Understanding postural control requires considering various mechanisms underlying a person's ability to stand, to walk, and to interact with the environment safely and efficiently. The purpose of this paper is to summarize the functional relation between biomechanical and neurophysiological perspectives related to postural control in both standing and walking based on movement efficiency. Evidence related to the biomechanical and neurophysiological mechanisms is explored as well as the role of proprioceptive input on postural and movement control.

Objective: To analyse the relation between contralesional and ipsilesional limbs in subjects with stroke during step-to-step transition of walking.Design: Observational, transversal, analytical study with a convenience sample. Setting:Patients from a physical medicine and rehabilitation clinic in Portugal (Braga). Participants:Sixteen subjects with post-stroke hemiparesis with the ability to walk independently and twenty-two healthy controls.Interventions: Not applicable. Conclusions:The findings obtained suggest that the lower performance of the contralesional limb in forward propulsion during gait is not only related to contralateral supraspinal damage but also to a dysfunctional influence of the ipsilesional limb.

one composed by ten healthy subjects and the other by ten subjects with history of stroke and increased H-reflex. Electromyographic activity (EMGa) of SOL and TA was analyzed during SitTS and StandTS in the ipsilateral (IPSI) and the contralateral (CONTRA) limb to the side lesion in stroke subjects, and in one limb in the healthy subjects. A force plate was used to identify the movement onset. Results: In both sequences, in the stroke group SOL activation timing occurred prior to movement onset, contrary to the pattern observed in the healthy subjects. Statistical significant differences were found in SOL activation timings between each lower limbs of the stroke and healthy groups, but no significant differences were found between the IPSI and the CONTRA limb. The TA activation timing seems to be delayed in the CONTRA limb when compared to the healthy subjects and showed also a better organization of TA timing activation in StandTS when compared to SitTS. Conclusion: Compared to healthy subjects, APAs seems to be altered in both limbs of the post-stroke subjects, with the SOL activation timing being anticipated in both SitTS and StandTS.