Article

People with knee osteoarthritis (OA) are at twice the risk of falling
compared to older people without knee OA, however the mechanism for this is
poorly understood. This study investigated the biomechanical response of the
trunk and lower limb joints during a forward induced fall under different task
conditions in people with and without knee OA. METHOD: Twenty-four participants
with OA (68.6+/-6.2 years) and 15 asymptomatic controls
(72.4+/-4.8 years)
participated in the study. Forward fall was induced by releasing participants
from a static forward leaning position. Participants were required to recover
balance during three conditions: normal, physical (obstacle clearance) and
cognitive dual tasks (counting backwards). Spatiotemporal parameters, lower limb
joint kinematics and kinetics of the recovery limb were compared between the two
groups and across the three task conditions. RESULTS:
The OA group demonstrated
slower spatio-temporal characteristics and reduced hip and knee flexion angles,
joint moments/powers and reduced muscle negative work at the knee and ankle
(p<0.05). Cognitive dual task resulted in reduced centre of mass velocity and
step length (p=0.03) compared to the physical dual task condition. Reduced knee
(p=0.02) and hip joint powers (p=0.03) were demonstrated in the OA group in the
physical task condition. CONCLUSION: When simulating a forward fall, participants
with OA demonstrated difficulty in absorbing the impact and slowing down the
forward momentum of the body during a recovery step. Moreover, poor dynamic
postural control was demonstrated as task complexity increased.
CI - Copyright (c) 2016 Elsevier B.V. All rights reserved.

Langue : ANGLAIS