Quantification of the Effect of Dorsi-/ Plantarflexibility of Ankle-Foot Orthoses on Hemiplegic Gait: A Preliminary Report

Yamamoto, Sumiko; Kubo, Shigeru; Ebina, Masahiko; Hayashi, Takeo; Iwasak, Mitsuo; Kawai, Hideo; Kubota, Toshio; Miyazaki, Satoru

doi:10.1097/00008526-199307000-00006

Cited by 16 publications

(8 citation statements)

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“…The results of this study also show that wearing the AFO on the stance leg (i.e., in the O-St and O-Bi condition) reduces the activity of the stance leg soleus EMG during single-support, as shown in studies investigating steady-state walking (Yamamoto et al, 1993 ; Boninger and Leonard, 1996 ; Miyazaki et al, 1997 ; Akizuki et al, 2001 ). In normal gait, during the single-stance phase, the body rotates around the ankle-forefoot articulation system causing the CoM to accelerate downwards.…”

Section: Discussionsupporting

confidence: 75%

Rigid Ankle Foot Orthosis Deteriorates Mediolateral Balance Control and Vertical Braking during Gait Initiation

Delafontaine

Gagey

Colnaghi

et al. 2017

Front. Hum. Neurosci.

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Rigid ankle-foot orthoses (AFO) are commonly used for impeding foot drop during the swing phase of gait. They also reduce pain and improve gait kinematics in patients with weakness or loss of integrity of ankle-foot complex structures due to various pathological conditions. However, this comes at the price of constraining ankle joint mobility, which might affect propulsive force generation and balance control. The present study examined the effects of wearing an AFO on biomechanical variables and electromyographic activity of tibialis anterior (TA) and soleus muscles during gait initiation (GI). Nineteen healthy adults participated in the study. They initiated gait at a self-paced speed with no ankle constraint as well as wearing an AFO on the stance leg, or bilaterally. Constraining the stance leg ankle decreased TA activity ipsilaterally during the anticipatory postural adjustment (APA) of GI, and ipsilateral soleus activity during step execution. In the sagittal plane, the decrease in the stance leg TA activity reduced the backward displacement of the center of pressure (CoP) resulting in a reduction of the forward velocity of the center of mass (CoM) measured at foot contact (FC). In the frontal plane, wearing the AFO reduced the displacement of the CoP in the direction of the swing leg during the APA phase. The mediolateral velocity of the CoM increased during single-stance prompting a larger step width to recover balance. During step execution, the CoM vertical downward velocity is normally reduced in order to lessen the impact of the swing leg with the floor and facilitates the rise of the CoM that occurs during the subsequent double-support phase. The reduction in stance leg soleus activity caused by constraining the ankle weakened the vertical braking of the CoM during step execution. This caused the absolute instantaneous vertical velocity of the CoM at FC to be greater in the constrained conditions with respect to the control condition. From a rehabilitation perspective, passively- or actively-powered assistive AFOs could correct for the reduction in muscle activity and enhance balance control during GI of patients.

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Section: Discussionsupporting

confidence: 75%

Rigid Ankle Foot Orthosis Deteriorates Mediolateral Balance Control and Vertical Braking during Gait Initiation

Delafontaine

Gagey

Colnaghi

et al. 2017

Front. Hum. Neurosci.

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show abstract

“…The ankle angle controlled by the orthosis' elastic should be as close as possible to 0 • (in a neutral position) when patients are standing. Yamamoto et al, (1993) observed that plantarflexion during swing decreased as rigidity of AFO increased allowing better limb clearance. Since the initial contact was performed in plantarflexion, the rigidity of the elastic in the evaluated DAFO was not maximal.…”

Section: Discussionmentioning

confidence: 95%

“…In the systematic review of Leung and Moseley (2003), contradictories results about the changes in EMG signal between plantarflexors and dorsiflexors prevented an unquestionable conclusion. For example, several studies highlighted that EMG activity of tibialis anterior (TA) decreased with the use of an AFO (Lairamore et al, 2011;Hesse et al, 1999;Yamamoto et al, 1993). However, no differences were observed in other studies (Ohata et al, 2011;Lee and Johnston, 1973).…”

Section: Introductionmentioning

confidence: 99%

Effects of a dynamic-ankle-foot orthosis (Liberté®) on kinematics and electromyographic activity during gait in hemiplegic patients with spastic foot equinus

Boudarham

Pradon

Roche

et al. 2014

NRE

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BACKGROUND: A dynamic-ankle-foot orthosis has recently emerged and consists of an elastic band allowing the variation of stiffness degree and adjusts dorsiflexion assistance in swing. The aim of this study was to quantify the biomechanical adaptations induced by this orthosis during gait in hemiplegic patients. METHODS: Twelve hemiplegic patients performed two gait analyses (without and with the ankle-foot orthosis). Spatiotemporal, kinematic, kinetic and electromyographic gait parameters were quantified using an instrumented gait analysis system during the stance and swing phases. RESULTS: During swing, peak ankle dorsiflexion was greater with the orthosis and associated with a decrease of pelvic obliquity angle. In stance, peak ankle plantarflexion and dorsiflexion were greater with the orthosis and associated with an increase of ankle angle at heel strike and toe-off. Electromyographic activities of both the tibialis anterior and the medial gastrocnemius were greater with the orthosis. CONCLUSIONS: This dynamic-ankle-foot orthosis improved gait in hemiplegic patients with spastic foot equinus. The spatiotemporal adaptations seem to be caused mainly by the increase of ankle dorsiflexion during stance and swing phases. The changes in electromyographic activity were related to an active dorsiflexion in stance and swing phases and an active plantarflexion in stance phase.

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“…Moreover, most studies that quantify the contribution generated by an AFO are dated back to the 1990s showing a gap in the literature in recent years. 1,2,7 –14…”

Section: Introductionmentioning

confidence: 99%

Determination of loads carried by polypropylene ankle–foot orthoses: A preliminary study

Papi

Maclean

Bowers

et al. 2015

Proc Inst Mech Eng H

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Ankle-foot orthoses (AFOs) are prescribed for the management of gait-related problems. Prescription of AFOs is based on empirical techniques due to the low level of evidence-based research on their efficacy, but primarily poor understanding of their mechanical characteristics. This study aimed to establish a method that would allow the quantification of the contribution of AFOs in the control of the ankle joint during gait. A possible way of achieving this aim would be to measure strain on the AFO during walking by the use of strain gauges. Following successful experimentation with the application of strain gauges to polypropylene tensile specimens, an AFO was instrumented by attaching strain gauges to it so as to allow the moment generated on the AFO in the sagittal plane about the ankle to be measured. Walking trials using this AFO on an able-bodied subject indicated good step-to-step repeatability. The use of an instrumented AFO in conjunction with kinematic and kinetic data acquisition would allow the contribution of the AFO and the residual anatomical loads to be determined. The advantage of such procedure over previously reported ones resides on the use of the actual orthosis being worn by patients thereby conducting tests under real-life situations. It is believed that such analysis of the load actions of an orthosis, which may in future be carried out in three dimensions, would allow a better understanding of the interaction between the leg and the orthosis. This should ultimately enhance AFO prescription criteria and help in optimising patient/device matching.

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Quantification of the Effect of Dorsi-/ Plantarflexibility of Ankle-Foot Orthoses on Hemiplegic Gait: A Preliminary Report

Cited by 16 publications

References 0 publications

Rigid Ankle Foot Orthosis Deteriorates Mediolateral Balance Control and Vertical Braking during Gait Initiation

Rigid Ankle Foot Orthosis Deteriorates Mediolateral Balance Control and Vertical Braking during Gait Initiation

Effects of a dynamic-ankle-foot orthosis (Liberté®) on kinematics and electromyographic activity during gait in hemiplegic patients with spastic foot equinus

Determination of loads carried by polypropylene ankle–foot orthoses: A preliminary study

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