Citation: Khandan, A.; Fathian, R.;
Carey, J.P.; Rouhani, H. Assessment
of Three-Dimensional Kinematics of
High- and Low-Calibre Hockey
Skaters on Synthetic ice Using
Wearable Sensors. Sensors 2023, 23,
334. https://doi.org/10.3390/
s23010334
Academic Editors: Pietro Picerno,
Andrea Mannini and Clive D’Souza
Received: 5 December 2022
Revised: 26 December 2022
Accepted: 26 December 2022
Published: 28 December 2022
Copyright: © 2022 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Article
Assessment of Three-Dimensional Kinematics of High- and
Low-Calibre Hockey Skaters on Synthetic ice Using
Wearable Sensors
Aminreza Khandan , Ramin Fathian, Jason P. Carey and Hossein Rouhani *
Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
* Correspondence: hrouhani@ualberta.ca
Abstract:
Hockey skating objective assessment can help coaches detect players’ performance drop
early and avoid fatigue-induced injuries. This study aimed to calculate and experimentally validate
the 3D angles of lower limb joints of hockey skaters obtained by inertial measurement units and
explore the effectiveness of the on-ice distinctive features measured using these wearable sensors in
differentiating low- and high-calibre skaters. Twelve able-bodied individuals, six high-calibre and
six low-calibre skaters, were recruited to skate forward on a synthetic ice surface. Five IMUs were
placed on their dominant leg and pelvis. The 3D lower-limb joint angles were obtained by IMUs
and experimentally validated against those obtained by a motion capture system with a maximum
root mean square error of 5 deg. Additionally, among twelve joint angle-based distinctive features
identified in other on-ice studies, only three were significantly different (p-value < 0.05) between
high- and low-calibre skaters in this synthetic ice experiment. This study thus indicated that skating
on synthetic ice alters the skating patterns such that the on-ice distinctive features can no longer
differentiate between low- and high-calibre skating joint angles. This wearable technology has
the potential to help skating coaches keep track of the players’ progress by assessing the skaters’
performance, wheresoever.
Keywords:
inertial measurement unit; objective performance assessment; synthetic ice skating;
three-dimensional kinematics; supervised classification analysis
1. Introduction
One of the key components of ice hockey players’ skills is skating [
1
,
2
]. Like other
sports activities, skating has traditionally been assessed by video and motion capture
cameras [
3
–
5
]. These cameras have been used to study two-dimensional (2D) or three-
dimensional (3D) kinematics of the lower-limb joints of individuals skating. A setup of
digital video cameras was used to obtain 2D or 3D joint angles on ice [
6
–
9
] or on a skating
treadmill [
5
,
10
]. Moreover, in [
6
–
9
], motion capture systems were used to obtain the kine-
matics of high- and low-calibre or male and female high-calibre hockey players. Although
these motion capture systems are precise and taken as a reference system, their application
is bounded to in-lab measurements due to their limited availability and capturing vol-
ume. Instead, wearable technology is a trended and acclaimed alternative for performance
assessment and can be used in in-field measurements [11].
Wearable technologies such as GPS and accelerometers measure essential kinematics
in team sports [
12
–
18
]. A 3D accelerometer enables researchers to determine temporal
events during ice hockey skating and also differentiate players in terms of their skill lev-
els [
16
,
17
,
19
]. However, neither 3D accelerometers alone nor GPS can measure 3D joint
angles. GPS works precisely in open-field sports; however, the signals of GPS may be
considerably affected by errors in indoor areas. Moreover, GPS does not provide phys-
iologically relevant information, such as the players’ phase of play during ice hockey.
Sensors 2023, 23, 334. https://doi.org/10.3390/s23010334 https://www.mdpi.com/journal/sensors
