Ankle antagonist coactivation in the double-support phase of walking: Stroke vs. healthy subjects

Abstract

Introduction: Lesions at ipsilateral systems related to postural control at ipsilesional side, may justify the lower performance of stroke subjects during walking. Purpose: To analyse bilateral ankle antagonist coactivation during double-support in stroke subjects. Methods: Sixteen (8 females; 8 males) subjects with a first isquemic stroke, and twenty two controls (12 females; 10 males) participated in this study. The double support phase was assessed through ground reaction forces and electromyography of ankle muscles was assessed in both limbs. Results: Ipsilesional limb presented statistical significant differences from control when assuming specific roles during double support, being the tibialis anterior and soleus pair the one in which this atypical behavior was more pronounced. Conclusion: The ipsilesional limb presents a dysfunctional behavior when a higher postural control activity was demanded.

The role of the ipsilesional side in the rehabilitation of post-stroke subjects

“…The leading limb's ankle dorsiflexors attenuate the initial contact, being important in weight acceptance (Winter, 1983). In fact, the hypothesis that the neuronal injury is the cause for the ipsilesional limb's atypical behaviour instead of a compensatory mechanism is supported both by the fact that the performance of ipsilesional plantar flexors, in stroke subjects, changes according to the limb's position (Silva et al, 2015) and by the fact that, during step-to-step transition, the contralesional limb is influenced by the ipsilesional limb and not the opposite (Sousa et al, 2013a). This also reinforces the evidence that the muscles associated with the ventral-medial systems' activity may present a more pronounced atypical behaviour while assuming an agonist role.…”

“…Considering that muscle activation's timing on postural adjustments depends on the corticoreticular connection, these findings suggest that this atypical behaviour is related to the lesion. The evidence demonstrating that the atypical behaviour of the ipsilesional plantar flexors changes according to their role during gait double support strengthens this association (Silva et al, 2015). Walking is the task where, in a rhythmic way, muscle roles change automatically.…”

“…Moreover, the study of these tasks must focus the subphases with higher postural control demand, i.e. the initial phase of sit-to-stand and standto-sit (Silva et al, 2012b;Silva et al, 2012c), middle stance (Silva et al, 2012d;, double support (Silva et al, 2015;Sousa et al, 2013a;Sousa et al, 2013b) and gait initiation (Sousa et al, 2015a(Sousa et al, , 2015b.…”

Muscle Co-Activation around the Knee during Different Walking Speeds in Healthy Females

“…Especially during complex tasks such as walking, it is necessary to allow for changes in the agonist and antagonist roles around the knee and ankle during the gait cycle [15]. Kitatani et al (2016) investigated muscle co-activation around the ankle joint, as did several previous studies [16][17][18][19], but they did not include any EMG information for the knee [20], so our study focused on the knee joint.…”

Análise cinemática da marcha em indivíduos com hemiparesia espástica após acidente vascular cerebral

“…Em pacientes que sofreram AVC e apresentam hipertonia espástica, quanto maior for a duração do ciclo da marcha, mais haverá diminuição do tamanho do passo, da velocidade e da cadência, que são causados pela instabilidade na transferência de peso do membro inferior afetado para o sadio. Além disso, quanto maiores forem as exigências sobre o membro afetado, maiores serão as disfunções observadas no membro hemiparético [10,19,20].…”