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In JoVE (1)
Other Publications (4)
Articles by Timothy W. Cacciatore in JoVE
JoVE Clinical and Translational Medicine
Method to Measure Tone of Axial and Proximal Muscle
1Department of Biomedical Engineering, Oregon Health and Science University, 2UCL Institute of Neurology, Queen Square, 3Department of Neurology, Oregon Health and Science University
We have developed a device (Twister) to study the regulation of tonic muscle activity during active postural maintenance. Twister measures torsional resistance and muscular responses in standing subjects during twisting of the body axis. The device can be flexibly configured to study various aspects of tonic control across the neck, trunk, and/or hips.
Other articles by Timothy W. Cacciatore on PubMed
Improvement in Automatic Postural Coordination Following Alexander Technique Lessons in a Person with Low Back Pain
The relationship between abnormal postural coordination and back pain is unclear. The Alexander Technique (AT) aims to improve postural coordination by using conscious processes to alter automatic postural coordination and ongoing muscular activity, and it has been reported to reduce low back pain. This case report describes the use of the AT with a client with low back pain and the observed changes in automatic postural responses and back pain.
Postural Muscle Tone in the Body Axis of Healthy Humans
Across the entire human body, postural tone might play its most critical role in the body's axis because the axis joins the four limbs and head into a single functioning unit during complex motor tasks as well as in static postures. Although postural tone is commonly viewed as low-level, tonic motor activity, we hypothesized that postural tone is both tonically and dynamically regulated in the human axis even during quiet stance. Our results describe the vertical distribution of postural muscle tone in the neck, trunk, and hips of standing human adults. Each subject stood blindfolded on a platform that axially rotated the neck, trunk, or pelvis at 1 degrees /s and +/-10 degrees relative to the neutral position (i.e., facing forward). The measured resistance to axial rotation was highest in the trunk and lowest in the neck and was characterized by several nonlinear features including short-range stiffness and hysteresis. In half of the subjects, axial muscle activity was relatively constant during axial rotation, and in the other half, muscle activity was modulated by lengthening and shortening reactions, i.e., decreasing activity in lengthening muscles and increasing activity in shortening muscles, respectively. Axial resistance to rotation was reduced in subjects whose muscle activity was modulated. The results indicate that axial tone is modulated sensitively and dynamically, this control originates, at least in part, from tonic lengthening and shortening reactions, and a similar type of control appears to exist for postural tone in the proximal muscles of the arm.
Multi-segmental Torso Coordination During the Transition from Sitting to Standing
Research into the multi-segmental mobility of the torso could add to our understanding of the contributions of the head and torso to human movement. The purpose of this study was to determine the motion and temporal coordination of the head and multiple torso segments during the sit-to-stand task.
Prolonged Weight-shift and Altered Spinal Coordination During Sit-to-stand in Practitioners of the Alexander Technique
The Alexander Technique (AT) is used to improve postural and movement coordination and has been reported to be clinically beneficial, however its effect on movement coordination is not well-characterized. In this study we examined the sit-to-stand (STS) movement by comparing coordination (phasing, weight-shift and spinal movement) between AT teachers (n=15) and matched control subjects (n=14). We found AT teachers had a longer weight-shift (p<0.001) and shorter momentum transfer phase (p=0.01), than control subjects. AT teachers also increased vertical foot force monotonically, rather than unweighting the feet prior to seat-off, suggesting they generate less forward momentum with hip flexors. The prolonged weight-shift of AT teachers occurred over a greater range of trunk inclination, such that their weight shifted continuously onto the feet while bringing the body mass forward. Finally, AT teachers had greatly reduced spinal bending during STS (cervical, p<0.001; thoracic, p<0.001; lumbar, p<0.05). We hypothesize that the low hip joint stiffness and adaptive axial postural tone previously reported in AT teachers underlies this novel "continuous" STS strategy by facilitating eccentric contractions during weight-shift.
