Determinants and consequences for standing balance of spontaneous weight-bearing on the paretic side among individuals with chronic stroke

Abstract

Hemiparetic stroke patients commonly bear more weight on the non-paretic side which seems intuitively linked to unilateral control deficits. However, there is evidence that some post-stroke favour weighting the paretic side, which may be problematic given altered capacity of the paretic limb to contribute to the control of upright posture. This study explores the prevalence and clinical determinants of stance asymmetry, and the relationship between stance asymmetry and postural control among chronic stroke patients. Subjects (n=147; >6 months post-stroke) stood on two force plates in eyes-open and eyes-closed conditions; 59 were symmetric, 18 had paretic asymmetry (PA), and 70 had non-paretic asymmetry (NPA). Root mean square (RMS) of antero-posterior and medio-lateral centre-of-pressure under each limb and both limbs combined were compared. RMS of total medio-lateral centre-of-pressure was greater for both asymmetric groups compared with the symmetric group. PA subjects relied less on the loaded limb for control than NPA subjects and relied more on visual information for postural control than those who were symmetric. There were no differences in the characteristics of individuals between the PA and NPA groups. The loading of the paretic limb was not related to impaired postural control during stationary standing which was attributable, in part, to individuals relying on control from the non-paretic limb, in spite of lower vertical load, and a greater dependence on visual contributions. There was no evidence that greater loading on the paretic limb was related to persisting dyscontrol but may rather reflect a learned strategy.

Cross-cultural adaptation to Brazilian Portuguese of the Waterloo Footedness Questionnaire-Revised: WFQ-R-Brazil

“…Mansfield et al 9 did not find differences in the prevalence of perceptual disturbances, such as negligence and history of pushing, between the groups that overloaded the unaffected limb or the affected hemibody and the group with symmetrical weight-bearing distribution. Although recent studies 9,11,12,13 point to the relationship between sensory deficits and asymmetry in the weight-bearing distribution during upright stance, more robust evidence must be attained.…”

“…This choice seems to reflect a strategy to overcome the motor and sensory deficits of the affected body. However, non-Pusher' s syndrome asymmetries with overload on the affected side have also been identified as a motor strategy 7,9 . Asymmetric strategies overloading both hemibodies bring to mind that factors such as severity of motor and sensory impairments and pushing behavior have been identified as being responsible for the asymmetric distribution with overload of the affected limb in chronic stroke survivors 10 , reinforcing the relevance of the footedness assessment.…”

“…Although recent studies 9,11,12,13 point to the relationship between sensory deficits and asymmetry in the weight-bearing distribution during upright stance, more robust evidence must be attained.…”

“…According to the relationship between the severity of post-stroke motor deficits and the weight-bearing distribution, some evidence indicates that individuals with more severe hemiparesis tend to adopt a more asymmetric strategy when compared to those with mild hemiparesis 6,9,11,13 . In this regard, Mundim et al 7 have hypothesized that the lower limb predominantly used for support during an upright stance is established by preference for post-stroke hemiparesis patients presenting with mild to moderate hemiparesis, or by convenience in the patients with moderate to severe hemiparesis.…”

Improved walking ability with wearable robot-assisted training in patients suffering chronic stroke

“…(SKG) [1], limited or absent ankle dorsiflexion, impairment of loading ability on the paretic side [2], and abnormal or insufficient muscle activation or contraction [3,4], which can greatly influence their quality of life. Experience-dependent plasticity, regarded as a potential mechanism of the neural networks, allows stroke survivors to recover motor function control and partially offset impairments [5,6].…”