Kinematics and forces in the above-knee prosthesis during the stair climbing

Abstract

The most modern generation of controlled AK prostheses is considered as important step forward in technology of manufacture of AK prostheses, since they offer the highest proximity to human walk. However, so far the problem of climbing the stairs by transfemoral amputee has not been resolved. The reason for unresolved problem of upstairs movement of persons with AK prosthesis lies in a need to introduce an external source of energy, which would provide the user with energy required for lifting a body when climbing the stairs. The kinematic analysis of movement of the AK prosthesis with a build-in hydraulic cylinder connected to an external source of power is intended to prove that there is a real possibility for a person with an AK prosthesis to climb stairs. An analysis was carried out of the prosthesis movement in a sagital plane for the period of climbing from the first contact of the artificial foot with the step of a stair until the moment of its separation. Trajectories of characteristic points on the prosthesis were recorded for the examinee climbing three staircases with different gradients: shallow SH (25º), moderate M (30º) and steep ST (36º). The reaction force on stair during the movement of an AK prosthesis is analyzed. For more detailed analysis of climbing of a transfemoral amputee, an analysis of reaction force of stair for healthy persons has been carried out. The ELITE system with two CCD cameras and a Kistler platform for measuring the force on the surface were used during measurements.

Lower extremity joint kinematics of stair ascent in transfemoral amputees

“…At the instant of touchdown, the PST knee was rapidly extended and remained at the full-extension angle until toeoff ( Figure 2B). Although no study has reported these kinematic features during step-over-step stair ascent in able-bodied subjects, 11,14 similar knee kinematics in TFAs were observed not only during stair ascent using an aboveknee prosthesis with a built-in hydraulic cylinder connected to an external source of power, 15 but also during running 16 and uphill walking. 17 These common joint movements may represent a singular posture in mechanics.…”

Above-knee Prosthesis Control Based on Posture Recognition by Support Vector Machine

“…(7 K (xi, x~~~~~~~ ( 7) Solving (4) gives a decision function of the form f(x) = sign(rn1aiyi K(xi, xj)+ b). (8) The degrees of freedom of the SVMs model are decided by the choice of kernel, the parameters of the kernel and the choice of the regularization parameter as shown in Table I [16]. B.…”

Gait analysis of amputee people in limiting situations of daily living

“…Indeed, Vickers et al (2008), Vrieling et al (2008) and Williams et al (2009), Bellmann et al (2010 and Fradet et al (2010) investigated gait mechanisms during slope walking. Powers et al (1997), Nielsen (1999), Vucina (2005), Schmalz et al (2007) and Alimusaj et al (2009) investigated stair ambulation of amputee people. Finally, only one study was conducted with amputees on cross-slopes by Tulchin and Cummings (2010) who studied the mechanisms of inversion/eversion of one prosthetic ankle on a cross-slope device.…”