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KNEE MOMENT SYMMETRY DURING HILL WALKING 155

Table 1. Degree of Asymmetry for Knee Moment during Hill Walking
Table 1. Degree of Asymmetry for Knee Moment during Hill Walking
Walking Speed Slow Self-selected Fast
Hill Measurement
Condition Parameter C-Leg Genium C-Leg Genium C-Leg Genium
M
S
Uphill DoA (mn ± sd) 0.03 (0.15) 0.00 (0.04)* 0.01 (0.23) -0.01 (0.07) NA 0.00 (0.11) 0.00 (0.00)*
Downhill DoA (mn ± sd) 0.03 (0.06) 0.01 (0.10)* 0.07 (0.10) 0.00 (0.01)* 0.03 (0.04) 0.08 (0.29)
NA
L
S

DoA is degree of Asymmetry. *significantly different from C-Leg (p ≤ 0.05). When differences are significant, effect sizes are S for small,
M for medium and L for large. When differences are not significant, effect size is NA (not available).
DoA is degree of Asymmetry. *significantly different from C-Leg (p ≤ 0.05). When differences are
significant, effect sizes are S for small, M for medium and L for large. When differences are not
symmetry with Genium use. The fourth signifi- groups (24). This reduced gait speed may be related to
significant, effect size is NA (not available).
cant finding yielded no mean difference but, rather, a fear of falling, which could be intensified in ampu-

decreased variance in knee moment with Genium tees, thus contributing to notably reduced walking
use, which was a common trend in the results when speed (21-23,25). Results of this work suggest that
compared to C-Leg. These findings indicate accom- the Genium MPK system may be a desirable inter-
modation and use of the Genium MPK enabled vention for patients with transfemoral limb loss who
increased prosthetic gait control as reflected by more range in function from high-functioning community
favorable DoA values and variability in knee flexion ambulators to older amputees who walk slower and
moment in stance phase during ramp ascent and require more consistent knee performance. Current
descent for unilateral TFA patients capable of unlim- U.S. healthcare regulations mandate the ability to
ited community ambulation. vary cadence in order to be considered for MPK eli-
Previous work has shown improved stability and gibility. Elderly persons with TFA are thus at risk of
knee flexion with C-Leg use compared to non-MPK denial of MPK consideration due to this requirement.
(17,18) and MPK systems alike (19). Use of the However, limited community ambulators have been
Genium MPK has been shown to provide a more con- shown to gain as many (or more) of the benefits of
sistent stance flexion knee angle in a variety of walking MPK technology than their unlimited community
speeds and terrains compared with C-Leg (6). The ambulating peers (26).
results of the present study corroborate the previously
identified kinematic symmetry, as maximum stance CONCLUSION
flexion moments were markedly symmetrical and Accommodation and use of the Genium knee sys-
minimally varied with Genium MPK use compared tem, compared with C-Leg, improved knee moment
with C-Leg use in this sample of high-functioning symmetry in slow speed walking up and down a five
persons with TFA. degree ramp. Additionally, the Genium improved
Although these findings were derived from gen- knee moment symmetry when walking downhill at
erally young, healthy, and highly-active amputees, comfortable speed. At fast walking speed, variance
clinical application exists for elderly amputees who in knee moment symmetry was lower when using
may display high variation in gait parameters, which Genium. These results were found in a sample of
leads to falls (20). Prosthetic components that reduce high functioning persons with unilateral transfemoral
biomechanical gait variability may be an effective amputation; however, the results likely have applica-
means to facilitate independence for amputees at tion in other patients who could benefit from more
increased fall risk (21-23). consistent knee function, such as older patients and
A notable finding from this work is the improved others who have slower walking speeds.
knee moment symmetry and reduced variance in
knee kinetics at slow walking conditions among ACKNOWLEDGMENTS
MPKs. Older individuals are consistently found to Contents of this manuscript represent the opin-
have reduced gait speed relative to those in other age ions of the authors and not necessarily those of the