Effect of AFO Design on Walking after Stroke

Abstract

This study was conducted to compare the effects of three ankle-foot orthosis (AFO) designs on walking after stroke and determine whether an ankle plantar flexion contracture impacts response to the AFOs. A total of 30 individuals, ranging from 6-215 months post-stroke, were tested in four conditions: shoes only (SH), dorsi-assist/dorsi-stop AFO (DA-DS), plantar stop/free dorsiflexion AFO (PS), and rigid AFO (Rigid). Kinematics, kinetics, and electromyographic (EMG) activity were recorded from the hemiparetic lower extremity while participants walked at a self-selected pace. Gait parameters were compared between conditions and between participants with and without a moderate ankle plantar flexion contracture. All AFOs increased ankle dorsiflexion in swing and early stance. Anterior tibialis EMG was reduced only in the PS AFO. Both PS and Rigid AFOs restricted ankle plantar flexion and increased knee flexion in loading. Peak ankle dorsiflexion in stance and soleus EMG intensity were greatest in the PS AFO. The Rigid AFO tended to restrict dorsiflexion in stance and knee flexion in swing only in participants without a plantar flexion contracture. Individuals without a contracture benefit from an AFO that permits dorsiflexion mobility in stance and those with quadriceps weakness may more easily tolerate an AFO with plantar flexion mobility in loading.

A Single Trial of Transcutaneous Electrical Nerve Stimulation (TENS) Improves Spasticity and Balance in Patients with Chronic Stroke

“…Stroke patients are commonly accompanied by ankle plantarflexion contracture due to spasticity of the calf muscle and tibialis anterior weakness (Mulroy et al 2010). As was observed in a previous study (Tinazzi et al 2005), TENS stimulation of calf muscles in this study changed the excitability of brain cortical areas, or rather reciprocal inhibition and facilitation that enabled efficient movement and increased balance function was observed.…”

Comparison of tibialis anterior muscle electromyography, ankle angle, and velocity when individuals post stroke walk with different orthoses

“…7,13 Hesse et al 7 investigated electromyography (EMG) of the TA muscle and recorded a decrease in activation when individuals post stroke walked with a rigid AFO compared to walking without an AFO. Mulroy et al 14 found that a plantarflexion stop AFO reduces TA muscle activity in patients post stroke; however, they also demonstrated that a rigid AFO and a dorsiflexion assist/dorsiflexion stop (DA/DS) AFO did not reduce TA muscle activity. 14 The DA/DS orthosis was hinged with elastic bands to provide dorsiflexion assistance during swing and a posterior strap to limit dorsiflexion to five degrees.…”

“…Mulroy et al 14 found that a plantarflexion stop AFO reduces TA muscle activity in patients post stroke; however, they also demonstrated that a rigid AFO and a dorsiflexion assist/dorsiflexion stop (DA/DS) AFO did not reduce TA muscle activity. 14 The DA/DS orthosis was hinged with elastic bands to provide dorsiflexion assistance during swing and a posterior strap to limit dorsiflexion to five degrees.…”

How does a Personalized Rehabilitative Model influence the Functional Response of Different Ankle Foot Orthoses in a Cohort of Patients Affected by Neurological Gait Pattern?

“…The current modern design of AFOs includes articulated devices capable of assisting plantar lexion during stance. Whereas some studies con irmed the bene its of assistive AFOs [12,13], other studies demonstrated a minimal effect of traditional AFOs on global gait kinematics in hemiplegic patients [14]. For this reason, taken into consideration the economic cost and the bulkiness of some articulated AFOs, often the clinical attitude is to use standard rigid model in the daily rehabilitation practices.…”