Article

It is well known that ankle joint power generation (A2) is reduced in healthy
older adults (OG) during gait. No general consensus exists, however, as to what
fundamental compensatory actions are made at the knee and hip joints by the OG to
compensate for this loss of power. The failure to control gait speed may account
for this lack of agreement. This study investigated the effect of aging on lower
limb joint power and work during gait. The gait patterns of eight old (OG:
66.8+/-5.4 yr) and 12 young adults (YG: 26.6+/-2.9 yr) were recorded for a range
of matched speeds (1.0 m s(-1), 1.3 m s(-1), 1.6 m s(-1)). Speed did not differ
between the groups. Combining speeds, the OG generated 17% less A2 power and 21%
less A2 work (p<0.05). Compared to the YG, the OG generated 46% more H1 work, 30%
more H2 peak power, 16% more H3 peak power, 30% more K3 peak power and 19% more
K4 peak power (p<0.05). These actions by the OG were associated with less ankle
plantar-flexion, more hip flexion and anterior pelvic tilt (p<0.05). The OG
adopted a different gait pattern at the faster speeds by generating more H3 work
than A2 work. This shows the OG rely on hip flexors to propel the leg into swing
when ankle plantar-flexor function is reduced. This may partly explain how gait
changes emerge with aging.
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Langue : ANGLAIS