Evaluation of upper extremity reachable workspace using Kinect camera

Abstract

BACKGROUND: In clinical evaluation of upper extremity, there is a lack of assessment methods that are quantitative, reliable, and informative of the overall functional capability of an individual. OBJECTIVE: We present new methodology for the assessment of upper extremity impairments based on the concept of 3dimensional reachable workspace using Microsoft Kinect. METHODS: We quantify the reachable workspace by the relative surface area representing the portion of the unit hemisphere that is covered by the hand movement. We examine accuracy of joint positions, joint angles, and reachable workspace computation between the Kinect and motion capture system. RESULTS:The results of our analysis in 10 healthy subjects showed that the accuracy of the joint positions was within 66.3 mm for our experimental protocol. We found that the dynamic angle measurements had relatively large deviations (between 9 • to 28 • ). The acquired reachable workspace envelope showed high agreement between the two systems with high repeatability between trials (correlation coefficients between 0.86 and 0.93). CONCLUSIONS:The findings indicate that the proposed Kinect-based 3D reachable workspace analysis provides sufficiently accurate and reliable results as compared to motion capture system. The proposed method could be promising for clinical evaluation of upper extremity in neurological or musculoskeletal conditions.

Reachable workspace reflects dynamometer‐measured upper extremity strength in facioscapulohumeral muscular dystrophy

“…Taking advantage of currently available unobtrusive markerless sensor technology, a novel upper extremity outcome measure based on Kinect sensor-acquired 3-dimensional (3D) reachable workspace was recently developed by the study investigators 13,14 and applied in FSHD. 15 In a previous study, the novel reachable workspace outcome measure demonstrated its validity against the upper extremity-specific components of the FSHD evaluation scale (subscale II: scapular girdle; subscale III: upper limb).…”

Validity and reliability of two protocols for measuring Reachable Workspace Volume in able-bodied and stroke subjects

“…At this point it's unclear if virtual targets are as useful as real-life targets. Recent studies using the Kinect depth sensor for upper extremity function and workspace analysis [13][14][15] are promising and should be carefully designed with the results of this study in mind.…”

Reachable workspace and performance of upper limb (PUL) in duchenne muscular dystrophy

“…In a series of recent studies, [6][7][8][9][10][11][12] the utility of a novel upper extremity reachable workspace outcome measure, acquired using a 3D vision-based sensor, have demonstrated promising potential in various neuromuscular disorders. Specifically in DMD, the Kinect sensor-based reachable workspace RSA has been demonstrated to be applicable, reliable, and valid in both pediatric and adult populations with DMD, as well as ambulatory and nonambulatory individuals with a wide range of upper limb impairment.…”

“…The absolute total and quadrant reachable workspace surface envelope areas (m 2 ) were calculated and normalized by each individual's arm length to obtain the RSA. 6,7 This RSA representing the portion of a frontal unit hemi-sphere, is determined by dividing the absolute reachable workspace area by the factor 4pr 2 3 (1/2), where r represents the arm length. This provides normalization of the data by each individual's arm length to allow comparison between subjects.…”

“…Two of the innovative approaches are the performance of upper limb (PUL) 4,5 assessment and the Kinect sensor-based 3-dimensional (3D) upper extremity reachable workspace analysis system. [6][7][8] The PUL was developed specifically for DMD and is capable of assessing a wide-spectrum of upper extremity function in both ambulant and nonambulant individuals with DMD. 4 The PUL was designed with a conceptual framework reflecting the progression of weakness and natural history of functional decline in the disease.…”