Head and Neck Loading in Everyday and Vigorous Activities

Abstract

The purpose of this study was to document head and neck loading in a group of ordinary people engaged in non-injurious everyday and more vigorous physical activities. Twenty (20) volunteers that were representative of the general population were subjected to seven test scenarios: a soccer ball impact to the forehead, a self-imposed hand strike to the forehead, vigorous head shaking, plopping down in a chair, jumping off a step, a seated drop onto the buttocks, and a vertical drop while seated supine in a chair. Some scenarios involved prescribed and well-controlled stimuli, while others allowed the volunteers to perform common activities at a self-selected level of intensity. Head accelerations up to 31 g and 2888 rad/s(2) and neck loads up to 268 N in posterior shear, 526 N in compression, and 36 Nm in extension were recorded. Most head and neck injury criteria predicted a low risk of injury in all activities. However, rotational head accelerations and Neck Injury Criterion (NIC) values were much higher than some proposed tolerance limits in a large number of tests, all of which were non-injurious. The data from this study help us to establish an envelope of head and neck loading that is commonly encountered and presents a minimal risk of injury.

The ROI-C zero-profile anchored spacer for anterior cervical discectomy and fusion: biomechanical profile and clinical outcomes

“…ROI-C also had less range of motion (% of Intact ROM) in all directions compared to a stand-alone PEEK cage with two screws, as well as to a traditional PEEK cage with cervical plate construct (Figure 2). Average pullout loads for ROI-C were greater than reported pullout loads for a conventional cervical plate (232.7 N vs 202 N, respectively), which are well above the expected physiologic loads 20. Pullout failure of the ROI-C only occurred due to plowing of the device through the bone and opening (lordosing) of the segment.…”

Quantifying Head Impact Exposure in Collegiate Women's Soccer

“…Furthermore, previous research suggests that soccer headers typically only produce head accelerations less than 30g. 9,10,12,13,[18][19][20] Therefore, it would be impractical to use this optimal threshold for a soccer head impact study, seeing that most impacts would still be missed by the sensors. The ROC curves generated for these data actually look fairly good, which is mainly because the sensors did a good job of filtering out nonimpact events.…”

The influence of headform orientation and flooring systems on impact dynamics during simulated fall-related head impacts

“…The National Operating Committee on Standards for Athletic Equipment (NOCSAE) has also developed biofidelic headforms, which include a glycerin-filled 'brain cavity' to optimally simulate the behaviour of the human head in response to impact [22,23]. Decades of head impact research have produced risk curves and associated injury thresholds for skull fracture and TBI following impact based on force and acceleration profiles, as well as derived injury criteria such as the Head Injury Criterion (HIC) [24][25][26][27][28]. Simulated head impacts have been widely used to evaluate head injury risk, including during falls on taekwondo mats [29], falls onto playground surfaces [27], and impacts during athletic competition [30].…”