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

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.

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

ASME 2011 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2011-53302 ◽

2011 ◽

Cited By ~ 1

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.

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A Transducer for the Measurement of Lower Limb Orthotic Loads

Engineering in Medicine ◽

10.1243/emed_jour_1981_010_040_02 ◽

1981 ◽

Vol 10 (3) ◽

pp. 149-153 ◽

Cited By ~ 8

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.

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

Clinical Biomechanics ◽

10.1016/j.clinbiomech.2016.05.001 ◽

2016 ◽

Vol 37 ◽

pp. 13-21 ◽

Cited By ~ 12

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

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Surrogate Lower Limb Design for Ankle-Foot Orthosis Testing

10.26226/morressier.614ca2d987a68d83cb5d5d7b ◽

2021 ◽

Author(s):

Alexis Thibodeau ◽

Patrick Dumond ◽

Edward Lemaire

Keyword(s):

Lower Limb ◽

Ankle Foot Orthosis ◽

Foot Orthosis

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Passive-dynamic ankle-foot orthosis improves medium-term clinical outcomes after severe lower extremity trauma

Journal of the Royal Army Medical Corps ◽

10.1136/jramc-2018-001082 ◽

2018 ◽

Vol 165 (5) ◽

pp. 330-337 ◽

Cited By ~ 2

Author(s):

Peter Ladlow ◽

N Bennett ◽

R Phillip ◽

S Dharm-Datta ◽

L McMenemy ◽

...

Keyword(s):

Lower Extremity ◽

Clinical Outcomes ◽

Limb Salvage ◽

Care Pathway ◽

Medium Term ◽

Rehabilitation Care ◽

Ankle Foot Orthosis ◽

Lower Extremity Trauma ◽

Extremity Trauma ◽

Foot Orthosis

IntroductionIndividuals with delayed below-knee amputation have previously reported superior clinical outcomes compared with lower limb reconstruction. The UK military have since introduced a passive-dynamic ankle-foot orthosis (PDAFO) into its rehabilitation care pathway to improve limb salvage outcomes. The aims were to determine if wearing a PDAFO improves medium-term clinical outcomes and what influence does multidisciplinary team (MDT) rehabilitation have after PDAFO fitting? Also, what longitudinal changes in clinical outcomes occur with MDT rehabilitation and how do these results compare with patients with previous lower extremity trauma discharged prior to PDAFO availability?MethodsWe retrospectively evaluated levels of mobility, activities of daily living, anxiety, depression and pain in a heterogeneous group of 23 injured UK servicemen 34±11 months after PDAFO provision. We also retrospectively analysed 16 patients across four time points (pre-PDAFO provision, first, second and final inpatient admissions post-PDAFO provision) using identical outcome measures, plus the 6 min walk test.ResultsOutcomes were compared with previous below-knee limb salvage and amputees. Before PDAFO, 74% were able to walk and 4% were able to run independently. At follow-up, this increased to 91% and 57%, respectively. Mean depression and anxiety scores remained stable over time (p>0.05). After 3 weeks, all patients could walk independently (pre-PDAFO=31%). Mean 6 min walk distance significantly increased from 440±75 m (pre-PDAFO) to 533±68 m at last admission (p=0.003). The ability to run increased from 6% to 44% after one admission.ConclusionsAll functional and most psychosocial outcomes in PDAFO users were superior to previous limb salvage and comparable to previous below-knee amputees. The PDAFO facilitated favourable short-term and medium-term changes in all clinical outcome measurements.

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Three-dimensional angular kinematics of the paretic lower limb according to different orthotic angles of an ankle-foot-orthosis in stroke patients

Physiotherapy ◽

10.1016/j.physio.2015.03.3617 ◽

2015 ◽

Vol 101 ◽

pp. e750-e751

Author(s):

K. Kim ◽

H.Y. Lee ◽

J.H. Lee

Keyword(s):

Lower Limb ◽

Three Dimensional ◽

Stroke Patients ◽

Ankle Foot Orthosis ◽

Foot Orthosis

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

Prosthetics and Orthotics International ◽

10.1177/0309364620971407 ◽

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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