Nadia R. Azar

Universal Design: A Step toward Successful Aging

The concept of aging successfully has become increasingly important as demographics shift towards an aging population. Successful aging has been defined to include (1) a low probability of disease and disease-related disability; (2) a high level of physical and cognitive functioning; and (3) an active engagement in life. The built environment can create opportunities or constraints for seniors to participate in social and productive activities. Universally designed spaces are more easily accessed and used by a spectrum of people without specialized adaptations. Thus, a universally designed environment creates opportunities for older adults to participate in these activities without the stigmatization associated with adapted or accessible designs. Providing older adults with specific universal design options (e.g., lever handle faucets) has the potential to increase the ease of completing activities of daily living, which promotes a continual engagement in life. Literature regarding universal design is promising; however, its theory requires further attention from professionals designing the built environment, evidence of the significance of its application from academics, and the embracement of its core principles from society. Overall, universal design has the potential to provide a stepping stone toward successful aging.

Transient pain developers show increased abdominal muscle activity during prolonged sitting.

BACKGROUND Sitting is a commonly adopted posture during work and prolonged exposures may have detrimental effects. Little attention has been paid to the thoracic spine and/or multiple axes of motion during prolonged sitting. Accordingly, this study examined three-dimensional motion and muscle activity of the trunk during two hours of uninterrupted sitting. METHODS Ten asymptomatic males sat during a simulated office task. Kinematics were analyzed from six segments (Neck, Upper-, Mid-, and Lower-thoracic, Lumbar, and Pelvis) and electromyography was recorded from eight muscles bilaterally. RESULTS Four participants developed transient pain. These participants showed higher average muscle activations in the abdominal muscles. Additionally, the non-pain group showed less lateral bend positional change in the mid-thoracic region compared to the upper- and lower-thoracic regions. Weak-to-moderate positive correlations were also found between rated pain and low back muscle activation. DISCUSSION The results provided further evidence of reduced movement in non-pain developers and altered muscle activation patterns in pain developers. Low-level, prolonged static contractions could lead to an increased risk of injury; and though the increased abdominal activity in the pain developers was not directly associated with increased rated pain scores, this could indicate a pre-disposition to, or enhancer of, transient pain development.

Three-dimensional peak and cumulative shoulder loads and postures during non-occupational tasks: A preliminary investigation

BACKGROUND In order to obtain a complete understanding of the etiology of upper extremity musculoskeletal disorders, a spectrum of risk factors needs to be evaluated, within and external to the workplace. To date, cumulative shoulder loads (forces and moments) have only been documented during automotive assembly tasks. No information on shoulder loads during non-occupational tasks has been reported. OBJECTIVE To document 3D peak and cumulative shoulder loads and postures associated with non-occupational tasks. METHODS Seven male (35.8 ± 15.7 years) and six female (44.0 ± 14.3 years) healthy working-aged individuals volunteered for this study. A video-based 3D posture sampling approach was used to document shoulder joint postures while participants performed non-repetitive tasks in and around their own homes over a 2-hour period. A 3D rigid link segment model was used to calculate reaction forces and moments at the shoulder. RESULTS Peak shoulder moments approached, and in some cases exceeded, published maximum isometric strength measurements, particularly in female participants. When extrapolated to a 7-hour shift, cumulative shoulder flexion and abduction moments, cumulative reaction caudal shear forces, and the time spent in non-neutral flexion and abduction were comparable in magnitude to those reported for light automotive assembly tasks. CONCLUSIONS Non-occupational tasks should be evaluated more widely if a complete picture of the risk of musculoskeletal injury associated with shoulder loading is to be established. More work is needed to develop threshold limits for both peak and cumulative shoulder loads to improve injury prevention strategies.

On-Site Observations of Spine Angle Data During Prolonged Office Sitting While Performing Computer-Aided Drafting Work: A Case Study

OCCUPATIONAL APPLICATIONS Cervical, thoracic, and lumbar spine angles were recorded from five office workers in their workplace to evaluate how individuals normally sit during a workday and to observe movement patterns. Postural data were collected continuously for 2 hours, and the development of pain/discomfort was documented concurrently. Within participants, mean spine angles varied by less than 13° over the measurement period. One initially asymptomatic participant developed discomfort in the mid-back region, and further analysis showed a distinctly different posture in the thoracic region compared to the other participants. Thus, there may be associations between differences in spine region movement and localized areas of pain development. This also highlights the potential importance of individual variations associated with pain development, accentuates the potential negative effects of remaining in an unchanged posture for a prolonged period of time, and reinforces the notion that frequent breaks or postural adjustments may be beneficial.

Three-dimensional peak and cumulative L4/L5 spine loads and trunk postures during non-occupational tasks

Cumulative low back loading has been shown to be a risk factor for low back pain reporting in the workplace. Evaluation of tasks outside of work might offer insight into why workers continue to have low back pain and may report pain differentially even when doing the same job. This study utilized a video-based 3D posture sampling approach to document joint postures of 18 people over a 2-hour period while performing non-repetitive tasks in and around their own homes. A 3D rigid link segment model was used to calculate reaction forces and moments at L4/L5 and joint models were used to calculate joint forces. Average peak (4.0 kN) and cumulative (9.9 MN·s) compression force estimates indicate significant loads o n the low back occur during non-occupational tasks, despite the fact that participants spent most of their time (86.2%) in neutra l trunk postures. Cumulative anterior reaction shear force (440 kN·s) was found to be comparable to those documented for a wide variety of occupational tasks, when extrapolated to an 8-hour shift. To our knowledge, this study is the first to include a full complement of 3D low back forces and moments, in conjunction with an assessment of trunk posture, for non-occupational activities. The evidence suggests that considering 3D peak and cumulative low back loading during non-occupational tasks is warranted and may help to explain some of the variability in the reporting of workplace-related low back disorders despite extensive ergonomic intervention.