Ground reaction forces and center of pressure patterns in the gait of children with amputation: preliminary report.
Ground reaction forces and center of pressure (CP) were studied during gait in children with unilateral lower extremity amputations. Five children, three with knee disarticulations and two with above-knee amputations, walked at slow, normal, and fast speeds, while wearing a conventional SACH prosthetic foot and again, while wearing an experimental CAPP prosthetic foot. Fore-aft (F-A) and vertical force (VF) components and CP patterns were examined for a total of 90 trials. Walking speed had a significant effect on both F-A and VF amplitudes. No differences, however, were found between the force amplitudes of the SACH foot and CAPP foot. Significant asymmetries were found in the force and amplitudes of a child's natural limb versus the prosthetic limb; the retarding and propelling F-A forces in the prosthetic limb were significantly less than the corresponding forces in a child's natural limb. The CP patterns during stance phase were markedly different for a child's natural limb, prosthetic limb with the SACH foot, and prosthetic limb with the CAPP foot. With the CAPP foot, the CP remained in the forefoot region during stance. In contrast with the CAPP foot, the SACH foot had a potential for producing a flexor moment at the knee joint at the initiation of the foot-ground contact. Stability in the prosthetic knee was enhanced when the children wore a CAPP prosthetic foot.
D000293:Adolescent; D000674:Amputees; D000704:Analysis of Variance; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D005684:Gait; D006801:Humans; D008124:Locomotion; D008297:Male; D011312:Pressure; D011474:Prosthesis Design