Article

Abnormalities of gait and changes in posture during walking are more
common in older adults than in young adults and may contribute to an increase in
the energy expended for walking. OBJECTIVE: The objective of this study was to
examine the contributions of abnormalities of gait biomechanics (hip extension,
trunk flexion, and foot-floor angle at heel-strike) and gait characteristics
(step width, stance time, and cadence) to the energy cost of walking in older
adults with impaired mobility. DESIGN: A cross-sectional design was used.
METHODS: Gait speed, step width, stance time, and cadence were derived during
walking on an instrumented walkway. Trunk flexion, hip extension, and foot-floor
angle at heel contact were assessed during overground walking. The energy cost of
walking was determined from oxygen consumption data collected during treadmill
walking. All measurements were collected at the participants' usual,
self-selected walking speed. RESULTS: Fifty community-dwelling older adults with
slow and variable gait participated. Hip extension, trunk flexion, and step width
were factors related to the energy cost of walking. Hip extension, step width,
and cadence were the only gait measures beyond age and gait speed that provided
additional contributions to the variance of the energy cost, with mean R(2)
changes of .22, .12, and .07, respectively. Limitations Other factors not
investigated in this study (interactions among variables, psychosocial factors,
muscle strength [force-generating capacity], range of motion, body composition,
and resting metabolic rate) may further explain the greater energy cost of
walking in older adults with slow and variable gait. CONCLUSIONS: Closer
inspection of hip extension, step width, and cadence during physical therapy gait
assessments may assist physical therapists in recognizing factors that contribute
to the greater energy cost of walking in older adults.

Langue : ANGLAIS