Article

OBJECTIVES: To examine differences in hip abductor strength and composition
between older adults who primarily use medial step versus cross-step recovery
strategies to lateral balance perturbations. DESIGN:
Cross-sectional. SETTING:
University research laboratory. PARTICIPANTS: Community-dwelling older adults
(N=40) divided into medial steppers (n=14) and cross-steppers (n=26) based on the
first step of balance recovery after a lateral balance perturbation.
INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Computed tomography scans
to quantify lean tissue and intramuscular adipose tissue (IMAT) areas in the hip
abductor, hip abductor isokinetic torque, and first step length. RESULTS: Medial
steppers took medial steps in 71.1% of trials versus 4.6% of trials with
cross-steps. The cross-steppers when compared with medial steppers, had lower hip
abductor IMAT (24.7+/-0.7% vs 29.9+/-2.8%; P<.05), greater abductor torque
(63.3+/-3.6Nm vs 48.4+/-4.1Nm; P<.01), and greater normalized first step length
(.75+/-.03 vs .43+/-.08; P<.001). There was no difference in hip abductor lean
tissue between the groups (P>.05). CONCLUSIONS: Our findings suggest that older
adults who initially use a medial step to recover lateral balance have lower hip
abductor torque and may be less able to execute a biomechanically more stable
cross-step. This may be related to increased IMAT levels. Assessments and
interventions for enhancing balance and decreasing fall risk should take the role
of the hip abductor into account.
CI - Copyright (c) 2016 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS