Fig. 3.
Post-stroke gait displayed a substantial reduction of energy recovery within the stride. (A) BCoM, Ep and Ek for a control participant, the stride cycle is defined as the time period of contact of the heel strike to next contact of the same limb; note the accumulation of energy recovery when exchanging Ep to Ek with both limbs (grey). (B) For post-stroke participants the stride cycle is defined as the time period from contact of paretic limb with the treadmill to the next contact of the same limb. During the initial contact of the paretic limb with the treadmill, stroke survivors used the paretic limb as a rigid shaft while pushing off using the non-paretic lower limb (green); but a substantial reduction of energy recovery occurred when exchanging Ep to Ek using the paretic limb to push off (red). Note that this transduction seems to occur more briefly and with a reduced increase in Ek. (C–F) Stroke survivors showed relative maintenance of energy recovery while walking at 40% of PWS. A substantial reduction of the energy transduction within the step (ΔRint) accumulated from 0–25%, 25–50% and 50–75% of the stride was evident for stroke survivors walking at the PWS. (G) Rint during the full stride was substantially reduced for stroke participants at the PWS; note that stroke participants maintain a relatively constant energy recovery, regardless of speed, whereas the control group shows the expected increase in energy recovery at PWS. Data are Mean±s.d.; two-way ANOVA (speed and lesion) followed by Tukey’s post-hoc test, *P<0.05 between groups as indicated, nStroke=6, nControl=10. Rint, energy transduction within the step.