Development and Validation of a Portable and Inexpensive Tool to Measure the Drop Vertical Jump Using the Microsoft Kinect V2

Abstract

Background:Noncontact anterior cruciate ligament (ACL) injury in adolescent female athletes is an increasing problem. The knee-ankle separation ratio (KASR), calculated at initial contact (IC) and peak flexion (PF) during the drop vertical jump (DVJ), is a measure of dynamic knee valgus. The Microsoft Kinect V2 has shown promise as a reliable and valid marker-less motion capture device.Hypothesis:The Kinect V2 will demonstrate good to excellent correlation between KASR results at IC and PF during the DVJ, as compared with a “gold standard” Vicon motion analysis system.Study Design:Descriptive laboratory study.Level of Evidence:Level 2.Methods:Thirty-eight healthy volunteer subjects (20 male, 18 female) performed 5 DVJ trials, simultaneously measured by a Vicon MX-T40S system, 2 AMTI force platforms, and a Kinect V2 with customized software. A total of 190 jumps were completed. The KASR was calculated at IC and PF during the DVJ. The intraclass correlation coefficient (ICC) assessed the degree of KASR agreement between the Kinect and Vicon systems.Results:The ICCs of the Kinect V2 and Vicon KASR at IC and PF were 0.84 and 0.95, respectively, showing excellent agreement between the 2 measures. The Kinect V2 successfully identified the KASR at PF and IC frames in 182 of 190 trials, demonstrating 95.8% reliability.Conclusion:The Kinect V2 demonstrated excellent ICC of the KASR at IC and PF during the DVJ when compared with the Vicon system. A customized Kinect V2 software program demonstrated good reliability in identifying the KASR at IC and PF during the DVJ.Clinical Relevance:Reliable, valid, inexpensive, and efficient screening tools may improve the accessibility of motion analysis assessment of adolescent female athletes.

3D Analysis of Upper Limbs Motion During Rehabilitation Exercises Using the Kinect^TM Sensor: Development, Laboratory Validation and Clinical Application

“…In total 19 local coordinate systems (LCS), following ISB recommendations [27] for axis orientation, were located in the origins indicated by numbers (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) in Figure 1. Then 33 LCSs origin motions relative to parent LCSs (Table 1) Each of 33 trajectory plots was processed to assess different properties of the shape created by hodograph.…”

“…motion analysis, posture analysis, feedback during rehabilitation exercises,etc.) [1][2][3][4][5][6][7].…”

Relationship Between 2-Dimensional Frontal Plane Measures and the Knee Abduction Angle During the Drop Vertical Jump

“…2,4,5 Unfortunately, 3-dimensional motion capture systems are expensive, space prohibitive, and require advanced training to operate, precluding widespread usage. 5,6 Consequently, investigations into simplified surrogate 2-dimensional measures to monitor knee valgus collapse during motions such as the DVJ have garnered attention in recent years. 5,6 The knee-to-ankle separation ratio (KASR), a bilateral lower-extremity measure defined as the frontal plane distance between the knee joint centers divided by the frontal plane distance between the ankle joint centers, has been suggested.…”

“…5,6 Consequently, investigations into simplified surrogate 2-dimensional measures to monitor knee valgus collapse during motions such as the DVJ have garnered attention in recent years. 5,6 The knee-to-ankle separation ratio (KASR), a bilateral lower-extremity measure defined as the frontal plane distance between the knee joint centers divided by the frontal plane distance between the ankle joint centers, has been suggested. 5,6 Mizner et al 5 highlighted the KASR as a potential surrogate to KAA, but demonstrated only a weak to moderate relationship (r 2 = .25) to the KAA at peak flexion of the DVJ.…”

“…5,6 The knee-to-ankle separation ratio (KASR), a bilateral lower-extremity measure defined as the frontal plane distance between the knee joint centers divided by the frontal plane distance between the ankle joint centers, has been suggested. 5,6 Mizner et al 5 highlighted the KASR as a potential surrogate to KAA, but demonstrated only a weak to moderate relationship (r 2 = .25) to the KAA at peak flexion of the DVJ. In this study, Mizner et al 5 only examined peak knee flexion of the DVJ, excluding analysis at initial contact.…”