Does tester experience influence the reliability with which 3D gait kinematics are collected in healthy adults?

OBJECTIVES

To determine whether tester experience influences the reliability of three-dimensional gait collections.

DESIGN

Reliability study.

PARTICIPANTS

Ten healthy subjects visited a university gait laboratory on two separate days and underwent a walking gait analysis. During each visit, kinematic data were collected by a biomechanist with 8 years of 3D gait analysis experience (EXP) and a physical therapist with no previous 3D gait analysis experience (NOV).

MAIN OUTCOME MEASURES

Joint kinematic angles were calculated using either a functional or predictive joint identification method. Within-tester and between-tester measures of reliability were determined by calculating the root mean square error (RMS) and coefficient of multiple correlations (CMC).

RESULTS

Within-tester RMS and CMC values were not significantly different (P > 0.05) between the EXP and NOV testers using either a functional or predictive joint approach. Within-tester CMC values exceeded 0.90 for both testers across all kinematic variables. Between-tester CMC reliability values were greater than 0.85 for all variables measured.

CONCLUSIONS

Following basic training, a physiotherapy clinician with no previous 3D gait experience is as reliable as an experienced gait biomechanist with respect to marker placement accuracy. In addition, reliability comparisons between an experienced and novice tester appear independent of the joint identification method chosen.