The use of real-time feedback to improve kinematic marker placement consistency among novice examiners

Abstract

Marker placement deviation has been shown to be the largest source of error in gait kinematic data, limiting the ability of clinicians and researchers to conduct between-day or between-center investigations. Prior marker-placement standardization methods are either impractical for a clinical setting or rely on expert marker placement. However, a recently developed, real-time feedback tool has been developed and shown to improve marker placement and downstream kinematic calculations. The purpose of this study was to determine whether this real-time marker-placement tool could improve the consistency of gait kinematic data collected by a group of novice examiners. Twelve novice examiners identified anatomical landmarks and placed retroreflective markers on a single subject. For each examiner, a running trial was analyzed separately using two static trials: (1) PRE and (2) POST implementation of the feedback tool. The protocol was repeated a second time, one week later. Between-examiner consistency was represented by the 95% confidence interval (CI) of the mean joint angles for the entire stride, and compared between the PRE and POST conditions. The POST feedback trials showed an average 27.45% reduction of the 95%CI range for eight out of nine joint angles on day one, and an average 24.73% for five out of nine joint angles on day two, compared to POST. The results indicate a real-time feedback tool improves the consistency in marker placement for novice users.

A hierarchical cluster analysis to determine whether injured runners exhibit similar kinematic gait patterns

“…However, systematic differences were apparent in data collected during the end of the year. Thus, future research involving a large cohort should take into consideration the number of people collecting the data and/or use appropriate feedback methods to minimize marker placement error.…”

Can the fusion of motion capture and 3D medical imaging reduce the extrinsic variability due to marker misplacements?

“…patients that underwent orthopaedic surgery or children with cerebral palsy that grew up. The real-time feedback system developed by Macaulay et al [11] could reduce the variability (95% confidence interval) between novice examiners by 47% for the hip frontal plane and 56% for the hip flexion angle in an healthy subjects. Although promising, this device has not yet been tested for a pathological population.…”

“…The latter has been identified as the largest source of extrinsic variability between measurements [7,8]. Multiple methods have been proposed to correct this source of errors such as: palpation methods [9], real-time feedback methods [10,11], external devices [12,13], fusion with static 3D medical imaging [14,15] and dynamic 3D imaging such as bi-plane fluoroscopy [16,17].…”