Wearable sensors (WS) have been increasingly used to quantify training loads in team sports but can also be used to identify impacts. Helmet worn sensors have been used to identify head impacts, but there is currently no data with regard to whole-body impacts incurred by players in ice hockey using trunk-worn sensors.
PURPOSE: To use video to corroborate impacts identified by trunk-worn WS and determine validity of player incurred impacts (PII) among elite national ice hockey team members.
METHODS: 23 players on the U.S. National Team Development Program (NTDP) U18 team consented to procedures approved by EMU Human Subjects Committee. Players wore a BH-3 (Zephyr, MD) WS to measure occurrences of PII during games. Of the 23 players, 8 with the top activity levels each game determined by WS, were observed using video. Game video was collected by NTDP staff and synchronized with accelerometer data. Previous pilot work determined only impacts of > 6 g were relevant, so, impacts identified by WS of 6 - 7.9 g (Z3), 8 - 9.9 g (Z4) and 10+ g (Z5) were used to corroborate PII. Magnitude and duration of each identified impact were compared by category using MANOVA with Tukey post hoc (α= 0.05; SPSS 22.0, IBM, NY).
RESULTS: WS logged 419 on-ice impacts, 358 were confirmed true PII (85.5%), 60 were confirmed as other non-PII (14.3%) and 1 false positive (0.2%). For 358 PII, 17 (4.1%) were categorized as 1) Board contact/no check, 74 (17.7%) as 2) Board contact/check, 202 (48.2%) as 3) Open ice check, 65 (15.5%) as 4) Player fall. For the 60 Non-PII, 19 (4.5%) as 5) other form of player to player event, 16 (3.8%) as 6) Hard Stop, 19 (4.5%) as 7) Slapshots and 6 (1.4%) as 8) other identifiable player events. 140 of the 200 Z3 events were confirmed PII (80%), 103 of 110 Z4 events (93.6%) and 95 of 109 Z5 events were PII (92.2%). The magnitude of impacts was not different by category, but the duration of category 6 (Hard stop; .058 s) was lower than categories 2, 4 and 7 (.112, .112, .133 s, respectively, p<.05).
CONCLUSION: These data show that using some limited criteria (e.g. impact magnitude and duration), PII can be identified with relatively high accuracy in ice hockey using trunk-worn wearable sensors. Use of these devices should allow a more complete understanding of the whole-body impacts incurred by players participating in ice hockey.
Supported by USA Hockey Foundation