Article

Calculation of lower limb kinetics is limited by floor-mounted
force-plates. OBJECTIVES: Comparison of hip joint moments, power and mechanical
work on the prosthetic limb of a transfemoral amputee calculated by inverse
dynamics using either the ground reactions (force-plates) or knee reactions
(transducer). Comparative analysis. METHODS: Kinematics, ground
reaction and knee reaction data were collected using a motion analysis system,
two force-plates, and a multi-axial transducer mounted below the socket,
respectively. RESULTS: The inverse dynamics using ground reaction underestimated
the peaks of hip energy generation and absorption occurring at 63% and 76% of the
gait cycle (GC) by 28% and 54%, respectively. This method also overestimated by
24% a phase of negative work at the hip (37%-56% GC), and underestimated the
phases of positive (57%-72% GC) and negative (73%-98%GC) work at the hip by 11%
and 58%, respectively. CONCLUSIONS: A transducer mounted within the prosthesis
has the capacity to provide more realistic kinetics of the prosthetic limb
because it enables assessment of multiple consecutive steps and a wide range of
activities without the issue of foot placement on force-plates. CLINICAL
RELEVANCE: The hip is the only joint an amputee controls directly to set the
prosthesis in motion. Hip joint kinetics are associated with joint degeneration,
low back pain, risk of falls, etc. Therefore, realistic assessment of hip
kinetics over multiple gait cycles and a wide range of activities is essential.

Langue : ANGLAIS