Changes in triceps surae muscle length and stiffness during intensive care admission: an observational study
This prospective descriptive study aimed to determine if changes in triceps surae muscle length and stiffness occur in ICU following acquired brain injury (ABI). Adult patients admitted to ICU for invasive ventilation and sedation for greater than 48 hours were studied. Twelve subjects met inclusion criteria over the six-week audit, five with ABI and seven with other diagnoses. Muscle stiffness was quantified by measuring ankle joint angles achieved from the application of three standardised torques (5, 10 and 15 Nm) via a modified Lidcombe template. Maximum dorsiflexion was used to indicate muscle length changes. Measurements were performed in knee flexion and extension to selectively bias soleus and gastrocnemius. Serial measurements were undertaken three times per week from admission to ICU until subjects were able to actively achieve ankle dorsiflexion, or were discharged from ICU. Subject comparisons were made between first and final day measurements, with comparison also made between subjects with ABI and those with other diagnoses. No significant differences were found between groups and neither group showed a significant change between admission and pre discharge measures. Analyses of all subjects showed a significant decrease in one of the measures of muscle stiffness. One subject developed extensor tone as sedation was withdrawn, which was reflected in all measures as decreased ankle dorsiflexion. Changes associated with contracture were evident only in one subject, and were related to the presence of extensor muscle tone. Some subjects exhibited increased ankle extensibility. The trend towards increased extensibility may have been related to muscle atrophy.
Nielsen, G., Gardner, P., & Patman, S. (2006). Changes in triceps surae muscle length and stiffness during intensive care admission: an observational study. Australian Journal of Physiotherapy, 52(1), S22.
Nielsen, G., Gardner, P., & Patman, S. (2005). Changes in triceps surae muscle length and stiffness during intensive care admission: an observational study. Paper presented at the Australian Physiotherapy Association 9th National Cardiothoracic Group Conference. Melbourne, VIC, 13-15 October, 2005.