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Abstract-
In this study, we performed a kinematic analysis of a new, low-cost sling for the lower limb, compared to a common ankle-foot orthosis (AFO). Gait with no orthosis, with the AFO, and with the new sling was analyzed in one hemiplegic subject. Both the AFO and the sling reduced the mean angle and ROM (range of movement) of the ankle and the vertical displacement of the center of mass. The sling, but not the AFO, restored the normal sequence heel-strike, forefoot contact of the affected side. The sling, but not the AFO, reduced the affected limb stance and stride duration, increased stride length, and improved walking speed. In conclusion, the proposed sling for the lower limb equally improved the affected ankle kinematics in contrast to the traditional AFO, and it also improved some gait variables in this hemiplegic subject.
Key words: AFO, gait, hemiplegia, kinematic, lower limb, orthosis, sling.
Abbreviations: AFO = ankle-foot orthosis, ANOVA = analysis of variance, ASIS = anterior superior iliac spine, COM = center of mass, KAFO = knce-ankle-foot orthosis, LSD = least significant difference, RGO = reciprocating gait orthosis, ROM = range of movement, SD = standard deviation.
The work published in this manuscript was unfunded at the time of manuscript preparation.
INTRODUCTION
Hemiplegic patients always show alterations of walking pattern kinematics [1,2] and slow walking speed, even if the gait is tripod- or cane-assisted [3], Ankle-foot orthoses (AFO) are often prescribed to those patients to obtain a better heel-strike, a more dynamic and balanced gait, and a lower energy expenditure during walking [47]. Knee-ankle-foot orthoses (KAFO) are rarely used in hemiplegic patients, because of their weight and their supposed disturbance of walking patterns [8]. While AFOs are mainly used to counteract the foot plantar flexion, they are also reported to enhance the paretic quadriceps muscle activity [6] and lower-limb swing in hemiplegic subjects [9].
This study developed a device for the lower limb that could correct the abnormal foot posture, while simultaneously facilitating the swing phase of the lower limb. In our opinion, this could be done by "linking" the patient's affected lower limb and the opposite body side. Following this idea, we developed a strap-based linkage system, which is a "sling-like" product. We then performed a...