Positioning in anesthesiology - Toward a better understanding of stretch-induced perioperative neuropathies

Background Stretch-induced neuropathy of the brachial plexus and median nerve in conventional perioperative care remains a relatively frequent and poorly understood complication. Guidelines for positioning have been formulated, although the protective effect of most recommendations remains unexamined. The similarity between the stipulated potentially dangerous positions and the components of the brachial plexus tension test (BPTT) justified the analysis of the BPTT to quantify the impact of various arm and neck positions on the peripheral nervous system. Methods: Four variations of the BPTT in three different shoulder positions were performed in 25 asymptomatic male participants. The impact of arm and neck positions on the peripheral nervous system was evaluated by analyzing the maximal available range of motion, pain intensity, and type of elicited symptoms during the BPTT. Results: Cervical contralateral lateral flexion, lateral rotation of the shoulder and fixation of the shoulder girdle in a neutral position In combination with shoulder abduction, and wrist extension all significantly reduced the available range of motion. Elbow extension also challenged the nervous system substantially. A cumulative impact could be observed when different components were simultaneously added, and a neutralizing effect was noted when an adjacent region allowed for unloading of the nervous system. Conclusions: The experimental findings support the experientially based guidelines for positioning. Especially when simultaneously applied, submaximal joint positions easily load the nervous system, which may substantially compromise vital physiologic processes in and around the nerve. Therefore, even when the positioning of all upper limb joints is carefully considered, complete prevention of perioperative neuropathy seems almost inconceivable

Psychosocial variables in patients with (sub) acute low back pain: an inception cohort in primary care physical therapy in The Netherlands

STUDY DESIGN. A prospective cohort study of patients with episodes of acute or subacute low back pain, seeking physical therapy in primary care, with follow-up at weeks 2, 4, 8, and 12. OBJECTIVES. To evaluate the association between psychosocial factors and the transition from acute or subacute low back pain to chronicity. SUMMARY OF BACKGROUND DATA. Psychosocial factors have long been thought to be associated with chronic pain only. Recent prospective studies, however, suggest that these factors may also be important in acute or subacute low back pain. METHODS. Demographic, psychosocial, and psychological baseline data were collected and analyzed from a sample of 66 acute or subacute patients with low back pain in order to predict the 3-month outcome. RESULTS. After 3 months, response rate was 85% (56 patients). Forty-five percent rated their current status as "not recovered." Twelve percent reported work absenteeism. Using multiple regression analyses, baseline scores on the Acute Low Back Pain Screening Questionnaire, Pain Coping Inventory, Fear-Avoidance Beliefs Questionnaire, and Tampa Scale for Kinesiophobia were not significantly associated with nonrecovery at 3 months. The only significant predictor at baseline was the subscale pain of the ALBPSQ, correctly classifying 80% of the patients. The relative risk for not being recovered was 3.72 (95% confidence interval, 1.63-8.52) for the subjects with high scores on the subscale for pain. Pain scores and scores on psychosocial variables at 12 weeks were not associated. CONCLUSIONS. The study strongly revealed pain-related items to be essential factors in the development of chronicity and long-term disability in primary care physical therapy. Health status at 8 weeks seems crucial in developing chronicity. © 2007 Lippincott Williams & Wilkins, Inc

Measuring small linear displacements with a three-dimensional video motion analysis system: Determining its accuracy and precision

Objectives: To determine accuracy, precision, and smallest detectable difference for a three-dimensional (3D) video motion analysis system specifically configured for measuring small and slow displacements within a small measurement volume (0 7 x 0 5 x 0 3m). Design: Repeated measurements with random sequence of conditions. Setting: Rehabilitation research laboratory. Intervention: A reference sliding device was used to control cyclic displacements of two reflective markers over 5 calibrated ranges (l, 3, 10, 30, and 60mm). Nine cycles were performed for each of 9 conditions (3 directions x 3 zones). Four cameras recorded all trials on tapes, which were digitized with a Kinemetrix system. Main Outcome Measures: Change in distance of the moving markers relative to a third static marker was averaged over 50 frames per trial. Mean error, mean absolute error, and intertrial and intratrial standard deviations (SDs) were calculated for each zone and direction. Results: For 810 trials, mean error and absolute error were, respectively, 034mm and 094 mm. The mean intertrial and intratrial SDs and 99% confidence interval were .047mm (CI = ± 121mm) and 030mm (CI = ± .077mm). The corresponding smallest detectable differences were .171 mm and 109 mm. Conclusion: Motion analysis configured for registration within small volumes allows measurement of minuscule displacements with great accuracy and may therefore be suitable for many applications in rehabilitation research other than gait analysis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe