Article

Ascending stairs is an important functional activity that is affected by lower
extremity pathology including amputation. Although several studies have
demonstrated stair ascent is more challenging than level ground walking, our
understanding of the mechanics remains limited. The purpose of this study was to
determine the association between lower extremity joint power generation and
vertical COM acceleration (COM(A)) during stair ascent.
Twenty-two healthy
individuals underwent a biomechanical gait assessment while walking up a 16-step
instrumented staircase. The association between the peak joint powers and peak
COM(A) during stance were assessed with respect to timing and magnitude. With
respect to timing, peak ankle joint power was highly correlated with peak COM(A)
(R(2)=0.93), while peak knee and hip joint powers demonstrated limited
association with COM(A) (R(2)=0.41 and 0.08, respectively). Only the magnitude of
peak ankle power was associated with peak COM(A)
(R(2)=0.3). Significant temporal
and magnitude associations between peak ankle joint power and peak COM(A) suggest
ankle power is a key contributor to COM(A). Although peak knee joint power and
COM(A) are temporally associated, the association is weaker and the occurrence of
peak joint knee power is nearly 10% after peak COM(A), suggesting knee joint
power plays a lesser role in COM(A). These combined findings indicate the role of
trail limb ankle plantarflexors should be recognized in the stair ascent cycle
definition and demonstrate the potential importance of a power generated by the
ankle plantarflexors to normalize stair ascent performance following lower extremity amputation.
CI - Published by Elsevier B.V.

Langue : ANGLAIS