Citation

Crenshaw JR, Kaufman KR. Gait Posture 2014; 39(2): 810-815.

Affiliation

Motion Analysis Laboratory, Division of Orthopedic Research, Mayo Clinic, 200 1st Street SW, Charlton North L-110K, Rochester, MN 55905, USA. Electronic address: crenshaw.jeremy@mayo.edu.

Copyright

(Copyright © 2014, Elsevier Publishing)

DOI

10.1016/j.gaitpost.2013.11.006

PMID

24300837

Abstract

The purpose of this study was to evaluate the test-retest, intra-rater reliability and agreement of compensatory stepping thresholds. A protocol was developed to establish anteroposterior single-stepping thresholds, anteroposterior multiple-stepping thresholds, and lateral single-stepping thresholds. Healthy, young subjects stood on a microprocessor-controlled treadmill, and responded to three series of progressively challenging surface translations. Subjects were instructed to "try not to step" when establishing single-stepping thresholds or "try to take only one step" when establishing multiple-stepping thresholds. Stepping thresholds were defined as the minimum disturbance magnitude that consistently elicited a single or second compensatory step. Thresholds were expressed as the ankle torque necessary to maintain upright posture. Thresholds studied included anterior single-stepping thresholds (τ=273.0±82.3Nm), posterior single-stepping, thresholds (τ=235.5±98.0Nm), anterior multiple-stepping thresholds (τ=977.0±416.3Nm), posterior multiple-stepping thresholds (τ=701.9±237.5Nm), stability-side lateral single-stepping thresholds (τ=225.7±77.7Nm), and mobility-side lateral single-stepping thresholds (τ=236.8± 85.4Nm). Based on intraclass correlation coefficients (ICC) and Bland-Altman plots, all thresholds demonstrated excellent reliability (ICC(2,1)=0.87-0.97) and agreement. These results suggest that compensatory stepping thresholds have sufficient repeatability to be used in clinical and research-related assessments of fall-risk. Additional study is needed to determine the intra- and inter-rater reliabilities and validity of thresholds specific to the patient populations of interest.

Language: en