEMG) electrodes within the inner wall of the socket interface, located to target specific superficial muscles in the amputee’s residual limb. While myoelectric upper-limb control is commonplace in prosthetic practice, its use in lower-extremity devices has been slow to follow suit. Various research efforts have studied approaches to implementing myoelectric control of artificial leg behavior [1–4], but the need for myoelectric control in lower-limb prostheses has been limited by the lack of commercial prototypes with the capability of net power generation.

A Transducer for the Measurement of Lower Limb Orthotic Loads

1981 ◽  
Vol 10 (3) ◽  
pp. 149-153 ◽  
Author(s):  
A E Trappitt ◽  
N Berme
Keyword(s):  
System Design ◽  
Lower Limb ◽  
Test Results ◽  
Ankle Foot Orthosis ◽  
Design Considerations ◽  
Sample Test ◽  
Foot Orthosis

A six channel transducer designed to measure loads in a conventional knee/ankle/foot orthosis is described. Four such transducers are employed to describe fully the orthotic load system. Design considerations, construction and response of the load transducers together with sample test results are presented.

Surrogate Lower Limb Design for Ankle-Foot Orthosis Testing

2021 ◽  
Author(s):  
Alexis Thibodeau ◽  
Patrick Dumond ◽  
Edward Lemaire
Keyword(s):  
Lower Limb ◽  
Ankle Foot Orthosis ◽  
Foot Orthosis

scholarly journals How Does Ankle-foot Orthosis Stiffness Affect Gait in Patients With Lower Limb Salvage?

2014 ◽  
Vol 472 (10) ◽  
pp. 3026-3035 ◽  
Author(s):  
Elizabeth Russell Esposito ◽  
Ryan V. Blanck ◽  
Nicole G. Harper ◽  
Joseph R. Hsu ◽  
Jason M. Wilken
Keyword(s):  
Limb Salvage ◽  
Lower Limb ◽  
Ankle Foot Orthosis ◽  
Foot Orthosis

The effect of custom carbon ankle-foot orthosis alignment on roll-over shape and center of pressure velocity

2020 ◽  
pp. 030936462097140
Author(s):  
Elizabeth Russell Esposito ◽  
Mitchell D Ruble ◽  
Andrea J Ikeda ◽  
Jason M Wilken
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Center Of Pressure ◽  
Heel Strike ◽  
Control Group ◽  
Foot Orthoses ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis ◽  
Center Of Pressure Velocity

Background: Maintaining an optimal rolling of the foot over the ground is thought to increase the stability and efficiency of pathologic gait. Ankle-foot orthoses are often prescribed to improve gait mechanics in individuals with lower extremity injuries; however, their design may compromise how the foot rolls over the ground. Objectives: The aim of this study was to investigate the effects of the sagittal plane ankle-foot orthosis alignment on roll-over shape and center of pressure velocity in individuals with lower limb reconstructions. Study design: Randomized cross-over study with a control group comparison. Methods: In total, 12 individuals with lower limb reconstruction who used a custom carbon ankle-foot orthosis and 12 uninjured controls underwent gait analysis. Ankle-foot orthosis users were tested in their clinically-provided ankle-foot orthosis alignment, with an alignment that was 3° more plantarflexed, and with an alignment that was 3° more dorsiflexed. Components of roll-over shape and center of pressure velocity were calculated from heel strike on the ankle-foot orthosis limb to contralateral heel strike. Results: Roll-over shape radius was not affected by 3° changes to alignment and was not significantly different from controls. Aligning the ankle-foot orthosis in more dorsiflexion than clinically provided resulted in a smaller peak center of pressure velocity that occurred later in stance. Conclusion: Individuals using custom carbon ankle-foot orthoses can accommodate 3° alterations in the dorsiflexion or plantarflexion alignment.

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