Posture and movement kinematics for individuals with idiopathic chronic neck pain using computers

<p dir="ltr">Abstract</p><p dir="ltr">Background</p><p dir="ltr">Chronic neck pain is a debilitating condition with significant health effects for individuals and high economic burden. Neck pain is common when individuals use computers in the workplace. Evidence suggests sub-optimal working postures and movement (or lack of movement) may contribute. However, the types of postures that may relate to neck pain have not been comprehensively reported using gold standard measures. Providing real-time feedback on postures may be one approach to managing neck pain in the workplace, but few interventions using posture feedback have been reported. The development of innovative interventions to address posture in the workplace is needed to reduce and manage the risks of neck pain related to computer use.</p><p dir="ltr">Aim/Purpose</p><p dir="ltr">The primary aims of this thesis were to 1) investigate postural differences between individuals with and without chronic neck pain using computers (Chapter3), 2) examine wearable feedback technologies and their effectiveness during work-related activities (Chapter 4,), 3) validate devices for measuring upper body posture using computers (Chapter 5), and 4) develop a real-time posture feedback application for computer users (Chapter 6).</p><p dir="ltr">Methods</p><p dir="ltr">This thesis reports the results of three studies and a project developing a real-time posture feedback application. A cross-sectional study investigated upper body kinematics measured by three-dimensional (3D) motion capture in 22 individuals with chronic neck pain compared to 22 age and gender matched individuals without pain across four computer conditions (Chapter 3). A scoping review of seven databases summarised studies reporting the effectiveness of feedback from wearable technology to alter postures and movement in computer users (Chapter 4). A cross-sectional study investigated the concurrent validity of two commercially available IMU systems (Wi-Fi IMUs and Bluetooth IMUs) compared to 3D motion capture for measuring upper body postures in twenty-six individuals across three computer conditions (Chapter 5). The initial development of a real-time feedback prototype for providing posture feedback to computer users is described, including technical challenges (Chapter 6).</p><p dir="ltr">Results</p><p dir="ltr">Kinematic analysis showed those with chronic neck pain had significantly greater upper trunk flexion relative to the laboratory (between group mean difference -6.15˚, CI -10.9, -1.3, p = .066), less flexion of their head/neck to upper trunk segment (7.15˚, 2.1, 12.2, p = .006), greater bilateral shoulder flexion (left 12.35˚, 6.7, 17.9, p < .001; right 13.49˚, 7.9, 19.1, p < .001) and greater forward head (-6.37˚, -12.7, -0.1 p = .052) compared to those without neck pain (Chapter 3). The review of the fourteen included studies showed that wearable feedback technologies improved posture and movement during computer activities, but they did not reduce pain and validation of the reported technologies was lacking (Chapter 4). Wi-Fi IMUs demonstrated acceptable accuracy for flexion and extension during the desktop correct condition compared to 3D motion capture system (head IMU R2 = 0.91 and upper trunk IMU R2 = 0.82), but Bluetooth IMUs performed poorly due to data loss and gyroscopic drift (head IMU R2 = 0.54 and upper trunk IMU R2 = 0.63), (Chapter 5). Initial development of a wearable device for posture feedback resulted in an application that was technologically feasible and may be acceptable to computer users, however testing the protype in real-world settings was beyond the scope of this thesis (Chapter 6).</p><p dir="ltr">Conclusion</p><p dir="ltr">This thesis provides evidence that postures in individuals with chronic neck pain are significantly different from those without pain when using computers, and wearable feedback technologies may improve postures and movement behaviours in computer users. The importance of device validation was demonstrated by variation in the performance of two IMU systems when concurrently measuring the same task. The device considerations and parameters required to develop an initial IMU prototype for posture feedback were established. Overall, this thesis provides evidence to support further research on feedback technologies to remediate neck pain in the workplace.</p>