The objective of this study was to compare reaction time, joint torque, rate of torque
development, and magnitude of neuromuscular activation of lower-extremity muscles
in elderly female fallers and nonfallers. Participants included 11, elderly, female
fallers (71.3+/-5.4 years) and twelve nonfallers (71.3+/-6.2 years) who completed
a fall risk questionnaire. Then, maximal, voluntary, isometric contractions of the
knee and ankle muscles were performed in reaction to a visual cue to determine joint
torque, rate of torque development, reaction time, and nervous activation of agonists
and antagonists. Results indicated that significantly more fallers reported "dizziness
upon rising", "use of balance altering medications", "stress or depression", "not
enough sleep", "arthritis in lower body", "chronic pain in lower body", and "tiring
easily while walking" (all P<0.05). Normalized dorsiflexion and plantarflexion strength
scores (summation of peak torque, rate of torque development and impulse) were lower
in fallers than in nonfallers (P<0.05). When summed across lower-extremity muscle
groups, fallers demonstrated 19% lower peak torque and 29% longer motor time (P<0.05).
In conclusion, comprehensive fall risk screening and prevention programs should address
both neuromuscular and non-muscular factors, and, weakness of the ankle dorsiflexors
and plantarflexors should be further studied as potential contributors to falls in
older adults.
(c) 2009 Elsevier Ltd. All rights reserved.