Leonard O'Sullivan

Forearm torque strengths and discomfort profiles in pronation and supination

This experiment investigated maximum forearm pronation and supination torques and forearm discomfort, for intermittent torque exertions in supine and prone forearm angles for the right arm. Twenty-two subjects participated in the study that comprised two parts, the first of which involved measurement of maximum forearm torque in both twisting directions at five forearm angles including neutral. This was followed by endurance tests at 50% maximum voluntary contraction (MVC) in both directions. The second part of the study involved subjects performing 5-min duration of intermittent isometric torque exercises at 20% MVC in both directions at 11 forearm angles. Regression equations were developed that accurately predict torques as a function of forearm angle expressed as a percentage of maximum motion. Analysis of the discomfort data for the intermittent isometric torque exertions indicated that both forearm angle and twisting direction significantly affected forearm discomfort (p < 0.001). A significant two-way interaction (p < 0.01) was identified between forearm angle and direction for supine forearm angles only. The results provide important strength and discomfort models for the design of tasks involving static or repetitive forearm twisting. Such tasks have a strong association with forearm injuries including lateral and medial epicondylitis. These results provide needed data on the risk factors associated with these injuries so they can be prevented.

What do physiotherapists consider to be the best sitting spinal posture

While sitting is a common aggravating factor in low back pain (LBP), the best sitting posture remains unclear. This study investigated the perceptions of 295 physiotherapists in four different European countries on sitting posture. Physiotherapists selected their perceived best sitting posture from a sample of nine options that ranged from slumped to upright sitting, as well as completing the back beliefs questionnaire (BBQ). 85% of physiotherapists selected one of two postures as best, with one posture being selected significantly more frequently than the remainder (p < 0.05). Interestingly, these two most frequently selected postures were very different from each other. Those who selected the more upright sitting posture had more negative LBP beliefs on the BBQ (p < 0.05). The choice of best sitting posture also varied between countries (p < 0.05). Overall, disagreement remains on what constitutes a neutral spine posture, and what is the best sitting posture. Qualitative comments indicated that sitting postures which matched the natural shape of the spine, and appeared comfortable and/or relaxed without excessive muscle tone were often deemed advantageous. Further research on the perceptions of people with LBP on sitting posture are indicated.

Exoskeletons for industrial application and their potential effects on physical work load

Abstract The aim of this review was to provide an overview of assistive exoskeletons that have specifically been developed for industrial purposes and to assess the potential effect of these exoskeletons on reduction of physical loading on the body. The search resulted in 40 papers describing 26 different industrial exoskeletons, of which 19 were active (actuated) and 7 were passive (non-actuated). For 13 exoskeletons, the effect on physical loading has been evaluated, mainly in terms of muscle activity. All passive exoskeletons retrieved were aimed to support the low back. Ten-forty per cent reductions in back muscle activity during dynamic lifting and static holding have been reported. Both lower body, trunk and upper body regions could benefit from active exoskeletons. Muscle activity reductions up to 80% have been reported as an effect of active exoskeletons. Exoskeletons have the potential to considerably reduce the underlying factors associated with work-related musculoskeletal injury. Practitioner Summary: Worldwide, a significant interest in industrial exoskeletons does exist, but a lack of specific safety standards and several technical issues hinder mainstay practical use of exoskeletons in industry. Specific issues include discomfort (for passive and active exoskeletons), weight of device, alignment with human anatomy and kinematics, and detection of human intention to enable smooth movement (for active exoskeletons).

Work related psychosocial risks and musculoskeletal disorders: potential risk factors, causation and evaluation methods

Musculo Skeletal Disorders (MSDs) are the focus of considerable attention and research in occupational health, which is in part due to high prevalence rates and associated costs. In the United States, the total cost associated with MSDs increased from

The effect of dynamic sitting on the prevention and management of low back pain and low back discomfort: a systematic review

81 billion in 1986 to

Lumbar posture and trunk muscle activation during a typing task when sitting on a novel dynamic ergonomic chair

215 billion in 2005 [3]. Epidemiological studies have repeatedly shown associations between work-related psychosocial factors and MSDs, and the role of psychosocial factors and stress in these disorders has received increased attention. Several reviews have reported associations between MSDs and work-related psychosocial factors such as high workload/demands, high perceived stress levels, low social support, low job control, low job satisfaction and monotonous work. Several theories have been proposed to explain the apparent relationship between stress and MSDs in the workplace from a biological perspective. These include the biopsychosocial model of job stress, the hyperventilation theory, the migraine theory, the muscle spindle theory and the Cinderella hypothesis. Within the literature, a vast array of questionnaires have been developed in an attempt to measure the psychosocial factors that occur within the workplace. This article presents a discussion of existing knowledge of the psychosocial risk factors potentially linked to MSDs and potential pathways to injury. A discussion of evaluation approaches used to estimate psychosocial risk exposures in workplaces is also presented.

The between-day and inter-rater reliability of a novel wireless system to analyse lumbar spine posture

Dynamic sitting has been proposed to reduce low back pain (LBP) and/or low back discomfort (LBD) while sitting. This is supported by studies suggesting that subjects with LBP assume more static, sustained postures while sitting. This systematic review investigated the effect of dynamic sitting on LBP among subjects with LBP and the development of LBD among pain-free subjects. Electronic databases were searched by two independent assessors. All prospective studies which compared the effect of a dynamic sitting condition on LBP or LBD to another sitting condition were eligible, with no minimum follow-up period applied. The quality of the included studies was assessed using the PEDro scale. Seven high-quality studies were eligible, including five crossover studies and two randomised controlled trials. The results suggest there is currently no evidence to support the use of dynamic sitting as a stand-alone approach in the management of LBP. Practitioner Summary: This systematic review investigated the effect of dynamic sitting on LBP or LBD. Seven high-quality studies met the inclusion and exclusion criteria. Overall, the evidence suggests that dynamic sitting approaches are not effective as a stand-alone management approach for LBP.

Human Centred Design Considerations for Connected Health Devices for the Older Adult

Low back pain (LBP) is a common musculoskeletal disorder and prolonged sitting often aggravates LBP. A novel dynamic ergonomic chair (‘Back App’), which facilitates less hip flexion while sitting on an unstable base has been developed. This study compared lumbar posture and trunk muscle activation on this novel chair with a standard backless office chair. Twelve painfree participants completed a typing task on both chairs. Lumbar posture and trunk muscle activation were collected simultaneously and were analysed using paired t-tests. Sitting on the novel dynamic chair significantly (p < 0.05) reduced both lumbar flexion and the activation of one back muscle (Iliocostalis Lumborum pars Thoracis). The discomfort experienced was mild and was similar (p > 0.05) between chairs. Maintaining lordosis with less muscle activation during prolonged sitting could reduce the fatigue associated with upright sitting postures. Studies with longer sitting durations, and in people with LBP, are required. Practitioner Summary: Sitting on a novel dynamic chair resulted in less lumbar flexion and less back muscle activation than sitting on a standard backless office chair during a typing task among pain-free participants. Facilitating lordotic sitting with less muscle activation may reduce the fatigue and discomfort often associated with lordotic sitting postures.

Effects of combined wrist deviation and forearm rotation on discomfort score

Lumbar posture is commonly assessed in non-specific chronic low back pain (NSCLBP), although quantitative measures have mostly been limited to laboratory environments. The BodyGuard™ is a spinal position monitoring device that can monitor posture in real time, both inside and outside the laboratory. The reliability of this wireless device was examined in 18 healthy participants during usual sitting and forward bending, two tasks that are commonly provocative in NSCLBP. Reliability was determined using intraclass correlation coefficients (ICC), the standard error of measurement (SEM), the mean difference and the minimal detectable change (MDC90). Between-day ICC values ranged from 0.84 to 0.87, with small SEM (5%), mean difference (<9%) and MDC90 (<14%) values. Inter-rater ICC values ranged from 0.91 to 0.94, with small SEM (4%), mean difference (6%) and MDC90 (9%) values. Between-day and inter-rater reliability are essential requirements for clinical utility and were excellent in this study. Further studies into the validity of this device and its application in clinical trials in occupational settings are required. Statement of Relevance:A novel device that can analyse spinal posture exposure in occupational settings in a minimally invasive manner has been developed. This study established that the device has excellent between-day and inter-rater reliability in healthy pain-free subjects. Further studies in people with low back pain are planned.

Cognitive Functional Therapy for Disabling Nonspecific Chronic Low Back Pain: Multiple Case-Cohort Study

Connected health devices are generally designed for unsupervised use, by non-healthcare professionals, facilitating independent control of the individuals own healthcare. Older adults are major users of such devices and are a population significantly increasing in size. This group presents challenges due to the wide spectrum of capabilities and attitudes towards technology. The fit between capabilities of the user and demands of the device can be optimised in a process called Human Centred Design. Here we review examples of some connected health devices chosen by random selection, assess older adult known capabilities and attitudes and finally make analytical recommendations for design approaches and design specifications.