Lam, Tania

Presented at the <a href="https://ispgr.org/past-congresses/">International Society of Posture and Gait Research</a> Congress, Bologna, Italy (June 21-25, 2009). <p>During curved walking, muscle activity and foot pressure distribution must be adapted according to path curvature in order to accommodate to the specific demands of turning. The purpose of this study was to assess whether stroke participants would adapt to the task of turning by modulating muscle activity and foot pressure distribution with changes to path curvature as seen in able-bodied individuals.

Presented at the <a href="https://ispgr.org/past-congresses/">International Society of Posture and Gait Research</a> Congress, Bologna, Italy (June 21-25, 2009). <p>Despite the significance of turning during walking in everyday life there has been very little research on turning capacity in ambulatory individuals suffering from stroke-related hemiparesis. In able-bodied gait, temporal features required for straight walking become increasingly asymmetric when travelling along a path of increasing curvature. For example, the inner leg of the turn remains in single support longer while the outer leg swings around to direct the body along the curved path. During straight walking post-stroke, stance duration on the non-paretic side tends to be longer compared to the paretic side. The tendency to favor weight bearing on the non-paretic limb might restrict the extent to which interlimb asymmetry can be adapted to increasing path curvature during turns to the paretic side (ie: when the paretic leg is the inner leg of the turn). Hence, turns to the non-paretic side may be favored. The purpose of this study was to examine the pattern of asymmetry in stroke survivors when walking along a curved path. It was hypothesized that stroke participants would show more difficulty turning to their paretic side than turning to their non-paretic side.

Presented at the <a href="https://acrm.org/meetings/2012-conference/">American Congress of Rehabilitation Medecine (ACRM)</a>, Vancouver, British Columbia, Canada (October 9 – 13, 2012). <p>Objective: The ability to turn while walking is compromised in people with stroke. The aim of this study was to understand the contribution of biomechanical gait impairments to locomotor adapta- tions to path curvature in people with stroke. Data were collected from eight individuals with hemiparesis due to a stroke and 12 age-matched able-bodied individuals. Participants walked along four paths of different curvature (straight line, large circle, medium circle, small circle) while whole body kinematic data in three dimensions were collected. A modulation index representing the slope of the regression line between peak joint angle and path curvature at specific phases of the step cycle was computed to represent joint kinematic modulation patterns. <p>Results: In able-bodied individuals, we observed consistent modula- tion of transverse and frontal plane movements at the ankle and hip as path curvature increased. For example, in order to walk smoothly around the circle, the control group increased the amplitude of hip adduction in the leg located on the inside of the circle during stance. In individuals with stroke, we observed disordered modulation of the adaptation of frontal and transverse kinematic movement parameters as path curvature increased. In general, the stroke group would show reduced hip adduction on their affected leg even if it was on the inside of the turn. Conclusions: Adaptations in the kinematic pattern seen during curved walking in able-bodied participants were not seen in the stroke group.