Citation

Doherty C, Delahunt E, Bleakley C, Hertel J, Ryan J, Caulfield B. Br. J. Sports Med. 2014; 48(7): 586.

Affiliation

School of Public Health, Physiotherapy and Population Science, University College Dublin, Dublin, Ireland.

Copyright

(Copyright © 2014, BMJ Publishing Group)

DOI

10.1136/bjsports-2014-093494.72

PMID

24620113

Abstract

BACKGROUND: Upright single-limb stance (SLS) is maintained via integration of visual, vestibular and somatosensory afferents. The presence of redundancies between these afferents allows the sensorimotor system to simplify a specific task within a number of strategies. Musculoskeletal injury challenges the somatosensory system to reweight distorted sensory afferents. No current investigation has supplemented kinetic analysis of eyes-open and eyes-closed SLS tasks with a kinematic profile of lower limb postural orientation in an acute lateral ankle sprain (LAS) group to assess the adaptive capacity of the sensorimotor system to injury. OBJECTIVE: To compare centre of pressure (COP) and lower limb postural orientation characteristics of participants with acute LAS to non-injured participants during a SLS task. DESIGN: Cross-sectional. SETTING: University biomechanics laboratory. PARTICIPANTS: 66 participants with acute LAS completed a task of eyes-open SLS on their injured and non-injured limbs (task 1). 23 of these participants successfully completed the SLS task with their eyes closed (task 2). A non-injured control group of nineteen participants completed task 1, with 16 completing task 2. MAIN OUTCOME MEASURES: 3D kinematics of the hip, knee and ankle joints as well as associated fractal dimension (FD) of the COP path. RESULTS: Between trial analyses of groups revealed significant differences in lower limb kinematics and FD of the COP path for task 2. Post-hoc testing revealed that non-injured control group bilaterally assumed a position of greater hip flexion compared to LAS participants (injured limb=7.41±6.1 vs 1.44±4.8; non-injured limb=9.59±8.5 vs 2.16±5.6), with a corollary of greater FD of the COP path (injured limb=1.39±0.16 vs 1.25±0.14; non-injured limb=1.37±0.21 vs 1.23±0.14). CONCLUSION: Acute LAS causes bilateral impairment in postural control strategies.

Language: en