Accidents vasculaires Cérébraux

Le 16/10/2021 de 09:00 à 11:00

Président(s): Alain Yelnik (Paris);

Retour Session


Quels sont les paramètres des fléchisseurs plantaires associés à la vitesse de marche chez les marcheurs hémiparétiques rapides ?

François Jabouille (Créteil, France), Waël Maktouf (Créteil, France), Jean-Michel Gracies (Créteil, France), Maud Pradines (Créteil, France)

Objective : At the onset of hemiparesis, muscle tissue is normal and spastic overactivity is nil. Rapidly, spastic myopathy develops, followed by spastic cocontraction. At a chronic stage, both factors along with paresis increasingly partner to compromise motor function. Plantar flexors become particularly affected, but the respective role of these disorders in impeding ambulation is not clear.

Material / Patients and Methods : Subjects with stroke-induced chronic hemiparesis (> 6 months), who were able to walk independently barefoot with 10-meters maximal speed >0.7m/sec were included. Ultrasonography was used to quantify medial gastrocnemius (MG) fascicle length and thickness in an isokinetic ergometer at a position of 80% of XV1GAS (PROMGAS), knee extended. Then, peak torques during maximal voluntary contraction in plantar- and dorsiflexion were collected. Correlations were explored between maximal 10-meter ambulation speed barefoot and both muscle architectural parameters and peak torques.

Results : Seven adults (age 57.1±7.9, (mean±SD), all male, time since lesion 10.2±6.9 yrs) were recruited. Ambulation speed was 1.04±0.23m/sec; fascicle length 57.1±18.1mm; thickness 19.0±3.9mm, peak torque: Plantar Flexion, 53.9±35.2N, Dorsiflexion, 21.8±17.5N.
Ambulation speed correlated with MG thickness (R=0.91, p=0.004), MG fascicle length (R=0.86, p=0.013), and plantar flexion peak torque (R=0.71, p=0.07). Each architectural parameter correlated with peak torque.

Discussion - Conclusion : The amount of plantar flexor atrophy and shortening may be an important factor associated with ambulation speed in fast hemiparetic walkers. These architectural modifications might relate to command impairment. Once ambulation speed around 1m/sec has been reached, restoration of not only extensibility but also mass and strength in plantar flexors should be considered as potentially important objectives in further gait rehabilitation.

Keywords : fascicle length - hemiparesis - spastic myopathy - muscle thickness - propulsion