Upper extremity reachable workspace evaluation with Kinect.

We propose a novel low-cost method for quantitative assessment of upper extremity workspace envelope using Microsoft Kinect camera. In clinical environment there are currently no practical and cost-effective methods available to provide arm-function evaluation in three-dimensional space. In this paper we examine the accuracy of the proposed technique for workspace estimation using Kinect in comparison with a motion capture system. The experimental results show that the developed system is capable of capturing the workspace with sufficient accuracy and robustness.

mHealth application for upper extremity range of motion and reachable workspace.

We present mobile health (mHealth) applications utilizing embedded phone sensors as an angle-measuring device for upper-limb range of motion (ROM) and estimation of reachable workspace to assist in evaluation of upper limb functional capacity. Our results show that the phone can record accurate measurements, as well as provide additional functionalities for clinicians.

Validity and reliability of smartphone magnetometer-based goniometer evaluation of shoulder abduction--A pilot study.

BACKGROUND: Goniometers are commonly used by physical therapists to measure range-of-motion (ROM) in the musculoskeletal system. These measurements are used to assist in diagnosis and to help monitor treatment efficacy. With newly emerging technologies, smartphone-based applications are being explored for measuring joint angles and movement. OBJECTIVE: This pilot study investigates the intra- and inter-rater reliability as well as concurrent validity of a newly-developed smartphone magnetometer-based goniometer (MG) application for measuring passive shoulder abduction in both sitting and supine positions, and compare against the traditional universal goniometer (UG). DESIGN: This is a comparative study with repeated measurement design. METHODS: Three physical therapists utilized both the smartphone MG and a traditional UG to measure various angles of passive shoulder abduction in a healthy subject, whose shoulder was positioned in eight different positions with pre-determined degree of abduction while seated or supine. Each therapist was blinded to the measured angles. Concordance correlation coefficients (CCCs), Bland-Altman plotting methods, and Analysis of Variance (ANOVA) were used for statistical analyses. RESULTS: Both traditional UG and smartphone MG were reliable in repeated measures of standardized joint angle positions (average CCC > 0.997) with similar variability in both measurement tools (standard deviation (SD) ± 4°). Agreement between the UG and MG measurements was greater than 0.99 in all positions. CONCLUSION: Our results show that the smartphone MG has equivalent reliability compared to the traditional UG when measuring passive shoulder abduction ROM. With concordant measures and comparable reliability to the UG, the newly developed MG application shows potential as a useful tool to assess joint angles.

Development and application of stereo camera-based upper extremity workspace evaluation in patients with neuromuscular diseases.

BACKGROUND: The concept of reachable workspace is closely tied to upper limb joint range of motion and functional capability. Currently, no practical and cost-effective methods are available in clinical and research settings to provide arm-function evaluation using an individual's three-dimensional (3D) reachable workspace. A method to intuitively display and effectively analyze reachable workspace would not only complement traditional upper limb functional assessments, but also provide an innovative approach to quantify and monitor upper limb function. METHODOLOGY/PRINCIPAL FINDINGS: A simple stereo camera-based reachable workspace acquisition system combined with customized 3D workspace analysis algorithm was developed and compared against a sub-millimeter motion capture system. The stereo camera-based system was robust, with minimal loss of data points, and with the average hand trajectory error of about 40 mm, which resulted to ~5% error of the total arm distance. As a proof-of-concept, a pilot study was undertaken with healthy individuals (n = 20) and a select group of patients with various neuromuscular diseases and varying degrees of shoulder girdle weakness (n = 9). The workspace envelope surface areas generated from the 3D hand trajectory captured by the stereo camera were compared. Normalization of acquired reachable workspace surface areas to the surface area of the unit hemi-sphere allowed comparison between subjects. The healthy group's relative surface areas were 0.618±0.09 and 0.552±0.092 (right and left), while the surface areas for the individuals with neuromuscular diseases ranged from 0.03 and 0.09 (the most severely affected individual) to 0.62 and 0.50 (very mildly affected individual). Neuromuscular patients with severe arm weakness demonstrated movement largely limited to the ipsilateral lower quadrant of their reachable workspace. CONCLUSIONS/SIGNIFICANCE: The findings indicate that the proposed stereo camera-based reachable workspace analysis system is capable of distinguishing individuals with varying degrees of proximal upper limb functional impairments.