Walking symmetry and energy cost in persons with unilateral transtibial amputations: Matching prosthetic and intact limb inertial properties  Sarah J. Mattes, MS, Philip E. Martin, PhD, Todd D. Royer, MS  Archives of Physical Medicine and Rehabilitation  Volume 81, Issue 5, Pages 561-568 (May 2000) DOI: 10.1016/S0003-9993(00)90035-2 Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 1 Moment of inertia of the prosthetic (Pros) and intact shank and foot relative to a transverse axis through the knee joint (Iknee). The mass was positioned on the distal aspect of the prosthetic limb such that Iknee for the two limbs was the same under the 100% load condition. NL, no load. Archives of Physical Medicine and Rehabilitation 2000 81, 561-568DOI: (10.1016/S0003-9993(00)90035-2) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 2 Moment of inertia of the entire prosthetic (Pros) and intact legs relative to a transverse axis through the hip joint (Ihip). A reasonably close agreement in Ihip for the two legs was produced by loading the distal aspect of the prosthetic limb. NL, no load. Archives of Physical Medicine and Rehabilitation 2000 81, 561-568DOI: (10.1016/S0003-9993(00)90035-2) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 3 Although step length for the prosthetic limb was not significantly different for the three load conditions, there was a trend for step length to increase as its mass and moment of inertia were increased. There was no change in step length for the unloaded, intact leg. NL, no load. Archives of Physical Medicine and Rehabilitation 2000 81, 561-568DOI: (10.1016/S0003-9993(00)90035-2) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 4 Swing time for the prosthetic (Pros) limb increased as its mass and moment of inertia were increased, whereas there was no change in swing time for the unloaded, intact leg. NL, no load. Archives of Physical Medicine and Rehabilitation 2000 81, 561-568DOI: (10.1016/S0003-9993(00)90035-2) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 5 Stance time decreased for the prosthetic (Pros) limb and increased for the unloaded, intact leg as the mass and moment of inertia of the prosthetic limb were increased. NL, no load. Archives of Physical Medicine and Rehabilitation 2000 81, 561-568DOI: (10.1016/S0003-9993(00)90035-2) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 6 Symmetry indices for swing and stance times indicate the increasing asymmetries that developed for both variables in response to increased mass and moment of inertia of the prosthetic leg. Positive symmetry indices for swing time indicate that the prosthetic limb values were greater than those of the intact limb. Negative symmetry indices for stance time reflect greater values for the intact limb. NL, no load. Archives of Physical Medicine and Rehabilitation 2000 81, 561-568DOI: (10.1016/S0003-9993(00)90035-2) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 7 Energy cost of walking was not different for the unloaded (NL) and 50% load conditions, but was significantly higher (6.9%) under the 100% load condition. Archives of Physical Medicine and Rehabilitation 2000 81, 561-568DOI: (10.1016/S0003-9993(00)90035-2) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions