Kinematic metrics based on the virtual reality system Toyra as an assessment of the upper limb rehabilitation in people with spinal cord injury

Abstract

The aim of this study was to develop new strategies based on virtual reality that can provide additional information to clinicians for the rehabilitation assessment. Virtual reality system Toyra has been used to record kinematic information of 15 patients with cervical spinal cord injury (SCI) while performing evaluation sessions using the mentioned system. Positive correlation, with a moderate and very strong association, has been found between clinical scales and kinematic data, considering only the subscales more closely related to the upper limb function. A set of metrics was defined combining these kinematic data to obtain parameters of reaching amplitude, joint amplitude, agility, accuracy, and repeatability during the evaluation sessions of the virtual reality system Toyra. Strong and moderate correlations have been also found between the metrics reaching and joint amplitude and the clinical scales.

Figure 1

Placement of inertial sensors: (a) frontal view; (b) posterior view. The sensors were located on the trunk (1), the back of the head (2), the right arm (3), the forearm (4), and the hand (5) [23].

Figure 2

Patient performing a Toyra session.

Figure 3

Example of the curves of shoulder abduction recorded during 2 repetitions of the same movement by a patient.

Figure 4

Example illustrating the calculation of the repeatability for the 2 repetitions previously shown in Figure 3.

Figure 5

Kinematic metric joint amplitude per level of injury (mean ± SD). It is expressed in percentage with respect to the reference value of healthy subjects.

Figure 6

Kinematic metric accuracy per level of injury (mean ± SD). It is expressed in percentage with respect to the reference value of healthy subjects.

Figure 7

Kinematic metric agility per level of injury (mean ± SD). It is expressed in percentage with respect to the reference value of healthy subjects.

Figure 8

Kinematic metric repeatability per level of injury (mean ± SD). It is expressed in absolute value. It has been calculated only for levels C5, C6, and C7 because the number of registers for C8 level was not sufficient to establish a reliable value. For the same reason, the reference value of healthy subjects for this metric has not been calculated.