DigitalROM: Development and validation of a system for assessment of shoulder range of motion.

Assessing shoulder mobility is traditionally performed by a clinician using a goniometer, however this method suffers from inter-rater reliability issues. Wearable inertial sensors, image-based systems and 3D-cameras are proposed to objectively quantify shoulder range of motion (ROM). Standardised data collection platforms are required to ensure the consistency of measurements. This paper describes DigitalROM, a Microsoft Kinect 3D camera based system, and a standardised data collection protocol for shoulder ROM assessment optimised for multi-centre clinical trial deployments. DigitalROM is shown to compare very well against image-based ground truth measures (R2= 0.98 and RMSE≤7°) and shows slightly better performance than inertial sensor based ROM measurements (R2= 0.96 and RMSE≤9°). Additionally, DigitalROM offers the ability to ensure patient adherence to the movement protocol during data collection.

Gait Symmetry Assessment with a Low Back 3D Accelerometer in Post-Stroke Patients.

Gait asymmetry is an important marker of mobility impairment post stroke. This study proposes a new gait symmetry index (GSI) to quantify gait symmetry with one 3D accelerometer at L3 (GSIL3). GSIL3 was evaluated with 16 post stroke patients and nine healthy controls in the Six-Minute-Walk-Test (6-MWT). Discriminative power was evaluated with Wilcoxon test and the effect size (ES) was computed with Cliff's Delta. GSIL3 estimated during the entire 6-MWT and during a short segment straight walk (GSIL3straight) have comparable effect size to one another (ES = 0.89, p < 0.001) and to the symmetry indices derived from feet sensors (|ES| = [0.22, 0.89]). Furthermore, while none of the indices derived from feet sensors showed significant differences between post stroke patients walking with a cane compared to those able to walk without, GSIL3 was able to discriminate between these two groups with a significantly lower value in the group using a cane (ES = 0.70, p = 0.02). In addition, GSIL3 was strongly associated with several symmetry indices measured by feet sensors during the straight walking cycles (Spearman correlation: |ρ| = [0.82, 0.88], p < 0.05). The proposed index can be a reliable and cost-efficient post stroke gait symmetry assessment with implications for research and clinical practice.