Head Impact Sensor Studies In Sports: A Systematic Review Of Exposure Confirmation Methods

Abstract

To further the understanding of long-term sequelae as a result of repetitive head impacts in sports, in vivo head impact exposure data are critical to expand on existing evidence from animal model and laboratory studies. Recent technological advances have enabled the development of head impact sensors to estimate the head impact exposure of human subjects in vivo. Previous research has identified the limitations of filtering algorithms to process sensor data. In addition, observer and/or video confirmation of sensor-recorded events is crucial to remove false positives. The purpose of the current study was to conduct a systematic review to determine the proportion of published head impact sensor data studies that used filtering algorithms, observer confirmation and/or video confirmation of sensor-recorded events to remove false positives. Articles were eligible for inclusion if collection of head impact sensor data during live sport was reported in the methods section. Descriptive data, confirmation methods and algorithm use for included articles were coded. The primary objective of each study was reviewed to identify the primary measure of exposure, primary outcome and any additional covariates. A total of 168 articles met the inclusion criteria, the publication of which has increased in recent years. The majority used filtering algorithms (74%). The majority did not use observer and/or video confirmation for all sensor-recorded events (64%), which suggests estimates of head impact exposure from these studies may be imprecise.

The Use of Wearable Sensor Technology to Detect Shock Impacts in Sports and Occupational Settings: A Scoping Review

“…With regard to head impacts, placement of the wearable sensors may be challenging, as they are prone to be broken by the impact. Wearable sensors for assessments of head impacts are available in several systems; they are embedded in instrumented helmets, headbands, mouthguards, and skin patches [ 89 , 90 ]. Of the ten studies included in the data material, skin patches (xPatch) were used in four studies [ 36 , 41 , 54 , 58 ], instrumented helmets (GForce Tracker and SpeedFlex/HIT) were used in five studies [ 36 , 40 , 42 , 45 , 51 ], a headband (SIM-G) was used in one study [ 48 ], and finally MVTrak, with a sensor placed in the ear canal, was used in one study [ 53 ] (number summarizes to eleven, as the study by Cortes et al [ 36 ] utilized xPatch for females and GForce Tracker for males).…”

“…Linear and rotational acceleration magnitudes from lab studies have been shown to be over-predicted for sensor solutions in both skin patches and instrumented helmets [ 92 ]. False positive high acceleration impacts have further been revealed in field studies, and the importance of video confirmation of sensor-recorded events to remove false positives is in a recent systematic review by Patton et al emphasized to avoid overestimation of head impact exposure [ 90 ]. Still, two-thirds of the included studies in their review did not include video.…”

“…This underlines the ambiguity of using 10 g as a threshold for head impacts, especially if not adding video to confirm events. The systematic review by Patton et al [ 90 ] finally also states that even though the majority (74%) of the included studies used filtering algorithms, these remain inadequate. Thus, the studies included in this scoping review, as well as previous reviews, suggest that trusting wearable sensors as the only data source for assessments of head impacts in sports could imply an overestimation of potential harmful impacts, both in number and in severity.…”

Video Analysis and Verification of Direct Head Impacts Recorded by Wearable Sensors in Junior Rugby League Players

“…Recently, various technology has been introduced to assist in the identification of head impacts and suspected concussions during athlete competitions. For instance, sideline video review [9,10], and to a lesser extent, impact sensors in helmeted and non-helmeted sports have been introduced to measure kinematic forces to the head [11,12].…”

Special Issue on Concussions in Sports

“…22 This is especially concerning since head impact sensor data is often taken at face value without using video to verify that all recorded impacts were true positives. 20 To provide an objective evaluation of both laboratory and on-field performance of head impact sensors, Kieffer et al developed a twophase approach to sensor testing. 13 The first phase used a pendulum impactor to test laboratory performance, followed by the second phase of on-field testing from video verification of impacts if the sensor performed adequately in the laboratory.…”