Lumbar posture and muscular activity while sitting during office work.

PURPOSE: Field study, cross-sectional study to measure the posture and sEMG of the lumbar spine during office work for a better understanding of the lumbar spine within such conditions. SCOPE: There is high incidence of low back pain in office workers. Currently there is little information about lumbar posture and the activity of lumbar muscles during extended office work. METHODS: Thirteen volunteers were examined for around 2h of their normal office work. Typical tasks were documented and synchronised to a portable long term measuring device for sEMG and posture examination. The correlation of lumbar spine posture and sEMG was tested statistically. RESULTS: The majority of time spent in office work was sedentary (82%). Only 5% of the measured time was undertaken in erect body position (standing or walking). The sEMG of the lumbar muscles under investigation was task dependent. A strong relation to lumbar spine posture was found within each task. The more the lumbar spine was flexed, the less there was activation of lumbar muscles (P < .01). Periods of very low or no activation of lumbar muscles accounted for about 30% of relaxed sitting postures. CONCLUSION: Because of very low activation of lumbar muscles while sitting, the load is transmitted by passive structures like ligaments and intervertebral discs. Due to the viscoelasticity of passive structures and low activation of lumbar muscles, the lumbar spine may incline into de-conditioning. This may be a reason for low back pain.

Pain relief due to physiotherapy doesn't change the motor function of the shoulder.

OBJECTIVE: The purpose of this study is to evaluate the effect of different training methods in physiotherapy on pain relief and change in proprioception and kinesthesia of the shoulder. Further, the connections between pain relief and change in motor function of the shoulder will be investigated. DESIGN: Randomised trial. SETTING: Ambulatory care. PARTICIPANTS: Two groups of unspecific shoulder pain patients (group1 n = 12, group2 n = 10). One group (n = 8) of non-symptomatic subjects. INTERVENTION: The first shoulder-pain group was trained using flexible foil, whilst flexible bands were used to train the patients in the second group. Training period was 12 weeks. MAIN OUTCOME MEASURES: Pain of the shoulder was evaluated through functional pain assessment (Constant-Murley score) before, halfway through and after intervention. Proprioceptive and kinaesthetic ability was measured by an active-active angle-replication test for the shoulder before and after intervention. The data of the shoulder patients was compared to the group of non-symptomatic subjects. RESULTS: Pain was reduced significantly in both groups (p < .05) whereas no changes were measured for the ability to replicate angles of the shoulder. CONCLUSION: This suggests that pain relief in the shoulder is not associated with enhancement of the investigated parameters in motor function.

Muscular activation patterns of healthy persons and low back pain patients performing a functional capacity evaluation test.

The results of most reported studies show differences between the muscular activity of low back pain patients and healthy subjects, but the focus has usually been on trunk muscles only, and they have not involved work-related tests or exercises. The reintegration of chronic low back pain patients to job market is a common problem. Therefore assessment systems like the functional capacity evaluation (FCE) according to Isernhagen [S.J. Isernhagen, Work Injury: Management and Prevention, Aspen Publishers Inc., Gaithersburg, MD, 1988] are often used tools to determine the physical abilities and deficits of long-time incapacitated persons. The aim of the present study was to compare the healthy persons and chronic low back pain patients in performing a FCE-test and to analyse their muscular activation and motion patterns. The results indicate differences in the activation patterns of the groups in the test task "floor to waist lift" common in many occupations.