Relationships Between Muscle Activity and Anteroposterior Ground Reaction Forces in Hemiparetic Walking

Bins associated with the AP ground reaction forces of the paretic leg are illustrated (solid line). The gray shaded regions represent double-support phases. Abbreviations: NHS, nonparetic heel-strike; NTO, nonparetic toe-off; PHS, paretic heel-strike; PTO, paretic toe-off.

AP ground reaction force, impulse, and bin electromyographic data for a representative subject classified as mildly hemiparetic with a self-selected walking speed of 1.26m/s. Net bin impulses are similar, as is the duration of stance spent on each leg. Vertical lines in the ground reaction force plot indicate bin boundaries. Note that bins 1 through 4 correspond to the stance phase only. The units for the AP impulse (AP Imp) and bin electromyography are percentage of body weight (BW) × seconds and percentage of total integrated electromyography, respectively. Abbreviations: BF, biceps femoris; GM, gluteus medius; MG, medial gastrocnemius; RF, rectus femoris; SM, semimembranosus; SO, soleus; TA, tibialis anterior; VL, vastus lateralis.

AP ground reaction force, bin impulse, and bin electromyographic data for a representative subject classified as moderately hemiparetic with a self-selected walking speed of .73m/s. Net bin impulses are asymmetrical, however this subject generated some paretic propulsion in bin 4. Vertical lines in the ground reaction force plot indicate bin boundaries. Note that bins 1 through 4 correspond to the stance phase only. The units for the AP impulse (AP Imp) and bin electromyography are percentage of body weight × seconds and percentage of total integrated electromyography, respectively. Abbreviations: see fig 2 legend.

AP ground reaction force, bin impulse, and bin electromyographic data for a subject classified as severely hemiparetic with a self-selected walking speed of .44m/s. Net bin impulses are asymmetrical, with the paretic leg primarily generating braking and the nonparetic leg primarily generating propulsion. Vertical lines in the ground reaction force plot indicate bin boundaries. Note that bins 1 through 4 correspond to the stance phase only. The units for the AP impulse (AP Imp) and bin electromyography are percentage of body weight × seconds and percentage of total integrated electromyography, respectively. Abbreviations: see fig 2 legend.