Motion capture systems (MCS) are used in neurological rehabilitation and for diagnosis of movement disorders. We aimed to explore the usefulness of MCS to obtain an objective measurement of functional status after stroke, especially in patients with minor or without deficit when measured by current motor clinical scales.
Methods: Prospective observational case-control pilot study using Microsoft Kinect® analyzed with the software Akira®. Patients after acute stroke were included. All subjects performed the same exercises (standing, walking, sitting position, abduction of the upper limb in pronation and supination during 5 seconds each position and flexion of the upper limbs) that were recorded in a three-dimensional space. Joint angles and time of execution were registered and analyzed. The differences in execution between both sides of the body were compared between cases and controls. The relationship with the NIHSS score was analyzed with linear regression analysis and the mRS score with Pearson’s correlation coefficient (PCC).
Results: 50 controls and 33 stroke patients were analyzed. The median NIHSS score was 2 (rank 0-12) and the median mRS was 0 (rank 0-4). The measurements that showed better discrimination capacity were those obtained from abduction of the upper limb: shift of the joint angles were different between cases and controls in the frontal plane for the elbow in pronation (p=0.01) and in supination (p< 0.001); and for the shoulder both in pronation and supination (p=0.01). These differences were independent of the NIHSS score, but were moderately correlated to the mRS score at the moment of the evaluation: elbow in pronation (PCC=0.48 IC=0.051-0.12) and in supination (PCC=0.61 IC=0.16-0.29); and shoulder in pronation (PCC=0.39 IC=0.02-0.08) and in supination (PCC=0.63 IC=0.13-0.25).
Conclusion: Computational analysis of movement could be a useful tool for evaluation of upper limb function in stroke patients with slight deficit underestimated using current motor clinical scales and this is correlated with mRS. Further studies are needed to determine the better exercises to be considered and the relationship with functional outcome.