Technology in Rehabilitation: Evaluating the Single Leg Squat Exercise with Wearable Inertial Measurement Units
Publication Type:
Refereed Original Article
Abstract:
Background: The single leg squat (SLS) is a common lower limb rehabilitation
exercise. It is also frequently used as an evaluative exercise to screen for an
increased risk of lower limb injury. To date athlete/patient SLS technique has
been assessed using expensive laboratory equipment or subjective clinical
judgement; both of which are not without shortcomings. Inertial measurement
units (IMUs) may offer a low cost solution for the objective evaluation of
athlete/patient SLS technique.
Objectives: The aims of this study were to determine if in combination or in
isolation IMUs positioned on the lumbar spine, thigh and shank are capable of:
(A) distinguishing between acceptable and aberrant SLS technique; (B)
identifying specific deviations from acceptable SLS technique.
Methods: Eighty-three healthy volunteers participated (60 males, 23 females,
age: 24.68 +/- 4.91 years, height: 1.75 +/- 0.09 m, body mass: 76.01 +/- 13.29
kg). All participants performed 10 SLSs on their left leg. IMUs were positioned on
participants’ lumbar spine, left shank and left thigh. These were utilized to
record tri-axial accelerometer, gyroscope and magnetometer data during all
repetitions of the SLS. SLS technique was labelled by a Chartered Physiotherapist
using an evaluation framework. Features were extracted from the labelled
sensor data. These features were used to train and evaluate a variety of randomforests
classifiers that assessed SLS technique.
Results: A three IMU system was moderately successful in detecting the overall
quality of SLS performance (77% accuracy, 77% sensitivity and 78% specificity).
A single IMU worn on the shank can complete the same analysis with 76%
accuracy, 75% sensitivity and 76% specificity. Single sensors also produce
competitive classification scores relative to multi-sensor systems in identifying
specific deviations from acceptable SLS technique.
Conclusions: A single IMU positioned on the shank can differentiate between
acceptable and aberrant SLS technique with moderate levels of accuracy. It can
also capably identify specific deviations from optimal SLS performance. IMUs
may offer a low cost solution for the objective evaluation of SLS performance
Digital Object Identifer (DOI):
10.3414/ME16-02-0002
Publication Status:
Published
Date Accepted for Publication:
Monday, 3 October, 2016
Publication Date:
02/10/2016
Journal:
Methods of Information in Medicine
Research Group:
Institution:
National University of Ireland, Dublin (UCD)
Open access repository:
No