Analysis of tetraplegic reaching in their 3D workspace following posterior deltoid-triceps tendon transfer

Abstract

Study design: Cross-sectional study. Objectives: To quantify three-dimensional (3D) reachable workspace in different groups of tetraplegic participants and to assess their reaching performance within this workspace. Setting: Northwest Regional Spinal Injuries Centre, UK. Methods: The 3D reachable workspace of three groups of tetraplegics (NON-OP, operated group (OP) and tetraplegic control group (CON Tetraplegic ) with varying levels of triceps function together with a healthy control group (CON Healthy )) was defined by reaching to five target positions (anterior, medial, lateral, superior and inferior) located on the periphery of their workspace. Joint angles and inter-joint coordination were analysed after a 3D reconstruction of the thorax, humerus and forearm. The performance related variables of movement time, peak velocity, time-to-peak velocity and curvature index were also examined. Results: The reachable volumes covered were consistent with the level of triceps function as CON Healthy covered a significantly greater volume than the tetraplegic groups and in turn the OP covered a larger workspace volume than NON-OP. The reduced workspace of tetraplegics was identified as being due to restrictions in workspace above shoulder height and across the body. Coordination data identified some differences in movement patterns but when reaching to targets on the workspace there were no significant differences between the OP and NON-OP groups. Conclusion: This study provided a detailed assessment of reachable workspace and target reaching. Tetraplegic participants found the superior and medial parts of the workspace were the most challenging directions. Standardised biomechanical analysis of tetraplegic upper-limb function is required for objective assessment.

Primary and submovement control of aiming in C6 tetraplegics following posterior deltoid transfer

“…Moreover, when a submovement was made during the limb-target control phase, these were mostly functional thus indicating tetraplegic participants were able to use visual and/or proprioceptive feedback to aim at the horizontal targets with similar end-point error as neurotypical controls. We have reported a similar movement strategy in 3-dimensional aiming [17], thus adding support to clinical observations of a benefit for PD transfer in functional reaching tasks. As these results are from a small sample, it is not known how generalizable they are to the wider population of tetraplegics with a posterior-deltoid transfer.…”

“…In terms of functional implications, it should first be borne in mind that the inertia of the limb did not have to be independently supported in this experiment, unlike in some earlier studies of reaching [17,18]. In this respect, the constraints of the current study are somewhat similar to those that would be experienced by the tetraplegic participants when performing tasks such as manipulating a computer mouse or motorised wheelchair control.…”

Reliability of movement workspace measurements in a passive arm orthosis used in spinal cord injury rehabilitation

“…To evaluate reliability between different seating conditions as well as intra- and inter-rater reliability, the volume of the active movement workspace [22,23] was calculated for each measurement. Therefore, distances between the endpoints of each movement axis (left-right, top-bottom, far-close) were calculated and then multiplied.…”

Proof of Concept of the Ability of the Kinect to Quantify Upper Extremity Function in Dystrophinopathy

“…Through the capture of participant motion, the Kinect has the potential to gather information related to functional reaching volume (FRV), velocity of movement, and rate of fatigue. Functional reaching volume is the space within which a person can interact with the environment around them 20 - 22. Measurement of this variable, would allow researchers to quantify functional ability.…”

“…Measurement of this variable, would allow researchers to quantify functional ability. A larger FRV would likely correlate with an increase in functional ability 20 - 22. Velocity of reaching is a second component of UE function necessary for independence and is important because, if activity performance is too slow and cumbersome, a caregiver will likely take over the task and an area of independence is lost 23.…”